/* DO NOT EDIT!
** This file is automatically generated by the script in the canonical
** SQLite source tree at tool/mkshellc.tcl.  That script combines source
** code from various constituent source files of SQLite into this single
** "shell.c" file used to implement the SQLite command-line shell.
**
** Most of the code found below comes from the "src/shell.c.in" file in
** the canonical SQLite source tree.  That main file contains "INCLUDE"
** lines that specify other files in the canonical source tree that are
** inserted to getnerate this complete program source file.
**
** The code from multiple files is combined into this single "shell.c"
** source file to help make the command-line program easier to compile.
**
** To modify this program, get a copy of the canonical SQLite source tree,
** edit the src/shell.c.in" and/or some of the other files that are included
** by "src/shell.c.in", then rerun the tool/mkshellc.tcl script.
*/
/*
** 2001 September 15
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains code to implement the "sqlite" command line
** utility for accessing SQLite databases.
*/
#if (defined(_WIN32) || defined(WIN32)) && !defined(_CRT_SECURE_NO_WARNINGS)
/* This needs to come before any includes for MSVC compiler */
#define _CRT_SECURE_NO_WARNINGS
#endif
typedef unsigned int u32;
typedef unsigned short int u16;

/*
** Optionally #include a user-defined header, whereby compilation options
** may be set prior to where they take effect, but after platform setup.
** If SQLITE_CUSTOM_INCLUDE=? is defined, its value names the #include
** file. Note that this macro has a like effect on sqlite3.c compilation.
*/
# define SHELL_STRINGIFY_(f) #f
# define SHELL_STRINGIFY(f) SHELL_STRINGIFY_(f)
#ifdef SQLITE_CUSTOM_INCLUDE
# include SHELL_STRINGIFY(SQLITE_CUSTOM_INCLUDE)
#endif

/*
** Determine if we are dealing with WinRT, which provides only a subset of
** the full Win32 API.
*/
#if !defined(SQLITE_OS_WINRT)
# define SQLITE_OS_WINRT 0
#endif

/*
** If SQLITE_SHELL_FIDDLE is defined then the shell is modified
** somewhat for use as a WASM module in a web browser. This flag
** should only be used when building the "fiddle" web application, as
** the browser-mode build has much different user input requirements
** and this build mode rewires the user input subsystem to account for
** that.
*/

/*
** Warning pragmas copied from msvc.h in the core.
*/
#if defined(_MSC_VER)
#pragma warning(disable : 4054)
#pragma warning(disable : 4055)
#pragma warning(disable : 4100)
#pragma warning(disable : 4127)
#pragma warning(disable : 4130)
#pragma warning(disable : 4152)
#pragma warning(disable : 4189)
#pragma warning(disable : 4206)
#pragma warning(disable : 4210)
#pragma warning(disable : 4232)
#pragma warning(disable : 4244)
#pragma warning(disable : 4305)
#pragma warning(disable : 4306)
#pragma warning(disable : 4702)
#pragma warning(disable : 4706)
#endif /* defined(_MSC_VER) */

/*
** No support for loadable extensions in VxWorks.
*/
#if (defined(__RTP__) || defined(_WRS_KERNEL)) && !SQLITE_OMIT_LOAD_EXTENSION
# define SQLITE_OMIT_LOAD_EXTENSION 1
#endif

/*
** Enable large-file support for fopen() and friends on unix.
*/
#ifndef SQLITE_DISABLE_LFS
# define _LARGE_FILE       1
# ifndef _FILE_OFFSET_BITS
#   define _FILE_OFFSET_BITS 64
# endif
# define _LARGEFILE_SOURCE 1
#endif

#if defined(SQLITE_SHELL_FIDDLE) && !defined(_POSIX_SOURCE)
/*
** emcc requires _POSIX_SOURCE (or one of several similar defines)
** to expose strdup().
*/
# define _POSIX_SOURCE
#endif

#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <assert.h>
#include <math.h>
#include "sqlite3.h"
typedef sqlite3_int64 i64;
typedef sqlite3_uint64 u64;
typedef unsigned char u8;
#if SQLITE_USER_AUTHENTICATION
# include "sqlite3userauth.h"
#endif
#include <ctype.h>
#include <stdarg.h>

#if !defined(_WIN32) && !defined(WIN32)
# include <signal.h>
# if !defined(__RTP__) && !defined(_WRS_KERNEL) && !defined(SQLITE_WASI)
#  include <pwd.h>
# endif
#endif
#if (!defined(_WIN32) && !defined(WIN32)) || defined(__MINGW32__)
# include <unistd.h>
# include <dirent.h>
# define GETPID getpid
# if defined(__MINGW32__)
#  define DIRENT dirent
#  ifndef S_ISLNK
#   define S_ISLNK(mode) (0)
#  endif
# endif
#else
# define GETPID (int)GetCurrentProcessId
#endif
#include <sys/types.h>
#include <sys/stat.h>

#if HAVE_READLINE
# include <readline/readline.h>
# include <readline/history.h>
#endif

#if HAVE_EDITLINE
# include <editline/readline.h>
#endif

#if HAVE_EDITLINE || HAVE_READLINE

# define shell_add_history(X) add_history(X)
# define shell_read_history(X) read_history(X)
# define shell_write_history(X) write_history(X)
# define shell_stifle_history(X) stifle_history(X)
# define shell_readline(X) readline(X)

#elif HAVE_LINENOISE

# include "linenoise.h"
# define shell_add_history(X) linenoiseHistoryAdd(X)
# define shell_read_history(X) linenoiseHistoryLoad(X)
# define shell_write_history(X) linenoiseHistorySave(X)
# define shell_stifle_history(X) linenoiseHistorySetMaxLen(X)
# define shell_readline(X) linenoise(X)

#else

# define shell_read_history(X)
# define shell_write_history(X)
# define shell_stifle_history(X)

# define SHELL_USE_LOCAL_GETLINE 1
#endif

#ifndef deliberate_fall_through
/* Quiet some compilers about some of our intentional code. */
# if defined(GCC_VERSION) && GCC_VERSION>=7000000
#  define deliberate_fall_through __attribute__((fallthrough));
# else
#  define deliberate_fall_through
# endif
#endif

#if defined(_WIN32) || defined(WIN32)
# if SQLITE_OS_WINRT
#  define SQLITE_OMIT_POPEN 1
# else
#  include <io.h>
#  include <fcntl.h>
#  define isatty(h) _isatty(h)
#  ifndef access
#   define access(f,m) _access((f),(m))
#  endif
#  ifndef unlink
#   define unlink _unlink
#  endif
#  ifndef strdup
#   define strdup _strdup
#  endif
#  undef pclose
#  define pclose _pclose
# endif
#else
 /* Make sure isatty() has a prototype. */
 extern int isatty(int);

# if !defined(__RTP__) && !defined(_WRS_KERNEL) && !defined(SQLITE_WASI)
  /* popen and pclose are not C89 functions and so are
  ** sometimes omitted from the <stdio.h> header */
   extern FILE *popen(const char*,const char*);
   extern int pclose(FILE*);
# else
#  define SQLITE_OMIT_POPEN 1
# endif
#endif

#if defined(_WIN32_WCE)
/* Windows CE (arm-wince-mingw32ce-gcc) does not provide isatty()
 * thus we always assume that we have a console. That can be
 * overridden with the -batch command line option.
 */
#define isatty(x) 1
#endif

/* ctype macros that work with signed characters */
#define IsSpace(X)  isspace((unsigned char)X)
#define IsDigit(X)  isdigit((unsigned char)X)
#define ToLower(X)  (char)tolower((unsigned char)X)

#if defined(_WIN32) || defined(WIN32)
#if SQLITE_OS_WINRT
#include <intrin.h>
#endif
#undef WIN32_LEAN_AND_MEAN
#define WIN32_LEAN_AND_MEAN
#include <windows.h>

/* string conversion routines only needed on Win32 */
extern char *sqlite3_win32_unicode_to_utf8(LPCWSTR);
extern LPWSTR sqlite3_win32_utf8_to_unicode(const char *zText);
#endif

/************************* Begin ../ext/misc/sqlite3_stdio.h ******************/
/*
** 2024-09-24
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
**
** This header file contains definitions of interfaces that provide 
** cross-platform I/O for UTF-8 content.
**
** On most platforms, the interfaces definitions in this file are
** just #defines.  For example sqlite3_fopen() is a macro that resolves
** to the standard fopen() in the C-library.
**
** But Windows does not have a standard C-library, at least not one that
** can handle UTF-8.  So for windows build, the interfaces resolve to new
** C-language routines contained in the separate sqlite3_stdio.c source file.
**
** So on all non-Windows platforms, simply #include this header file and
** use the interfaces defined herein.  Then to run your application on Windows,
** also link in the accompanying sqlite3_stdio.c source file when compiling
** to get compatible interfaces.
*/
#ifndef _SQLITE3_STDIO_H_
#define _SQLITE3_STDIO_H_ 1
#ifdef _WIN32
/**** Definitions For Windows ****/
#include <stdio.h>
#include <windows.h>

FILE *sqlite3_fopen(const char *zFilename, const char *zMode);
FILE *sqlite3_popen(const char *zCommand, const char *type);
char *sqlite3_fgets(char *s, int size, FILE *stream);
int sqlite3_fputs(const char *s, FILE *stream);
int sqlite3_fprintf(FILE *stream, const char *format, ...);
void sqlite3_fsetmode(FILE *stream, int mode);


#else
/**** Definitions For All Other Platforms ****/
#include <stdio.h>
#define sqlite3_fopen     fopen
#define sqlite3_popen     popen
#define sqlite3_fgets     fgets
#define sqlite3_fputs     fputs
#define sqlite3_fprintf   fprintf
#define sqlite3_fsetmode(F,X)   /*no-op*/

#endif
#endif /* _SQLITE3_STDIO_H_ */

/************************* End ../ext/misc/sqlite3_stdio.h ********************/
/************************* Begin ../ext/misc/sqlite3_stdio.c ******************/
/*
** 2024-09-24
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
**
** Implementation of standard I/O interfaces for UTF-8 that are missing
** on Windows.
*/
#ifdef _WIN32  /* This file is a no-op on all platforms except Windows */
#ifndef _SQLITE3_STDIO_H_
/* #include "sqlite3_stdio.h" */
#endif
#undef WIN32_LEAN_AND_MEAN
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <assert.h>
/* #include "sqlite3.h" */
#include <ctype.h>
#include <stdarg.h>
#include <io.h>
#include <fcntl.h>

/*
** If the SQLITE_U8TEXT_ONLY option is defined, then use O_U8TEXT
** when appropriate on all output.  (Sometimes use O_BINARY when
** rendering ASCII text in cases where NL-to-CRLF expansion would
** not be correct.)
**
** If the SQLITE_U8TEXT_STDIO option is defined, then use O_U8TEXT
** when appropriate when writing to stdout or stderr.  Use O_BINARY
** or O_TEXT (depending on things like the .mode and the .crlf setting
** in the CLI, or other context clues in other applications) for all
** other output channels.
**
** The default behavior, if neither of the above is defined is to
** use O_U8TEXT when writing to the Windows console (or anything
** else for which _isatty() returns true) and to use O_BINARY or O_TEXT
** for all other output channels.
*/
#if defined(SQLITE_U8TEXT_ONLY)
# define UseWtextForOutput(fd) 1
# define UseWtextForInput(fd)  1
# define IsConsole(fd)         _isatty(_fileno(fd))
#elif defined(SQLITE_U8TEXT_STDIO)
# define UseWtextForOutput(fd) ((fd)==stdout || (fd)==stderr)
# define UseWtextForInput(fd)  ((fd)==stdin)
# define IsConsole(fd)         _isatty(_fileno(fd))
#else
# define UseWtextForOutput(fd) _isatty(_fileno(fd))
# define UseWtextForInput(fd)  _isatty(_fileno(fd))
# define IsConsole(fd)         1
#endif

/*
** Global variables determine if simulated O_BINARY mode is to be
** used for stdout or other, respectively.  Simulated O_BINARY mode
** means the mode is usually O_BINARY, but switches to O_U8TEXT for
** unicode characters U+0080 or greater (any character that has a
** multi-byte representation in UTF-8).  This is the only way we
** have found to render Unicode characters on a Windows console while
** at the same time avoiding undesirable \n to \r\n translation.
*/
static int simBinaryStdout = 0;
static int simBinaryOther = 0;


/*
** Determine if simulated binary mode should be used for output to fd
*/
static int UseBinaryWText(FILE *fd){
  if( fd==stdout || fd==stderr ){
    return simBinaryStdout;
  }else{
    return simBinaryOther;
  }
}


/*
** Work-alike for the fopen() routine from the standard C library.
*/
FILE *sqlite3_fopen(const char *zFilename, const char *zMode){
  FILE *fp = 0;
  wchar_t *b1, *b2;
  int sz1, sz2;

  sz1 = (int)strlen(zFilename);
  sz2 = (int)strlen(zMode);
  b1 = malloc( (sz1+1)*sizeof(b1[0]) );
  b2 = malloc( (sz2+1)*sizeof(b1[0]) );
  if( b1 && b2 ){
    sz1 = MultiByteToWideChar(CP_UTF8, 0, zFilename, sz1, b1, sz1);
    b1[sz1] = 0;
    sz2 = MultiByteToWideChar(CP_UTF8, 0, zMode, sz2, b2, sz2);
    b2[sz2] = 0;
    fp = _wfopen(b1, b2);
  }
  free(b1);
  free(b2);
  simBinaryOther = 0;
  return fp;
}


/*
** Work-alike for the popen() routine from the standard C library.
*/
FILE *sqlite3_popen(const char *zCommand, const char *zMode){
  FILE *fp = 0;
  wchar_t *b1, *b2;
  int sz1, sz2;

  sz1 = (int)strlen(zCommand);
  sz2 = (int)strlen(zMode);
  b1 = malloc( (sz1+1)*sizeof(b1[0]) );
  b2 = malloc( (sz2+1)*sizeof(b1[0]) );
  if( b1 && b2 ){
    sz1 = MultiByteToWideChar(CP_UTF8, 0, zCommand, sz1, b1, sz1);
    b1[sz1] = 0;
    sz2 = MultiByteToWideChar(CP_UTF8, 0, zMode, sz2, b2, sz2);
    b2[sz2] = 0;
    fp = _wpopen(b1, b2);
  }
  free(b1);
  free(b2);
  return fp;
}

/*
** Work-alike for fgets() from the standard C library.
*/
char *sqlite3_fgets(char *buf, int sz, FILE *in){
  if( UseWtextForInput(in) ){
    /* When reading from the command-prompt in Windows, it is necessary
    ** to use _O_WTEXT input mode to read UTF-16 characters, then translate
    ** that into UTF-8.  Otherwise, non-ASCII characters all get translated
    ** into '?'.
    */
    wchar_t *b1 = sqlite3_malloc( sz*sizeof(wchar_t) );
    if( b1==0 ) return 0;
    _setmode(_fileno(in), IsConsole(in) ? _O_WTEXT : _O_U8TEXT);
    if( fgetws(b1, sz/4, in)==0 ){
      sqlite3_free(b1);
      return 0;
    }
    WideCharToMultiByte(CP_UTF8, 0, b1, -1, buf, sz, 0, 0);
    sqlite3_free(b1);
    return buf;
  }else{
    /* Reading from a file or other input source, just read bytes without
    ** any translation. */
    return fgets(buf, sz, in);
  }
}

/*
** Send ASCII text as O_BINARY.  But for Unicode characters U+0080 and
** greater, switch to O_U8TEXT.
*/
static void piecemealOutput(wchar_t *b1, int sz, FILE *out){
  int i;
  wchar_t c;
  while( sz>0 ){
    for(i=0; i<sz && b1[i]>=0x80; i++){}
    if( i>0 ){
      c = b1[i];
      b1[i] = 0;
      fflush(out);
      _setmode(_fileno(out), _O_U8TEXT);
      fputws(b1, out);
      fflush(out);
      b1 += i;
      b1[0] = c;
      sz -= i;
    }else{
      fflush(out);
      _setmode(_fileno(out), _O_TEXT);
      _setmode(_fileno(out), _O_BINARY);
      fwrite(&b1[0], 1, 1, out);
      for(i=1; i<sz && b1[i]<0x80; i++){
        fwrite(&b1[i], 1, 1, out);
      }
      fflush(out);
      _setmode(_fileno(out), _O_U8TEXT);
      b1 += i;
      sz -= i;
    }
  }
}

/*
** Work-alike for fputs() from the standard C library.
*/
int sqlite3_fputs(const char *z, FILE *out){
  if( !UseWtextForOutput(out) ){
    /* Writing to a file or other destination, just write bytes without
    ** any translation. */
    return fputs(z, out);
  }else{
    /* When writing to the command-prompt in Windows, it is necessary
    ** to use O_U8TEXT to render Unicode U+0080 and greater.  Go ahead
    ** use O_U8TEXT for everything in text mode.
    */
    int sz = (int)strlen(z);
    wchar_t *b1 = sqlite3_malloc( (sz+1)*sizeof(wchar_t) );
    if( b1==0 ) return 0;
    sz = MultiByteToWideChar(CP_UTF8, 0, z, sz, b1, sz);
    b1[sz] = 0;
    _setmode(_fileno(out), _O_U8TEXT);
    if( UseBinaryWText(out) ){
      piecemealOutput(b1, sz, out);
    }else{
      fputws(b1, out);
    }
    sqlite3_free(b1);
    return 0;
  }
}


/*
** Work-alike for fprintf() from the standard C library.
*/
int sqlite3_fprintf(FILE *out, const char *zFormat, ...){
  int rc;
  if( UseWtextForOutput(out) ){
    /* When writing to the command-prompt in Windows, it is necessary
    ** to use _O_WTEXT input mode and write UTF-16 characters.
    */
    char *z;
    va_list ap;

    va_start(ap, zFormat);
    z = sqlite3_vmprintf(zFormat, ap);
    va_end(ap);
    sqlite3_fputs(z, out);
    rc = (int)strlen(z);
    sqlite3_free(z);
  }else{
    /* Writing to a file or other destination, just write bytes without
    ** any translation. */
    va_list ap;
    va_start(ap, zFormat);
    rc = vfprintf(out, zFormat, ap);
    va_end(ap);
  }
  return rc;
}

/*
** Set the mode for an output stream.  mode argument is typically _O_BINARY or
** _O_TEXT.
*/
void sqlite3_fsetmode(FILE *fp, int mode){
  if( !UseWtextForOutput(fp) ){
    fflush(fp);
    _setmode(_fileno(fp), mode);
  }else if( fp==stdout || fp==stderr ){
    simBinaryStdout = (mode==_O_BINARY);
  }else{
    simBinaryOther = (mode==_O_BINARY);
  }
}

#endif /* defined(_WIN32) */

/************************* End ../ext/misc/sqlite3_stdio.c ********************/

/* Use console I/O package as a direct INCLUDE. */
#define SQLITE_INTERNAL_LINKAGE static

#ifdef SQLITE_SHELL_FIDDLE
/* Deselect most features from the console I/O package for Fiddle. */
# define SQLITE_CIO_NO_REDIRECT
# define SQLITE_CIO_NO_CLASSIFY
# define SQLITE_CIO_NO_TRANSLATE
# define SQLITE_CIO_NO_SETMODE
# define SQLITE_CIO_NO_FLUSH
#endif

#define eputz(z) sqlite3_fputs(z,stderr)
#define sputz(fp,z) sqlite3_fputs(z,fp)

/* True if the timer is enabled */
static int enableTimer = 0;

/* A version of strcmp() that works with NULL values */
static int cli_strcmp(const char *a, const char *b){
  if( a==0 ) a = "";
  if( b==0 ) b = "";
  return strcmp(a,b);
}
static int cli_strncmp(const char *a, const char *b, size_t n){
  if( a==0 ) a = "";
  if( b==0 ) b = "";
  return strncmp(a,b,n);
}

/* Return the current wall-clock time */
static sqlite3_int64 timeOfDay(void){
  static sqlite3_vfs *clockVfs = 0;
  sqlite3_int64 t;
  if( clockVfs==0 ) clockVfs = sqlite3_vfs_find(0);
  if( clockVfs==0 ) return 0;  /* Never actually happens */
  if( clockVfs->iVersion>=2 && clockVfs->xCurrentTimeInt64!=0 ){
    clockVfs->xCurrentTimeInt64(clockVfs, &t);
  }else{
    double r;
    clockVfs->xCurrentTime(clockVfs, &r);
    t = (sqlite3_int64)(r*86400000.0);
  }
  return t;
}

#if !defined(_WIN32) && !defined(WIN32) && !defined(__minux)
#include <sys/time.h>
#include <sys/resource.h>

/* VxWorks does not support getrusage() as far as we can determine */
#if defined(_WRS_KERNEL) || defined(__RTP__)
struct rusage {
  struct timeval ru_utime; /* user CPU time used */
  struct timeval ru_stime; /* system CPU time used */
};
#define getrusage(A,B) memset(B,0,sizeof(*B))
#endif


/* Saved resource information for the beginning of an operation */
static struct rusage sBegin;  /* CPU time at start */
static sqlite3_int64 iBegin;  /* Wall-clock time at start */

/*
** Begin timing an operation
*/
static void beginTimer(void){
  if( enableTimer ){
    getrusage(RUSAGE_SELF, &sBegin);
    iBegin = timeOfDay();
  }
}

/* Return the difference of two time_structs in seconds */
static double timeDiff(struct timeval *pStart, struct timeval *pEnd){
  return (pEnd->tv_usec - pStart->tv_usec)*0.000001 +
         (double)(pEnd->tv_sec - pStart->tv_sec);
}

/*
** Print the timing results.
*/
static void endTimer(FILE *out){
  if( enableTimer ){
    sqlite3_int64 iEnd = timeOfDay();
    struct rusage sEnd;
    getrusage(RUSAGE_SELF, &sEnd);
    sqlite3_fprintf(out, "Run Time: real %.3f user %f sys %f\n",
          (iEnd - iBegin)*0.001,
          timeDiff(&sBegin.ru_utime, &sEnd.ru_utime),
          timeDiff(&sBegin.ru_stime, &sEnd.ru_stime));
  }
}

#define BEGIN_TIMER beginTimer()
#define END_TIMER(X) endTimer(X)
#define HAS_TIMER 1

#elif (defined(_WIN32) || defined(WIN32))

/* Saved resource information for the beginning of an operation */
static HANDLE hProcess;
static FILETIME ftKernelBegin;
static FILETIME ftUserBegin;
static sqlite3_int64 ftWallBegin;
typedef BOOL (WINAPI *GETPROCTIMES)(HANDLE, LPFILETIME, LPFILETIME,
                                    LPFILETIME, LPFILETIME);
static GETPROCTIMES getProcessTimesAddr = NULL;

/*
** Check to see if we have timer support.  Return 1 if necessary
** support found (or found previously).
*/
static int hasTimer(void){
  if( getProcessTimesAddr ){
    return 1;
  } else {
#if !SQLITE_OS_WINRT
    /* GetProcessTimes() isn't supported in WIN95 and some other Windows
    ** versions. See if the version we are running on has it, and if it
    ** does, save off a pointer to it and the current process handle.
    */
    hProcess = GetCurrentProcess();
    if( hProcess ){
      HINSTANCE hinstLib = LoadLibrary(TEXT("Kernel32.dll"));
      if( NULL != hinstLib ){
        getProcessTimesAddr =
            (GETPROCTIMES) GetProcAddress(hinstLib, "GetProcessTimes");
        if( NULL != getProcessTimesAddr ){
          return 1;
        }
        FreeLibrary(hinstLib);
      }
    }
#endif
  }
  return 0;
}

/*
** Begin timing an operation
*/
static void beginTimer(void){
  if( enableTimer && getProcessTimesAddr ){
    FILETIME ftCreation, ftExit;
    getProcessTimesAddr(hProcess,&ftCreation,&ftExit,
                        &ftKernelBegin,&ftUserBegin);
    ftWallBegin = timeOfDay();
  }
}

/* Return the difference of two FILETIME structs in seconds */
static double timeDiff(FILETIME *pStart, FILETIME *pEnd){
  sqlite_int64 i64Start = *((sqlite_int64 *) pStart);
  sqlite_int64 i64End = *((sqlite_int64 *) pEnd);
  return (double) ((i64End - i64Start) / 10000000.0);
}

/*
** Print the timing results.
*/
static void endTimer(FILE *out){
  if( enableTimer && getProcessTimesAddr){
    FILETIME ftCreation, ftExit, ftKernelEnd, ftUserEnd;
    sqlite3_int64 ftWallEnd = timeOfDay();
    getProcessTimesAddr(hProcess,&ftCreation,&ftExit,&ftKernelEnd,&ftUserEnd);
    sqlite3_fprintf(out, "Run Time: real %.3f user %f sys %f\n",
          (ftWallEnd - ftWallBegin)*0.001,
          timeDiff(&ftUserBegin, &ftUserEnd),
          timeDiff(&ftKernelBegin, &ftKernelEnd));
  }
}

#define BEGIN_TIMER beginTimer()
#define END_TIMER(X) endTimer(X)
#define HAS_TIMER hasTimer()

#else
#define BEGIN_TIMER
#define END_TIMER(X)  /*no-op*/
#define HAS_TIMER 0
#endif

/*
** Used to prevent warnings about unused parameters
*/
#define UNUSED_PARAMETER(x) (void)(x)

/*
** Number of elements in an array
*/
#define ArraySize(X)  (int)(sizeof(X)/sizeof(X[0]))

/*
** If the following flag is set, then command execution stops
** at an error if we are not interactive.
*/
static int bail_on_error = 0;

/*
** Treat stdin as an interactive input if the following variable
** is true.  Otherwise, assume stdin is connected to a file or pipe.
*/
static int stdin_is_interactive = 1;

/*
** On Windows systems we need to know if standard output is a console
** in order to show that UTF-16 translation is done in the sign-on
** banner. The following variable is true if it is the console.
*/
static int stdout_is_console = 1;

/*
** The following is the open SQLite database.  We make a pointer
** to this database a static variable so that it can be accessed
** by the SIGINT handler to interrupt database processing.
*/
static sqlite3 *globalDb = 0;

/*
** True if an interrupt (Control-C) has been received.
*/
static volatile int seenInterrupt = 0;

/*
** This is the name of our program. It is set in main(), used
** in a number of other places, mostly for error messages.
*/
static char *Argv0;

/*
** Prompt strings. Initialized in main. Settable with
**   .prompt main continue
*/
#define PROMPT_LEN_MAX 20
/* First line prompt.   default: "sqlite> " */
static char mainPrompt[PROMPT_LEN_MAX];
/* Continuation prompt. default: "   ...> " */
static char continuePrompt[PROMPT_LEN_MAX];

/* This is variant of the standard-library strncpy() routine with the
** one change that the destination string is always zero-terminated, even
** if there is no zero-terminator in the first n-1 characters of the source
** string.
*/
static char *shell_strncpy(char *dest, const char *src, size_t n){
  size_t i;
  for(i=0; i<n-1 && src[i]!=0; i++) dest[i] = src[i];
  dest[i] = 0;
  return dest;
}

/*
** strcpy() workalike to squelch an unwarranted link-time warning
** from OpenBSD.
*/
static void shell_strcpy(char *dest, const char *src){
  while( (*(dest++) = *(src++))!=0 ){}
}

/*
** Optionally disable dynamic continuation prompt.
** Unless disabled, the continuation prompt shows open SQL lexemes if any,
** or open parentheses level if non-zero, or continuation prompt as set.
** This facility interacts with the scanner and process_input() where the
** below 5 macros are used.
*/
#ifdef SQLITE_OMIT_DYNAPROMPT
# define CONTINUATION_PROMPT continuePrompt
# define CONTINUE_PROMPT_RESET
# define CONTINUE_PROMPT_AWAITS(p,s)
# define CONTINUE_PROMPT_AWAITC(p,c)
# define CONTINUE_PAREN_INCR(p,n)
# define CONTINUE_PROMPT_PSTATE 0
typedef void *t_NoDynaPrompt;
# define SCAN_TRACKER_REFTYPE t_NoDynaPrompt
#else
# define CONTINUATION_PROMPT dynamicContinuePrompt()
# define CONTINUE_PROMPT_RESET \
  do {setLexemeOpen(&dynPrompt,0,0); trackParenLevel(&dynPrompt,0);} while(0)
# define CONTINUE_PROMPT_AWAITS(p,s) \
  if(p && stdin_is_interactive) setLexemeOpen(p, s, 0)
# define CONTINUE_PROMPT_AWAITC(p,c) \
  if(p && stdin_is_interactive) setLexemeOpen(p, 0, c)
# define CONTINUE_PAREN_INCR(p,n) \
  if(p && stdin_is_interactive) (trackParenLevel(p,n))
# define CONTINUE_PROMPT_PSTATE (&dynPrompt)
typedef struct DynaPrompt *t_DynaPromptRef;
# define SCAN_TRACKER_REFTYPE t_DynaPromptRef

static struct DynaPrompt {
  char dynamicPrompt[PROMPT_LEN_MAX];
  char acAwait[2];
  int inParenLevel;
  char *zScannerAwaits;
} dynPrompt = { {0}, {0}, 0, 0 };

/* Record parenthesis nesting level change, or force level to 0. */
static void trackParenLevel(struct DynaPrompt *p, int ni){
  p->inParenLevel += ni;
  if( ni==0 ) p->inParenLevel = 0;
  p->zScannerAwaits = 0;
}

/* Record that a lexeme is opened, or closed with args==0. */
static void setLexemeOpen(struct DynaPrompt *p, char *s, char c){
  if( s!=0 || c==0 ){
    p->zScannerAwaits = s;
    p->acAwait[0] = 0;
  }else{
    p->acAwait[0] = c;
    p->zScannerAwaits = p->acAwait;
  }
}

/* Upon demand, derive the continuation prompt to display. */
static char *dynamicContinuePrompt(void){
  if( continuePrompt[0]==0
      || (dynPrompt.zScannerAwaits==0 && dynPrompt.inParenLevel == 0) ){
    return continuePrompt;
  }else{
    if( dynPrompt.zScannerAwaits ){
      size_t ncp = strlen(continuePrompt);
      size_t ndp = strlen(dynPrompt.zScannerAwaits);
      if( ndp > ncp-3 ) return continuePrompt;
      shell_strcpy(dynPrompt.dynamicPrompt, dynPrompt.zScannerAwaits);
      while( ndp<3 ) dynPrompt.dynamicPrompt[ndp++] = ' ';
      shell_strncpy(dynPrompt.dynamicPrompt+3, continuePrompt+3,
              PROMPT_LEN_MAX-4);
    }else{
      if( dynPrompt.inParenLevel>9 ){
        shell_strncpy(dynPrompt.dynamicPrompt, "(..", 4);
      }else if( dynPrompt.inParenLevel<0 ){
        shell_strncpy(dynPrompt.dynamicPrompt, ")x!", 4);
      }else{
        shell_strncpy(dynPrompt.dynamicPrompt, "(x.", 4);
        dynPrompt.dynamicPrompt[2] = (char)('0'+dynPrompt.inParenLevel);
      }
      shell_strncpy(dynPrompt.dynamicPrompt+3, continuePrompt+3,
                    PROMPT_LEN_MAX-4);
    }
  }
  return dynPrompt.dynamicPrompt;
}
#endif /* !defined(SQLITE_OMIT_DYNAPROMPT) */

/* Indicate out-of-memory and exit. */
static void shell_out_of_memory(void){
  eputz("Error: out of memory\n");
  exit(1);
}

/* Check a pointer to see if it is NULL.  If it is NULL, exit with an
** out-of-memory error.
*/
static void shell_check_oom(const void *p){
  if( p==0 ) shell_out_of_memory();
}

/*
** Write I/O traces to the following stream.
*/
#ifdef SQLITE_ENABLE_IOTRACE
static FILE *iotrace = 0;
#endif

/*
** This routine works like printf in that its first argument is a
** format string and subsequent arguments are values to be substituted
** in place of % fields.  The result of formatting this string
** is written to iotrace.
*/
#ifdef SQLITE_ENABLE_IOTRACE
static void SQLITE_CDECL iotracePrintf(const char *zFormat, ...){
  va_list ap;
  char *z;
  if( iotrace==0 ) return;
  va_start(ap, zFormat);
  z = sqlite3_vmprintf(zFormat, ap);
  va_end(ap);
  sqlite3_fprintf(iotrace, "%s", z);
  sqlite3_free(z);
}
#endif

/* Lookup table to estimate the number of columns consumed by a Unicode
** character.
*/
static const struct {
  unsigned char w;    /* Width of the character in columns */
  int iFirst;         /* First character in a span having this width */
} aUWidth[] = {
   /* {1, 0x00000}, */
  {0, 0x00300},  {1, 0x00370},  {0, 0x00483},  {1, 0x00487},  {0, 0x00488},
  {1, 0x0048a},  {0, 0x00591},  {1, 0x005be},  {0, 0x005bf},  {1, 0x005c0},
  {0, 0x005c1},  {1, 0x005c3},  {0, 0x005c4},  {1, 0x005c6},  {0, 0x005c7},
  {1, 0x005c8},  {0, 0x00600},  {1, 0x00604},  {0, 0x00610},  {1, 0x00616},
  {0, 0x0064b},  {1, 0x0065f},  {0, 0x00670},  {1, 0x00671},  {0, 0x006d6},
  {1, 0x006e5},  {0, 0x006e7},  {1, 0x006e9},  {0, 0x006ea},  {1, 0x006ee},
  {0, 0x0070f},  {1, 0x00710},  {0, 0x00711},  {1, 0x00712},  {0, 0x00730},
  {1, 0x0074b},  {0, 0x007a6},  {1, 0x007b1},  {0, 0x007eb},  {1, 0x007f4},
  {0, 0x00901},  {1, 0x00903},  {0, 0x0093c},  {1, 0x0093d},  {0, 0x00941},
  {1, 0x00949},  {0, 0x0094d},  {1, 0x0094e},  {0, 0x00951},  {1, 0x00955},
  {0, 0x00962},  {1, 0x00964},  {0, 0x00981},  {1, 0x00982},  {0, 0x009bc},
  {1, 0x009bd},  {0, 0x009c1},  {1, 0x009c5},  {0, 0x009cd},  {1, 0x009ce},
  {0, 0x009e2},  {1, 0x009e4},  {0, 0x00a01},  {1, 0x00a03},  {0, 0x00a3c},
  {1, 0x00a3d},  {0, 0x00a41},  {1, 0x00a43},  {0, 0x00a47},  {1, 0x00a49},
  {0, 0x00a4b},  {1, 0x00a4e},  {0, 0x00a70},  {1, 0x00a72},  {0, 0x00a81},
  {1, 0x00a83},  {0, 0x00abc},  {1, 0x00abd},  {0, 0x00ac1},  {1, 0x00ac6},
  {0, 0x00ac7},  {1, 0x00ac9},  {0, 0x00acd},  {1, 0x00ace},  {0, 0x00ae2},
  {1, 0x00ae4},  {0, 0x00b01},  {1, 0x00b02},  {0, 0x00b3c},  {1, 0x00b3d},
  {0, 0x00b3f},  {1, 0x00b40},  {0, 0x00b41},  {1, 0x00b44},  {0, 0x00b4d},
  {1, 0x00b4e},  {0, 0x00b56},  {1, 0x00b57},  {0, 0x00b82},  {1, 0x00b83},
  {0, 0x00bc0},  {1, 0x00bc1},  {0, 0x00bcd},  {1, 0x00bce},  {0, 0x00c3e},
  {1, 0x00c41},  {0, 0x00c46},  {1, 0x00c49},  {0, 0x00c4a},  {1, 0x00c4e},
  {0, 0x00c55},  {1, 0x00c57},  {0, 0x00cbc},  {1, 0x00cbd},  {0, 0x00cbf},
  {1, 0x00cc0},  {0, 0x00cc6},  {1, 0x00cc7},  {0, 0x00ccc},  {1, 0x00cce},
  {0, 0x00ce2},  {1, 0x00ce4},  {0, 0x00d41},  {1, 0x00d44},  {0, 0x00d4d},
  {1, 0x00d4e},  {0, 0x00dca},  {1, 0x00dcb},  {0, 0x00dd2},  {1, 0x00dd5},
  {0, 0x00dd6},  {1, 0x00dd7},  {0, 0x00e31},  {1, 0x00e32},  {0, 0x00e34},
  {1, 0x00e3b},  {0, 0x00e47},  {1, 0x00e4f},  {0, 0x00eb1},  {1, 0x00eb2},
  {0, 0x00eb4},  {1, 0x00eba},  {0, 0x00ebb},  {1, 0x00ebd},  {0, 0x00ec8},
  {1, 0x00ece},  {0, 0x00f18},  {1, 0x00f1a},  {0, 0x00f35},  {1, 0x00f36},
  {0, 0x00f37},  {1, 0x00f38},  {0, 0x00f39},  {1, 0x00f3a},  {0, 0x00f71},
  {1, 0x00f7f},  {0, 0x00f80},  {1, 0x00f85},  {0, 0x00f86},  {1, 0x00f88},
  {0, 0x00f90},  {1, 0x00f98},  {0, 0x00f99},  {1, 0x00fbd},  {0, 0x00fc6},
  {1, 0x00fc7},  {0, 0x0102d},  {1, 0x01031},  {0, 0x01032},  {1, 0x01033},
  {0, 0x01036},  {1, 0x01038},  {0, 0x01039},  {1, 0x0103a},  {0, 0x01058},
  {1, 0x0105a},  {2, 0x01100},  {0, 0x01160},  {1, 0x01200},  {0, 0x0135f},
  {1, 0x01360},  {0, 0x01712},  {1, 0x01715},  {0, 0x01732},  {1, 0x01735},
  {0, 0x01752},  {1, 0x01754},  {0, 0x01772},  {1, 0x01774},  {0, 0x017b4},
  {1, 0x017b6},  {0, 0x017b7},  {1, 0x017be},  {0, 0x017c6},  {1, 0x017c7},
  {0, 0x017c9},  {1, 0x017d4},  {0, 0x017dd},  {1, 0x017de},  {0, 0x0180b},
  {1, 0x0180e},  {0, 0x018a9},  {1, 0x018aa},  {0, 0x01920},  {1, 0x01923},
  {0, 0x01927},  {1, 0x01929},  {0, 0x01932},  {1, 0x01933},  {0, 0x01939},
  {1, 0x0193c},  {0, 0x01a17},  {1, 0x01a19},  {0, 0x01b00},  {1, 0x01b04},
  {0, 0x01b34},  {1, 0x01b35},  {0, 0x01b36},  {1, 0x01b3b},  {0, 0x01b3c},
  {1, 0x01b3d},  {0, 0x01b42},  {1, 0x01b43},  {0, 0x01b6b},  {1, 0x01b74},
  {0, 0x01dc0},  {1, 0x01dcb},  {0, 0x01dfe},  {1, 0x01e00},  {0, 0x0200b},
  {1, 0x02010},  {0, 0x0202a},  {1, 0x0202f},  {0, 0x02060},  {1, 0x02064},
  {0, 0x0206a},  {1, 0x02070},  {0, 0x020d0},  {1, 0x020f0},  {2, 0x02329},
  {1, 0x0232b},  {2, 0x02e80},  {0, 0x0302a},  {2, 0x03030},  {1, 0x0303f},
  {2, 0x03040},  {0, 0x03099},  {2, 0x0309b},  {1, 0x0a4d0},  {0, 0x0a806},
  {1, 0x0a807},  {0, 0x0a80b},  {1, 0x0a80c},  {0, 0x0a825},  {1, 0x0a827},
  {2, 0x0ac00},  {1, 0x0d7a4},  {2, 0x0f900},  {1, 0x0fb00},  {0, 0x0fb1e},
  {1, 0x0fb1f},  {0, 0x0fe00},  {2, 0x0fe10},  {1, 0x0fe1a},  {0, 0x0fe20},
  {1, 0x0fe24},  {2, 0x0fe30},  {1, 0x0fe70},  {0, 0x0feff},  {2, 0x0ff00},
  {1, 0x0ff61},  {2, 0x0ffe0},  {1, 0x0ffe7},  {0, 0x0fff9},  {1, 0x0fffc},
  {0, 0x10a01},  {1, 0x10a04},  {0, 0x10a05},  {1, 0x10a07},  {0, 0x10a0c},
  {1, 0x10a10},  {0, 0x10a38},  {1, 0x10a3b},  {0, 0x10a3f},  {1, 0x10a40},
  {0, 0x1d167},  {1, 0x1d16a},  {0, 0x1d173},  {1, 0x1d183},  {0, 0x1d185},
  {1, 0x1d18c},  {0, 0x1d1aa},  {1, 0x1d1ae},  {0, 0x1d242},  {1, 0x1d245},
  {2, 0x20000},  {1, 0x2fffe},  {2, 0x30000},  {1, 0x3fffe},  {0, 0xe0001},
  {1, 0xe0002},  {0, 0xe0020},  {1, 0xe0080},  {0, 0xe0100},  {1, 0xe01f0}
};

/*
** Return an estimate of the width, in columns, for the single Unicode
** character c.  For normal characters, the answer is always 1.  But the
** estimate might be 0 or 2 for zero-width and double-width characters.
**
** Different display devices display unicode using different widths.  So
** it is impossible to know that true display width with 100% accuracy.
** Inaccuracies in the width estimates might cause columns to be misaligned.
** Unfortunately, there is nothing we can do about that.
*/
int cli_wcwidth(int c){
  int iFirst, iLast;

  /* Fast path for common characters */
  if( c<=0x300 ) return 1;

  /* The general case */
  iFirst = 0;
  iLast = sizeof(aUWidth)/sizeof(aUWidth[0]) - 1;
  while( iFirst<iLast-1 ){
    int iMid = (iFirst+iLast)/2;
    int cMid = aUWidth[iMid].iFirst;
    if( cMid < c ){
      iFirst = iMid;
    }else if( cMid > c ){
      iLast = iMid - 1;
    }else{
      return aUWidth[iMid].w;
    }
  }
  if( aUWidth[iLast].iFirst > c ) return aUWidth[iFirst].w;
  return aUWidth[iLast].w;
}

/*
** Compute the value and length of a multi-byte UTF-8 character that
** begins at z[0].   Return the length.  Write the Unicode value into *pU.
**
** This routine only works for *multi-byte* UTF-8 characters.
*/
static int decodeUtf8(const unsigned char *z, int *pU){
  if( (z[0] & 0xe0)==0xc0 && (z[1] & 0xc0)==0x80 ){
    *pU = ((z[0] & 0x1f)<<6) | (z[1] & 0x3f);
    return 2;
  }
  if( (z[0] & 0xf0)==0xe0 && (z[1] & 0xc0)==0x80 && (z[2] & 0xc0)==0x80 ){
    *pU = ((z[0] & 0x0f)<<12) | ((z[1] & 0x3f)<<6) | (z[2] & 0x3f);
    return 3;
  }
  if( (z[0] & 0xf8)==0xf0 && (z[1] & 0xc0)==0x80 && (z[2] & 0xc0)==0x80
   && (z[3] & 0xc0)==0x80
  ){
    *pU = ((z[0] & 0x0f)<<18) | ((z[1] & 0x3f)<<12) | ((z[2] & 0x3f))<<6
                              | (z[4] & 0x3f);
    return 4;
  }
  *pU = 0;
  return 1;
}


#if 0 /* NOT USED */
/*
** Return the width, in display columns, of a UTF-8 string.
**
** Each normal character counts as 1.  Zero-width characters count
** as zero, and double-width characters count as 2.
*/
int cli_wcswidth(const char *z){
  const unsigned char *a = (const unsigned char*)z;
  int n = 0;
  int i = 0;
  unsigned char c;
  while( (c = a[i])!=0 ){
    if( c>=0xc0 ){
      int u;
      int len = decodeUtf8(&a[i], &u);
      i += len;
      n += cli_wcwidth(u);
    }else if( c>=' ' ){
      n++;
      i++;
    }else{
      i++;
    }
  }
  return n;
}
#endif

/*
** Output string zUtf to stdout as w characters.  If w is negative,
** then right-justify the text.  W is the width in UTF-8 characters, not
** in bytes.  This is different from the %*.*s specification in printf
** since with %*.*s the width is measured in bytes, not characters.
**
** Take into account zero-width and double-width Unicode characters.
** In other words, a zero-width character does not count toward the
** the w limit.  A double-width character counts as two.
*/
static void utf8_width_print(FILE *out, int w, const char *zUtf){
  const unsigned char *a = (const unsigned char*)zUtf;
  unsigned char c;
  int i = 0;
  int n = 0;
  int aw = w<0 ? -w : w;
  if( zUtf==0 ) zUtf = "";
  while( (c = a[i])!=0 ){
    if( (c&0xc0)==0xc0 ){
      int u;
      int len = decodeUtf8(a+i, &u);
      int x = cli_wcwidth(u);
      if( x+n>aw ){
        break;
      }
      i += len;
      n += x;
    }else if( n>=aw ){
      break;
    }else{
      n++;
      i++;
    }
  }
  if( n>=aw ){
    sqlite3_fprintf(out, "%.*s", i, zUtf);
  }else if( w<0 ){
    sqlite3_fprintf(out, "%*s%s", aw-n, "", zUtf);
  }else{
    sqlite3_fprintf(out, "%s%*s", zUtf, aw-n, "");
  }
}


/*
** Determines if a string is a number of not.
*/
static int isNumber(const char *z, int *realnum){
  if( *z=='-' || *z=='+' ) z++;
  if( !IsDigit(*z) ){
    return 0;
  }
  z++;
  if( realnum ) *realnum = 0;
  while( IsDigit(*z) ){ z++; }
  if( *z=='.' ){
    z++;
    if( !IsDigit(*z) ) return 0;
    while( IsDigit(*z) ){ z++; }
    if( realnum ) *realnum = 1;
  }
  if( *z=='e' || *z=='E' ){
    z++;
    if( *z=='+' || *z=='-' ) z++;
    if( !IsDigit(*z) ) return 0;
    while( IsDigit(*z) ){ z++; }
    if( realnum ) *realnum = 1;
  }
  return *z==0;
}

/*
** Compute a string length that is limited to what can be stored in
** lower 30 bits of a 32-bit signed integer.
*/
static int strlen30(const char *z){
  const char *z2 = z;
  while( *z2 ){ z2++; }
  return 0x3fffffff & (int)(z2 - z);
}

/*
** Return the length of a string in characters.  Multibyte UTF8 characters
** count as a single character.
*/
static int strlenChar(const char *z){
  int n = 0;
  while( *z ){
    if( (0xc0&*(z++))!=0x80 ) n++;
  }
  return n;
}

/*
** Return open FILE * if zFile exists, can be opened for read
** and is an ordinary file or a character stream source.
** Otherwise return 0.
*/
static FILE * openChrSource(const char *zFile){
#if defined(_WIN32) || defined(WIN32)
  struct __stat64 x = {0};
# define STAT_CHR_SRC(mode) ((mode & (_S_IFCHR|_S_IFIFO|_S_IFREG))!=0)
  /* On Windows, open first, then check the stream nature. This order
  ** is necessary because _stat() and sibs, when checking a named pipe,
  ** effectively break the pipe as its supplier sees it. */
  FILE *rv = sqlite3_fopen(zFile, "rb");
  if( rv==0 ) return 0;
  if( _fstat64(_fileno(rv), &x) != 0
      || !STAT_CHR_SRC(x.st_mode)){
    fclose(rv);
    rv = 0;
  }
  return rv;
#else
  struct stat x = {0};
  int rc = stat(zFile, &x);
# define STAT_CHR_SRC(mode) (S_ISREG(mode)||S_ISFIFO(mode)||S_ISCHR(mode))
  if( rc!=0 ) return 0;
  if( STAT_CHR_SRC(x.st_mode) ){
    return sqlite3_fopen(zFile, "rb");
  }else{
    return 0;
  }
#endif
#undef STAT_CHR_SRC
}

/*
** This routine reads a line of text from FILE in, stores
** the text in memory obtained from malloc() and returns a pointer
** to the text.  NULL is returned at end of file, or if malloc()
** fails.
**
** If zLine is not NULL then it is a malloced buffer returned from
** a previous call to this routine that may be reused.
*/
static char *local_getline(char *zLine, FILE *in){
  int nLine = zLine==0 ? 0 : 100;
  int n = 0;

  while( 1 ){
    if( n+100>nLine ){
      nLine = nLine*2 + 100;
      zLine = realloc(zLine, nLine);
      shell_check_oom(zLine);
    }
    if( sqlite3_fgets(&zLine[n], nLine - n, in)==0 ){
      if( n==0 ){
        free(zLine);
        return 0;
      }
      zLine[n] = 0;
      break;
    }
    while( zLine[n] ) n++;
    if( n>0 && zLine[n-1]=='\n' ){
      n--;
      if( n>0 && zLine[n-1]=='\r' ) n--;
      zLine[n] = 0;
      break;
    }
  }
  return zLine;
}

/*
** Retrieve a single line of input text.
**
** If in==0 then read from standard input and prompt before each line.
** If isContinuation is true, then a continuation prompt is appropriate.
** If isContinuation is zero, then the main prompt should be used.
**
** If zPrior is not NULL then it is a buffer from a prior call to this
** routine that can be reused.
**
** The result is stored in space obtained from malloc() and must either
** be freed by the caller or else passed back into this routine via the
** zPrior argument for reuse.
*/
#ifndef SQLITE_SHELL_FIDDLE
static char *one_input_line(FILE *in, char *zPrior, int isContinuation){
  char *zPrompt;
  char *zResult;
  if( in!=0 ){
    zResult = local_getline(zPrior, in);
  }else{
    zPrompt = isContinuation ? CONTINUATION_PROMPT : mainPrompt;
#if SHELL_USE_LOCAL_GETLINE
    sputz(stdout, zPrompt);
    fflush(stdout);
    do{
      zResult = local_getline(zPrior, stdin);
      zPrior = 0;
      /* ^C trap creates a false EOF, so let "interrupt" thread catch up. */
      if( zResult==0 ) sqlite3_sleep(50);
    }while( zResult==0 && seenInterrupt>0 );
#else
    free(zPrior);
    zResult = shell_readline(zPrompt);
    while( zResult==0 ){
      /* ^C trap creates a false EOF, so let "interrupt" thread catch up. */
      sqlite3_sleep(50);
      if( seenInterrupt==0 ) break;
      zResult = shell_readline("");
    }
    if( zResult && *zResult ) shell_add_history(zResult);
#endif
  }
  return zResult;
}
#endif /* !SQLITE_SHELL_FIDDLE */

/*
** Return the value of a hexadecimal digit.  Return -1 if the input
** is not a hex digit.
*/
static int hexDigitValue(char c){
  if( c>='0' && c<='9' ) return c - '0';
  if( c>='a' && c<='f' ) return c - 'a' + 10;
  if( c>='A' && c<='F' ) return c - 'A' + 10;
  return -1;
}

/*
** Interpret zArg as an integer value, possibly with suffixes.
*/
static sqlite3_int64 integerValue(const char *zArg){
  sqlite3_int64 v = 0;
  static const struct { char *zSuffix; int iMult; } aMult[] = {
    { "KiB", 1024 },
    { "MiB", 1024*1024 },
    { "GiB", 1024*1024*1024 },
    { "KB",  1000 },
    { "MB",  1000000 },
    { "GB",  1000000000 },
    { "K",   1000 },
    { "M",   1000000 },
    { "G",   1000000000 },
  };
  int i;
  int isNeg = 0;
  if( zArg[0]=='-' ){
    isNeg = 1;
    zArg++;
  }else if( zArg[0]=='+' ){
    zArg++;
  }
  if( zArg[0]=='0' && zArg[1]=='x' ){
    int x;
    zArg += 2;
    while( (x = hexDigitValue(zArg[0]))>=0 ){
      v = (v<<4) + x;
      zArg++;
    }
  }else{
    while( IsDigit(zArg[0]) ){
      v = v*10 + zArg[0] - '0';
      zArg++;
    }
  }
  for(i=0; i<ArraySize(aMult); i++){
    if( sqlite3_stricmp(aMult[i].zSuffix, zArg)==0 ){
      v *= aMult[i].iMult;
      break;
    }
  }
  return isNeg? -v : v;
}

/*
** A variable length string to which one can append text.
*/
typedef struct ShellText ShellText;
struct ShellText {
  char *z;
  int n;
  int nAlloc;
};

/*
** Initialize and destroy a ShellText object
*/
static void initText(ShellText *p){
  memset(p, 0, sizeof(*p));
}
static void freeText(ShellText *p){
  free(p->z);
  initText(p);
}

/* zIn is either a pointer to a NULL-terminated string in memory obtained
** from malloc(), or a NULL pointer. The string pointed to by zAppend is
** added to zIn, and the result returned in memory obtained from malloc().
** zIn, if it was not NULL, is freed.
**
** If the third argument, quote, is not '\0', then it is used as a
** quote character for zAppend.
*/
static void appendText(ShellText *p, const char *zAppend, char quote){
  i64 len;
  i64 i;
  i64 nAppend = strlen30(zAppend);

  len = nAppend+p->n+1;
  if( quote ){
    len += 2;
    for(i=0; i<nAppend; i++){
      if( zAppend[i]==quote ) len++;
    }
  }

  if( p->z==0 || p->n+len>=p->nAlloc ){
    p->nAlloc = p->nAlloc*2 + len + 20;
    p->z = realloc(p->z, p->nAlloc);
    shell_check_oom(p->z);
  }

  if( quote ){
    char *zCsr = p->z+p->n;
    *zCsr++ = quote;
    for(i=0; i<nAppend; i++){
      *zCsr++ = zAppend[i];
      if( zAppend[i]==quote ) *zCsr++ = quote;
    }
    *zCsr++ = quote;
    p->n = (int)(zCsr - p->z);
    *zCsr = '\0';
  }else{
    memcpy(p->z+p->n, zAppend, nAppend);
    p->n += nAppend;
    p->z[p->n] = '\0';
  }
}

/*
** Attempt to determine if identifier zName needs to be quoted, either
** because it contains non-alphanumeric characters, or because it is an
** SQLite keyword.  Be conservative in this estimate:  When in doubt assume
** that quoting is required.
**
** Return '"' if quoting is required.  Return 0 if no quoting is required.
*/
static char quoteChar(const char *zName){
  int i;
  if( zName==0 ) return '"';
  if( !isalpha((unsigned char)zName[0]) && zName[0]!='_' ) return '"';
  for(i=0; zName[i]; i++){
    if( !isalnum((unsigned char)zName[i]) && zName[i]!='_' ) return '"';
  }
  return sqlite3_keyword_check(zName, i) ? '"' : 0;
}

/*
** Construct a fake object name and column list to describe the structure
** of the view, virtual table, or table valued function zSchema.zName.
*/
static char *shellFakeSchema(
  sqlite3 *db,            /* The database connection containing the vtab */
  const char *zSchema,    /* Schema of the database holding the vtab */
  const char *zName       /* The name of the virtual table */
){
  sqlite3_stmt *pStmt = 0;
  char *zSql;
  ShellText s;
  char cQuote;
  char *zDiv = "(";
  int nRow = 0;

  zSql = sqlite3_mprintf("PRAGMA \"%w\".table_info=%Q;",
                         zSchema ? zSchema : "main", zName);
  shell_check_oom(zSql);
  sqlite3_prepare_v2(db, zSql, -1, &pStmt, 0);
  sqlite3_free(zSql);
  initText(&s);
  if( zSchema ){
    cQuote = quoteChar(zSchema);
    if( cQuote && sqlite3_stricmp(zSchema,"temp")==0 ) cQuote = 0;
    appendText(&s, zSchema, cQuote);
    appendText(&s, ".", 0);
  }
  cQuote = quoteChar(zName);
  appendText(&s, zName, cQuote);
  while( sqlite3_step(pStmt)==SQLITE_ROW ){
    const char *zCol = (const char*)sqlite3_column_text(pStmt, 1);
    nRow++;
    appendText(&s, zDiv, 0);
    zDiv = ",";
    if( zCol==0 ) zCol = "";
    cQuote = quoteChar(zCol);
    appendText(&s, zCol, cQuote);
  }
  appendText(&s, ")", 0);
  sqlite3_finalize(pStmt);
  if( nRow==0 ){
    freeText(&s);
    s.z = 0;
  }
  return s.z;
}

/*
** SQL function:  strtod(X)
**
** Use the C-library strtod() function to convert string X into a double.
** Used for comparing the accuracy of SQLite's internal text-to-float conversion
** routines against the C-library.
*/
static void shellStrtod(
  sqlite3_context *pCtx,
  int nVal,
  sqlite3_value **apVal
){
  char *z = (char*)sqlite3_value_text(apVal[0]);
  UNUSED_PARAMETER(nVal);
  if( z==0 ) return;
  sqlite3_result_double(pCtx, strtod(z,0));
}

/*
** SQL function:  dtostr(X)
**
** Use the C-library printf() function to convert real value X into a string.
** Used for comparing the accuracy of SQLite's internal float-to-text conversion
** routines against the C-library.
*/
static void shellDtostr(
  sqlite3_context *pCtx,
  int nVal,
  sqlite3_value **apVal
){
  double r = sqlite3_value_double(apVal[0]);
  int n = nVal>=2 ? sqlite3_value_int(apVal[1]) : 26;
  char z[400];
  if( n<1 ) n = 1;
  if( n>350 ) n = 350;
  sqlite3_snprintf(sizeof(z), z, "%#+.*e", n, r);
  sqlite3_result_text(pCtx, z, -1, SQLITE_TRANSIENT);
}


/*
** SQL function:  shell_module_schema(X)
**
** Return a fake schema for the table-valued function or eponymous virtual
** table X.
*/
static void shellModuleSchema(
  sqlite3_context *pCtx,
  int nVal,
  sqlite3_value **apVal
){
  const char *zName;
  char *zFake;
  UNUSED_PARAMETER(nVal);
  zName = (const char*)sqlite3_value_text(apVal[0]);
  zFake = zName? shellFakeSchema(sqlite3_context_db_handle(pCtx), 0, zName) : 0;
  if( zFake ){
    sqlite3_result_text(pCtx, sqlite3_mprintf("/* %s */", zFake),
                        -1, sqlite3_free);
    free(zFake);
  }
}

/*
** SQL function:  shell_add_schema(S,X)
**
** Add the schema name X to the CREATE statement in S and return the result.
** Examples:
**
**    CREATE TABLE t1(x)   ->   CREATE TABLE xyz.t1(x);
**
** Also works on
**
**    CREATE INDEX
**    CREATE UNIQUE INDEX
**    CREATE VIEW
**    CREATE TRIGGER
**    CREATE VIRTUAL TABLE
**
** This UDF is used by the .schema command to insert the schema name of
** attached databases into the middle of the sqlite_schema.sql field.
*/
static void shellAddSchemaName(
  sqlite3_context *pCtx,
  int nVal,
  sqlite3_value **apVal
){
  static const char *aPrefix[] = {
     "TABLE",
     "INDEX",
     "UNIQUE INDEX",
     "VIEW",
     "TRIGGER",
     "VIRTUAL TABLE"
  };
  int i = 0;
  const char *zIn = (const char*)sqlite3_value_text(apVal[0]);
  const char *zSchema = (const char*)sqlite3_value_text(apVal[1]);
  const char *zName = (const char*)sqlite3_value_text(apVal[2]);
  sqlite3 *db = sqlite3_context_db_handle(pCtx);
  UNUSED_PARAMETER(nVal);
  if( zIn!=0 && cli_strncmp(zIn, "CREATE ", 7)==0 ){
    for(i=0; i<ArraySize(aPrefix); i++){
      int n = strlen30(aPrefix[i]);
      if( cli_strncmp(zIn+7, aPrefix[i], n)==0 && zIn[n+7]==' ' ){
        char *z = 0;
        char *zFake = 0;
        if( zSchema ){
          char cQuote = quoteChar(zSchema);
          if( cQuote && sqlite3_stricmp(zSchema,"temp")!=0 ){
            z = sqlite3_mprintf("%.*s \"%w\".%s", n+7, zIn, zSchema, zIn+n+8);
          }else{
            z = sqlite3_mprintf("%.*s %s.%s", n+7, zIn, zSchema, zIn+n+8);
          }
        }
        if( zName
         && aPrefix[i][0]=='V'
         && (zFake = shellFakeSchema(db, zSchema, zName))!=0
        ){
          if( z==0 ){
            z = sqlite3_mprintf("%s\n/* %s */", zIn, zFake);
          }else{
            z = sqlite3_mprintf("%z\n/* %s */", z, zFake);
          }
          free(zFake);
        }
        if( z ){
          sqlite3_result_text(pCtx, z, -1, sqlite3_free);
          return;
        }
      }
    }
  }
  sqlite3_result_value(pCtx, apVal[0]);
}

/*
** The source code for several run-time loadable extensions is inserted
** below by the ../tool/mkshellc.tcl script.  Before processing that included
** code, we need to override some macros to make the included program code
** work here in the middle of this regular program.
*/
#define SQLITE_EXTENSION_INIT1
#define SQLITE_EXTENSION_INIT2(X) (void)(X)

#if defined(_WIN32) && defined(_MSC_VER)
/************************* Begin test_windirent.h ******************/
/*
** 2015 November 30
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains declarations for most of the opendir() family of
** POSIX functions on Win32 using the MSVCRT.
*/

#if defined(_WIN32) && defined(_MSC_VER) && !defined(SQLITE_WINDIRENT_H)
#define SQLITE_WINDIRENT_H

/*
** We need several data types from the Windows SDK header.
*/

#ifndef WIN32_LEAN_AND_MEAN
#define WIN32_LEAN_AND_MEAN
#endif

#include "windows.h"

/*
** We need several support functions from the SQLite core.
*/

/* #include "sqlite3.h" */

/*
** We need several things from the ANSI and MSVCRT headers.
*/

#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <io.h>
#include <limits.h>
#include <sys/types.h>
#include <sys/stat.h>

/*
** We may need several defines that should have been in "sys/stat.h".
*/

#ifndef S_ISREG
#define S_ISREG(mode) (((mode) & S_IFMT) == S_IFREG)
#endif

#ifndef S_ISDIR
#define S_ISDIR(mode) (((mode) & S_IFMT) == S_IFDIR)
#endif

#ifndef S_ISLNK
#define S_ISLNK(mode) (0)
#endif

/*
** We may need to provide the "mode_t" type.
*/

#ifndef MODE_T_DEFINED
  #define MODE_T_DEFINED
  typedef unsigned short mode_t;
#endif

/*
** We may need to provide the "ino_t" type.
*/

#ifndef INO_T_DEFINED
  #define INO_T_DEFINED
  typedef unsigned short ino_t;
#endif

/*
** We need to define "NAME_MAX" if it was not present in "limits.h".
*/

#ifndef NAME_MAX
#  ifdef FILENAME_MAX
#    define NAME_MAX (FILENAME_MAX)
#  else
#    define NAME_MAX (260)
#  endif
#endif

/*
** We need to define "NULL_INTPTR_T" and "BAD_INTPTR_T".
*/

#ifndef NULL_INTPTR_T
#  define NULL_INTPTR_T ((intptr_t)(0))
#endif

#ifndef BAD_INTPTR_T
#  define BAD_INTPTR_T ((intptr_t)(-1))
#endif

/*
** We need to provide the necessary structures and related types.
*/

#ifndef DIRENT_DEFINED
#define DIRENT_DEFINED
typedef struct DIRENT DIRENT;
typedef DIRENT *LPDIRENT;
struct DIRENT {
  ino_t d_ino;               /* Sequence number, do not use. */
  unsigned d_attributes;     /* Win32 file attributes. */
  char d_name[NAME_MAX + 1]; /* Name within the directory. */
};
#endif

#ifndef DIR_DEFINED
#define DIR_DEFINED
typedef struct DIR DIR;
typedef DIR *LPDIR;
struct DIR {
  intptr_t d_handle; /* Value returned by "_findfirst". */
  DIRENT d_first;    /* DIRENT constructed based on "_findfirst". */
  DIRENT d_next;     /* DIRENT constructed based on "_findnext". */
};
#endif

/*
** Provide a macro, for use by the implementation, to determine if a
** particular directory entry should be skipped over when searching for
** the next directory entry that should be returned by the readdir() or
** readdir_r() functions.
*/

#ifndef is_filtered
#  define is_filtered(a) ((((a).attrib)&_A_HIDDEN) || (((a).attrib)&_A_SYSTEM))
#endif

/*
** Provide the function prototype for the POSIX compatible getenv()
** function.  This function is not thread-safe.
*/

extern const char *windirent_getenv(const char *name);

/*
** Finally, we can provide the function prototypes for the opendir(),
** readdir(), readdir_r(), and closedir() POSIX functions.
*/

extern LPDIR opendir(const char *dirname);
extern LPDIRENT readdir(LPDIR dirp);
extern INT readdir_r(LPDIR dirp, LPDIRENT entry, LPDIRENT *result);
extern INT closedir(LPDIR dirp);

#endif /* defined(WIN32) && defined(_MSC_VER) */

/************************* End test_windirent.h ********************/
/************************* Begin test_windirent.c ******************/
/*
** 2015 November 30
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains code to implement most of the opendir() family of
** POSIX functions on Win32 using the MSVCRT.
*/

#if defined(_WIN32) && defined(_MSC_VER)
/* #include "test_windirent.h" */

/*
** Implementation of the POSIX getenv() function using the Win32 API.
** This function is not thread-safe.
*/
const char *windirent_getenv(
  const char *name
){
  static char value[32768]; /* Maximum length, per MSDN */
  DWORD dwSize = sizeof(value) / sizeof(char); /* Size in chars */
  DWORD dwRet; /* Value returned by GetEnvironmentVariableA() */

  memset(value, 0, sizeof(value));
  dwRet = GetEnvironmentVariableA(name, value, dwSize);
  if( dwRet==0 || dwRet>dwSize ){
    /*
    ** The function call to GetEnvironmentVariableA() failed -OR-
    ** the buffer is not large enough.  Either way, return NULL.
    */
    return 0;
  }else{
    /*
    ** The function call to GetEnvironmentVariableA() succeeded
    ** -AND- the buffer contains the entire value.
    */
    return value;
  }
}

/*
** Implementation of the POSIX opendir() function using the MSVCRT.
*/
LPDIR opendir(
  const char *dirname
){
  struct _finddata_t data;
  LPDIR dirp = (LPDIR)sqlite3_malloc(sizeof(DIR));
  SIZE_T namesize = sizeof(data.name) / sizeof(data.name[0]);

  if( dirp==NULL ) return NULL;
  memset(dirp, 0, sizeof(DIR));

  /* TODO: Remove this if Unix-style root paths are not used. */
  if( sqlite3_stricmp(dirname, "/")==0 ){
    dirname = windirent_getenv("SystemDrive");
  }

  memset(&data, 0, sizeof(struct _finddata_t));
  _snprintf(data.name, namesize, "%s\\*", dirname);
  dirp->d_handle = _findfirst(data.name, &data);

  if( dirp->d_handle==BAD_INTPTR_T ){
    closedir(dirp);
    return NULL;
  }

  /* TODO: Remove this block to allow hidden and/or system files. */
  if( is_filtered(data) ){
next:

    memset(&data, 0, sizeof(struct _finddata_t));
    if( _findnext(dirp->d_handle, &data)==-1 ){
      closedir(dirp);
      return NULL;
    }

    /* TODO: Remove this block to allow hidden and/or system files. */
    if( is_filtered(data) ) goto next;
  }

  dirp->d_first.d_attributes = data.attrib;
  strncpy(dirp->d_first.d_name, data.name, NAME_MAX);
  dirp->d_first.d_name[NAME_MAX] = '\0';

  return dirp;
}

/*
** Implementation of the POSIX readdir() function using the MSVCRT.
*/
LPDIRENT readdir(
  LPDIR dirp
){
  struct _finddata_t data;

  if( dirp==NULL ) return NULL;

  if( dirp->d_first.d_ino==0 ){
    dirp->d_first.d_ino++;
    dirp->d_next.d_ino++;

    return &dirp->d_first;
  }

next:

  memset(&data, 0, sizeof(struct _finddata_t));
  if( _findnext(dirp->d_handle, &data)==-1 ) return NULL;

  /* TODO: Remove this block to allow hidden and/or system files. */
  if( is_filtered(data) ) goto next;

  dirp->d_next.d_ino++;
  dirp->d_next.d_attributes = data.attrib;
  strncpy(dirp->d_next.d_name, data.name, NAME_MAX);
  dirp->d_next.d_name[NAME_MAX] = '\0';

  return &dirp->d_next;
}

/*
** Implementation of the POSIX readdir_r() function using the MSVCRT.
*/
INT readdir_r(
  LPDIR dirp,
  LPDIRENT entry,
  LPDIRENT *result
){
  struct _finddata_t data;

  if( dirp==NULL ) return EBADF;

  if( dirp->d_first.d_ino==0 ){
    dirp->d_first.d_ino++;
    dirp->d_next.d_ino++;

    entry->d_ino = dirp->d_first.d_ino;
    entry->d_attributes = dirp->d_first.d_attributes;
    strncpy(entry->d_name, dirp->d_first.d_name, NAME_MAX);
    entry->d_name[NAME_MAX] = '\0';

    *result = entry;
    return 0;
  }

next:

  memset(&data, 0, sizeof(struct _finddata_t));
  if( _findnext(dirp->d_handle, &data)==-1 ){
    *result = NULL;
    return ENOENT;
  }

  /* TODO: Remove this block to allow hidden and/or system files. */
  if( is_filtered(data) ) goto next;

  entry->d_ino = (ino_t)-1; /* not available */
  entry->d_attributes = data.attrib;
  strncpy(entry->d_name, data.name, NAME_MAX);
  entry->d_name[NAME_MAX] = '\0';

  *result = entry;
  return 0;
}

/*
** Implementation of the POSIX closedir() function using the MSVCRT.
*/
INT closedir(
  LPDIR dirp
){
  INT result = 0;

  if( dirp==NULL ) return EINVAL;

  if( dirp->d_handle!=NULL_INTPTR_T && dirp->d_handle!=BAD_INTPTR_T ){
    result = _findclose(dirp->d_handle);
  }

  sqlite3_free(dirp);
  return result;
}

#endif /* defined(WIN32) && defined(_MSC_VER) */

/************************* End test_windirent.c ********************/
#define dirent DIRENT
#endif
/************************* Begin ../ext/misc/memtrace.c ******************/
/*
** 2019-01-21
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
**
** This file implements an extension that uses the SQLITE_CONFIG_MALLOC
** mechanism to add a tracing layer on top of SQLite.  If this extension
** is registered prior to sqlite3_initialize(), it will cause all memory
** allocation activities to be logged on standard output, or to some other
** FILE specified by the initializer.
**
** This file needs to be compiled into the application that uses it.
**
** This extension is used to implement the --memtrace option of the
** command-line shell.
*/
#include <assert.h>
#include <string.h>
#include <stdio.h>

/* The original memory allocation routines */
static sqlite3_mem_methods memtraceBase;
static FILE *memtraceOut;

/* Methods that trace memory allocations */
static void *memtraceMalloc(int n){
  if( memtraceOut ){
    fprintf(memtraceOut, "MEMTRACE: allocate %d bytes\n", 
            memtraceBase.xRoundup(n));
  }
  return memtraceBase.xMalloc(n);
}
static void memtraceFree(void *p){
  if( p==0 ) return;
  if( memtraceOut ){
    fprintf(memtraceOut, "MEMTRACE: free %d bytes\n", memtraceBase.xSize(p));
  }
  memtraceBase.xFree(p);
}
static void *memtraceRealloc(void *p, int n){
  if( p==0 ) return memtraceMalloc(n);
  if( n==0 ){
    memtraceFree(p);
    return 0;
  }
  if( memtraceOut ){
    fprintf(memtraceOut, "MEMTRACE: resize %d -> %d bytes\n",
            memtraceBase.xSize(p), memtraceBase.xRoundup(n));
  }
  return memtraceBase.xRealloc(p, n);
}
static int memtraceSize(void *p){
  return memtraceBase.xSize(p);
}
static int memtraceRoundup(int n){
  return memtraceBase.xRoundup(n);
}
static int memtraceInit(void *p){
  return memtraceBase.xInit(p);
}
static void memtraceShutdown(void *p){
  memtraceBase.xShutdown(p);
}

/* The substitute memory allocator */
static sqlite3_mem_methods ersaztMethods = {
  memtraceMalloc,
  memtraceFree,
  memtraceRealloc,
  memtraceSize,
  memtraceRoundup,
  memtraceInit,
  memtraceShutdown,
  0
};

/* Begin tracing memory allocations to out. */
int sqlite3MemTraceActivate(FILE *out){
  int rc = SQLITE_OK;
  if( memtraceBase.xMalloc==0 ){
    rc = sqlite3_config(SQLITE_CONFIG_GETMALLOC, &memtraceBase);
    if( rc==SQLITE_OK ){
      rc = sqlite3_config(SQLITE_CONFIG_MALLOC, &ersaztMethods);
    }
  }
  memtraceOut = out;
  return rc;
}

/* Deactivate memory tracing */
int sqlite3MemTraceDeactivate(void){
  int rc = SQLITE_OK;
  if( memtraceBase.xMalloc!=0 ){
    rc = sqlite3_config(SQLITE_CONFIG_MALLOC, &memtraceBase);
    if( rc==SQLITE_OK ){
      memset(&memtraceBase, 0, sizeof(memtraceBase));
    }
  }
  memtraceOut = 0;
  return rc;
}

/************************* End ../ext/misc/memtrace.c ********************/
/************************* Begin ../ext/misc/pcachetrace.c ******************/
/*
** 2023-06-21
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
**
** This file implements an extension that uses the SQLITE_CONFIG_PCACHE2
** mechanism to add a tracing layer on top of pluggable page cache of
** SQLite.  If this extension is registered prior to sqlite3_initialize(),
** it will cause all page cache activities to be logged on standard output,
** or to some other FILE specified by the initializer.
**
** This file needs to be compiled into the application that uses it.
**
** This extension is used to implement the --pcachetrace option of the
** command-line shell.
*/
#include <assert.h>
#include <string.h>
#include <stdio.h>

/* The original page cache routines */
static sqlite3_pcache_methods2 pcacheBase;
static FILE *pcachetraceOut;

/* Methods that trace pcache activity */
static int pcachetraceInit(void *pArg){
  int nRes;
  if( pcachetraceOut ){
    fprintf(pcachetraceOut, "PCACHETRACE: xInit(%p)\n", pArg);
  }
  nRes = pcacheBase.xInit(pArg);
  if( pcachetraceOut ){
    fprintf(pcachetraceOut, "PCACHETRACE: xInit(%p) -> %d\n", pArg, nRes);
  }
  return nRes;
}
static void pcachetraceShutdown(void *pArg){
  if( pcachetraceOut ){
    fprintf(pcachetraceOut, "PCACHETRACE: xShutdown(%p)\n", pArg);
  }
  pcacheBase.xShutdown(pArg);
}
static sqlite3_pcache *pcachetraceCreate(int szPage, int szExtra, int bPurge){
  sqlite3_pcache *pRes;
  if( pcachetraceOut ){
    fprintf(pcachetraceOut, "PCACHETRACE: xCreate(%d,%d,%d)\n",
            szPage, szExtra, bPurge);
  }
  pRes = pcacheBase.xCreate(szPage, szExtra, bPurge);
  if( pcachetraceOut ){
    fprintf(pcachetraceOut, "PCACHETRACE: xCreate(%d,%d,%d) -> %p\n",
            szPage, szExtra, bPurge, pRes);
  }
  return pRes;
}
static void pcachetraceCachesize(sqlite3_pcache *p, int nCachesize){
  if( pcachetraceOut ){
    fprintf(pcachetraceOut, "PCACHETRACE: xCachesize(%p, %d)\n", p, nCachesize);
  }
  pcacheBase.xCachesize(p, nCachesize);
}
static int pcachetracePagecount(sqlite3_pcache *p){
  int nRes;
  if( pcachetraceOut ){
    fprintf(pcachetraceOut, "PCACHETRACE: xPagecount(%p)\n", p);
  }
  nRes = pcacheBase.xPagecount(p);
  if( pcachetraceOut ){
    fprintf(pcachetraceOut, "PCACHETRACE: xPagecount(%p) -> %d\n", p, nRes);
  }
  return nRes;
}
static sqlite3_pcache_page *pcachetraceFetch(
  sqlite3_pcache *p,
  unsigned key,
  int crFg
){
  sqlite3_pcache_page *pRes;
  if( pcachetraceOut ){
    fprintf(pcachetraceOut, "PCACHETRACE: xFetch(%p,%u,%d)\n", p, key, crFg);
  }
  pRes = pcacheBase.xFetch(p, key, crFg);
  if( pcachetraceOut ){
    fprintf(pcachetraceOut, "PCACHETRACE: xFetch(%p,%u,%d) -> %p\n",
            p, key, crFg, pRes);
  }
  return pRes;
}
static void pcachetraceUnpin(
  sqlite3_pcache *p,
  sqlite3_pcache_page *pPg,
  int bDiscard
){
  if( pcachetraceOut ){
    fprintf(pcachetraceOut, "PCACHETRACE: xUnpin(%p, %p, %d)\n",
            p, pPg, bDiscard);
  }
  pcacheBase.xUnpin(p, pPg, bDiscard);
}
static void pcachetraceRekey(
  sqlite3_pcache *p,
  sqlite3_pcache_page *pPg,
  unsigned oldKey,
  unsigned newKey
){
  if( pcachetraceOut ){
    fprintf(pcachetraceOut, "PCACHETRACE: xRekey(%p, %p, %u, %u)\n",
        p, pPg, oldKey, newKey);
  }
  pcacheBase.xRekey(p, pPg, oldKey, newKey);
}
static void pcachetraceTruncate(sqlite3_pcache *p, unsigned n){
  if( pcachetraceOut ){
    fprintf(pcachetraceOut, "PCACHETRACE: xTruncate(%p, %u)\n", p, n);
  }
  pcacheBase.xTruncate(p, n);
}
static void pcachetraceDestroy(sqlite3_pcache *p){
  if( pcachetraceOut ){
    fprintf(pcachetraceOut, "PCACHETRACE: xDestroy(%p)\n", p);
  }
  pcacheBase.xDestroy(p);
}
static void pcachetraceShrink(sqlite3_pcache *p){
  if( pcachetraceOut ){
    fprintf(pcachetraceOut, "PCACHETRACE: xShrink(%p)\n", p);
  }
  pcacheBase.xShrink(p);
}

/* The substitute pcache methods */
static sqlite3_pcache_methods2 ersaztPcacheMethods = {
  0,
  0,
  pcachetraceInit,
  pcachetraceShutdown,
  pcachetraceCreate,
  pcachetraceCachesize,
  pcachetracePagecount,
  pcachetraceFetch,
  pcachetraceUnpin,
  pcachetraceRekey,
  pcachetraceTruncate,
  pcachetraceDestroy,
  pcachetraceShrink
};

/* Begin tracing memory allocations to out. */
int sqlite3PcacheTraceActivate(FILE *out){
  int rc = SQLITE_OK;
  if( pcacheBase.xFetch==0 ){
    rc = sqlite3_config(SQLITE_CONFIG_GETPCACHE2, &pcacheBase);
    if( rc==SQLITE_OK ){
      rc = sqlite3_config(SQLITE_CONFIG_PCACHE2, &ersaztPcacheMethods);
    }
  }
  pcachetraceOut = out;
  return rc;
}

/* Deactivate memory tracing */
int sqlite3PcacheTraceDeactivate(void){
  int rc = SQLITE_OK;
  if( pcacheBase.xFetch!=0 ){
    rc = sqlite3_config(SQLITE_CONFIG_PCACHE2, &pcacheBase);
    if( rc==SQLITE_OK ){
      memset(&pcacheBase, 0, sizeof(pcacheBase));
    }
  }
  pcachetraceOut = 0;
  return rc;
}

/************************* End ../ext/misc/pcachetrace.c ********************/
/************************* Begin ../ext/misc/shathree.c ******************/
/*
** 2017-03-08
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
******************************************************************************
**
** This SQLite extension implements functions that compute SHA3 hashes
** in the way described by the (U.S.) NIST FIPS 202 SHA-3 Standard.
** Two SQL functions are implemented:
**
**     sha3(X,SIZE)
**     sha3_agg(Y,SIZE)
**     sha3_query(Z,SIZE)
**
** The sha3(X) function computes the SHA3 hash of the input X, or NULL if
** X is NULL.  If inputs X is text, the UTF-8 rendering of that text is
** used to compute the hash.  If X is a BLOB, then the binary data of the
** blob is used to compute the hash.  If X is an integer or real number,
** then that number if converted into UTF-8 text and the hash is computed
** over the text.
**
** The sha3_agg(Y) function computes the SHA3 hash of all Y inputs.  Since
** order is important for the hash, it is recommended that the Y expression
** by followed by an ORDER BY clause to guarantee that the inputs occur
** in the desired order.
**
** The sha3_query(Y) function evaluates all queries in the SQL statements of Y
** and returns a hash of their results.
**
** The SIZE argument is optional.  If omitted, the SHA3-256 hash algorithm
** is used.  If SIZE is included it must be one of the integers 224, 256,
** 384, or 512, to determine SHA3 hash variant that is computed.
**
** Because the sha3_agg() and sha3_query() functions compute a hash over
** multiple values, the values are encode to use include type information.
**
** In sha3_agg(), the sequence of bytes that gets hashed for each input
** Y depends on the datatype of Y:
**
**    typeof(Y)='null'         A single "N" is hashed.  (One byte)
**
**    typeof(Y)='integer'      The data hash is the character "I" followed
**                             by an 8-byte big-endian binary of the
**                             64-bit signed integer.  (Nine bytes total.)
**
**    typeof(Y)='real'         The character "F" followed by an 8-byte
**                             big-ending binary of the double.  (Nine
**                             bytes total.)
**
**    typeof(Y)='text'         The hash is over prefix "Tnnn:" followed
**                             by the UTF8 encoding of the text.  The "nnn"
**                             in the prefix is the minimum-length decimal
**                             representation of the octet_length of the text.
**                             Notice the ":" at the end of the prefix, which
**                             is needed to separate the prefix from the
**                             content in cases where the content starts
**                             with a digit.
**
**    typeof(Y)='blob'         The hash is taken over prefix "Bnnn:" followed
**                             by the binary content of the blob.  The "nnn"
**                             in the prefix is the mimimum-length decimal
**                             representation of the byte-length of the blob.
**
** According to the rules above, all of the following SELECT statements
** should return TRUE:
**
**    SELECT sha3(1) = sha3('1');
**
**    SELECT sha3('hello') = sha3(x'68656c6c6f');
**
**    WITH a(x) AS (VALUES('xyzzy'))
**      SELECT sha3_agg(x) = sha3('T5:xyzzy')            FROM a;
**
**    WITH a(x) AS (VALUES(x'010203'))
**      SELECT sha3_agg(x) = sha3(x'42333a010203')       FROM a;
**
**    WITH a(x) AS (VALUES(0x123456))
**      SELECT sha3_agg(x) = sha3(x'490000000000123456') FROM a;
**
**    WITH a(x) AS (VALUES(100.015625))
**      SELECT sha3_agg(x) = sha3(x'464059010000000000') FROM a;
**
**    WITH a(x) AS (VALUES(NULL))
**      SELECT sha3_agg(x) = sha3('N') FROM a;
**
**
** In sha3_query(), individual column values are encoded as with
** sha3_agg(), but with the addition that a single "R" character is
** inserted at the start of each row.
**
** Note that sha3_agg() hashes rows for which Y is NULL.  Add a FILTER
** clause if NULL rows should be excluded:
**
**    SELECT sha3_agg(x ORDER BY rowid) FILTER(WHERE x NOT NULL) FROM t1;
*/
/* #include "sqlite3ext.h" */
SQLITE_EXTENSION_INIT1
#include <assert.h>
#include <string.h>
#include <stdarg.h>

#ifndef SQLITE_AMALGAMATION
/* typedef sqlite3_uint64 u64; */
#endif /* SQLITE_AMALGAMATION */

/******************************************************************************
** The Hash Engine
*/
/*
** Macros to determine whether the machine is big or little endian,
** and whether or not that determination is run-time or compile-time.
**
** For best performance, an attempt is made to guess at the byte-order
** using C-preprocessor macros.  If that is unsuccessful, or if
** -DSHA3_BYTEORDER=0 is set, then byte-order is determined
** at run-time.
*/
#ifndef SHA3_BYTEORDER
# if defined(i386)     || defined(__i386__)   || defined(_M_IX86) ||    \
     defined(__x86_64) || defined(__x86_64__) || defined(_M_X64)  ||    \
     defined(_M_AMD64) || defined(_M_ARM)     || defined(__x86)   ||    \
     defined(__arm__)
#   define SHA3_BYTEORDER    1234
# elif defined(sparc)    || defined(__ppc__)
#   define SHA3_BYTEORDER    4321
# else
#   define SHA3_BYTEORDER 0
# endif
#endif


/*
** State structure for a SHA3 hash in progress
*/
typedef struct SHA3Context SHA3Context;
struct SHA3Context {
  union {
    u64 s[25];                /* Keccak state. 5x5 lines of 64 bits each */
    unsigned char x[1600];    /* ... or 1600 bytes */
  } u;
  unsigned nRate;        /* Bytes of input accepted per Keccak iteration */
  unsigned nLoaded;      /* Input bytes loaded into u.x[] so far this cycle */
  unsigned ixMask;       /* Insert next input into u.x[nLoaded^ixMask]. */
  unsigned iSize;        /* 224, 256, 358, or 512 */
};

/*
** A single step of the Keccak mixing function for a 1600-bit state
*/
static void KeccakF1600Step(SHA3Context *p){
  int i;
  u64 b0, b1, b2, b3, b4;
  u64 c0, c1, c2, c3, c4;
  u64 d0, d1, d2, d3, d4;
  static const u64 RC[] = {
    0x0000000000000001ULL,  0x0000000000008082ULL,
    0x800000000000808aULL,  0x8000000080008000ULL,
    0x000000000000808bULL,  0x0000000080000001ULL,
    0x8000000080008081ULL,  0x8000000000008009ULL,
    0x000000000000008aULL,  0x0000000000000088ULL,
    0x0000000080008009ULL,  0x000000008000000aULL,
    0x000000008000808bULL,  0x800000000000008bULL,
    0x8000000000008089ULL,  0x8000000000008003ULL,
    0x8000000000008002ULL,  0x8000000000000080ULL,
    0x000000000000800aULL,  0x800000008000000aULL,
    0x8000000080008081ULL,  0x8000000000008080ULL,
    0x0000000080000001ULL,  0x8000000080008008ULL
  };
# define a00 (p->u.s[0])
# define a01 (p->u.s[1])
# define a02 (p->u.s[2])
# define a03 (p->u.s[3])
# define a04 (p->u.s[4])
# define a10 (p->u.s[5])
# define a11 (p->u.s[6])
# define a12 (p->u.s[7])
# define a13 (p->u.s[8])
# define a14 (p->u.s[9])
# define a20 (p->u.s[10])
# define a21 (p->u.s[11])
# define a22 (p->u.s[12])
# define a23 (p->u.s[13])
# define a24 (p->u.s[14])
# define a30 (p->u.s[15])
# define a31 (p->u.s[16])
# define a32 (p->u.s[17])
# define a33 (p->u.s[18])
# define a34 (p->u.s[19])
# define a40 (p->u.s[20])
# define a41 (p->u.s[21])
# define a42 (p->u.s[22])
# define a43 (p->u.s[23])
# define a44 (p->u.s[24])
# define ROL64(a,x) ((a<<x)|(a>>(64-x)))

  for(i=0; i<24; i+=4){
    c0 = a00^a10^a20^a30^a40;
    c1 = a01^a11^a21^a31^a41;
    c2 = a02^a12^a22^a32^a42;
    c3 = a03^a13^a23^a33^a43;
    c4 = a04^a14^a24^a34^a44;
    d0 = c4^ROL64(c1, 1);
    d1 = c0^ROL64(c2, 1);
    d2 = c1^ROL64(c3, 1);
    d3 = c2^ROL64(c4, 1);
    d4 = c3^ROL64(c0, 1);

    b0 = (a00^d0);
    b1 = ROL64((a11^d1), 44);
    b2 = ROL64((a22^d2), 43);
    b3 = ROL64((a33^d3), 21);
    b4 = ROL64((a44^d4), 14);
    a00 =   b0 ^((~b1)&  b2 );
    a00 ^= RC[i];
    a11 =   b1 ^((~b2)&  b3 );
    a22 =   b2 ^((~b3)&  b4 );
    a33 =   b3 ^((~b4)&  b0 );
    a44 =   b4 ^((~b0)&  b1 );

    b2 = ROL64((a20^d0), 3);
    b3 = ROL64((a31^d1), 45);
    b4 = ROL64((a42^d2), 61);
    b0 = ROL64((a03^d3), 28);
    b1 = ROL64((a14^d4), 20);
    a20 =   b0 ^((~b1)&  b2 );
    a31 =   b1 ^((~b2)&  b3 );
    a42 =   b2 ^((~b3)&  b4 );
    a03 =   b3 ^((~b4)&  b0 );
    a14 =   b4 ^((~b0)&  b1 );

    b4 = ROL64((a40^d0), 18);
    b0 = ROL64((a01^d1), 1);
    b1 = ROL64((a12^d2), 6);
    b2 = ROL64((a23^d3), 25);
    b3 = ROL64((a34^d4), 8);
    a40 =   b0 ^((~b1)&  b2 );
    a01 =   b1 ^((~b2)&  b3 );
    a12 =   b2 ^((~b3)&  b4 );
    a23 =   b3 ^((~b4)&  b0 );
    a34 =   b4 ^((~b0)&  b1 );

    b1 = ROL64((a10^d0), 36);
    b2 = ROL64((a21^d1), 10);
    b3 = ROL64((a32^d2), 15);
    b4 = ROL64((a43^d3), 56);
    b0 = ROL64((a04^d4), 27);
    a10 =   b0 ^((~b1)&  b2 );
    a21 =   b1 ^((~b2)&  b3 );
    a32 =   b2 ^((~b3)&  b4 );
    a43 =   b3 ^((~b4)&  b0 );
    a04 =   b4 ^((~b0)&  b1 );

    b3 = ROL64((a30^d0), 41);
    b4 = ROL64((a41^d1), 2);
    b0 = ROL64((a02^d2), 62);
    b1 = ROL64((a13^d3), 55);
    b2 = ROL64((a24^d4), 39);
    a30 =   b0 ^((~b1)&  b2 );
    a41 =   b1 ^((~b2)&  b3 );
    a02 =   b2 ^((~b3)&  b4 );
    a13 =   b3 ^((~b4)&  b0 );
    a24 =   b4 ^((~b0)&  b1 );

    c0 = a00^a20^a40^a10^a30;
    c1 = a11^a31^a01^a21^a41;
    c2 = a22^a42^a12^a32^a02;
    c3 = a33^a03^a23^a43^a13;
    c4 = a44^a14^a34^a04^a24;
    d0 = c4^ROL64(c1, 1);
    d1 = c0^ROL64(c2, 1);
    d2 = c1^ROL64(c3, 1);
    d3 = c2^ROL64(c4, 1);
    d4 = c3^ROL64(c0, 1);

    b0 = (a00^d0);
    b1 = ROL64((a31^d1), 44);
    b2 = ROL64((a12^d2), 43);
    b3 = ROL64((a43^d3), 21);
    b4 = ROL64((a24^d4), 14);
    a00 =   b0 ^((~b1)&  b2 );
    a00 ^= RC[i+1];
    a31 =   b1 ^((~b2)&  b3 );
    a12 =   b2 ^((~b3)&  b4 );
    a43 =   b3 ^((~b4)&  b0 );
    a24 =   b4 ^((~b0)&  b1 );

    b2 = ROL64((a40^d0), 3);
    b3 = ROL64((a21^d1), 45);
    b4 = ROL64((a02^d2), 61);
    b0 = ROL64((a33^d3), 28);
    b1 = ROL64((a14^d4), 20);
    a40 =   b0 ^((~b1)&  b2 );
    a21 =   b1 ^((~b2)&  b3 );
    a02 =   b2 ^((~b3)&  b4 );
    a33 =   b3 ^((~b4)&  b0 );
    a14 =   b4 ^((~b0)&  b1 );

    b4 = ROL64((a30^d0), 18);
    b0 = ROL64((a11^d1), 1);
    b1 = ROL64((a42^d2), 6);
    b2 = ROL64((a23^d3), 25);
    b3 = ROL64((a04^d4), 8);
    a30 =   b0 ^((~b1)&  b2 );
    a11 =   b1 ^((~b2)&  b3 );
    a42 =   b2 ^((~b3)&  b4 );
    a23 =   b3 ^((~b4)&  b0 );
    a04 =   b4 ^((~b0)&  b1 );

    b1 = ROL64((a20^d0), 36);
    b2 = ROL64((a01^d1), 10);
    b3 = ROL64((a32^d2), 15);
    b4 = ROL64((a13^d3), 56);
    b0 = ROL64((a44^d4), 27);
    a20 =   b0 ^((~b1)&  b2 );
    a01 =   b1 ^((~b2)&  b3 );
    a32 =   b2 ^((~b3)&  b4 );
    a13 =   b3 ^((~b4)&  b0 );
    a44 =   b4 ^((~b0)&  b1 );

    b3 = ROL64((a10^d0), 41);
    b4 = ROL64((a41^d1), 2);
    b0 = ROL64((a22^d2), 62);
    b1 = ROL64((a03^d3), 55);
    b2 = ROL64((a34^d4), 39);
    a10 =   b0 ^((~b1)&  b2 );
    a41 =   b1 ^((~b2)&  b3 );
    a22 =   b2 ^((~b3)&  b4 );
    a03 =   b3 ^((~b4)&  b0 );
    a34 =   b4 ^((~b0)&  b1 );

    c0 = a00^a40^a30^a20^a10;
    c1 = a31^a21^a11^a01^a41;
    c2 = a12^a02^a42^a32^a22;
    c3 = a43^a33^a23^a13^a03;
    c4 = a24^a14^a04^a44^a34;
    d0 = c4^ROL64(c1, 1);
    d1 = c0^ROL64(c2, 1);
    d2 = c1^ROL64(c3, 1);
    d3 = c2^ROL64(c4, 1);
    d4 = c3^ROL64(c0, 1);

    b0 = (a00^d0);
    b1 = ROL64((a21^d1), 44);
    b2 = ROL64((a42^d2), 43);
    b3 = ROL64((a13^d3), 21);
    b4 = ROL64((a34^d4), 14);
    a00 =   b0 ^((~b1)&  b2 );
    a00 ^= RC[i+2];
    a21 =   b1 ^((~b2)&  b3 );
    a42 =   b2 ^((~b3)&  b4 );
    a13 =   b3 ^((~b4)&  b0 );
    a34 =   b4 ^((~b0)&  b1 );

    b2 = ROL64((a30^d0), 3);
    b3 = ROL64((a01^d1), 45);
    b4 = ROL64((a22^d2), 61);
    b0 = ROL64((a43^d3), 28);
    b1 = ROL64((a14^d4), 20);
    a30 =   b0 ^((~b1)&  b2 );
    a01 =   b1 ^((~b2)&  b3 );
    a22 =   b2 ^((~b3)&  b4 );
    a43 =   b3 ^((~b4)&  b0 );
    a14 =   b4 ^((~b0)&  b1 );

    b4 = ROL64((a10^d0), 18);
    b0 = ROL64((a31^d1), 1);
    b1 = ROL64((a02^d2), 6);
    b2 = ROL64((a23^d3), 25);
    b3 = ROL64((a44^d4), 8);
    a10 =   b0 ^((~b1)&  b2 );
    a31 =   b1 ^((~b2)&  b3 );
    a02 =   b2 ^((~b3)&  b4 );
    a23 =   b3 ^((~b4)&  b0 );
    a44 =   b4 ^((~b0)&  b1 );

    b1 = ROL64((a40^d0), 36);
    b2 = ROL64((a11^d1), 10);
    b3 = ROL64((a32^d2), 15);
    b4 = ROL64((a03^d3), 56);
    b0 = ROL64((a24^d4), 27);
    a40 =   b0 ^((~b1)&  b2 );
    a11 =   b1 ^((~b2)&  b3 );
    a32 =   b2 ^((~b3)&  b4 );
    a03 =   b3 ^((~b4)&  b0 );
    a24 =   b4 ^((~b0)&  b1 );

    b3 = ROL64((a20^d0), 41);
    b4 = ROL64((a41^d1), 2);
    b0 = ROL64((a12^d2), 62);
    b1 = ROL64((a33^d3), 55);
    b2 = ROL64((a04^d4), 39);
    a20 =   b0 ^((~b1)&  b2 );
    a41 =   b1 ^((~b2)&  b3 );
    a12 =   b2 ^((~b3)&  b4 );
    a33 =   b3 ^((~b4)&  b0 );
    a04 =   b4 ^((~b0)&  b1 );

    c0 = a00^a30^a10^a40^a20;
    c1 = a21^a01^a31^a11^a41;
    c2 = a42^a22^a02^a32^a12;
    c3 = a13^a43^a23^a03^a33;
    c4 = a34^a14^a44^a24^a04;
    d0 = c4^ROL64(c1, 1);
    d1 = c0^ROL64(c2, 1);
    d2 = c1^ROL64(c3, 1);
    d3 = c2^ROL64(c4, 1);
    d4 = c3^ROL64(c0, 1);

    b0 = (a00^d0);
    b1 = ROL64((a01^d1), 44);
    b2 = ROL64((a02^d2), 43);
    b3 = ROL64((a03^d3), 21);
    b4 = ROL64((a04^d4), 14);
    a00 =   b0 ^((~b1)&  b2 );
    a00 ^= RC[i+3];
    a01 =   b1 ^((~b2)&  b3 );
    a02 =   b2 ^((~b3)&  b4 );
    a03 =   b3 ^((~b4)&  b0 );
    a04 =   b4 ^((~b0)&  b1 );

    b2 = ROL64((a10^d0), 3);
    b3 = ROL64((a11^d1), 45);
    b4 = ROL64((a12^d2), 61);
    b0 = ROL64((a13^d3), 28);
    b1 = ROL64((a14^d4), 20);
    a10 =   b0 ^((~b1)&  b2 );
    a11 =   b1 ^((~b2)&  b3 );
    a12 =   b2 ^((~b3)&  b4 );
    a13 =   b3 ^((~b4)&  b0 );
    a14 =   b4 ^((~b0)&  b1 );

    b4 = ROL64((a20^d0), 18);
    b0 = ROL64((a21^d1), 1);
    b1 = ROL64((a22^d2), 6);
    b2 = ROL64((a23^d3), 25);
    b3 = ROL64((a24^d4), 8);
    a20 =   b0 ^((~b1)&  b2 );
    a21 =   b1 ^((~b2)&  b3 );
    a22 =   b2 ^((~b3)&  b4 );
    a23 =   b3 ^((~b4)&  b0 );
    a24 =   b4 ^((~b0)&  b1 );

    b1 = ROL64((a30^d0), 36);
    b2 = ROL64((a31^d1), 10);
    b3 = ROL64((a32^d2), 15);
    b4 = ROL64((a33^d3), 56);
    b0 = ROL64((a34^d4), 27);
    a30 =   b0 ^((~b1)&  b2 );
    a31 =   b1 ^((~b2)&  b3 );
    a32 =   b2 ^((~b3)&  b4 );
    a33 =   b3 ^((~b4)&  b0 );
    a34 =   b4 ^((~b0)&  b1 );

    b3 = ROL64((a40^d0), 41);
    b4 = ROL64((a41^d1), 2);
    b0 = ROL64((a42^d2), 62);
    b1 = ROL64((a43^d3), 55);
    b2 = ROL64((a44^d4), 39);
    a40 =   b0 ^((~b1)&  b2 );
    a41 =   b1 ^((~b2)&  b3 );
    a42 =   b2 ^((~b3)&  b4 );
    a43 =   b3 ^((~b4)&  b0 );
    a44 =   b4 ^((~b0)&  b1 );
  }
}

/*
** Initialize a new hash.  iSize determines the size of the hash
** in bits and should be one of 224, 256, 384, or 512.  Or iSize
** can be zero to use the default hash size of 256 bits.
*/
static void SHA3Init(SHA3Context *p, int iSize){
  memset(p, 0, sizeof(*p));
  p->iSize = iSize;
  if( iSize>=128 && iSize<=512 ){
    p->nRate = (1600 - ((iSize + 31)&~31)*2)/8;
  }else{
    p->nRate = (1600 - 2*256)/8;
  }
#if SHA3_BYTEORDER==1234
  /* Known to be little-endian at compile-time. No-op */
#elif SHA3_BYTEORDER==4321
  p->ixMask = 7;  /* Big-endian */
#else
  {
    static unsigned int one = 1;
    if( 1==*(unsigned char*)&one ){
      /* Little endian.  No byte swapping. */
      p->ixMask = 0;
    }else{
      /* Big endian.  Byte swap. */
      p->ixMask = 7;
    }
  }
#endif
}

/*
** Make consecutive calls to the SHA3Update function to add new content
** to the hash
*/
static void SHA3Update(
  SHA3Context *p,
  const unsigned char *aData,
  unsigned int nData
){
  unsigned int i = 0;
  if( aData==0 ) return;
#if SHA3_BYTEORDER==1234
  if( (p->nLoaded % 8)==0 && ((aData - (const unsigned char*)0)&7)==0 ){
    for(; i+7<nData; i+=8){
      p->u.s[p->nLoaded/8] ^= *(u64*)&aData[i];
      p->nLoaded += 8;
      if( p->nLoaded>=p->nRate ){
        KeccakF1600Step(p);
        p->nLoaded = 0;
      }
    }
  }
#endif
  for(; i<nData; i++){
#if SHA3_BYTEORDER==1234
    p->u.x[p->nLoaded] ^= aData[i];
#elif SHA3_BYTEORDER==4321
    p->u.x[p->nLoaded^0x07] ^= aData[i];
#else
    p->u.x[p->nLoaded^p->ixMask] ^= aData[i];
#endif
    p->nLoaded++;
    if( p->nLoaded==p->nRate ){
      KeccakF1600Step(p);
      p->nLoaded = 0;
    }
  }
}

/*
** After all content has been added, invoke SHA3Final() to compute
** the final hash.  The function returns a pointer to the binary
** hash value.
*/
static unsigned char *SHA3Final(SHA3Context *p){
  unsigned int i;
  if( p->nLoaded==p->nRate-1 ){
    const unsigned char c1 = 0x86;
    SHA3Update(p, &c1, 1);
  }else{
    const unsigned char c2 = 0x06;
    const unsigned char c3 = 0x80;
    SHA3Update(p, &c2, 1);
    p->nLoaded = p->nRate - 1;
    SHA3Update(p, &c3, 1);
  }
  for(i=0; i<p->nRate; i++){
    p->u.x[i+p->nRate] = p->u.x[i^p->ixMask];
  }
  return &p->u.x[p->nRate];
}
/* End of the hashing logic
*****************************************************************************/

/*
** Implementation of the sha3(X,SIZE) function.
**
** Return a BLOB which is the SIZE-bit SHA3 hash of X.  The default
** size is 256.  If X is a BLOB, it is hashed as is.  
** For all other non-NULL types of input, X is converted into a UTF-8 string
** and the string is hashed without the trailing 0x00 terminator.  The hash
** of a NULL value is NULL.
*/
static void sha3Func(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  SHA3Context cx;
  int eType = sqlite3_value_type(argv[0]);
  int nByte = sqlite3_value_bytes(argv[0]);
  int iSize;
  if( argc==1 ){
    iSize = 256;
  }else{
    iSize = sqlite3_value_int(argv[1]);
    if( iSize!=224 && iSize!=256 && iSize!=384 && iSize!=512 ){
      sqlite3_result_error(context, "SHA3 size should be one of: 224 256 "
                                    "384 512", -1);
      return;
    }
  }
  if( eType==SQLITE_NULL ) return;
  SHA3Init(&cx, iSize);
  if( eType==SQLITE_BLOB ){
    SHA3Update(&cx, sqlite3_value_blob(argv[0]), nByte);
  }else{
    SHA3Update(&cx, sqlite3_value_text(argv[0]), nByte);
  }
  sqlite3_result_blob(context, SHA3Final(&cx), iSize/8, SQLITE_TRANSIENT);
}

/* Compute a string using sqlite3_vsnprintf() with a maximum length
** of 50 bytes and add it to the hash.
*/
static void sha3_step_vformat(
  SHA3Context *p,                 /* Add content to this context */
  const char *zFormat,
  ...
){
  va_list ap;
  int n;
  char zBuf[50];
  va_start(ap, zFormat);
  sqlite3_vsnprintf(sizeof(zBuf),zBuf,zFormat,ap);
  va_end(ap);
  n = (int)strlen(zBuf);
  SHA3Update(p, (unsigned char*)zBuf, n);
}

/*
** Update a SHA3Context using a single sqlite3_value.
*/
static void sha3UpdateFromValue(SHA3Context *p, sqlite3_value *pVal){
  switch( sqlite3_value_type(pVal) ){
    case SQLITE_NULL: {
      SHA3Update(p, (const unsigned char*)"N",1);
      break;
    }
    case SQLITE_INTEGER: {
      sqlite3_uint64 u;
      int j;
      unsigned char x[9];
      sqlite3_int64 v = sqlite3_value_int64(pVal);
      memcpy(&u, &v, 8);
      for(j=8; j>=1; j--){
        x[j] = u & 0xff;
        u >>= 8;
      }
      x[0] = 'I';
      SHA3Update(p, x, 9);
      break;
    }
    case SQLITE_FLOAT: {
      sqlite3_uint64 u;
      int j;
      unsigned char x[9];
      double r = sqlite3_value_double(pVal);
      memcpy(&u, &r, 8);
      for(j=8; j>=1; j--){
        x[j] = u & 0xff;
        u >>= 8;
      }
      x[0] = 'F';
      SHA3Update(p,x,9);
      break;
    }
    case SQLITE_TEXT: {
      int n2 = sqlite3_value_bytes(pVal);
      const unsigned char *z2 = sqlite3_value_text(pVal);
      sha3_step_vformat(p,"T%d:",n2);
      SHA3Update(p, z2, n2);
      break;
    }
    case SQLITE_BLOB: {
      int n2 = sqlite3_value_bytes(pVal);
      const unsigned char *z2 = sqlite3_value_blob(pVal);
      sha3_step_vformat(p,"B%d:",n2);
      SHA3Update(p, z2, n2);
      break;
    }
  }
}

/*
** Implementation of the sha3_query(SQL,SIZE) function.
**
** This function compiles and runs the SQL statement(s) given in the
** argument. The results are hashed using a SIZE-bit SHA3.  The default
** size is 256.
**
** The format of the byte stream that is hashed is summarized as follows:
**
**       S<n>:<sql>
**       R
**       N
**       I<int>
**       F<ieee-float>
**       B<size>:<bytes>
**       T<size>:<text>
**
** <sql> is the original SQL text for each statement run and <n> is
** the size of that text.  The SQL text is UTF-8.  A single R character
** occurs before the start of each row.  N means a NULL value.
** I mean an 8-byte little-endian integer <int>.  F is a floating point
** number with an 8-byte little-endian IEEE floating point value <ieee-float>.
** B means blobs of <size> bytes.  T means text rendered as <size>
** bytes of UTF-8.  The <n> and <size> values are expressed as an ASCII
** text integers.
**
** For each SQL statement in the X input, there is one S segment.  Each
** S segment is followed by zero or more R segments, one for each row in the
** result set.  After each R, there are one or more N, I, F, B, or T segments,
** one for each column in the result set.  Segments are concatentated directly
** with no delimiters of any kind.
*/
static void sha3QueryFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  sqlite3 *db = sqlite3_context_db_handle(context);
  const char *zSql = (const char*)sqlite3_value_text(argv[0]);
  sqlite3_stmt *pStmt = 0;
  int nCol;                   /* Number of columns in the result set */
  int i;                      /* Loop counter */
  int rc;
  int n;
  const char *z;
  SHA3Context cx;
  int iSize;

  if( argc==1 ){
    iSize = 256;
  }else{
    iSize = sqlite3_value_int(argv[1]);
    if( iSize!=224 && iSize!=256 && iSize!=384 && iSize!=512 ){
      sqlite3_result_error(context, "SHA3 size should be one of: 224 256 "
                                    "384 512", -1);
      return;
    }
  }
  if( zSql==0 ) return;
  SHA3Init(&cx, iSize);
  while( zSql[0] ){
    rc = sqlite3_prepare_v2(db, zSql, -1, &pStmt, &zSql);
    if( rc ){
      char *zMsg = sqlite3_mprintf("error SQL statement [%s]: %s",
                                   zSql, sqlite3_errmsg(db));
      sqlite3_finalize(pStmt);
      sqlite3_result_error(context, zMsg, -1);
      sqlite3_free(zMsg);
      return;
    }
    if( !sqlite3_stmt_readonly(pStmt) ){
      char *zMsg = sqlite3_mprintf("non-query: [%s]", sqlite3_sql(pStmt));
      sqlite3_finalize(pStmt);
      sqlite3_result_error(context, zMsg, -1);
      sqlite3_free(zMsg);
      return;
    }
    nCol = sqlite3_column_count(pStmt);
    z = sqlite3_sql(pStmt);
    if( z ){
      n = (int)strlen(z);
      sha3_step_vformat(&cx,"S%d:",n);
      SHA3Update(&cx,(unsigned char*)z,n);
    }

    /* Compute a hash over the result of the query */
    while( SQLITE_ROW==sqlite3_step(pStmt) ){
      SHA3Update(&cx,(const unsigned char*)"R",1);
      for(i=0; i<nCol; i++){
        sha3UpdateFromValue(&cx, sqlite3_column_value(pStmt,i));
      }
    }
    sqlite3_finalize(pStmt);
  }
  sqlite3_result_blob(context, SHA3Final(&cx), iSize/8, SQLITE_TRANSIENT);
}

/*
** xStep function for sha3_agg().
*/
static void sha3AggStep(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  SHA3Context *p;
  p = (SHA3Context*)sqlite3_aggregate_context(context, sizeof(*p));
  if( p==0 ) return;
  if( p->nRate==0 ){
    int sz = 256;
    if( argc==2 ){
      sz = sqlite3_value_int(argv[1]);
      if( sz!=224 && sz!=384 && sz!=512 ){
        sz = 256;
      }
    }
    SHA3Init(p, sz);
  }
  sha3UpdateFromValue(p, argv[0]);
}


/*
** xFinal function for sha3_agg().
*/
static void sha3AggFinal(sqlite3_context *context){
  SHA3Context *p;
  p = (SHA3Context*)sqlite3_aggregate_context(context, sizeof(*p));
  if( p==0 ) return;
  if( p->iSize ){
    sqlite3_result_blob(context, SHA3Final(p), p->iSize/8, SQLITE_TRANSIENT);
  }
}



#ifdef _WIN32

#endif
int sqlite3_shathree_init(
  sqlite3 *db,
  char **pzErrMsg,
  const sqlite3_api_routines *pApi
){
  int rc = SQLITE_OK;
  SQLITE_EXTENSION_INIT2(pApi);
  (void)pzErrMsg;  /* Unused parameter */
  rc = sqlite3_create_function(db, "sha3", 1,
                      SQLITE_UTF8 | SQLITE_INNOCUOUS | SQLITE_DETERMINISTIC,
                      0, sha3Func, 0, 0);
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_function(db, "sha3", 2,
                      SQLITE_UTF8 | SQLITE_INNOCUOUS | SQLITE_DETERMINISTIC,
                      0, sha3Func, 0, 0);
  }
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_function(db, "sha3_agg", 1,
                      SQLITE_UTF8 | SQLITE_INNOCUOUS | SQLITE_DETERMINISTIC,
                      0, 0, sha3AggStep, sha3AggFinal);
  }
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_function(db, "sha3_agg", 2,
                      SQLITE_UTF8 | SQLITE_INNOCUOUS | SQLITE_DETERMINISTIC,
                      0, 0, sha3AggStep, sha3AggFinal);
  }
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_function(db, "sha3_query", 1,
                      SQLITE_UTF8 | SQLITE_DIRECTONLY,
                      0, sha3QueryFunc, 0, 0);
  }
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_function(db, "sha3_query", 2,
                      SQLITE_UTF8 | SQLITE_DIRECTONLY,
                      0, sha3QueryFunc, 0, 0);
  }
  return rc;
}

/************************* End ../ext/misc/shathree.c ********************/
/************************* Begin ../ext/misc/sha1.c ******************/
/*
** 2017-01-27
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
******************************************************************************
**
** This SQLite extension implements functions that compute SHA1 hashes.
** Two SQL functions are implemented:
**
**     sha1(X)
**     sha1_query(Y)
**
** The sha1(X) function computes the SHA1 hash of the input X, or NULL if
** X is NULL.
**
** The sha1_query(Y) function evalutes all queries in the SQL statements of Y
** and returns a hash of their results.
*/
/* #include "sqlite3ext.h" */
SQLITE_EXTENSION_INIT1
#include <assert.h>
#include <string.h>
#include <stdarg.h>

/******************************************************************************
** The Hash Engine
*/
/* Context for the SHA1 hash */
typedef struct SHA1Context SHA1Context;
struct SHA1Context {
  unsigned int state[5];
  unsigned int count[2];
  unsigned char buffer[64];
};

#define SHA_ROT(x,l,r) ((x) << (l) | (x) >> (r))
#define rol(x,k) SHA_ROT(x,k,32-(k))
#define ror(x,k) SHA_ROT(x,32-(k),k)

#define blk0le(i) (block[i] = (ror(block[i],8)&0xFF00FF00) \
    |(rol(block[i],8)&0x00FF00FF))
#define blk0be(i) block[i]
#define blk(i) (block[i&15] = rol(block[(i+13)&15]^block[(i+8)&15] \
    ^block[(i+2)&15]^block[i&15],1))

/*
 * (R0+R1), R2, R3, R4 are the different operations (rounds) used in SHA1
 *
 * Rl0() for little-endian and Rb0() for big-endian.  Endianness is
 * determined at run-time.
 */
#define Rl0(v,w,x,y,z,i) \
    z+=((w&(x^y))^y)+blk0le(i)+0x5A827999+rol(v,5);w=ror(w,2);
#define Rb0(v,w,x,y,z,i) \
    z+=((w&(x^y))^y)+blk0be(i)+0x5A827999+rol(v,5);w=ror(w,2);
#define R1(v,w,x,y,z,i) \
    z+=((w&(x^y))^y)+blk(i)+0x5A827999+rol(v,5);w=ror(w,2);
#define R2(v,w,x,y,z,i) \
    z+=(w^x^y)+blk(i)+0x6ED9EBA1+rol(v,5);w=ror(w,2);
#define R3(v,w,x,y,z,i) \
    z+=(((w|x)&y)|(w&x))+blk(i)+0x8F1BBCDC+rol(v,5);w=ror(w,2);
#define R4(v,w,x,y,z,i) \
    z+=(w^x^y)+blk(i)+0xCA62C1D6+rol(v,5);w=ror(w,2);

/*
 * Hash a single 512-bit block. This is the core of the algorithm.
 */
static void SHA1Transform(unsigned int state[5], const unsigned char buffer[64]){
  unsigned int qq[5]; /* a, b, c, d, e; */
  static int one = 1;
  unsigned int block[16];
  memcpy(block, buffer, 64);
  memcpy(qq,state,5*sizeof(unsigned int));

#define a qq[0]
#define b qq[1]
#define c qq[2]
#define d qq[3]
#define e qq[4]

  /* Copy p->state[] to working vars */
  /*
  a = state[0];
  b = state[1];
  c = state[2];
  d = state[3];
  e = state[4];
  */

  /* 4 rounds of 20 operations each. Loop unrolled. */
  if( 1 == *(unsigned char*)&one ){
    Rl0(a,b,c,d,e, 0); Rl0(e,a,b,c,d, 1); Rl0(d,e,a,b,c, 2); Rl0(c,d,e,a,b, 3);
    Rl0(b,c,d,e,a, 4); Rl0(a,b,c,d,e, 5); Rl0(e,a,b,c,d, 6); Rl0(d,e,a,b,c, 7);
    Rl0(c,d,e,a,b, 8); Rl0(b,c,d,e,a, 9); Rl0(a,b,c,d,e,10); Rl0(e,a,b,c,d,11);
    Rl0(d,e,a,b,c,12); Rl0(c,d,e,a,b,13); Rl0(b,c,d,e,a,14); Rl0(a,b,c,d,e,15);
  }else{
    Rb0(a,b,c,d,e, 0); Rb0(e,a,b,c,d, 1); Rb0(d,e,a,b,c, 2); Rb0(c,d,e,a,b, 3);
    Rb0(b,c,d,e,a, 4); Rb0(a,b,c,d,e, 5); Rb0(e,a,b,c,d, 6); Rb0(d,e,a,b,c, 7);
    Rb0(c,d,e,a,b, 8); Rb0(b,c,d,e,a, 9); Rb0(a,b,c,d,e,10); Rb0(e,a,b,c,d,11);
    Rb0(d,e,a,b,c,12); Rb0(c,d,e,a,b,13); Rb0(b,c,d,e,a,14); Rb0(a,b,c,d,e,15);
  }
  R1(e,a,b,c,d,16); R1(d,e,a,b,c,17); R1(c,d,e,a,b,18); R1(b,c,d,e,a,19);
  R2(a,b,c,d,e,20); R2(e,a,b,c,d,21); R2(d,e,a,b,c,22); R2(c,d,e,a,b,23);
  R2(b,c,d,e,a,24); R2(a,b,c,d,e,25); R2(e,a,b,c,d,26); R2(d,e,a,b,c,27);
  R2(c,d,e,a,b,28); R2(b,c,d,e,a,29); R2(a,b,c,d,e,30); R2(e,a,b,c,d,31);
  R2(d,e,a,b,c,32); R2(c,d,e,a,b,33); R2(b,c,d,e,a,34); R2(a,b,c,d,e,35);
  R2(e,a,b,c,d,36); R2(d,e,a,b,c,37); R2(c,d,e,a,b,38); R2(b,c,d,e,a,39);
  R3(a,b,c,d,e,40); R3(e,a,b,c,d,41); R3(d,e,a,b,c,42); R3(c,d,e,a,b,43);
  R3(b,c,d,e,a,44); R3(a,b,c,d,e,45); R3(e,a,b,c,d,46); R3(d,e,a,b,c,47);
  R3(c,d,e,a,b,48); R3(b,c,d,e,a,49); R3(a,b,c,d,e,50); R3(e,a,b,c,d,51);
  R3(d,e,a,b,c,52); R3(c,d,e,a,b,53); R3(b,c,d,e,a,54); R3(a,b,c,d,e,55);
  R3(e,a,b,c,d,56); R3(d,e,a,b,c,57); R3(c,d,e,a,b,58); R3(b,c,d,e,a,59);
  R4(a,b,c,d,e,60); R4(e,a,b,c,d,61); R4(d,e,a,b,c,62); R4(c,d,e,a,b,63);
  R4(b,c,d,e,a,64); R4(a,b,c,d,e,65); R4(e,a,b,c,d,66); R4(d,e,a,b,c,67);
  R4(c,d,e,a,b,68); R4(b,c,d,e,a,69); R4(a,b,c,d,e,70); R4(e,a,b,c,d,71);
  R4(d,e,a,b,c,72); R4(c,d,e,a,b,73); R4(b,c,d,e,a,74); R4(a,b,c,d,e,75);
  R4(e,a,b,c,d,76); R4(d,e,a,b,c,77); R4(c,d,e,a,b,78); R4(b,c,d,e,a,79);

  /* Add the working vars back into context.state[] */
  state[0] += a;
  state[1] += b;
  state[2] += c;
  state[3] += d;
  state[4] += e;

#undef a
#undef b
#undef c
#undef d
#undef e
}


/* Initialize a SHA1 context */
static void hash_init(SHA1Context *p){
  /* SHA1 initialization constants */
  p->state[0] = 0x67452301;
  p->state[1] = 0xEFCDAB89;
  p->state[2] = 0x98BADCFE;
  p->state[3] = 0x10325476;
  p->state[4] = 0xC3D2E1F0;
  p->count[0] = p->count[1] = 0;
}

/* Add new content to the SHA1 hash */
static void hash_step(
  SHA1Context *p,                 /* Add content to this context */
  const unsigned char *data,      /* Data to be added */
  unsigned int len                /* Number of bytes in data */
){
  unsigned int i, j;

  j = p->count[0];
  if( (p->count[0] += len << 3) < j ){
    p->count[1] += (len>>29)+1;
  }
  j = (j >> 3) & 63;
  if( (j + len) > 63 ){
    (void)memcpy(&p->buffer[j], data, (i = 64-j));
    SHA1Transform(p->state, p->buffer);
    for(; i + 63 < len; i += 64){
      SHA1Transform(p->state, &data[i]);
    }
    j = 0;
  }else{
    i = 0;
  }
  (void)memcpy(&p->buffer[j], &data[i], len - i);
}

/* Compute a string using sqlite3_vsnprintf() and hash it */
static void hash_step_vformat(
  SHA1Context *p,                 /* Add content to this context */
  const char *zFormat,
  ...
){
  va_list ap;
  int n;
  char zBuf[50];
  va_start(ap, zFormat);
  sqlite3_vsnprintf(sizeof(zBuf),zBuf,zFormat,ap);
  va_end(ap);
  n = (int)strlen(zBuf);
  hash_step(p, (unsigned char*)zBuf, n);
}


/* Add padding and compute the message digest.  Render the
** message digest as lower-case hexadecimal and put it into
** zOut[].  zOut[] must be at least 41 bytes long. */
static void hash_finish(
  SHA1Context *p,           /* The SHA1 context to finish and render */
  char *zOut,               /* Store hex or binary hash here */
  int bAsBinary             /* 1 for binary hash, 0 for hex hash */
){
  unsigned int i;
  unsigned char finalcount[8];
  unsigned char digest[20];
  static const char zEncode[] = "0123456789abcdef";

  for (i = 0; i < 8; i++){
    finalcount[i] = (unsigned char)((p->count[(i >= 4 ? 0 : 1)]
       >> ((3-(i & 3)) * 8) ) & 255); /* Endian independent */
  }
  hash_step(p, (const unsigned char *)"\200", 1);
  while ((p->count[0] & 504) != 448){
    hash_step(p, (const unsigned char *)"\0", 1);
  }
  hash_step(p, finalcount, 8);  /* Should cause a SHA1Transform() */
  for (i = 0; i < 20; i++){
    digest[i] = (unsigned char)((p->state[i>>2] >> ((3-(i & 3)) * 8) ) & 255);
  }
  if( bAsBinary ){
    memcpy(zOut, digest, 20);
  }else{
    for(i=0; i<20; i++){
      zOut[i*2] = zEncode[(digest[i]>>4)&0xf];
      zOut[i*2+1] = zEncode[digest[i] & 0xf];
    }
    zOut[i*2]= 0;
  }
}
/* End of the hashing logic
*****************************************************************************/

/*
** Implementation of the sha1(X) function.
**
** Return a lower-case hexadecimal rendering of the SHA1 hash of the
** argument X.  If X is a BLOB, it is hashed as is.  For all other
** types of input, X is converted into a UTF-8 string and the string
** is hash without the trailing 0x00 terminator.  The hash of a NULL
** value is NULL.
*/
static void sha1Func(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  SHA1Context cx;
  int eType = sqlite3_value_type(argv[0]);
  int nByte = sqlite3_value_bytes(argv[0]);
  char zOut[44];

  assert( argc==1 );
  if( eType==SQLITE_NULL ) return;
  hash_init(&cx);
  if( eType==SQLITE_BLOB ){
    hash_step(&cx, sqlite3_value_blob(argv[0]), nByte);
  }else{
    hash_step(&cx, sqlite3_value_text(argv[0]), nByte);
  }
  if( sqlite3_user_data(context)!=0 ){
    hash_finish(&cx, zOut, 1);
    sqlite3_result_blob(context, zOut, 20, SQLITE_TRANSIENT);
  }else{
    hash_finish(&cx, zOut, 0);
    sqlite3_result_blob(context, zOut, 40, SQLITE_TRANSIENT);
  }
}

/*
** Implementation of the sha1_query(SQL) function.
**
** This function compiles and runs the SQL statement(s) given in the
** argument. The results are hashed using SHA1 and that hash is returned.
**
** The original SQL text is included as part of the hash.
**
** The hash is not just a concatenation of the outputs.  Each query
** is delimited and each row and value within the query is delimited,
** with all values being marked with their datatypes.
*/
static void sha1QueryFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  sqlite3 *db = sqlite3_context_db_handle(context);
  const char *zSql = (const char*)sqlite3_value_text(argv[0]);
  sqlite3_stmt *pStmt = 0;
  int nCol;                   /* Number of columns in the result set */
  int i;                      /* Loop counter */
  int rc;
  int n;
  const char *z;
  SHA1Context cx;
  char zOut[44];

  assert( argc==1 );
  if( zSql==0 ) return;
  hash_init(&cx);
  while( zSql[0] ){
    rc = sqlite3_prepare_v2(db, zSql, -1, &pStmt, &zSql);
    if( rc ){
      char *zMsg = sqlite3_mprintf("error SQL statement [%s]: %s",
                                   zSql, sqlite3_errmsg(db));
      sqlite3_finalize(pStmt);
      sqlite3_result_error(context, zMsg, -1);
      sqlite3_free(zMsg);
      return;
    }
    if( !sqlite3_stmt_readonly(pStmt) ){
      char *zMsg = sqlite3_mprintf("non-query: [%s]", sqlite3_sql(pStmt));
      sqlite3_finalize(pStmt);
      sqlite3_result_error(context, zMsg, -1);
      sqlite3_free(zMsg);
      return;
    }
    nCol = sqlite3_column_count(pStmt);
    z = sqlite3_sql(pStmt);
    n = (int)strlen(z);
    hash_step_vformat(&cx,"S%d:",n);
    hash_step(&cx,(unsigned char*)z,n);

    /* Compute a hash over the result of the query */
    while( SQLITE_ROW==sqlite3_step(pStmt) ){
      hash_step(&cx,(const unsigned char*)"R",1);
      for(i=0; i<nCol; i++){
        switch( sqlite3_column_type(pStmt,i) ){
          case SQLITE_NULL: {
            hash_step(&cx, (const unsigned char*)"N",1);
            break;
          }
          case SQLITE_INTEGER: {
            sqlite3_uint64 u;
            int j;
            unsigned char x[9];
            sqlite3_int64 v = sqlite3_column_int64(pStmt,i);
            memcpy(&u, &v, 8);
            for(j=8; j>=1; j--){
              x[j] = u & 0xff;
              u >>= 8;
            }
            x[0] = 'I';
            hash_step(&cx, x, 9);
            break;
          }
          case SQLITE_FLOAT: {
            sqlite3_uint64 u;
            int j;
            unsigned char x[9];
            double r = sqlite3_column_double(pStmt,i);
            memcpy(&u, &r, 8);
            for(j=8; j>=1; j--){
              x[j] = u & 0xff;
              u >>= 8;
            }
            x[0] = 'F';
            hash_step(&cx,x,9);
            break;
          }
          case SQLITE_TEXT: {
            int n2 = sqlite3_column_bytes(pStmt, i);
            const unsigned char *z2 = sqlite3_column_text(pStmt, i);
            hash_step_vformat(&cx,"T%d:",n2);
            hash_step(&cx, z2, n2);
            break;
          }
          case SQLITE_BLOB: {
            int n2 = sqlite3_column_bytes(pStmt, i);
            const unsigned char *z2 = sqlite3_column_blob(pStmt, i);
            hash_step_vformat(&cx,"B%d:",n2);
            hash_step(&cx, z2, n2);
            break;
          }
        }
      }
    }
    sqlite3_finalize(pStmt);
  }
  hash_finish(&cx, zOut, 0);
  sqlite3_result_text(context, zOut, 40, SQLITE_TRANSIENT);
}


#ifdef _WIN32

#endif
int sqlite3_sha_init(
  sqlite3 *db,
  char **pzErrMsg,
  const sqlite3_api_routines *pApi
){
  int rc = SQLITE_OK;
  static int one = 1;
  SQLITE_EXTENSION_INIT2(pApi);
  (void)pzErrMsg;  /* Unused parameter */
  rc = sqlite3_create_function(db, "sha1", 1, 
                       SQLITE_UTF8 | SQLITE_INNOCUOUS | SQLITE_DETERMINISTIC,
                                0, sha1Func, 0, 0);
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_function(db, "sha1b", 1, 
                       SQLITE_UTF8 | SQLITE_INNOCUOUS | SQLITE_DETERMINISTIC,
                          (void*)&one, sha1Func, 0, 0);
  }
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_function(db, "sha1_query", 1, 
                                 SQLITE_UTF8|SQLITE_DIRECTONLY, 0,
                                 sha1QueryFunc, 0, 0);
  }
  return rc;
}

/************************* End ../ext/misc/sha1.c ********************/
/************************* Begin ../ext/misc/uint.c ******************/
/*
** 2020-04-14
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
******************************************************************************
**
** This SQLite extension implements the UINT collating sequence.
**
** UINT works like BINARY for text, except that embedded strings
** of digits compare in numeric order.
**
**     *   Leading zeros are handled properly, in the sense that
**         they do not mess of the maginitude comparison of embedded
**         strings of digits.  "x00123y" is equal to "x123y".
**
**     *   Only unsigned integers are recognized.  Plus and minus
**         signs are ignored.  Decimal points and exponential notation
**         are ignored.
**
**     *   Embedded integers can be of arbitrary length.  Comparison
**         is *not* limited integers that can be expressed as a
**         64-bit machine integer.
*/
/* #include "sqlite3ext.h" */
SQLITE_EXTENSION_INIT1
#include <assert.h>
#include <string.h>
#include <ctype.h>

/*
** Compare text in lexicographic order, except strings of digits
** compare in numeric order.
*/
static int uintCollFunc(
  void *notUsed,
  int nKey1, const void *pKey1,
  int nKey2, const void *pKey2
){
  const unsigned char *zA = (const unsigned char*)pKey1;
  const unsigned char *zB = (const unsigned char*)pKey2;
  int i=0, j=0, x;
  (void)notUsed;
  while( i<nKey1 && j<nKey2 ){
    x = zA[i] - zB[j];
    if( isdigit(zA[i]) ){
      int k;
      if( !isdigit(zB[j]) ) return x;
      while( i<nKey1 && zA[i]=='0' ){ i++; }
      while( j<nKey2 && zB[j]=='0' ){ j++; }
      k = 0;
      while( i+k<nKey1 && isdigit(zA[i+k])
             && j+k<nKey2 && isdigit(zB[j+k]) ){
        k++;
      }
      if( i+k<nKey1 && isdigit(zA[i+k]) ){
        return +1;
      }else if( j+k<nKey2 && isdigit(zB[j+k]) ){
        return -1;
      }else{
        x = memcmp(zA+i, zB+j, k);
        if( x ) return x;
        i += k;
        j += k;
      }
    }else if( x ){
      return x;
    }else{
      i++;
      j++;
    }
  }
  return (nKey1 - i) - (nKey2 - j);
}

#ifdef _WIN32

#endif
int sqlite3_uint_init(
  sqlite3 *db, 
  char **pzErrMsg, 
  const sqlite3_api_routines *pApi
){
  SQLITE_EXTENSION_INIT2(pApi);
  (void)pzErrMsg;  /* Unused parameter */
  return sqlite3_create_collation(db, "uint", SQLITE_UTF8, 0, uintCollFunc);
}

/************************* End ../ext/misc/uint.c ********************/
/************************* Begin ../ext/misc/decimal.c ******************/
/*
** 2020-06-22
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
******************************************************************************
**
** Routines to implement arbitrary-precision decimal math.
**
** The focus here is on simplicity and correctness, not performance.
*/
/* #include "sqlite3ext.h" */
SQLITE_EXTENSION_INIT1
#include <assert.h>
#include <string.h>
#include <ctype.h>
#include <stdlib.h>

/* Mark a function parameter as unused, to suppress nuisance compiler
** warnings. */
#ifndef UNUSED_PARAMETER
# define UNUSED_PARAMETER(X)  (void)(X)
#endif


/* A decimal object */
typedef struct Decimal Decimal;
struct Decimal {
  char sign;        /* 0 for positive, 1 for negative */
  char oom;         /* True if an OOM is encountered */
  char isNull;      /* True if holds a NULL rather than a number */
  char isInit;      /* True upon initialization */
  int nDigit;       /* Total number of digits */
  int nFrac;        /* Number of digits to the right of the decimal point */
  signed char *a;   /* Array of digits.  Most significant first. */
};

/*
** Release memory held by a Decimal, but do not free the object itself.
*/
static void decimal_clear(Decimal *p){
  sqlite3_free(p->a);
}

/*
** Destroy a Decimal object
*/
static void decimal_free(Decimal *p){
  if( p ){
    decimal_clear(p);
    sqlite3_free(p);
  }
}

/*
** Allocate a new Decimal object initialized to the text in zIn[].
** Return NULL if any kind of error occurs.
*/
static Decimal *decimalNewFromText(const char *zIn, int n){
  Decimal *p = 0;
  int i;
  int iExp = 0;

  p = sqlite3_malloc( sizeof(*p) );
  if( p==0 ) goto new_from_text_failed;
  p->sign = 0;
  p->oom = 0;
  p->isInit = 1;
  p->isNull = 0;
  p->nDigit = 0;
  p->nFrac = 0;
  p->a = sqlite3_malloc64( n+1 );
  if( p->a==0 ) goto new_from_text_failed;
  for(i=0; isspace(zIn[i]); i++){}
  if( zIn[i]=='-' ){
    p->sign = 1;
    i++;
  }else if( zIn[i]=='+' ){
    i++;
  }
  while( i<n && zIn[i]=='0' ) i++;
  while( i<n ){
    char c = zIn[i];
    if( c>='0' && c<='9' ){
      p->a[p->nDigit++] = c - '0';
    }else if( c=='.' ){
      p->nFrac = p->nDigit + 1;
    }else if( c=='e' || c=='E' ){
      int j = i+1;
      int neg = 0;
      if( j>=n ) break;
      if( zIn[j]=='-' ){
        neg = 1;
        j++;
      }else if( zIn[j]=='+' ){
        j++;
      }
      while( j<n && iExp<1000000 ){
        if( zIn[j]>='0' && zIn[j]<='9' ){
          iExp = iExp*10 + zIn[j] - '0';
        }
        j++;
      }
      if( neg ) iExp = -iExp;
      break;
    }
    i++;
  }
  if( p->nFrac ){
    p->nFrac = p->nDigit - (p->nFrac - 1);
  }
  if( iExp>0 ){
    if( p->nFrac>0 ){
      if( iExp<=p->nFrac ){
        p->nFrac -= iExp;
        iExp = 0;
      }else{
        iExp -= p->nFrac;
        p->nFrac = 0;
      }
    }
    if( iExp>0 ){   
      p->a = sqlite3_realloc64(p->a, p->nDigit + iExp + 1 );
      if( p->a==0 ) goto new_from_text_failed;
      memset(p->a+p->nDigit, 0, iExp);
      p->nDigit += iExp;
    }
  }else if( iExp<0 ){
    int nExtra;
    iExp = -iExp;
    nExtra = p->nDigit - p->nFrac - 1;
    if( nExtra ){
      if( nExtra>=iExp ){
        p->nFrac += iExp;
        iExp  = 0;
      }else{
        iExp -= nExtra;
        p->nFrac = p->nDigit - 1;
      }
    }
    if( iExp>0 ){
      p->a = sqlite3_realloc64(p->a, p->nDigit + iExp + 1 );
      if( p->a==0 ) goto new_from_text_failed;
      memmove(p->a+iExp, p->a, p->nDigit);
      memset(p->a, 0, iExp);
      p->nDigit += iExp;
      p->nFrac += iExp;
    }
  }
  return p;

new_from_text_failed:
  if( p ){
    if( p->a ) sqlite3_free(p->a);
    sqlite3_free(p);
  }
  return 0;
}

/* Forward reference */
static Decimal *decimalFromDouble(double);

/*
** Allocate a new Decimal object from an sqlite3_value.  Return a pointer
** to the new object, or NULL if there is an error.  If the pCtx argument
** is not NULL, then errors are reported on it as well.
**
** If the pIn argument is SQLITE_TEXT or SQLITE_INTEGER, it is converted
** directly into a Decimal.  For SQLITE_FLOAT or for SQLITE_BLOB of length
** 8 bytes, the resulting double value is expanded into its decimal equivalent.
** If pIn is NULL or if it is a BLOB that is not exactly 8 bytes in length,
** then NULL is returned.
*/
static Decimal *decimal_new(
  sqlite3_context *pCtx,       /* Report error here, if not null */
  sqlite3_value *pIn,          /* Construct the decimal object from this */
  int bTextOnly                /* Always interpret pIn as text if true */
){
  Decimal *p = 0;
  int eType = sqlite3_value_type(pIn);
  if( bTextOnly && (eType==SQLITE_FLOAT || eType==SQLITE_BLOB) ){
    eType = SQLITE_TEXT;
  }
  switch( eType ){
    case SQLITE_TEXT:
    case SQLITE_INTEGER: {
      const char *zIn = (const char*)sqlite3_value_text(pIn);
      int n = sqlite3_value_bytes(pIn);
      p = decimalNewFromText(zIn, n);
      if( p==0 ) goto new_failed;
      break;
    }

    case SQLITE_FLOAT: {
      p = decimalFromDouble(sqlite3_value_double(pIn));
      break;
    }

    case SQLITE_BLOB: {
      const unsigned char *x;
      unsigned int i;
      sqlite3_uint64 v = 0;
      double r;

      if( sqlite3_value_bytes(pIn)!=sizeof(r) ) break;
      x = sqlite3_value_blob(pIn);
      for(i=0; i<sizeof(r); i++){
        v = (v<<8) | x[i];
      }
      memcpy(&r, &v, sizeof(r));
      p = decimalFromDouble(r);
      break;
    }

    case SQLITE_NULL: {
      break;
    }
  }
  return p;

new_failed:
  if( pCtx ) sqlite3_result_error_nomem(pCtx);
  sqlite3_free(p);
  return 0;
}

/*
** Make the given Decimal the result.
*/
static void decimal_result(sqlite3_context *pCtx, Decimal *p){
  char *z;
  int i, j;
  int n;
  if( p==0 || p->oom ){
    sqlite3_result_error_nomem(pCtx);
    return;
  }
  if( p->isNull ){
    sqlite3_result_null(pCtx);
    return;
  }
  z = sqlite3_malloc( p->nDigit+4 );
  if( z==0 ){
    sqlite3_result_error_nomem(pCtx);
    return;
  }
  i = 0;
  if( p->nDigit==0 || (p->nDigit==1 && p->a[0]==0) ){
    p->sign = 0;
  }
  if( p->sign ){
    z[0] = '-';
    i = 1;
  }
  n = p->nDigit - p->nFrac;
  if( n<=0 ){
    z[i++] = '0';
  }
  j = 0;
  while( n>1 && p->a[j]==0 ){
    j++;
    n--;
  }
  while( n>0  ){
    z[i++] = p->a[j] + '0';
    j++;
    n--;
  }
  if( p->nFrac ){
    z[i++] = '.';
    do{
      z[i++] = p->a[j] + '0';
      j++;
    }while( j<p->nDigit );
  }
  z[i] = 0;
  sqlite3_result_text(pCtx, z, i, sqlite3_free);
}

/*
** Make the given Decimal the result in an format similar to  '%+#e'.
** In other words, show exponential notation with leading and trailing
** zeros omitted.
*/
static void decimal_result_sci(sqlite3_context *pCtx, Decimal *p){
  char *z;       /* The output buffer */
  int i;         /* Loop counter */
  int nZero;     /* Number of leading zeros */
  int nDigit;    /* Number of digits not counting trailing zeros */
  int nFrac;     /* Digits to the right of the decimal point */
  int exp;       /* Exponent value */
  signed char zero;     /* Zero value */
  signed char *a;       /* Array of digits */

  if( p==0 || p->oom ){
    sqlite3_result_error_nomem(pCtx);
    return;
  }
  if( p->isNull ){
    sqlite3_result_null(pCtx);
    return;
  }
  for(nDigit=p->nDigit; nDigit>0 && p->a[nDigit-1]==0; nDigit--){}
  for(nZero=0; nZero<nDigit && p->a[nZero]==0; nZero++){}
  nFrac = p->nFrac + (nDigit - p->nDigit);
  nDigit -= nZero;
  z = sqlite3_malloc( nDigit+20 );
  if( z==0 ){
    sqlite3_result_error_nomem(pCtx);
    return;
  }
  if( nDigit==0 ){
    zero = 0;
    a = &zero;
    nDigit = 1;
    nFrac = 0;
  }else{
    a = &p->a[nZero];
  }
  if( p->sign && nDigit>0 ){
    z[0] = '-';
  }else{
    z[0] = '+';
  }
  z[1] = a[0]+'0';
  z[2] = '.';
  if( nDigit==1 ){
    z[3] = '0';
    i = 4;
  }else{
    for(i=1; i<nDigit; i++){
      z[2+i] = a[i]+'0';
    }
    i = nDigit+2;
  }
  exp = nDigit - nFrac - 1;
  sqlite3_snprintf(nDigit+20-i, &z[i], "e%+03d", exp);
  sqlite3_result_text(pCtx, z, -1, sqlite3_free);
}

/*
** Compare to Decimal objects.  Return negative, 0, or positive if the
** first object is less than, equal to, or greater than the second.
**
** Preconditions for this routine:
**
**    pA!=0
**    pA->isNull==0
**    pB!=0
**    pB->isNull==0
*/
static int decimal_cmp(const Decimal *pA, const Decimal *pB){
  int nASig, nBSig, rc, n;
  if( pA->sign!=pB->sign ){
    return pA->sign ? -1 : +1;
  }
  if( pA->sign ){
    const Decimal *pTemp = pA;
    pA = pB;
    pB = pTemp;
  }
  nASig = pA->nDigit - pA->nFrac;
  nBSig = pB->nDigit - pB->nFrac;
  if( nASig!=nBSig ){
    return nASig - nBSig;
  }
  n = pA->nDigit;
  if( n>pB->nDigit ) n = pB->nDigit;
  rc = memcmp(pA->a, pB->a, n);
  if( rc==0 ){
    rc = pA->nDigit - pB->nDigit;
  }
  return rc;
}

/*
** SQL Function:   decimal_cmp(X, Y)
**
** Return negative, zero, or positive if X is less then, equal to, or
** greater than Y.
*/
static void decimalCmpFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  Decimal *pA = 0, *pB = 0;
  int rc;

  UNUSED_PARAMETER(argc);
  pA = decimal_new(context, argv[0], 1);
  if( pA==0 || pA->isNull ) goto cmp_done;
  pB = decimal_new(context, argv[1], 1);
  if( pB==0 || pB->isNull ) goto cmp_done;
  rc = decimal_cmp(pA, pB);
  if( rc<0 ) rc = -1;
  else if( rc>0 ) rc = +1;
  sqlite3_result_int(context, rc);
cmp_done:
  decimal_free(pA);
  decimal_free(pB);
}

/*
** Expand the Decimal so that it has a least nDigit digits and nFrac
** digits to the right of the decimal point.
*/
static void decimal_expand(Decimal *p, int nDigit, int nFrac){
  int nAddSig;
  int nAddFrac;
  if( p==0 ) return;
  nAddFrac = nFrac - p->nFrac;
  nAddSig = (nDigit - p->nDigit) - nAddFrac;
  if( nAddFrac==0 && nAddSig==0 ) return;
  p->a = sqlite3_realloc64(p->a, nDigit+1);
  if( p->a==0 ){
    p->oom = 1;
    return;
  }
  if( nAddSig ){
    memmove(p->a+nAddSig, p->a, p->nDigit);
    memset(p->a, 0, nAddSig);
    p->nDigit += nAddSig;
  }
  if( nAddFrac ){
    memset(p->a+p->nDigit, 0, nAddFrac);
    p->nDigit += nAddFrac;
    p->nFrac += nAddFrac;
  }
}

/*
** Add the value pB into pA.   A := A + B.
**
** Both pA and pB might become denormalized by this routine.
*/
static void decimal_add(Decimal *pA, Decimal *pB){
  int nSig, nFrac, nDigit;
  int i, rc;
  if( pA==0 ){
    return;
  }
  if( pA->oom || pB==0 || pB->oom ){
    pA->oom = 1;
    return;
  }
  if( pA->isNull || pB->isNull ){
    pA->isNull = 1;
    return;
  }
  nSig = pA->nDigit - pA->nFrac;
  if( nSig && pA->a[0]==0 ) nSig--;
  if( nSig<pB->nDigit-pB->nFrac ){
    nSig = pB->nDigit - pB->nFrac;
  }
  nFrac = pA->nFrac;
  if( nFrac<pB->nFrac ) nFrac = pB->nFrac;
  nDigit = nSig + nFrac + 1;
  decimal_expand(pA, nDigit, nFrac);
  decimal_expand(pB, nDigit, nFrac);
  if( pA->oom || pB->oom ){
    pA->oom = 1;
  }else{
    if( pA->sign==pB->sign ){
      int carry = 0;
      for(i=nDigit-1; i>=0; i--){
        int x = pA->a[i] + pB->a[i] + carry;
        if( x>=10 ){
          carry = 1;
          pA->a[i] = x - 10;
        }else{
          carry = 0;
          pA->a[i] = x;
        }
      }
    }else{
      signed char *aA, *aB;
      int borrow = 0;
      rc = memcmp(pA->a, pB->a, nDigit);
      if( rc<0 ){
        aA = pB->a;
        aB = pA->a;
        pA->sign = !pA->sign;
      }else{
        aA = pA->a;
        aB = pB->a;
      }
      for(i=nDigit-1; i>=0; i--){
        int x = aA[i] - aB[i] - borrow;
        if( x<0 ){
          pA->a[i] = x+10;
          borrow = 1;
        }else{
          pA->a[i] = x;
          borrow = 0;
        }
      }
    }
  }
}

/*
** Multiply A by B.   A := A * B
**
** All significant digits after the decimal point are retained.
** Trailing zeros after the decimal point are omitted as long as
** the number of digits after the decimal point is no less than
** either the number of digits in either input.
*/
static void decimalMul(Decimal *pA, Decimal *pB){
  signed char *acc = 0;
  int i, j, k;
  int minFrac;

  if( pA==0 || pA->oom || pA->isNull
   || pB==0 || pB->oom || pB->isNull 
  ){
    goto mul_end;
  }
  acc = sqlite3_malloc64( pA->nDigit + pB->nDigit + 2 );
  if( acc==0 ){
    pA->oom = 1;
    goto mul_end;
  }
  memset(acc, 0, pA->nDigit + pB->nDigit + 2);
  minFrac = pA->nFrac;
  if( pB->nFrac<minFrac ) minFrac = pB->nFrac;
  for(i=pA->nDigit-1; i>=0; i--){
    signed char f = pA->a[i];
    int carry = 0, x;
    for(j=pB->nDigit-1, k=i+j+3; j>=0; j--, k--){
      x = acc[k] + f*pB->a[j] + carry;
      acc[k] = x%10;
      carry = x/10;
    }
    x = acc[k] + carry;
    acc[k] = x%10;
    acc[k-1] += x/10;
  }
  sqlite3_free(pA->a);
  pA->a = acc;
  acc = 0;
  pA->nDigit += pB->nDigit + 2;
  pA->nFrac += pB->nFrac;
  pA->sign ^= pB->sign;
  while( pA->nFrac>minFrac && pA->a[pA->nDigit-1]==0 ){
    pA->nFrac--;
    pA->nDigit--;
  }

mul_end:
  sqlite3_free(acc);
}

/*
** Create a new Decimal object that contains an integer power of 2.
*/
static Decimal *decimalPow2(int N){
  Decimal *pA = 0;      /* The result to be returned */
  Decimal *pX = 0;      /* Multiplier */
  if( N<-20000 || N>20000 ) goto pow2_fault;
  pA = decimalNewFromText("1.0", 3);
  if( pA==0 || pA->oom ) goto pow2_fault;
  if( N==0 ) return pA;
  if( N>0 ){
    pX = decimalNewFromText("2.0", 3);
  }else{
    N = -N;
    pX = decimalNewFromText("0.5", 3);
  }
  if( pX==0 || pX->oom ) goto pow2_fault;
  while( 1 /* Exit by break */ ){
    if( N & 1 ){
      decimalMul(pA, pX);
      if( pA->oom ) goto pow2_fault;
    }
    N >>= 1;
    if( N==0 ) break;
    decimalMul(pX, pX);
  }
  decimal_free(pX);
  return pA;

pow2_fault:
  decimal_free(pA);
  decimal_free(pX);
  return 0;
}

/*
** Use an IEEE754 binary64 ("double") to generate a new Decimal object.
*/
static Decimal *decimalFromDouble(double r){
  sqlite3_int64 m, a;
  int e;
  int isNeg;
  Decimal *pA;
  Decimal *pX;
  char zNum[100];
  if( r<0.0 ){
    isNeg = 1;
    r = -r;
  }else{
    isNeg = 0;
  }
  memcpy(&a,&r,sizeof(a));
  if( a==0 ){
    e = 0;
    m = 0;
  }else{
    e = a>>52;
    m = a & ((((sqlite3_int64)1)<<52)-1);
    if( e==0 ){
      m <<= 1;
    }else{
      m |= ((sqlite3_int64)1)<<52;
    }
    while( e<1075 && m>0 && (m&1)==0 ){
      m >>= 1;
      e++;
    }
    if( isNeg ) m = -m;
    e = e - 1075;
    if( e>971 ){
      return 0;  /* A NaN or an Infinity */
    }
  }

  /* At this point m is the integer significand and e is the exponent */
  sqlite3_snprintf(sizeof(zNum), zNum, "%lld", m);
  pA = decimalNewFromText(zNum, (int)strlen(zNum));
  pX = decimalPow2(e);
  decimalMul(pA, pX);
  decimal_free(pX);
  return pA;
}

/*
** SQL Function:   decimal(X)
** OR:             decimal_exp(X)
**
** Convert input X into decimal and then back into text.
**
** If X is originally a float, then a full decimal expansion of that floating
** point value is done.  Or if X is an 8-byte blob, it is interpreted
** as a float and similarly expanded.
**
** The decimal_exp(X) function returns the result in exponential notation.
** decimal(X) returns a complete decimal, without the e+NNN at the end.
*/
static void decimalFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  Decimal *p =  decimal_new(context, argv[0], 0);
  UNUSED_PARAMETER(argc);
  if( p ){
    if( sqlite3_user_data(context)!=0 ){
      decimal_result_sci(context, p);
    }else{
      decimal_result(context, p);
    }
    decimal_free(p);
  }
}

/*
** Compare text in decimal order.
*/
static int decimalCollFunc(
  void *notUsed,
  int nKey1, const void *pKey1,
  int nKey2, const void *pKey2
){
  const unsigned char *zA = (const unsigned char*)pKey1;
  const unsigned char *zB = (const unsigned char*)pKey2;
  Decimal *pA = decimalNewFromText((const char*)zA, nKey1);
  Decimal *pB = decimalNewFromText((const char*)zB, nKey2);
  int rc;
  UNUSED_PARAMETER(notUsed);
  if( pA==0 || pB==0 ){
    rc = 0;
  }else{
    rc = decimal_cmp(pA, pB);
  }
  decimal_free(pA);
  decimal_free(pB);
  return rc;
}


/*
** SQL Function:   decimal_add(X, Y)
**                 decimal_sub(X, Y)
**
** Return the sum or difference of X and Y.
*/
static void decimalAddFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  Decimal *pA = decimal_new(context, argv[0], 1);
  Decimal *pB = decimal_new(context, argv[1], 1);
  UNUSED_PARAMETER(argc);
  decimal_add(pA, pB);
  decimal_result(context, pA);
  decimal_free(pA);
  decimal_free(pB);
}
static void decimalSubFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  Decimal *pA = decimal_new(context, argv[0], 1);
  Decimal *pB = decimal_new(context, argv[1], 1);
  UNUSED_PARAMETER(argc);
  if( pB ){
    pB->sign = !pB->sign;
    decimal_add(pA, pB);
    decimal_result(context, pA);
  }
  decimal_free(pA);
  decimal_free(pB);
}

/* Aggregate funcion:   decimal_sum(X)
**
** Works like sum() except that it uses decimal arithmetic for unlimited
** precision.
*/
static void decimalSumStep(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  Decimal *p;
  Decimal *pArg;
  UNUSED_PARAMETER(argc);
  p = sqlite3_aggregate_context(context, sizeof(*p));
  if( p==0 ) return;
  if( !p->isInit ){
    p->isInit = 1;
    p->a = sqlite3_malloc(2);
    if( p->a==0 ){
      p->oom = 1;
    }else{
      p->a[0] = 0;
    }
    p->nDigit = 1;
    p->nFrac = 0;
  }
  if( sqlite3_value_type(argv[0])==SQLITE_NULL ) return;
  pArg = decimal_new(context, argv[0], 1);
  decimal_add(p, pArg);
  decimal_free(pArg);
}
static void decimalSumInverse(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  Decimal *p;
  Decimal *pArg;
  UNUSED_PARAMETER(argc);
  p = sqlite3_aggregate_context(context, sizeof(*p));
  if( p==0 ) return;
  if( sqlite3_value_type(argv[0])==SQLITE_NULL ) return;
  pArg = decimal_new(context, argv[0], 1);
  if( pArg ) pArg->sign = !pArg->sign;
  decimal_add(p, pArg);
  decimal_free(pArg);
}
static void decimalSumValue(sqlite3_context *context){
  Decimal *p = sqlite3_aggregate_context(context, 0);
  if( p==0 ) return;
  decimal_result(context, p);
}
static void decimalSumFinalize(sqlite3_context *context){
  Decimal *p = sqlite3_aggregate_context(context, 0);
  if( p==0 ) return;
  decimal_result(context, p);
  decimal_clear(p);
}

/*
** SQL Function:   decimal_mul(X, Y)
**
** Return the product of X and Y.
*/
static void decimalMulFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  Decimal *pA = decimal_new(context, argv[0], 1);
  Decimal *pB = decimal_new(context, argv[1], 1);
  UNUSED_PARAMETER(argc);
  if( pA==0 || pA->oom || pA->isNull
   || pB==0 || pB->oom || pB->isNull 
  ){
    goto mul_end;
  }
  decimalMul(pA, pB);
  if( pA->oom ){
    goto mul_end;
  }
  decimal_result(context, pA);

mul_end:
  decimal_free(pA);
  decimal_free(pB);
}

/*
** SQL Function:   decimal_pow2(N)
**
** Return the N-th power of 2.  N must be an integer.
*/
static void decimalPow2Func(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  UNUSED_PARAMETER(argc);
  if( sqlite3_value_type(argv[0])==SQLITE_INTEGER ){
    Decimal *pA = decimalPow2(sqlite3_value_int(argv[0]));
    decimal_result_sci(context, pA);
    decimal_free(pA);
  }
}

#ifdef _WIN32

#endif
int sqlite3_decimal_init(
  sqlite3 *db, 
  char **pzErrMsg, 
  const sqlite3_api_routines *pApi
){
  int rc = SQLITE_OK;
  static const struct {
    const char *zFuncName;
    int nArg;
    int iArg;
    void (*xFunc)(sqlite3_context*,int,sqlite3_value**);
  } aFunc[] = {
    { "decimal",       1, 0,  decimalFunc        },
    { "decimal_exp",   1, 1,  decimalFunc        },
    { "decimal_cmp",   2, 0,  decimalCmpFunc     },
    { "decimal_add",   2, 0,  decimalAddFunc     },
    { "decimal_sub",   2, 0,  decimalSubFunc     },
    { "decimal_mul",   2, 0,  decimalMulFunc     },
    { "decimal_pow2",  1, 0,  decimalPow2Func    },
  };
  unsigned int i;
  (void)pzErrMsg;  /* Unused parameter */

  SQLITE_EXTENSION_INIT2(pApi);

  for(i=0; i<(int)(sizeof(aFunc)/sizeof(aFunc[0])) && rc==SQLITE_OK; i++){
    rc = sqlite3_create_function(db, aFunc[i].zFuncName, aFunc[i].nArg,
                   SQLITE_UTF8|SQLITE_INNOCUOUS|SQLITE_DETERMINISTIC,
                   aFunc[i].iArg ? db : 0, aFunc[i].xFunc, 0, 0);
  }
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_window_function(db, "decimal_sum", 1,
                   SQLITE_UTF8|SQLITE_INNOCUOUS|SQLITE_DETERMINISTIC, 0,
                   decimalSumStep, decimalSumFinalize,
                   decimalSumValue, decimalSumInverse, 0);
  }
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_collation(db, "decimal", SQLITE_UTF8,
                                  0, decimalCollFunc);
  }
  return rc;
}

/************************* End ../ext/misc/decimal.c ********************/
/************************* Begin ../ext/misc/percentile.c ******************/
/*
** 2013-05-28
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
******************************************************************************
**
** This file contains code to implement the percentile(Y,P) SQL function
** and similar as described below:
**
**   (1)  The percentile(Y,P) function is an aggregate function taking
**        exactly two arguments.
**
**   (2)  If the P argument to percentile(Y,P) is not the same for every
**        row in the aggregate then an error is thrown.  The word "same"
**        in the previous sentence means that the value differ by less
**        than 0.001.
**
**   (3)  If the P argument to percentile(Y,P) evaluates to anything other
**        than a number in the range of 0.0 to 100.0 inclusive then an
**        error is thrown.
**
**   (4)  If any Y argument to percentile(Y,P) evaluates to a value that
**        is not NULL and is not numeric then an error is thrown.
**
**   (5)  If any Y argument to percentile(Y,P) evaluates to plus or minus
**        infinity then an error is thrown.  (SQLite always interprets NaN
**        values as NULL.)
**
**   (6)  Both Y and P in percentile(Y,P) can be arbitrary expressions,
**        including CASE WHEN expressions.
**
**   (7)  The percentile(Y,P) aggregate is able to handle inputs of at least
**        one million (1,000,000) rows.
**
**   (8)  If there are no non-NULL values for Y, then percentile(Y,P)
**        returns NULL.
**
**   (9)  If there is exactly one non-NULL value for Y, the percentile(Y,P)
**        returns the one Y value.
**
**  (10)  If there N non-NULL values of Y where N is two or more and
**        the Y values are ordered from least to greatest and a graph is
**        drawn from 0 to N-1 such that the height of the graph at J is
**        the J-th Y value and such that straight lines are drawn between
**        adjacent Y values, then the percentile(Y,P) function returns
**        the height of the graph at P*(N-1)/100.
**
**  (11)  The percentile(Y,P) function always returns either a floating
**        point number or NULL.
**
**  (12)  The percentile(Y,P) is implemented as a single C99 source-code
**        file that compiles into a shared-library or DLL that can be loaded
**        into SQLite using the sqlite3_load_extension() interface.
**
**  (13)  A separate median(Y) function is the equivalent percentile(Y,50).
**
**  (14)  A separate percentile_cont(Y,P) function is equivalent to
**        percentile(Y,P/100.0).  In other words, the fraction value in
**        the second argument is in the range of 0 to 1 instead of 0 to 100.
**
**  (15)  A separate percentile_disc(Y,P) function is like
**        percentile_cont(Y,P) except that instead of returning the weighted
**        average of the nearest two input values, it returns the next lower
**        value.  So the percentile_disc(Y,P) will always return a value
**        that was one of the inputs.
**
**  (16)  All of median(), percentile(Y,P), percentile_cont(Y,P) and
**        percentile_disc(Y,P) can be used as window functions.
**
** Differences from standard SQL:
**
**  *  The percentile_cont(X,P) function is equivalent to the following in
**     standard SQL:
**
**         (percentile_cont(P) WITHIN GROUP (ORDER BY X))
**
**     The SQLite syntax is much more compact.  The standard SQL syntax
**     is also supported if SQLite is compiled with the
**     -DSQLITE_ENABLE_ORDERED_SET_AGGREGATES option.
**
**  *  No median(X) function exists in the SQL standard.  App developers
**     are expected to write "percentile_cont(0.5)WITHIN GROUP(ORDER BY X)".
**
**  *  No percentile(Y,P) function exists in the SQL standard.  Instead of
**     percential(Y,P), developers must write this:
**     "percentile_cont(P/100.0) WITHIN GROUP (ORDER BY Y)".  Note that
**     the fraction parameter to percentile() goes from 0 to 100 whereas
**     the fraction parameter in SQL standard percentile_cont() goes from
**     0 to 1.
**
** Implementation notes as of 2024-08-31:
**
**  *  The regular aggregate-function versions of these routines work
**     by accumulating all values in an array of doubles, then sorting
**     that array using quicksort before computing the answer. Thus
**     the runtime is O(NlogN) where N is the number of rows of input.
**
**  *  For the window-function versions of these routines, the array of
**     inputs is sorted as soon as the first value is computed.  Thereafter,
**     the array is kept in sorted order using an insert-sort.  This
**     results in O(N*K) performance where K is the size of the window.
**     One can imagine alternative implementations that give O(N*logN*logK)
**     performance, but they require more complex logic and data structures.
**     The developers have elected to keep the asymptotically slower
**     algorithm for now, for simplicity, under the theory that window
**     functions are seldom used and when they are, the window size K is
**     often small.  The developers might revisit that decision later,
**     should the need arise.
*/
#if defined(SQLITE3_H)
  /* no-op */
#elif defined(SQLITE_STATIC_PERCENTILE)
/* #  include "sqlite3.h" */
#else
/* #  include "sqlite3ext.h" */
   SQLITE_EXTENSION_INIT1
#endif
#include <assert.h>
#include <string.h>
#include <stdlib.h>

/* The following object is the group context for a single percentile()
** aggregate.  Remember all input Y values until the very end.
** Those values are accumulated in the Percentile.a[] array.
*/
typedef struct Percentile Percentile;
struct Percentile {
  unsigned nAlloc;     /* Number of slots allocated for a[] */
  unsigned nUsed;      /* Number of slots actually used in a[] */
  char bSorted;        /* True if a[] is already in sorted order */
  char bKeepSorted;    /* True if advantageous to keep a[] sorted */
  char bPctValid;      /* True if rPct is valid */
  double rPct;         /* Fraction.  0.0 to 1.0 */
  double *a;           /* Array of Y values */
};

/* Details of each function in the percentile family */
typedef struct PercentileFunc PercentileFunc;
struct PercentileFunc {
  const char *zName;   /* Function name */
  char nArg;           /* Number of arguments */
  char mxFrac;         /* Maximum value of the "fraction" input */
  char bDiscrete;      /* True for percentile_disc() */
};
static const PercentileFunc aPercentFunc[] = {
  { "median",           1,   1, 0 },
  { "percentile",       2, 100, 0 },
  { "percentile_cont",  2,   1, 0 },
  { "percentile_disc",  2,   1, 1 },
};

/*
** Return TRUE if the input floating-point number is an infinity.
*/
static int percentIsInfinity(double r){
  sqlite3_uint64 u;
  assert( sizeof(u)==sizeof(r) );
  memcpy(&u, &r, sizeof(u));
  return ((u>>52)&0x7ff)==0x7ff;
}

/*
** Return TRUE if two doubles differ by 0.001 or less.
*/
static int percentSameValue(double a, double b){
  a -= b;
  return a>=-0.001 && a<=0.001;
}

/*
** Search p (which must have p->bSorted) looking for an entry with
** value y.  Return the index of that entry.
**
** If bExact is true, return -1 if the entry is not found.
**
** If bExact is false, return the index at which a new entry with
** value y should be insert in order to keep the values in sorted
** order.  The smallest return value in this case will be 0, and
** the largest return value will be p->nUsed.
*/
static int percentBinarySearch(Percentile *p, double y, int bExact){
  int iFirst = 0;              /* First element of search range */
  int iLast = p->nUsed - 1;    /* Last element of search range */
  while( iLast>=iFirst ){
    int iMid = (iFirst+iLast)/2;
    double x = p->a[iMid];
    if( x<y ){
      iFirst = iMid + 1;
    }else if( x>y ){
      iLast = iMid - 1;
    }else{
      return iMid;
    }
  }
  if( bExact ) return -1;
  return iFirst;
}

/*
** Generate an error for a percentile function.
**
** The error format string must have exactly one occurrance of "%%s()"
** (with two '%' characters).  That substring will be replaced by the name
** of the function.
*/
static void percentError(sqlite3_context *pCtx, const char *zFormat, ...){
  PercentileFunc *pFunc = (PercentileFunc*)sqlite3_user_data(pCtx);
  char *zMsg1;
  char *zMsg2;
  va_list ap;

  va_start(ap, zFormat);
  zMsg1 = sqlite3_vmprintf(zFormat, ap);
  va_end(ap);
  zMsg2 = zMsg1 ? sqlite3_mprintf(zMsg1, pFunc->zName) : 0;
  sqlite3_result_error(pCtx, zMsg2, -1);
  sqlite3_free(zMsg1);
  sqlite3_free(zMsg2);
}

/*
** The "step" function for percentile(Y,P) is called once for each
** input row.
*/
static void percentStep(sqlite3_context *pCtx, int argc, sqlite3_value **argv){
  Percentile *p;
  double rPct;
  int eType;
  double y;
  assert( argc==2 || argc==1 );

  if( argc==1 ){
    /* Requirement 13:  median(Y) is the same as percentile(Y,50). */
    rPct = 0.5;
  }else{
    /* Requirement 3:  P must be a number between 0 and 100 */
    PercentileFunc *pFunc = (PercentileFunc*)sqlite3_user_data(pCtx);
    eType = sqlite3_value_numeric_type(argv[1]);
    rPct = sqlite3_value_double(argv[1])/(double)pFunc->mxFrac;
    if( (eType!=SQLITE_INTEGER && eType!=SQLITE_FLOAT)
     || rPct<0.0 || rPct>1.0
    ){
      percentError(pCtx, "the fraction argument to %%s()"
                        " is not between 0.0 and %.1f",
                        (double)pFunc->mxFrac);
      return;
    }
  }

  /* Allocate the session context. */
  p = (Percentile*)sqlite3_aggregate_context(pCtx, sizeof(*p));
  if( p==0 ) return;

  /* Remember the P value.  Throw an error if the P value is different
  ** from any prior row, per Requirement (2). */
  if( !p->bPctValid ){
    p->rPct = rPct;
    p->bPctValid = 1;
  }else if( !percentSameValue(p->rPct,rPct) ){
    percentError(pCtx, "the fraction argument to %%s()"
                      " is not the same for all input rows");
    return;
  }

  /* Ignore rows for which Y is NULL */
  eType = sqlite3_value_type(argv[0]);
  if( eType==SQLITE_NULL ) return;

  /* If not NULL, then Y must be numeric.  Otherwise throw an error.
  ** Requirement 4 */
  if( eType!=SQLITE_INTEGER && eType!=SQLITE_FLOAT ){
    percentError(pCtx, "input to %%s() is not numeric");
    return;
  }

  /* Throw an error if the Y value is infinity or NaN */
  y = sqlite3_value_double(argv[0]);
  if( percentIsInfinity(y) ){
    percentError(pCtx, "Inf input to %%s()");
    return;
  }

  /* Allocate and store the Y */
  if( p->nUsed>=p->nAlloc ){
    unsigned n = p->nAlloc*2 + 250;
    double *a = sqlite3_realloc64(p->a, sizeof(double)*n);
    if( a==0 ){
      sqlite3_free(p->a);
      memset(p, 0, sizeof(*p));
      sqlite3_result_error_nomem(pCtx);
      return;
    }
    p->nAlloc = n;
    p->a = a;
  }
  if( p->nUsed==0 ){
    p->a[p->nUsed++] = y;
    p->bSorted = 1;
  }else if( !p->bSorted || y>=p->a[p->nUsed-1] ){
    p->a[p->nUsed++] = y;
  }else if( p->bKeepSorted ){
    int i;
    i = percentBinarySearch(p, y, 0);
    if( i<(int)p->nUsed ){
      memmove(&p->a[i+1], &p->a[i], (p->nUsed-i)*sizeof(p->a[0]));
    }
    p->a[i] = y;
    p->nUsed++;
  }else{
    p->a[p->nUsed++] = y;
    p->bSorted = 0;
  }
}

/*
** Interchange two doubles.
*/
#define SWAP_DOUBLE(X,Y)  {double ttt=(X);(X)=(Y);(Y)=ttt;}

/*
** Sort an array of doubles.
**
** Algorithm: quicksort
**
** This is implemented separately rather than using the qsort() routine
** from the standard library because:
**
**    (1)  To avoid a dependency on qsort()
**    (2)  To avoid the function call to the comparison routine for each
**         comparison.
*/
static void percentSort(double *a, unsigned int n){
  int iLt;  /* Entries before a[iLt] are less than rPivot */
  int iGt;  /* Entries at or after a[iGt] are greater than rPivot */
  int i;         /* Loop counter */
  double rPivot; /* The pivot value */
  
  assert( n>=2 );
  if( a[0]>a[n-1] ){
    SWAP_DOUBLE(a[0],a[n-1])
  }
  if( n==2 ) return;
  iGt = n-1;
  i = n/2;
  if( a[0]>a[i] ){
    SWAP_DOUBLE(a[0],a[i])
  }else if( a[i]>a[iGt] ){
    SWAP_DOUBLE(a[i],a[iGt])
  }
  if( n==3 ) return;
  rPivot = a[i];
  iLt = i = 1;
  do{
    if( a[i]<rPivot ){
      if( i>iLt ) SWAP_DOUBLE(a[i],a[iLt])
      iLt++;
      i++;
    }else if( a[i]>rPivot ){
      do{
        iGt--;
      }while( iGt>i && a[iGt]>rPivot );
      SWAP_DOUBLE(a[i],a[iGt])
    }else{
      i++;
    }
  }while( i<iGt );
  if( iLt>=2 ) percentSort(a, iLt);
  if( n-iGt>=2 ) percentSort(a+iGt, n-iGt);
    
/* Uncomment for testing */
#if 0
  for(i=0; i<n-1; i++){
    assert( a[i]<=a[i+1] );
  }
#endif
}


/*
** The "inverse" function for percentile(Y,P) is called to remove a
** row that was previously inserted by "step".
*/
static void percentInverse(sqlite3_context *pCtx,int argc,sqlite3_value **argv){
  Percentile *p;
  int eType;
  double y;
  int i;
  assert( argc==2 || argc==1 );

  /* Allocate the session context. */
  p = (Percentile*)sqlite3_aggregate_context(pCtx, sizeof(*p));
  assert( p!=0 );

  /* Ignore rows for which Y is NULL */
  eType = sqlite3_value_type(argv[0]);
  if( eType==SQLITE_NULL ) return;

  /* If not NULL, then Y must be numeric.  Otherwise throw an error.
  ** Requirement 4 */
  if( eType!=SQLITE_INTEGER && eType!=SQLITE_FLOAT ){
    return;
  }

  /* Ignore the Y value if it is infinity or NaN */
  y = sqlite3_value_double(argv[0]);
  if( percentIsInfinity(y) ){
    return;
  }
  if( p->bSorted==0 ){
    assert( p->nUsed>1 );
    percentSort(p->a, p->nUsed);
    p->bSorted = 1;
  }
  p->bKeepSorted = 1;

  /* Find and remove the row */
  i = percentBinarySearch(p, y, 1);
  if( i>=0 ){
    p->nUsed--;
    if( i<(int)p->nUsed ){
      memmove(&p->a[i], &p->a[i+1], (p->nUsed - i)*sizeof(p->a[0]));
    }
  }
}

/*
** Compute the final output of percentile().  Clean up all allocated
** memory if and only if bIsFinal is true.
*/
static void percentCompute(sqlite3_context *pCtx, int bIsFinal){
  Percentile *p;
  PercentileFunc *pFunc = (PercentileFunc*)sqlite3_user_data(pCtx);
  unsigned i1, i2;
  double v1, v2;
  double ix, vx;
  p = (Percentile*)sqlite3_aggregate_context(pCtx, 0);
  if( p==0 ) return;
  if( p->a==0 ) return;
  if( p->nUsed ){
    if( p->bSorted==0 ){
      assert( p->nUsed>1 );
      percentSort(p->a, p->nUsed);
      p->bSorted = 1;
    }
    ix = p->rPct*(p->nUsed-1);
    i1 = (unsigned)ix;
    if( pFunc->bDiscrete ){
      vx = p->a[i1];
    }else{
      i2 = ix==(double)i1 || i1==p->nUsed-1 ? i1 : i1+1;
      v1 = p->a[i1];
      v2 = p->a[i2];
      vx = v1 + (v2-v1)*(ix-i1);
    }
    sqlite3_result_double(pCtx, vx);
  }
  if( bIsFinal ){
    sqlite3_free(p->a);
    memset(p, 0, sizeof(*p));
  }else{
    p->bKeepSorted = 1;
  }
}
static void percentFinal(sqlite3_context *pCtx){
  percentCompute(pCtx, 1);
}
static void percentValue(sqlite3_context *pCtx){
  percentCompute(pCtx, 0);
}

#if defined(_WIN32) && !defined(SQLITE3_H) && !defined(SQLITE_STATIC_PERCENTILE)

#endif
int sqlite3_percentile_init(
  sqlite3 *db, 
  char **pzErrMsg, 
  const sqlite3_api_routines *pApi
){
  int rc = SQLITE_OK;
  unsigned int i;
#ifdef SQLITE3EXT_H
  SQLITE_EXTENSION_INIT2(pApi);
#else
  (void)pApi;      /* Unused parameter */
#endif
  (void)pzErrMsg;  /* Unused parameter */
  for(i=0; i<sizeof(aPercentFunc)/sizeof(aPercentFunc[0]); i++){
    rc = sqlite3_create_window_function(db,
            aPercentFunc[i].zName,
            aPercentFunc[i].nArg,
            SQLITE_UTF8|SQLITE_INNOCUOUS|SQLITE_SELFORDER1,
            (void*)&aPercentFunc[i],
            percentStep, percentFinal, percentValue, percentInverse, 0);
    if( rc ) break;
  }
  return rc;
}

/************************* End ../ext/misc/percentile.c ********************/
#undef sqlite3_base_init
#define sqlite3_base_init sqlite3_base64_init
/************************* Begin ../ext/misc/base64.c ******************/
/*
** 2022-11-18
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
**
** This is a SQLite extension for converting in either direction
** between a (binary) blob and base64 text. Base64 can transit a
** sane USASCII channel unmolested. It also plays nicely in CSV or
** written as TCL brace-enclosed literals or SQL string literals,
** and can be used unmodified in XML-like documents.
**
** This is an independent implementation of conversions specified in
** RFC 4648, done on the above date by the author (Larry Brasfield)
** who thereby has the right to put this into the public domain.
**
** The conversions meet RFC 4648 requirements, provided that this
** C source specifies that line-feeds are included in the encoded
** data to limit visible line lengths to 72 characters and to
** terminate any encoded blob having non-zero length.
**
** Length limitations are not imposed except that the runtime
** SQLite string or blob length limits are respected. Otherwise,
** any length binary sequence can be represented and recovered.
** Generated base64 sequences, with their line-feeds included,
** can be concatenated; the result converted back to binary will
** be the concatenation of the represented binary sequences.
**
** This SQLite3 extension creates a function, base64(x), which
** either: converts text x containing base64 to a returned blob;
** or converts a blob x to returned text containing base64. An
** error will be thrown for other input argument types.
**
** This code relies on UTF-8 encoding only with respect to the
** meaning of the first 128 (7-bit) codes matching that of USASCII.
** It will fail miserably if somehow made to try to convert EBCDIC.
** Because it is table-driven, it could be enhanced to handle that,
** but the world and SQLite have moved on from that anachronism.
**
** To build the extension:
** Set shell variable SQDIR=<your favorite SQLite checkout directory>
** *Nix: gcc -O2 -shared -I$SQDIR -fPIC -o base64.so base64.c
** OSX: gcc -O2 -dynamiclib -fPIC -I$SQDIR -o base64.dylib base64.c
** Win32: gcc -O2 -shared -I%SQDIR% -o base64.dll base64.c
** Win32: cl /Os -I%SQDIR% base64.c -link -dll -out:base64.dll
*/

#include <assert.h>

/* #include "sqlite3ext.h" */

#ifndef deliberate_fall_through
/* Quiet some compilers about some of our intentional code. */
# if GCC_VERSION>=7000000
#  define deliberate_fall_through __attribute__((fallthrough));
# else
#  define deliberate_fall_through
# endif
#endif

SQLITE_EXTENSION_INIT1;

#define PC 0x80 /* pad character */
#define WS 0x81 /* whitespace */
#define ND 0x82 /* Not above or digit-value */
#define PAD_CHAR '='

#ifndef U8_TYPEDEF
/* typedef unsigned char u8; */
#define U8_TYPEDEF
#endif

/* Decoding table, ASCII (7-bit) value to base 64 digit value or other */
static const u8 b64DigitValues[128] = {
  /*                             HT LF VT  FF CR       */
    ND,ND,ND,ND, ND,ND,ND,ND, ND,WS,WS,WS, WS,WS,ND,ND,
  /*                                                US */
    ND,ND,ND,ND, ND,ND,ND,ND, ND,ND,ND,ND, ND,ND,ND,ND,
  /*sp                                  +            / */
    WS,ND,ND,ND, ND,ND,ND,ND, ND,ND,ND,62, ND,ND,ND,63,
  /* 0  1            5            9            =       */
    52,53,54,55, 56,57,58,59, 60,61,ND,ND, ND,PC,ND,ND,
  /*    A                                            O */
    ND, 0, 1, 2,  3, 4, 5, 6,  7, 8, 9,10, 11,12,13,14,
  /* P                               Z                 */
    15,16,17,18, 19,20,21,22, 23,24,25,ND, ND,ND,ND,ND,
  /*    a                                            o */
    ND,26,27,28, 29,30,31,32, 33,34,35,36, 37,38,39,40,
  /* p                               z                 */
    41,42,43,44, 45,46,47,48, 49,50,51,ND, ND,ND,ND,ND
};

static const char b64Numerals[64+1]
= "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";

#define BX_DV_PROTO(c) \
  ((((u8)(c))<0x80)? (u8)(b64DigitValues[(u8)(c)]) : 0x80)
#define IS_BX_DIGIT(bdp) (((u8)(bdp))<0x80)
#define IS_BX_WS(bdp) ((bdp)==WS)
#define IS_BX_PAD(bdp) ((bdp)==PC)
#define BX_NUMERAL(dv) (b64Numerals[(u8)(dv)])
/* Width of base64 lines. Should be an integer multiple of 4. */
#define B64_DARK_MAX 72

/* Encode a byte buffer into base64 text with linefeeds appended to limit
** encoded group lengths to B64_DARK_MAX or to terminate the last group.
*/
static char* toBase64( u8 *pIn, int nbIn, char *pOut ){
  int nCol = 0;
  while( nbIn >= 3 ){
    /* Do the bit-shuffle, exploiting unsigned input to avoid masking. */
    pOut[0] = BX_NUMERAL(pIn[0]>>2);
    pOut[1] = BX_NUMERAL(((pIn[0]<<4)|(pIn[1]>>4))&0x3f);
    pOut[2] = BX_NUMERAL(((pIn[1]&0xf)<<2)|(pIn[2]>>6));
    pOut[3] = BX_NUMERAL(pIn[2]&0x3f);
    pOut += 4;
    nbIn -= 3;
    pIn += 3;
    if( (nCol += 4)>=B64_DARK_MAX || nbIn<=0 ){
      *pOut++ = '\n';
      nCol = 0;
    }
  }
  if( nbIn > 0 ){
    signed char nco = nbIn+1;
    int nbe;
    unsigned long qv = *pIn++;
    for( nbe=1; nbe<3; ++nbe ){
      qv <<= 8;
      if( nbe<nbIn ) qv |= *pIn++;
    }
    for( nbe=3; nbe>=0; --nbe ){
      char ce = (nbe<nco)? BX_NUMERAL((u8)(qv & 0x3f)) : PAD_CHAR;
      qv >>= 6;
      pOut[nbe] = ce;
    }
    pOut += 4;
    *pOut++ = '\n';
  }
  *pOut = 0;
  return pOut;
}

/* Skip over text which is not base64 numeral(s). */
static char * skipNonB64( char *s, int nc ){
  char c;
  while( nc-- > 0 && (c = *s) && !IS_BX_DIGIT(BX_DV_PROTO(c)) ) ++s;
  return s;
}

/* Decode base64 text into a byte buffer. */
static u8* fromBase64( char *pIn, int ncIn, u8 *pOut ){
  if( ncIn>0 && pIn[ncIn-1]=='\n' ) --ncIn;
  while( ncIn>0 && *pIn!=PAD_CHAR ){
    static signed char nboi[] = { 0, 0, 1, 2, 3 };
    char *pUse = skipNonB64(pIn, ncIn);
    unsigned long qv = 0L;
    int nti, nbo, nac;
    ncIn -= (pUse - pIn);
    pIn = pUse;
    nti = (ncIn>4)? 4 : ncIn;
    ncIn -= nti;
    nbo = nboi[nti];
    if( nbo==0 ) break;
    for( nac=0; nac<4; ++nac ){
      char c = (nac<nti)? *pIn++ : b64Numerals[0];
      u8 bdp = BX_DV_PROTO(c);
      switch( bdp ){
      case ND:
        /*  Treat dark non-digits as pad, but they terminate decode too. */
        ncIn = 0;
        deliberate_fall_through;
      case WS:
        /* Treat whitespace as pad and terminate this group.*/
        nti = nac;
        deliberate_fall_through;
      case PC:
        bdp = 0;
        --nbo;
        deliberate_fall_through;
      default: /* bdp is the digit value. */
        qv = qv<<6 | bdp;
        break;
      }
    }
    switch( nbo ){
    case 3:
      pOut[2] = (qv) & 0xff;
    case 2:
      pOut[1] = (qv>>8) & 0xff;
    case 1:
      pOut[0] = (qv>>16) & 0xff;
    }
    pOut += nbo;
  }
  return pOut;
}

/* This function does the work for the SQLite base64(x) UDF. */
static void base64(sqlite3_context *context, int na, sqlite3_value *av[]){
  int nb, nc, nv = sqlite3_value_bytes(av[0]);
  int nvMax = sqlite3_limit(sqlite3_context_db_handle(context),
                            SQLITE_LIMIT_LENGTH, -1);
  char *cBuf;
  u8 *bBuf;
  assert(na==1);
  switch( sqlite3_value_type(av[0]) ){
  case SQLITE_BLOB:
    nb = nv;
    nc = 4*(nv+2/3); /* quads needed */
    nc += (nc+(B64_DARK_MAX-1))/B64_DARK_MAX + 1; /* LFs and a 0-terminator */
    if( nvMax < nc ){
      sqlite3_result_error(context, "blob expanded to base64 too big", -1);
      return;
    }
    bBuf = (u8*)sqlite3_value_blob(av[0]);
    if( !bBuf ){
      if( SQLITE_NOMEM==sqlite3_errcode(sqlite3_context_db_handle(context)) ){
        goto memFail;
      }
      sqlite3_result_text(context,"",-1,SQLITE_STATIC);
      break;
    }
    cBuf = sqlite3_malloc(nc);
    if( !cBuf ) goto memFail;
    nc = (int)(toBase64(bBuf, nb, cBuf) - cBuf);
    sqlite3_result_text(context, cBuf, nc, sqlite3_free);
    break;
  case SQLITE_TEXT:
    nc = nv;
    nb = 3*((nv+3)/4); /* may overestimate due to LF and padding */
    if( nvMax < nb ){
      sqlite3_result_error(context, "blob from base64 may be too big", -1);
      return;
    }else if( nb<1 ){
      nb = 1;
    }
    cBuf = (char *)sqlite3_value_text(av[0]);
    if( !cBuf ){
      if( SQLITE_NOMEM==sqlite3_errcode(sqlite3_context_db_handle(context)) ){
        goto memFail;
      }
      sqlite3_result_zeroblob(context, 0);
      break;
    }
    bBuf = sqlite3_malloc(nb);
    if( !bBuf ) goto memFail;
    nb = (int)(fromBase64(cBuf, nc, bBuf) - bBuf);
    sqlite3_result_blob(context, bBuf, nb, sqlite3_free);
    break;
  default:
    sqlite3_result_error(context, "base64 accepts only blob or text", -1);
    return;
  }
  return;
 memFail:
  sqlite3_result_error(context, "base64 OOM", -1);
}

/*
** Establish linkage to running SQLite library.
*/
#ifndef SQLITE_SHELL_EXTFUNCS
#ifdef _WIN32

#endif
int sqlite3_base_init
#else
static int sqlite3_base64_init
#endif
(sqlite3 *db, char **pzErr, const sqlite3_api_routines *pApi){
  SQLITE_EXTENSION_INIT2(pApi);
  (void)pzErr;
  return sqlite3_create_function
    (db, "base64", 1,
     SQLITE_DETERMINISTIC|SQLITE_INNOCUOUS|SQLITE_DIRECTONLY|SQLITE_UTF8,
     0, base64, 0, 0);
}

/*
** Define some macros to allow this extension to be built into the shell
** conveniently, in conjunction with use of SQLITE_SHELL_EXTFUNCS. This
** allows shell.c, as distributed, to have this extension built in.
*/
#define BASE64_INIT(db) sqlite3_base64_init(db, 0, 0)
#define BASE64_EXPOSE(db, pzErr) /* Not needed, ..._init() does this. */

/************************* End ../ext/misc/base64.c ********************/
#undef sqlite3_base_init
#define sqlite3_base_init sqlite3_base85_init
#define OMIT_BASE85_CHECKER
/************************* Begin ../ext/misc/base85.c ******************/
/*
** 2022-11-16
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
**
** This is a utility for converting binary to base85 or vice-versa.
** It can be built as a standalone program or an SQLite3 extension.
**
** Much like base64 representations, base85 can be sent through a
** sane USASCII channel unmolested. It also plays nicely in CSV or
** written as TCL brace-enclosed literals or SQL string literals.
** It is not suited for unmodified use in XML-like documents.
**
** The encoding used resembles Ascii85, but was devised by the author
** (Larry Brasfield) before Mozilla, Adobe, ZMODEM or other Ascii85
** variant sources existed, in the 1984 timeframe on a VAX mainframe.
** Further, this is an independent implementation of a base85 system.
** Hence, the author has rightfully put this into the public domain.
**
** Base85 numerals are taken from the set of 7-bit USASCII codes,
** excluding control characters and Space ! " ' ( ) { | } ~ Del
** in code order representing digit values 0 to 84 (base 10.)
**
** Groups of 4 bytes, interpreted as big-endian 32-bit values,
** are represented as 5-digit base85 numbers with MS to LS digit
** order. Groups of 1-3 bytes are represented with 2-4 digits,
** still big-endian but 8-24 bit values. (Using big-endian yields
** the simplest transition to byte groups smaller than 4 bytes.
** These byte groups can also be considered base-256 numbers.)
** Groups of 0 bytes are represented with 0 digits and vice-versa.
** No pad characters are used; Encoded base85 numeral sequence
** (aka "group") length maps 1-to-1 to the decoded binary length.
**
** Any character not in the base85 numeral set delimits groups.
** When base85 is streamed or stored in containers of indefinite
** size, newline is used to separate it into sub-sequences of no
** more than 80 digits so that fgets() can be used to read it.
**
** Length limitations are not imposed except that the runtime
** SQLite string or blob length limits are respected. Otherwise,
** any length binary sequence can be represented and recovered.
** Base85 sequences can be concatenated by separating them with
** a non-base85 character; the conversion to binary will then
** be the concatenation of the represented binary sequences.

** The standalone program either converts base85 on stdin to create
** a binary file or converts a binary file to base85 on stdout.
** Read or make it blurt its help for invocation details.
**
** The SQLite3 extension creates a function, base85(x), which will
** either convert text base85 to a blob or a blob to text base85
** and return the result (or throw an error for other types.)
** Unless built with OMIT_BASE85_CHECKER defined, it also creates a
** function, is_base85(t), which returns 1 iff the text t contains
** nothing other than base85 numerals and whitespace, or 0 otherwise.
**
** To build the extension:
** Set shell variable SQDIR=<your favorite SQLite checkout directory>
** and variable OPTS to -DOMIT_BASE85_CHECKER if is_base85() unwanted.
** *Nix: gcc -O2 -shared -I$SQDIR $OPTS -fPIC -o base85.so base85.c
** OSX: gcc -O2 -dynamiclib -fPIC -I$SQDIR $OPTS -o base85.dylib base85.c
** Win32: gcc -O2 -shared -I%SQDIR% %OPTS% -o base85.dll base85.c
** Win32: cl /Os -I%SQDIR% %OPTS% base85.c -link -dll -out:base85.dll
**
** To build the standalone program, define PP symbol BASE85_STANDALONE. Eg.
** *Nix or OSX: gcc -O2 -DBASE85_STANDALONE base85.c -o base85
** Win32: gcc -O2 -DBASE85_STANDALONE -o base85.exe base85.c
** Win32: cl /Os /MD -DBASE85_STANDALONE base85.c
*/

#include <stdio.h>
#include <memory.h>
#include <string.h>
#include <assert.h>
#ifndef OMIT_BASE85_CHECKER
# include <ctype.h>
#endif

#ifndef BASE85_STANDALONE

/* # include "sqlite3ext.h" */

SQLITE_EXTENSION_INIT1;

#else

# ifdef _WIN32
#  include <io.h>
#  include <fcntl.h>
# else
#  define setmode(fd,m)
# endif

static char *zHelp =
  "Usage: base85 <dirFlag> <binFile>\n"
  " <dirFlag> is either -r to read or -w to write <binFile>,\n"
  "   content to be converted to/from base85 on stdout/stdin.\n"
  " <binFile> names a binary file to be rendered or created.\n"
  "   Or, the name '-' refers to the stdin or stdout stream.\n"
  ;

static void sayHelp(){
  printf("%s", zHelp);
}
#endif

#ifndef U8_TYPEDEF
/* typedef unsigned char u8; */
#define U8_TYPEDEF
#endif

/* Classify c according to interval within USASCII set w.r.t. base85
 * Values of 1 and 3 are base85 numerals. Values of 0, 2, or 4 are not.
 */
#define B85_CLASS( c ) (((c)>='#')+((c)>'&')+((c)>='*')+((c)>'z'))

/* Provide digitValue to b85Numeral offset as a function of above class. */
static u8 b85_cOffset[] = { 0, '#', 0, '*'-4, 0 };
#define B85_DNOS( c ) b85_cOffset[B85_CLASS(c)]

/* Say whether c is a base85 numeral. */
#define IS_B85( c ) (B85_CLASS(c) & 1)

#if 0 /* Not used, */
static u8 base85DigitValue( char c ){
  u8 dv = (u8)(c - '#');
  if( dv>87 ) return 0xff;
  return (dv > 3)? dv-3 : dv;
}
#endif

/* Width of base64 lines. Should be an integer multiple of 5. */
#define B85_DARK_MAX 80


static char * skipNonB85( char *s, int nc ){
  char c;
  while( nc-- > 0 && (c = *s) && !IS_B85(c) ) ++s;
  return s;
}

/* Convert small integer, known to be in 0..84 inclusive, to base85 numeral.
 * Do not use the macro form with argument expression having a side-effect.*/
#if 0
static char base85Numeral( u8 b ){
  return (b < 4)? (char)(b + '#') : (char)(b - 4 + '*');
}
#else
# define base85Numeral( dn )\
  ((char)(((dn) < 4)? (char)((dn) + '#') : (char)((dn) - 4 + '*')))
#endif

static char *putcs(char *pc, char *s){
  char c;
  while( (c = *s++)!=0 ) *pc++ = c;
  return pc;
}

/* Encode a byte buffer into base85 text. If pSep!=0, it's a C string
** to be appended to encoded groups to limit their length to B85_DARK_MAX
** or to terminate the last group (to aid concatenation.)
*/
static char* toBase85( u8 *pIn, int nbIn, char *pOut, char *pSep ){
  int nCol = 0;
  while( nbIn >= 4 ){
    int nco = 5;
    unsigned long qbv = (((unsigned long)pIn[0])<<24) |
                        (pIn[1]<<16) | (pIn[2]<<8) | pIn[3];
    while( nco > 0 ){
      unsigned nqv = (unsigned)(qbv/85UL);
      unsigned char dv = qbv - 85UL*nqv;
      qbv = nqv;
      pOut[--nco] = base85Numeral(dv);
    }
    nbIn -= 4;
    pIn += 4;
    pOut += 5;
    if( pSep && (nCol += 5)>=B85_DARK_MAX ){
      pOut = putcs(pOut, pSep);
      nCol = 0;
    }
  }
  if( nbIn > 0 ){
    int nco = nbIn + 1;
    unsigned long qv = *pIn++;
    int nbe = 1;
    while( nbe++ < nbIn ){
      qv = (qv<<8) | *pIn++;
    }
    nCol += nco;
    while( nco > 0 ){
      u8 dv = (u8)(qv % 85);
      qv /= 85;
      pOut[--nco] = base85Numeral(dv);
    }
    pOut += (nbIn+1);
  }
  if( pSep && nCol>0 ) pOut = putcs(pOut, pSep);
  *pOut = 0;
  return pOut;
}

/* Decode base85 text into a byte buffer. */
static u8* fromBase85( char *pIn, int ncIn, u8 *pOut ){
  if( ncIn>0 && pIn[ncIn-1]=='\n' ) --ncIn;
  while( ncIn>0 ){
    static signed char nboi[] = { 0, 0, 1, 2, 3, 4 };
    char *pUse = skipNonB85(pIn, ncIn);
    unsigned long qv = 0L;
    int nti, nbo;
    ncIn -= (pUse - pIn);
    pIn = pUse;
    nti = (ncIn>5)? 5 : ncIn;
    nbo = nboi[nti];
    if( nbo==0 ) break;
    while( nti>0 ){
      char c = *pIn++;
      u8 cdo = B85_DNOS(c);
      --ncIn;
      if( cdo==0 ) break;
      qv = 85 * qv + (c - cdo);
      --nti;
    }
    nbo -= nti; /* Adjust for early (non-digit) end of group. */
    switch( nbo ){
    case 4:
      *pOut++ = (qv >> 24)&0xff;
    case 3:
      *pOut++ = (qv >> 16)&0xff;
    case 2:
      *pOut++ = (qv >> 8)&0xff;
    case 1:
      *pOut++ = qv&0xff;
    case 0:
      break;
    }
  }
  return pOut;
}

#ifndef OMIT_BASE85_CHECKER
/* Say whether input char sequence is all (base85 and/or whitespace).*/
static int allBase85( char *p, int len ){
  char c;
  while( len-- > 0 && (c = *p++) != 0 ){
    if( !IS_B85(c) && !isspace(c) ) return 0;
  }
  return 1;
}
#endif

#ifndef BASE85_STANDALONE

# ifndef OMIT_BASE85_CHECKER
/* This function does the work for the SQLite is_base85(t) UDF. */
static void is_base85(sqlite3_context *context, int na, sqlite3_value *av[]){
  assert(na==1);
  switch( sqlite3_value_type(av[0]) ){
  case SQLITE_TEXT:
    {
      int rv = allBase85( (char *)sqlite3_value_text(av[0]),
                          sqlite3_value_bytes(av[0]) );
      sqlite3_result_int(context, rv);
    }
    break;
  case SQLITE_NULL:
    sqlite3_result_null(context);
    break;
  default:
    sqlite3_result_error(context, "is_base85 accepts only text or NULL", -1);
    return;
  }
}
# endif

/* This function does the work for the SQLite base85(x) UDF. */
static void base85(sqlite3_context *context, int na, sqlite3_value *av[]){
  int nb, nc, nv = sqlite3_value_bytes(av[0]);
  int nvMax = sqlite3_limit(sqlite3_context_db_handle(context),
                            SQLITE_LIMIT_LENGTH, -1);
  char *cBuf;
  u8 *bBuf;
  assert(na==1);
  switch( sqlite3_value_type(av[0]) ){
  case SQLITE_BLOB:
    nb = nv;
    /*    ulongs    tail   newlines  tailenc+nul*/
    nc = 5*(nv/4) + nv%4 + nv/64+1 + 2;
    if( nvMax < nc ){
      sqlite3_result_error(context, "blob expanded to base85 too big", -1);
      return;
    }
    bBuf = (u8*)sqlite3_value_blob(av[0]);
    if( !bBuf ){
      if( SQLITE_NOMEM==sqlite3_errcode(sqlite3_context_db_handle(context)) ){
        goto memFail;
      }
      sqlite3_result_text(context,"",-1,SQLITE_STATIC);
      break;
    }
    cBuf = sqlite3_malloc(nc);
    if( !cBuf ) goto memFail;
    nc = (int)(toBase85(bBuf, nb, cBuf, "\n") - cBuf);
    sqlite3_result_text(context, cBuf, nc, sqlite3_free);
    break;
  case SQLITE_TEXT:
    nc = nv;
    nb = 4*(nv/5) + nv%5; /* may overestimate */
    if( nvMax < nb ){
      sqlite3_result_error(context, "blob from base85 may be too big", -1);
      return;
    }else if( nb<1 ){
      nb = 1;
    }
    cBuf = (char *)sqlite3_value_text(av[0]);
    if( !cBuf ){
      if( SQLITE_NOMEM==sqlite3_errcode(sqlite3_context_db_handle(context)) ){
        goto memFail;
      }
      sqlite3_result_zeroblob(context, 0);
      break;
    }
    bBuf = sqlite3_malloc(nb);
    if( !bBuf ) goto memFail;
    nb = (int)(fromBase85(cBuf, nc, bBuf) - bBuf);
    sqlite3_result_blob(context, bBuf, nb, sqlite3_free);
    break;
  default:
    sqlite3_result_error(context, "base85 accepts only blob or text.", -1);
    return;
  }
  return;
 memFail:
  sqlite3_result_error(context, "base85 OOM", -1);
}

/*
** Establish linkage to running SQLite library.
*/
#ifndef SQLITE_SHELL_EXTFUNCS
#ifdef _WIN32

#endif
int sqlite3_base_init
#else
static int sqlite3_base85_init
#endif
(sqlite3 *db, char **pzErr, const sqlite3_api_routines *pApi){
  SQLITE_EXTENSION_INIT2(pApi);
  (void)pzErr;
# ifndef OMIT_BASE85_CHECKER
  {
    int rc = sqlite3_create_function
      (db, "is_base85", 1,
       SQLITE_DETERMINISTIC|SQLITE_INNOCUOUS|SQLITE_UTF8,
       0, is_base85, 0, 0);
    if( rc!=SQLITE_OK ) return rc;
  }
# endif
  return sqlite3_create_function
    (db, "base85", 1,
     SQLITE_DETERMINISTIC|SQLITE_INNOCUOUS|SQLITE_DIRECTONLY|SQLITE_UTF8,
     0, base85, 0, 0);
}

/*
** Define some macros to allow this extension to be built into the shell
** conveniently, in conjunction with use of SQLITE_SHELL_EXTFUNCS. This
** allows shell.c, as distributed, to have this extension built in.
*/
# define BASE85_INIT(db) sqlite3_base85_init(db, 0, 0)
# define BASE85_EXPOSE(db, pzErr) /* Not needed, ..._init() does this. */

#else /* standalone program */

int main(int na, char *av[]){
  int cin;
  int rc = 0;
  u8 bBuf[4*(B85_DARK_MAX/5)];
  char cBuf[5*(sizeof(bBuf)/4)+2];
  size_t nio;
# ifndef OMIT_BASE85_CHECKER
  int b85Clean = 1;
# endif
  char rw;
  FILE *fb = 0, *foc = 0;
  char fmode[3] = "xb";
  if( na < 3 || av[1][0]!='-' || (rw = av[1][1])==0 || (rw!='r' && rw!='w') ){
    sayHelp();
    return 0;
  }
  fmode[0] = rw;
  if( av[2][0]=='-' && av[2][1]==0 ){
    switch( rw ){
    case 'r':
      fb = stdin;
      setmode(fileno(stdin), O_BINARY);
      break;
    case 'w':
      fb = stdout;
      setmode(fileno(stdout), O_BINARY);
      break;
    }
  }else{
    fb = fopen(av[2], fmode);
    foc = fb;
  }
  if( !fb ){
    fprintf(stderr, "Cannot open %s for %c\n", av[2], rw);
    rc = 1;
  }else{
    switch( rw ){
    case 'r':
      while( (nio = fread( bBuf, 1, sizeof(bBuf), fb))>0 ){
        toBase85( bBuf, (int)nio, cBuf, 0 );
        fprintf(stdout, "%s\n", cBuf);
      }
      break;
    case 'w':
      while( 0 != fgets(cBuf, sizeof(cBuf), stdin) ){
        int nc = strlen(cBuf);
        size_t nbo = fromBase85( cBuf, nc, bBuf ) - bBuf;
        if( 1 != fwrite(bBuf, nbo, 1, fb) ) rc = 1;
# ifndef OMIT_BASE85_CHECKER
        b85Clean &= allBase85( cBuf, nc );
# endif
      }
      break;
    default:
      sayHelp();
      rc = 1;
    }
    if( foc ) fclose(foc);
  }
# ifndef OMIT_BASE85_CHECKER
  if( !b85Clean ){
    fprintf(stderr, "Base85 input had non-base85 dark or control content.\n");
  }
# endif
  return rc;
}

#endif

/************************* End ../ext/misc/base85.c ********************/
/************************* Begin ../ext/misc/ieee754.c ******************/
/*
** 2013-04-17
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
******************************************************************************
**
** This SQLite extension implements functions for the exact display
** and input of IEEE754 Binary64 floating-point numbers.
**
**   ieee754(X)
**   ieee754(Y,Z)
**
** In the first form, the value X should be a floating-point number.
** The function will return a string of the form 'ieee754(Y,Z)' where
** Y and Z are integers such that X==Y*pow(2,Z).
**
** In the second form, Y and Z are integers which are the mantissa and
** base-2 exponent of a new floating point number.  The function returns
** a floating-point value equal to Y*pow(2,Z).
**
** Examples:
**
**     ieee754(2.0)             ->     'ieee754(2,0)'
**     ieee754(45.25)           ->     'ieee754(181,-2)'
**     ieee754(2, 0)            ->     2.0
**     ieee754(181, -2)         ->     45.25
**
** Two additional functions break apart the one-argument ieee754()
** result into separate integer values:
**
**     ieee754_mantissa(45.25)  ->     181
**     ieee754_exponent(45.25)  ->     -2
**
** These functions convert binary64 numbers into blobs and back again.
**
**     ieee754_from_blob(x'3ff0000000000000')  ->  1.0
**     ieee754_to_blob(1.0)                    ->  x'3ff0000000000000'
**
** In all single-argument functions, if the argument is an 8-byte blob
** then that blob is interpreted as a big-endian binary64 value.
**
**
** EXACT DECIMAL REPRESENTATION OF BINARY64 VALUES
** -----------------------------------------------
**
** This extension in combination with the separate 'decimal' extension
** can be used to compute the exact decimal representation of binary64
** values.  To begin, first compute a table of exponent values:
**
**    CREATE TABLE pow2(x INTEGER PRIMARY KEY, v TEXT);
**    WITH RECURSIVE c(x,v) AS (
**      VALUES(0,'1')
**      UNION ALL
**      SELECT x+1, decimal_mul(v,'2') FROM c WHERE x+1<=971
**    ) INSERT INTO pow2(x,v) SELECT x, v FROM c;
**    WITH RECURSIVE c(x,v) AS (
**      VALUES(-1,'0.5')
**      UNION ALL
**      SELECT x-1, decimal_mul(v,'0.5') FROM c WHERE x-1>=-1075
**    ) INSERT INTO pow2(x,v) SELECT x, v FROM c;
**
** Then, to compute the exact decimal representation of a floating
** point value (the value 47.49 is used in the example) do:
**
**    WITH c(n) AS (VALUES(47.49))
**          ---------------^^^^^---- Replace with whatever you want
**    SELECT decimal_mul(ieee754_mantissa(c.n),pow2.v)
**      FROM pow2, c WHERE pow2.x=ieee754_exponent(c.n);
**
** Here is a query to show various boundry values for the binary64
** number format:
**
**    WITH c(name,bin) AS (VALUES
**       ('minimum positive value',        x'0000000000000001'),
**       ('maximum subnormal value',       x'000fffffffffffff'),
**       ('mininum positive nornal value', x'0010000000000000'),
**       ('maximum value',                 x'7fefffffffffffff'))
**    SELECT c.name, decimal_mul(ieee754_mantissa(c.bin),pow2.v)
**      FROM pow2, c WHERE pow2.x=ieee754_exponent(c.bin);
**
*/
/* #include "sqlite3ext.h" */
SQLITE_EXTENSION_INIT1
#include <assert.h>
#include <string.h>

/* Mark a function parameter as unused, to suppress nuisance compiler
** warnings. */
#ifndef UNUSED_PARAMETER
# define UNUSED_PARAMETER(X)  (void)(X)
#endif

/*
** Implementation of the ieee754() function
*/
static void ieee754func(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  if( argc==1 ){
    sqlite3_int64 m, a;
    double r;
    int e;
    int isNeg;
    char zResult[100];
    assert( sizeof(m)==sizeof(r) );
    if( sqlite3_value_type(argv[0])==SQLITE_BLOB
     && sqlite3_value_bytes(argv[0])==sizeof(r)
    ){
      const unsigned char *x = sqlite3_value_blob(argv[0]);
      unsigned int i;
      sqlite3_uint64 v = 0;
      for(i=0; i<sizeof(r); i++){
        v = (v<<8) | x[i];
      }
      memcpy(&r, &v, sizeof(r));
    }else{
      r = sqlite3_value_double(argv[0]);
    }
    if( r<0.0 ){
      isNeg = 1;
      r = -r;
    }else{
      isNeg = 0;
    }
    memcpy(&a,&r,sizeof(a));
    if( a==0 ){
      e = 0;
      m = 0;
    }else{
      e = a>>52;
      m = a & ((((sqlite3_int64)1)<<52)-1);
      if( e==0 ){
        m <<= 1;
      }else{
        m |= ((sqlite3_int64)1)<<52;
      }
      while( e<1075 && m>0 && (m&1)==0 ){
        m >>= 1;
        e++;
      }
      if( isNeg ) m = -m;
    }
    switch( *(int*)sqlite3_user_data(context) ){
      case 0:
        sqlite3_snprintf(sizeof(zResult), zResult, "ieee754(%lld,%d)",
                         m, e-1075);
        sqlite3_result_text(context, zResult, -1, SQLITE_TRANSIENT);
        break;
      case 1:
        sqlite3_result_int64(context, m);
        break;
      case 2:
        sqlite3_result_int(context, e-1075);
        break;
    }
  }else{
    sqlite3_int64 m, e, a;
    double r;
    int isNeg = 0;
    m = sqlite3_value_int64(argv[0]);
    e = sqlite3_value_int64(argv[1]);

    /* Limit the range of e.  Ticket 22dea1cfdb9151e4 2021-03-02 */
    if( e>10000 ){
      e = 10000;
    }else if( e<-10000 ){
      e = -10000;
    }

    if( m<0 ){
      isNeg = 1;
      m = -m;
      if( m<0 ) return;
    }else if( m==0 && e>-1000 && e<1000 ){
      sqlite3_result_double(context, 0.0);
      return;
    }
    while( (m>>32)&0xffe00000 ){
      m >>= 1;
      e++;
    }
    while( m!=0 && ((m>>32)&0xfff00000)==0 ){
      m <<= 1;
      e--;
    }
    e += 1075;
    if( e<=0 ){
      /* Subnormal */
      if( 1-e >= 64 ){
        m = 0;
      }else{
        m >>= 1-e;
      }
      e = 0;
    }else if( e>0x7ff ){
      e = 0x7ff;
    }
    a = m & ((((sqlite3_int64)1)<<52)-1);
    a |= e<<52;
    if( isNeg ) a |= ((sqlite3_uint64)1)<<63;
    memcpy(&r, &a, sizeof(r));
    sqlite3_result_double(context, r);
  }
}

/*
** Functions to convert between blobs and floats.
*/
static void ieee754func_from_blob(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  UNUSED_PARAMETER(argc);
  if( sqlite3_value_type(argv[0])==SQLITE_BLOB
   && sqlite3_value_bytes(argv[0])==sizeof(double)
  ){
    double r;
    const unsigned char *x = sqlite3_value_blob(argv[0]);
    unsigned int i;
    sqlite3_uint64 v = 0;
    for(i=0; i<sizeof(r); i++){
      v = (v<<8) | x[i];
    }
    memcpy(&r, &v, sizeof(r));
    sqlite3_result_double(context, r);
  }
}
static void ieee754func_to_blob(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  UNUSED_PARAMETER(argc);
  if( sqlite3_value_type(argv[0])==SQLITE_FLOAT
   || sqlite3_value_type(argv[0])==SQLITE_INTEGER
  ){
    double r = sqlite3_value_double(argv[0]);
    sqlite3_uint64 v;
    unsigned char a[sizeof(r)];
    unsigned int i;
    memcpy(&v, &r, sizeof(r));
    for(i=1; i<=sizeof(r); i++){
      a[sizeof(r)-i] = v&0xff;
      v >>= 8;
    }
    sqlite3_result_blob(context, a, sizeof(r), SQLITE_TRANSIENT);
  }
}

/*
** SQL Function:   ieee754_inc(r,N)
**
** Move the floating point value r by N quantums and return the new
** values.
**
** Behind the scenes: this routine merely casts r into a 64-bit unsigned
** integer, adds N, then casts the value back into float.
**
** Example:  To find the smallest positive number:
**
**     SELECT ieee754_inc(0.0,+1);
*/
static void ieee754inc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  double r;
  sqlite3_int64 N;
  sqlite3_uint64 m1, m2;
  double r2;
  UNUSED_PARAMETER(argc);
  r = sqlite3_value_double(argv[0]);
  N = sqlite3_value_int64(argv[1]);
  memcpy(&m1, &r, 8);
  m2 = m1 + N;
  memcpy(&r2, &m2, 8);
  sqlite3_result_double(context, r2);
}


#ifdef _WIN32

#endif
int sqlite3_ieee_init(
  sqlite3 *db, 
  char **pzErrMsg, 
  const sqlite3_api_routines *pApi
){
  static const struct {
    char *zFName;
    int nArg;
    int iAux;
    void (*xFunc)(sqlite3_context*,int,sqlite3_value**);
  } aFunc[] = {
    { "ieee754",           1,   0, ieee754func },
    { "ieee754",           2,   0, ieee754func },
    { "ieee754_mantissa",  1,   1, ieee754func },
    { "ieee754_exponent",  1,   2, ieee754func },
    { "ieee754_to_blob",   1,   0, ieee754func_to_blob },
    { "ieee754_from_blob", 1,   0, ieee754func_from_blob },
    { "ieee754_inc",       2,   0, ieee754inc  },
  };
  unsigned int i;
  int rc = SQLITE_OK;
  SQLITE_EXTENSION_INIT2(pApi);
  (void)pzErrMsg;  /* Unused parameter */
  for(i=0; i<sizeof(aFunc)/sizeof(aFunc[0]) && rc==SQLITE_OK; i++){
    rc = sqlite3_create_function(db, aFunc[i].zFName, aFunc[i].nArg,
                               SQLITE_UTF8|SQLITE_INNOCUOUS,
                               (void*)&aFunc[i].iAux,
                               aFunc[i].xFunc, 0, 0);
  }
  return rc;
}

/************************* End ../ext/misc/ieee754.c ********************/
/************************* Begin ../ext/misc/series.c ******************/
/*
** 2015-08-18, 2023-04-28
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
**
** This file demonstrates how to create a table-valued-function using
** a virtual table.  This demo implements the generate_series() function
** which gives the same results as the eponymous function in PostgreSQL,
** within the limitation that its arguments are signed 64-bit integers.
**
** Considering its equivalents to generate_series(start,stop,step): A
** value V[n] sequence is produced for integer n ascending from 0 where
**  ( V[n] == start + n * step  &&  sgn(V[n] - stop) * sgn(step) >= 0 )
** for each produced value (independent of production time ordering.)
**
** All parameters must be either integer or convertable to integer.
** The start parameter is required.
** The stop parameter defaults to (1<<32)-1 (aka 4294967295 or 0xffffffff)
** The step parameter defaults to 1 and 0 is treated as 1.
**
** Examples:
**
**      SELECT * FROM generate_series(0,100,5);
**
** The query above returns integers from 0 through 100 counting by steps
** of 5.
**
**      SELECT * FROM generate_series(0,100);
**
** Integers from 0 through 100 with a step size of 1.
**
**      SELECT * FROM generate_series(20) LIMIT 10;
**
** Integers 20 through 29.
**
**      SELECT * FROM generate_series(0,-100,-5);
**
** Integers 0 -5 -10 ... -100.
**
**      SELECT * FROM generate_series(0,-1);
**
** Empty sequence.
**
** HOW IT WORKS
**
** The generate_series "function" is really a virtual table with the
** following schema:
**
**     CREATE TABLE generate_series(
**       value,
**       start HIDDEN,
**       stop HIDDEN,
**       step HIDDEN
**     );
**
** The virtual table also has a rowid, logically equivalent to n+1 where
** "n" is the ascending integer in the aforesaid production definition.
**
** Function arguments in queries against this virtual table are translated
** into equality constraints against successive hidden columns.  In other
** words, the following pairs of queries are equivalent to each other:
**
**    SELECT * FROM generate_series(0,100,5);
**    SELECT * FROM generate_series WHERE start=0 AND stop=100 AND step=5;
**
**    SELECT * FROM generate_series(0,100);
**    SELECT * FROM generate_series WHERE start=0 AND stop=100;
**
**    SELECT * FROM generate_series(20) LIMIT 10;
**    SELECT * FROM generate_series WHERE start=20 LIMIT 10;
**
** The generate_series virtual table implementation leaves the xCreate method
** set to NULL.  This means that it is not possible to do a CREATE VIRTUAL
** TABLE command with "generate_series" as the USING argument.  Instead, there
** is a single generate_series virtual table that is always available without
** having to be created first.
**
** The xBestIndex method looks for equality constraints against the hidden
** start, stop, and step columns, and if present, it uses those constraints
** to bound the sequence of generated values.  If the equality constraints
** are missing, it uses 0 for start, 4294967295 for stop, and 1 for step.
** xBestIndex returns a small cost when both start and stop are available,
** and a very large cost if either start or stop are unavailable.  This
** encourages the query planner to order joins such that the bounds of the
** series are well-defined.
**
** Update on 2024-08-22:
** xBestIndex now also looks for equality and inequality constraints against
** the value column and uses those constraints as additional bounds against
** the sequence range.  Thus, a query like this:
**
**     SELECT value FROM generate_series($SA,$EA)
**      WHERE value BETWEEN $SB AND $EB;
**
** Is logically the same as:
**
**     SELECT value FROM generate_series(max($SA,$SB),min($EA,$EB));
**
** Constraints on the value column can server as substitutes for constraints
** on the hidden start and stop columns.  So, the following two queries
** are equivalent:
**
**     SELECT value FROM generate_series($S,$E);
**     SELECT value FROM generate_series WHERE value BETWEEN $S and $E;
**
*/
/* #include "sqlite3ext.h" */
SQLITE_EXTENSION_INIT1
#include <assert.h>
#include <string.h>
#include <limits.h>

#ifndef SQLITE_OMIT_VIRTUALTABLE
/*
** Return that member of a generate_series(...) sequence whose 0-based
** index is ix. The 0th member is given by smBase. The sequence members
** progress per ix increment by smStep.
*/
static sqlite3_int64 genSeqMember(
  sqlite3_int64 smBase,
  sqlite3_int64 smStep,
  sqlite3_uint64 ix
){
  static const sqlite3_uint64 mxI64 =
      ((sqlite3_uint64)0x7fffffff)<<32 | 0xffffffff;
  if( ix>=mxI64 ){
    /* Get ix into signed i64 range. */
    ix -= mxI64;
    /* With 2's complement ALU, this next can be 1 step, but is split into
     * 2 for UBSAN's satisfaction (and hypothetical 1's complement ALUs.) */
    smBase += (mxI64/2) * smStep;
    smBase += (mxI64 - mxI64/2) * smStep;
  }
  /* Under UBSAN (or on 1's complement machines), must do this last term
   * in steps to avoid the dreaded (and harmless) signed multiply overlow. */
  if( ix>=2 ){
    sqlite3_int64 ix2 = (sqlite3_int64)ix/2;
    smBase += ix2*smStep;
    ix -= ix2;
  }
  return smBase + ((sqlite3_int64)ix)*smStep;
}

/* typedef unsigned char u8; */

typedef struct SequenceSpec {
  sqlite3_int64 iOBase;        /* Original starting value ("start") */
  sqlite3_int64 iOTerm;        /* Original terminal value ("stop") */
  sqlite3_int64 iBase;         /* Starting value to actually use */
  sqlite3_int64 iTerm;         /* Terminal value to actually use */
  sqlite3_int64 iStep;         /* Increment ("step") */
  sqlite3_uint64 uSeqIndexMax; /* maximum sequence index (aka "n") */
  sqlite3_uint64 uSeqIndexNow; /* Current index during generation */
  sqlite3_int64 iValueNow;     /* Current value during generation */
  u8 isNotEOF;                 /* Sequence generation not exhausted */
  u8 isReversing;              /* Sequence is being reverse generated */
} SequenceSpec;

/*
** Prepare a SequenceSpec for use in generating an integer series
** given initialized iBase, iTerm and iStep values. Sequence is
** initialized per given isReversing. Other members are computed.
*/
static void setupSequence( SequenceSpec *pss ){
  int bSameSigns;
  pss->uSeqIndexMax = 0;
  pss->isNotEOF = 0;
  bSameSigns = (pss->iBase < 0)==(pss->iTerm < 0);
  if( pss->iTerm < pss->iBase ){
    sqlite3_uint64 nuspan = 0;
    if( bSameSigns ){
      nuspan = (sqlite3_uint64)(pss->iBase - pss->iTerm);
    }else{
      /* Under UBSAN (or on 1's complement machines), must do this in steps.
       * In this clause, iBase>=0 and iTerm<0 . */
      nuspan = 1;
      nuspan += pss->iBase;
      nuspan += -(pss->iTerm+1);
    }
    if( pss->iStep<0 ){
      pss->isNotEOF = 1;
      if( nuspan==ULONG_MAX ){
        pss->uSeqIndexMax = ( pss->iStep>LLONG_MIN )? nuspan/-pss->iStep : 1;
      }else if( pss->iStep>LLONG_MIN ){
        pss->uSeqIndexMax = nuspan/-pss->iStep;
      }
    }
  }else if( pss->iTerm > pss->iBase ){
    sqlite3_uint64 puspan = 0;
    if( bSameSigns ){
      puspan = (sqlite3_uint64)(pss->iTerm - pss->iBase);
    }else{
      /* Under UBSAN (or on 1's complement machines), must do this in steps.
       * In this clause, iTerm>=0 and iBase<0 . */
      puspan = 1;
      puspan += pss->iTerm;
      puspan += -(pss->iBase+1);
    }
    if( pss->iStep>0 ){
      pss->isNotEOF = 1;
      pss->uSeqIndexMax = puspan/pss->iStep;
    }
  }else if( pss->iTerm == pss->iBase ){
      pss->isNotEOF = 1;
      pss->uSeqIndexMax = 0;
  }
  pss->uSeqIndexNow = (pss->isReversing)? pss->uSeqIndexMax : 0;
  pss->iValueNow = (pss->isReversing)
    ? genSeqMember(pss->iBase, pss->iStep, pss->uSeqIndexMax)
    : pss->iBase;
}

/*
** Progress sequence generator to yield next value, if any.
** Leave its state to either yield next value or be at EOF.
** Return whether there is a next value, or 0 at EOF.
*/
static int progressSequence( SequenceSpec *pss ){
  if( !pss->isNotEOF ) return 0;
  if( pss->isReversing ){
    if( pss->uSeqIndexNow > 0 ){
      pss->uSeqIndexNow--;
      pss->iValueNow -= pss->iStep;
    }else{
      pss->isNotEOF = 0;
    }
  }else{
    if( pss->uSeqIndexNow < pss->uSeqIndexMax ){
      pss->uSeqIndexNow++;
      pss->iValueNow += pss->iStep;
    }else{
      pss->isNotEOF = 0;
    }
  }
  return pss->isNotEOF;
}

/* series_cursor is a subclass of sqlite3_vtab_cursor which will
** serve as the underlying representation of a cursor that scans
** over rows of the result
*/
typedef struct series_cursor series_cursor;
struct series_cursor {
  sqlite3_vtab_cursor base;  /* Base class - must be first */
  SequenceSpec ss;           /* (this) Derived class data */
};

/*
** The seriesConnect() method is invoked to create a new
** series_vtab that describes the generate_series virtual table.
**
** Think of this routine as the constructor for series_vtab objects.
**
** All this routine needs to do is:
**
**    (1) Allocate the series_vtab object and initialize all fields.
**
**    (2) Tell SQLite (via the sqlite3_declare_vtab() interface) what the
**        result set of queries against generate_series will look like.
*/
static int seriesConnect(
  sqlite3 *db,
  void *pUnused,
  int argcUnused, const char *const*argvUnused,
  sqlite3_vtab **ppVtab,
  char **pzErrUnused
){
  sqlite3_vtab *pNew;
  int rc;

/* Column numbers */
#define SERIES_COLUMN_VALUE 0
#define SERIES_COLUMN_START 1
#define SERIES_COLUMN_STOP  2
#define SERIES_COLUMN_STEP  3

  (void)pUnused;
  (void)argcUnused;
  (void)argvUnused;
  (void)pzErrUnused;
  rc = sqlite3_declare_vtab(db,
     "CREATE TABLE x(value,start hidden,stop hidden,step hidden)");
  if( rc==SQLITE_OK ){
    pNew = *ppVtab = sqlite3_malloc( sizeof(*pNew) );
    if( pNew==0 ) return SQLITE_NOMEM;
    memset(pNew, 0, sizeof(*pNew));
    sqlite3_vtab_config(db, SQLITE_VTAB_INNOCUOUS);
  }
  return rc;
}

/*
** This method is the destructor for series_cursor objects.
*/
static int seriesDisconnect(sqlite3_vtab *pVtab){
  sqlite3_free(pVtab);
  return SQLITE_OK;
}

/*
** Constructor for a new series_cursor object.
*/
static int seriesOpen(sqlite3_vtab *pUnused, sqlite3_vtab_cursor **ppCursor){
  series_cursor *pCur;
  (void)pUnused;
  pCur = sqlite3_malloc( sizeof(*pCur) );
  if( pCur==0 ) return SQLITE_NOMEM;
  memset(pCur, 0, sizeof(*pCur));
  *ppCursor = &pCur->base;
  return SQLITE_OK;
}

/*
** Destructor for a series_cursor.
*/
static int seriesClose(sqlite3_vtab_cursor *cur){
  sqlite3_free(cur);
  return SQLITE_OK;
}


/*
** Advance a series_cursor to its next row of output.
*/
static int seriesNext(sqlite3_vtab_cursor *cur){
  series_cursor *pCur = (series_cursor*)cur;
  progressSequence( & pCur->ss );
  return SQLITE_OK;
}

/*
** Return values of columns for the row at which the series_cursor
** is currently pointing.
*/
static int seriesColumn(
  sqlite3_vtab_cursor *cur,   /* The cursor */
  sqlite3_context *ctx,       /* First argument to sqlite3_result_...() */
  int i                       /* Which column to return */
){
  series_cursor *pCur = (series_cursor*)cur;
  sqlite3_int64 x = 0;
  switch( i ){
    case SERIES_COLUMN_START:  x = pCur->ss.iOBase;     break;
    case SERIES_COLUMN_STOP:   x = pCur->ss.iOTerm;     break;
    case SERIES_COLUMN_STEP:   x = pCur->ss.iStep;      break;
    default:                   x = pCur->ss.iValueNow;  break;
  }
  sqlite3_result_int64(ctx, x);
  return SQLITE_OK;
}

#ifndef LARGEST_UINT64
#define LARGEST_INT64  (0xffffffff|(((sqlite3_int64)0x7fffffff)<<32))
#define LARGEST_UINT64 (0xffffffff|(((sqlite3_uint64)0xffffffff)<<32))
#define SMALLEST_INT64 (((sqlite3_int64)-1) - LARGEST_INT64)
#endif

/*
** Return the rowid for the current row, logically equivalent to n+1 where
** "n" is the ascending integer in the aforesaid production definition.
*/
static int seriesRowid(sqlite3_vtab_cursor *cur, sqlite_int64 *pRowid){
  series_cursor *pCur = (series_cursor*)cur;
  sqlite3_uint64 n = pCur->ss.uSeqIndexNow;
  *pRowid = (sqlite3_int64)((n<LARGEST_UINT64)? n+1 : 0);
  return SQLITE_OK;
}

/*
** Return TRUE if the cursor has been moved off of the last
** row of output.
*/
static int seriesEof(sqlite3_vtab_cursor *cur){
  series_cursor *pCur = (series_cursor*)cur;
  return !pCur->ss.isNotEOF;
}

/* True to cause run-time checking of the start=, stop=, and/or step=
** parameters.  The only reason to do this is for testing the
** constraint checking logic for virtual tables in the SQLite core.
*/
#ifndef SQLITE_SERIES_CONSTRAINT_VERIFY
# define SQLITE_SERIES_CONSTRAINT_VERIFY 0
#endif

/*
** This method is called to "rewind" the series_cursor object back
** to the first row of output.  This method is always called at least
** once prior to any call to seriesColumn() or seriesRowid() or
** seriesEof().
**
** The query plan selected by seriesBestIndex is passed in the idxNum
** parameter.  (idxStr is not used in this implementation.)  idxNum
** is a bitmask showing which constraints are available:
**
**   0x0001:    start=VALUE
**   0x0002:    stop=VALUE
**   0x0004:    step=VALUE
**   0x0008:    descending order
**   0x0010:    ascending order
**   0x0020:    LIMIT  VALUE
**   0x0040:    OFFSET  VALUE
**   0x0080:    value=VALUE
**   0x0100:    value>=VALUE
**   0x0200:    value>VALUE
**   0x1000:    value<=VALUE
**   0x2000:    value<VALUE
**
** This routine should initialize the cursor and position it so that it
** is pointing at the first row, or pointing off the end of the table
** (so that seriesEof() will return true) if the table is empty.
*/
static int seriesFilter(
  sqlite3_vtab_cursor *pVtabCursor,
  int idxNum, const char *idxStrUnused,
  int argc, sqlite3_value **argv
){
  series_cursor *pCur = (series_cursor *)pVtabCursor;
  int i = 0;
  int returnNoRows = 0;
  sqlite3_int64 iMin = SMALLEST_INT64;
  sqlite3_int64 iMax = LARGEST_INT64;
  sqlite3_int64 iLimit = 0;
  sqlite3_int64 iOffset = 0;

  (void)idxStrUnused;
  if( idxNum & 0x01 ){
    pCur->ss.iBase = sqlite3_value_int64(argv[i++]);
  }else{
    pCur->ss.iBase = 0;
  }
  if( idxNum & 0x02 ){
    pCur->ss.iTerm = sqlite3_value_int64(argv[i++]);
  }else{
    pCur->ss.iTerm = 0xffffffff;
  }
  if( idxNum & 0x04 ){
    pCur->ss.iStep = sqlite3_value_int64(argv[i++]);
    if( pCur->ss.iStep==0 ){
      pCur->ss.iStep = 1;
    }else if( pCur->ss.iStep<0 ){
      if( (idxNum & 0x10)==0 ) idxNum |= 0x08;
    }
  }else{
    pCur->ss.iStep = 1;
  }

  /* If there are constraints on the value column but there are
  ** no constraints on  the start, stop, and step columns, then
  ** initialize the default range to be the entire range of 64-bit signed
  ** integers.  This range will contracted by the value column constraints
  ** further below.
  */
  if( (idxNum & 0x05)==0 && (idxNum & 0x0380)!=0 ){
    pCur->ss.iBase = SMALLEST_INT64;
  }
  if( (idxNum & 0x06)==0 && (idxNum & 0x3080)!=0 ){
    pCur->ss.iTerm = LARGEST_INT64;
  }
  pCur->ss.iOBase = pCur->ss.iBase;
  pCur->ss.iOTerm = pCur->ss.iTerm;

  /* Extract the LIMIT and OFFSET values, but do not apply them yet.
  ** The range must first be constrained by the limits on value.
  */
  if( idxNum & 0x20 ){
    iLimit = sqlite3_value_int64(argv[i++]);
    if( idxNum & 0x40 ){
      iOffset = sqlite3_value_int64(argv[i++]);
    }
  }

  if( idxNum & 0x3380 ){
    /* Extract the maximum range of output values determined by
    ** constraints on the "value" column.
    */
    if( idxNum & 0x0080 ){
      iMin = iMax = sqlite3_value_int64(argv[i++]);
    }else{
      if( idxNum & 0x0300 ){
        iMin = sqlite3_value_int64(argv[i++]);
        if( idxNum & 0x0200 ){
          if( iMin==LARGEST_INT64 ){
            returnNoRows = 1;
          }else{
            iMin++;
          }
        }
      }
      if( idxNum & 0x3000 ){
        iMax = sqlite3_value_int64(argv[i++]);
        if( idxNum & 0x2000 ){
          if( iMax==SMALLEST_INT64 ){
            returnNoRows = 1;
          }else{
            iMax--;
          }
        }
      }
      if( iMin>iMax ){
        returnNoRows = 1;
      }
    }

    /* Try to reduce the range of values to be generated based on
    ** constraints on the "value" column.
    */
    if( pCur->ss.iStep>0 ){
      sqlite3_int64 szStep = pCur->ss.iStep;
      if( pCur->ss.iBase<iMin ){
        sqlite3_uint64 d = iMin - pCur->ss.iBase;
        pCur->ss.iBase += ((d+szStep-1)/szStep)*szStep;
      }
      if( pCur->ss.iTerm>iMax ){
        sqlite3_uint64 d = pCur->ss.iTerm - iMax;
        pCur->ss.iTerm -= ((d+szStep-1)/szStep)*szStep;
      }
    }else{
      sqlite3_int64 szStep = -pCur->ss.iStep;
      assert( szStep>0 );
      if( pCur->ss.iBase>iMax ){
        sqlite3_uint64 d = pCur->ss.iBase - iMax;
        pCur->ss.iBase -= ((d+szStep-1)/szStep)*szStep;
      }
      if( pCur->ss.iTerm<iMin ){
        sqlite3_uint64 d = iMin - pCur->ss.iTerm;
        pCur->ss.iTerm += ((d+szStep-1)/szStep)*szStep;
      }
    }
  }

  /* Apply LIMIT and OFFSET constraints, if any */
  if( idxNum & 0x20 ){
    if( iOffset>0 ){
      pCur->ss.iBase += pCur->ss.iStep*iOffset;
    }
    if( iLimit>=0 ){
      sqlite3_int64 iTerm;
      iTerm = pCur->ss.iBase + (iLimit - 1)*pCur->ss.iStep;
      if( pCur->ss.iStep<0 ){
        if( iTerm>pCur->ss.iTerm ) pCur->ss.iTerm = iTerm;
      }else{
        if( iTerm<pCur->ss.iTerm ) pCur->ss.iTerm = iTerm;
      }
    }
  }


  for(i=0; i<argc; i++){
    if( sqlite3_value_type(argv[i])==SQLITE_NULL ){
      /* If any of the constraints have a NULL value, then return no rows.
      ** See ticket https://www.sqlite.org/src/info/fac496b61722daf2 */
      returnNoRows = 1;
      break;
    }
  }
  if( returnNoRows ){
    pCur->ss.iBase = 1;
    pCur->ss.iTerm = 0;
    pCur->ss.iStep = 1;
  }
  if( idxNum & 0x08 ){
    pCur->ss.isReversing = pCur->ss.iStep > 0;
  }else{
    pCur->ss.isReversing = pCur->ss.iStep < 0;
  }
  setupSequence( &pCur->ss );
  return SQLITE_OK;
}

/*
** SQLite will invoke this method one or more times while planning a query
** that uses the generate_series virtual table.  This routine needs to create
** a query plan for each invocation and compute an estimated cost for that
** plan.
**
** In this implementation idxNum is used to represent the
** query plan.  idxStr is unused.
**
** The query plan is represented by bits in idxNum:
**
**   0x0001  start = $num
**   0x0002  stop = $num
**   0x0004  step = $num
**   0x0008  output is in descending order
**   0x0010  output is in ascending order
**   0x0020  LIMIT $num
**   0x0040  OFFSET $num
**   0x0080  value = $num
**   0x0100  value >= $num
**   0x0200  value > $num
**   0x1000  value <= $num
**   0x2000  value < $num
**
** Only one of 0x0100 or 0x0200 will be returned.  Similarly, only
** one of 0x1000 or 0x2000 will be returned.  If the 0x0080 is set, then
** none of the 0xff00 bits will be set.
**
** The order of parameters passed to xFilter is as follows:
**
**    * The argument to start= if bit 0x0001 is in the idxNum mask
**    * The argument to stop= if bit 0x0002 is in the idxNum mask
**    * The argument to step= if bit 0x0004 is in the idxNum mask
**    * The argument to LIMIT if bit 0x0020 is in the idxNum mask
**    * The argument to OFFSET if bit 0x0040 is in the idxNum mask
**    * The argument to value=, or value>= or value> if any of
**      bits 0x0380 are in the idxNum mask
**    * The argument to value<= or value< if either of bits 0x3000
**      are in the mask
**
*/
static int seriesBestIndex(
  sqlite3_vtab *pVTab,
  sqlite3_index_info *pIdxInfo
){
  int i, j;              /* Loop over constraints */
  int idxNum = 0;        /* The query plan bitmask */
#ifndef ZERO_ARGUMENT_GENERATE_SERIES
  int bStartSeen = 0;    /* EQ constraint seen on the START column */
#endif
  int unusableMask = 0;  /* Mask of unusable constraints */
  int nArg = 0;          /* Number of arguments that seriesFilter() expects */
  int aIdx[7];           /* Constraints on start, stop, step, LIMIT, OFFSET,
                         ** and value.  aIdx[5] covers value=, value>=, and
                         ** value>,  aIdx[6] covers value<= and value< */
  const struct sqlite3_index_constraint *pConstraint;

  /* This implementation assumes that the start, stop, and step columns
  ** are the last three columns in the virtual table. */
  assert( SERIES_COLUMN_STOP == SERIES_COLUMN_START+1 );
  assert( SERIES_COLUMN_STEP == SERIES_COLUMN_START+2 );

  aIdx[0] = aIdx[1] = aIdx[2] = aIdx[3] = aIdx[4] = aIdx[5] = aIdx[6] = -1;
  pConstraint = pIdxInfo->aConstraint;
  for(i=0; i<pIdxInfo->nConstraint; i++, pConstraint++){
    int iCol;    /* 0 for start, 1 for stop, 2 for step */
    int iMask;   /* bitmask for those column */
    int op = pConstraint->op;
    if( op>=SQLITE_INDEX_CONSTRAINT_LIMIT
     && op<=SQLITE_INDEX_CONSTRAINT_OFFSET
    ){
      if( pConstraint->usable==0 ){
        /* do nothing */
      }else if( op==SQLITE_INDEX_CONSTRAINT_LIMIT ){
        aIdx[3] = i;
        idxNum |= 0x20;
      }else{
        assert( op==SQLITE_INDEX_CONSTRAINT_OFFSET );
        aIdx[4] = i;
        idxNum |= 0x40;
      }
      continue;
    }
    if( pConstraint->iColumn<SERIES_COLUMN_START ){
      if( pConstraint->iColumn==SERIES_COLUMN_VALUE && pConstraint->usable ){
        switch( op ){
          case SQLITE_INDEX_CONSTRAINT_EQ:
          case SQLITE_INDEX_CONSTRAINT_IS: {
            idxNum |=  0x0080;
            idxNum &= ~0x3300;
            aIdx[5] = i;
            aIdx[6] = -1;
#ifndef ZERO_ARGUMENT_GENERATE_SERIES
            bStartSeen = 1;
#endif
            break;
          }
          case SQLITE_INDEX_CONSTRAINT_GE: {
            if( idxNum & 0x0080 ) break;
            idxNum |=  0x0100;
            idxNum &= ~0x0200;
            aIdx[5] = i;
#ifndef ZERO_ARGUMENT_GENERATE_SERIES
            bStartSeen = 1;
#endif
            break;
          }
          case SQLITE_INDEX_CONSTRAINT_GT: {
            if( idxNum & 0x0080 ) break;
            idxNum |=  0x0200;
            idxNum &= ~0x0100;
            aIdx[5] = i;
#ifndef ZERO_ARGUMENT_GENERATE_SERIES
            bStartSeen = 1;
#endif
            break;
          }
          case SQLITE_INDEX_CONSTRAINT_LE: {
            if( idxNum & 0x0080 ) break;
            idxNum |=  0x1000;
            idxNum &= ~0x2000;
            aIdx[6] = i;
            break;
          }
          case SQLITE_INDEX_CONSTRAINT_LT: {
            if( idxNum & 0x0080 ) break;
            idxNum |=  0x2000;
            idxNum &= ~0x1000;
            aIdx[6] = i;
            break;
          }
        }
      }
      continue;
    }
    iCol = pConstraint->iColumn - SERIES_COLUMN_START;
    assert( iCol>=0 && iCol<=2 );
    iMask = 1 << iCol;
#ifndef ZERO_ARGUMENT_GENERATE_SERIES
    if( iCol==0 && op==SQLITE_INDEX_CONSTRAINT_EQ ){
      bStartSeen = 1;
    }
#endif
    if( pConstraint->usable==0 ){
      unusableMask |=  iMask;
      continue;
    }else if( op==SQLITE_INDEX_CONSTRAINT_EQ ){
      idxNum |= iMask;
      aIdx[iCol] = i;
    }
  }
  if( aIdx[3]==0 ){
    /* Ignore OFFSET if LIMIT is omitted */
    idxNum &= ~0x60;
    aIdx[4] = 0;
  }
  for(i=0; i<7; i++){
    if( (j = aIdx[i])>=0 ){
      pIdxInfo->aConstraintUsage[j].argvIndex = ++nArg;
      pIdxInfo->aConstraintUsage[j].omit =
         !SQLITE_SERIES_CONSTRAINT_VERIFY || i>=3;
    }
  }
  /* The current generate_column() implementation requires at least one
  ** argument (the START value).  Legacy versions assumed START=0 if the
  ** first argument was omitted.  Compile with -DZERO_ARGUMENT_GENERATE_SERIES
  ** to obtain the legacy behavior */
#ifndef ZERO_ARGUMENT_GENERATE_SERIES
  if( !bStartSeen ){
    sqlite3_free(pVTab->zErrMsg);
    pVTab->zErrMsg = sqlite3_mprintf(
        "first argument to \"generate_series()\" missing or unusable");
    return SQLITE_ERROR;
  }
#endif
  if( (unusableMask & ~idxNum)!=0 ){
    /* The start, stop, and step columns are inputs.  Therefore if there
    ** are unusable constraints on any of start, stop, or step then
    ** this plan is unusable */
    return SQLITE_CONSTRAINT;
  }
  if( (idxNum & 0x03)==0x03 ){
    /* Both start= and stop= boundaries are available.  This is the 
    ** the preferred case */
    pIdxInfo->estimatedCost = (double)(2 - ((idxNum&4)!=0));
    pIdxInfo->estimatedRows = 1000;
    if( pIdxInfo->nOrderBy>=1 && pIdxInfo->aOrderBy[0].iColumn==0 ){
      if( pIdxInfo->aOrderBy[0].desc ){
        idxNum |= 0x08;
      }else{
        idxNum |= 0x10;
      }
      pIdxInfo->orderByConsumed = 1;
    }
  }else if( (idxNum & 0x21)==0x21 ){
    /* We have start= and LIMIT */
    pIdxInfo->estimatedRows = 2500;
  }else{
    /* If either boundary is missing, we have to generate a huge span
    ** of numbers.  Make this case very expensive so that the query
    ** planner will work hard to avoid it. */
    pIdxInfo->estimatedRows = 2147483647;
  }
  pIdxInfo->idxNum = idxNum;
#ifdef SQLITE_INDEX_SCAN_HEX
  pIdxInfo->idxFlags = SQLITE_INDEX_SCAN_HEX;
#endif
  return SQLITE_OK;
}

/*
** This following structure defines all the methods for the 
** generate_series virtual table.
*/
static sqlite3_module seriesModule = {
  0,                         /* iVersion */
  0,                         /* xCreate */
  seriesConnect,             /* xConnect */
  seriesBestIndex,           /* xBestIndex */
  seriesDisconnect,          /* xDisconnect */
  0,                         /* xDestroy */
  seriesOpen,                /* xOpen - open a cursor */
  seriesClose,               /* xClose - close a cursor */
  seriesFilter,              /* xFilter - configure scan constraints */
  seriesNext,                /* xNext - advance a cursor */
  seriesEof,                 /* xEof - check for end of scan */
  seriesColumn,              /* xColumn - read data */
  seriesRowid,               /* xRowid - read data */
  0,                         /* xUpdate */
  0,                         /* xBegin */
  0,                         /* xSync */
  0,                         /* xCommit */
  0,                         /* xRollback */
  0,                         /* xFindMethod */
  0,                         /* xRename */
  0,                         /* xSavepoint */
  0,                         /* xRelease */
  0,                         /* xRollbackTo */
  0,                         /* xShadowName */
  0                          /* xIntegrity */
};

#endif /* SQLITE_OMIT_VIRTUALTABLE */

#ifdef _WIN32

#endif
int sqlite3_series_init(
  sqlite3 *db, 
  char **pzErrMsg, 
  const sqlite3_api_routines *pApi
){
  int rc = SQLITE_OK;
  SQLITE_EXTENSION_INIT2(pApi);
#ifndef SQLITE_OMIT_VIRTUALTABLE
  if( sqlite3_libversion_number()<3008012 && pzErrMsg!=0 ){
    *pzErrMsg = sqlite3_mprintf(
        "generate_series() requires SQLite 3.8.12 or later");
    return SQLITE_ERROR;
  }
  rc = sqlite3_create_module(db, "generate_series", &seriesModule, 0);
#endif
  return rc;
}

/************************* End ../ext/misc/series.c ********************/
/************************* Begin ../ext/misc/regexp.c ******************/
/*
** 2012-11-13
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
******************************************************************************
**
** The code in this file implements a compact but reasonably
** efficient regular-expression matcher for posix extended regular
** expressions against UTF8 text.
**
** This file is an SQLite extension.  It registers a single function
** named "regexp(A,B)" where A is the regular expression and B is the
** string to be matched.  By registering this function, SQLite will also
** then implement the "B regexp A" operator.  Note that with the function
** the regular expression comes first, but with the operator it comes
** second.
**
**  The following regular expression syntax is supported:
**
**     X*      zero or more occurrences of X
**     X+      one or more occurrences of X
**     X?      zero or one occurrences of X
**     X{p,q}  between p and q occurrences of X
**     (X)     match X
**     X|Y     X or Y
**     ^X      X occurring at the beginning of the string
**     X$      X occurring at the end of the string
**     .       Match any single character
**     \c      Character c where c is one of \{}()[]|*+?.
**     \c      C-language escapes for c in afnrtv.  ex: \t or \n
**     \uXXXX  Where XXXX is exactly 4 hex digits, unicode value XXXX
**     \xXX    Where XX is exactly 2 hex digits, unicode value XX
**     [abc]   Any single character from the set abc
**     [^abc]  Any single character not in the set abc
**     [a-z]   Any single character in the range a-z
**     [^a-z]  Any single character not in the range a-z
**     \b      Word boundary
**     \w      Word character.  [A-Za-z0-9_]
**     \W      Non-word character
**     \d      Digit
**     \D      Non-digit
**     \s      Whitespace character
**     \S      Non-whitespace character
**
** A nondeterministic finite automaton (NFA) is used for matching, so the
** performance is bounded by O(N*M) where N is the size of the regular
** expression and M is the size of the input string.  The matcher never
** exhibits exponential behavior.  Note that the X{p,q} operator expands
** to p copies of X following by q-p copies of X? and that the size of the
** regular expression in the O(N*M) performance bound is computed after
** this expansion.
*/
#include <string.h>
#include <stdlib.h>
/* #include "sqlite3ext.h" */
SQLITE_EXTENSION_INIT1

/*
** The following #defines change the names of some functions implemented in
** this file to prevent name collisions with C-library functions of the
** same name.
*/
#define re_match   sqlite3re_match
#define re_compile sqlite3re_compile
#define re_free    sqlite3re_free

/* The end-of-input character */
#define RE_EOF            0    /* End of input */
#define RE_START  0xfffffff    /* Start of input - larger than an UTF-8 */

/* The NFA is implemented as sequence of opcodes taken from the following
** set.  Each opcode has a single integer argument.
*/
#define RE_OP_MATCH       1    /* Match the one character in the argument */
#define RE_OP_ANY         2    /* Match any one character.  (Implements ".") */
#define RE_OP_ANYSTAR     3    /* Special optimized version of .* */
#define RE_OP_FORK        4    /* Continue to both next and opcode at iArg */
#define RE_OP_GOTO        5    /* Jump to opcode at iArg */
#define RE_OP_ACCEPT      6    /* Halt and indicate a successful match */
#define RE_OP_CC_INC      7    /* Beginning of a [...] character class */
#define RE_OP_CC_EXC      8    /* Beginning of a [^...] character class */
#define RE_OP_CC_VALUE    9    /* Single value in a character class */
#define RE_OP_CC_RANGE   10    /* Range of values in a character class */
#define RE_OP_WORD       11    /* Perl word character [A-Za-z0-9_] */
#define RE_OP_NOTWORD    12    /* Not a perl word character */
#define RE_OP_DIGIT      13    /* digit:  [0-9] */
#define RE_OP_NOTDIGIT   14    /* Not a digit */
#define RE_OP_SPACE      15    /* space:  [ \t\n\r\v\f] */
#define RE_OP_NOTSPACE   16    /* Not a digit */
#define RE_OP_BOUNDARY   17    /* Boundary between word and non-word */
#define RE_OP_ATSTART    18    /* Currently at the start of the string */

#if defined(SQLITE_DEBUG)
/* Opcode names used for symbolic debugging */
static const char *ReOpName[] = {
  "EOF",
  "MATCH",
  "ANY",
  "ANYSTAR",
  "FORK",
  "GOTO",
  "ACCEPT",
  "CC_INC",
  "CC_EXC",
  "CC_VALUE",
  "CC_RANGE",
  "WORD",
  "NOTWORD",
  "DIGIT",
  "NOTDIGIT",
  "SPACE",
  "NOTSPACE",
  "BOUNDARY",
  "ATSTART",
};
#endif /* SQLITE_DEBUG */


/* Each opcode is a "state" in the NFA */
typedef unsigned short ReStateNumber;

/* Because this is an NFA and not a DFA, multiple states can be active at
** once.  An instance of the following object records all active states in
** the NFA.  The implementation is optimized for the common case where the
** number of actives states is small.
*/
typedef struct ReStateSet {
  unsigned nState;            /* Number of current states */
  ReStateNumber *aState;      /* Current states */
} ReStateSet;

/* An input string read one character at a time.
*/
typedef struct ReInput ReInput;
struct ReInput {
  const unsigned char *z;  /* All text */
  int i;                   /* Next byte to read */
  int mx;                  /* EOF when i>=mx */
};

/* A compiled NFA (or an NFA that is in the process of being compiled) is
** an instance of the following object.
*/
typedef struct ReCompiled ReCompiled;
struct ReCompiled {
  ReInput sIn;                /* Regular expression text */
  const char *zErr;           /* Error message to return */
  char *aOp;                  /* Operators for the virtual machine */
  int *aArg;                  /* Arguments to each operator */
  unsigned (*xNextChar)(ReInput*);  /* Next character function */
  unsigned char zInit[12];    /* Initial text to match */
  int nInit;                  /* Number of bytes in zInit */
  unsigned nState;            /* Number of entries in aOp[] and aArg[] */
  unsigned nAlloc;            /* Slots allocated for aOp[] and aArg[] */
};

/* Add a state to the given state set if it is not already there */
static void re_add_state(ReStateSet *pSet, int newState){
  unsigned i;
  for(i=0; i<pSet->nState; i++) if( pSet->aState[i]==newState ) return;
  pSet->aState[pSet->nState++] = (ReStateNumber)newState;
}

/* Extract the next unicode character from *pzIn and return it.  Advance
** *pzIn to the first byte past the end of the character returned.  To
** be clear:  this routine converts utf8 to unicode.  This routine is 
** optimized for the common case where the next character is a single byte.
*/
static unsigned re_next_char(ReInput *p){
  unsigned c;
  if( p->i>=p->mx ) return 0;
  c = p->z[p->i++];
  if( c>=0x80 ){
    if( (c&0xe0)==0xc0 && p->i<p->mx && (p->z[p->i]&0xc0)==0x80 ){
      c = (c&0x1f)<<6 | (p->z[p->i++]&0x3f);
      if( c<0x80 ) c = 0xfffd;
    }else if( (c&0xf0)==0xe0 && p->i+1<p->mx && (p->z[p->i]&0xc0)==0x80
           && (p->z[p->i+1]&0xc0)==0x80 ){
      c = (c&0x0f)<<12 | ((p->z[p->i]&0x3f)<<6) | (p->z[p->i+1]&0x3f);
      p->i += 2;
      if( c<=0x7ff || (c>=0xd800 && c<=0xdfff) ) c = 0xfffd;
    }else if( (c&0xf8)==0xf0 && p->i+2<p->mx && (p->z[p->i]&0xc0)==0x80
           && (p->z[p->i+1]&0xc0)==0x80 && (p->z[p->i+2]&0xc0)==0x80 ){
      c = (c&0x07)<<18 | ((p->z[p->i]&0x3f)<<12) | ((p->z[p->i+1]&0x3f)<<6)
                       | (p->z[p->i+2]&0x3f);
      p->i += 3;
      if( c<=0xffff || c>0x10ffff ) c = 0xfffd;
    }else{
      c = 0xfffd;
    }
  }
  return c;
}
static unsigned re_next_char_nocase(ReInput *p){
  unsigned c = re_next_char(p);
  if( c>='A' && c<='Z' ) c += 'a' - 'A';
  return c;
}

/* Return true if c is a perl "word" character:  [A-Za-z0-9_] */
static int re_word_char(int c){
  return (c>='0' && c<='9') || (c>='a' && c<='z')
      || (c>='A' && c<='Z') || c=='_';
}

/* Return true if c is a "digit" character:  [0-9] */
static int re_digit_char(int c){
  return (c>='0' && c<='9');
}

/* Return true if c is a perl "space" character:  [ \t\r\n\v\f] */
static int re_space_char(int c){
  return c==' ' || c=='\t' || c=='\n' || c=='\r' || c=='\v' || c=='\f';
}

/* Run a compiled regular expression on the zero-terminated input
** string zIn[].  Return true on a match and false if there is no match.
*/
static int re_match(ReCompiled *pRe, const unsigned char *zIn, int nIn){
  ReStateSet aStateSet[2], *pThis, *pNext;
  ReStateNumber aSpace[100];
  ReStateNumber *pToFree;
  unsigned int i = 0;
  unsigned int iSwap = 0;
  int c = RE_START;
  int cPrev = 0;
  int rc = 0;
  ReInput in;

  in.z = zIn;
  in.i = 0;
  in.mx = nIn>=0 ? nIn : (int)strlen((char const*)zIn);

  /* Look for the initial prefix match, if there is one. */
  if( pRe->nInit ){
    unsigned char x = pRe->zInit[0];
    while( in.i+pRe->nInit<=in.mx 
     && (zIn[in.i]!=x ||
         strncmp((const char*)zIn+in.i, (const char*)pRe->zInit, pRe->nInit)!=0)
    ){
      in.i++;
    }
    if( in.i+pRe->nInit>in.mx ) return 0;
    c = RE_START-1;
  }

  if( pRe->nState<=(sizeof(aSpace)/(sizeof(aSpace[0])*2)) ){
    pToFree = 0;
    aStateSet[0].aState = aSpace;
  }else{
    pToFree = sqlite3_malloc64( sizeof(ReStateNumber)*2*pRe->nState );
    if( pToFree==0 ) return -1;
    aStateSet[0].aState = pToFree;
  }
  aStateSet[1].aState = &aStateSet[0].aState[pRe->nState];
  pNext = &aStateSet[1];
  pNext->nState = 0;
  re_add_state(pNext, 0);
  while( c!=RE_EOF && pNext->nState>0 ){
    cPrev = c;
    c = pRe->xNextChar(&in);
    pThis = pNext;
    pNext = &aStateSet[iSwap];
    iSwap = 1 - iSwap;
    pNext->nState = 0;
    for(i=0; i<pThis->nState; i++){
      int x = pThis->aState[i];
      switch( pRe->aOp[x] ){
        case RE_OP_MATCH: {
          if( pRe->aArg[x]==c ) re_add_state(pNext, x+1);
          break;
        }
        case RE_OP_ATSTART: {
          if( cPrev==RE_START ) re_add_state(pThis, x+1);
          break;
        }
        case RE_OP_ANY: {
          if( c!=0 ) re_add_state(pNext, x+1);
          break;
        }
        case RE_OP_WORD: {
          if( re_word_char(c) ) re_add_state(pNext, x+1);
          break;
        }
        case RE_OP_NOTWORD: {
          if( !re_word_char(c) && c!=0 ) re_add_state(pNext, x+1);
          break;
        }
        case RE_OP_DIGIT: {
          if( re_digit_char(c) ) re_add_state(pNext, x+1);
          break;
        }
        case RE_OP_NOTDIGIT: {
          if( !re_digit_char(c) && c!=0 ) re_add_state(pNext, x+1);
          break;
        }
        case RE_OP_SPACE: {
          if( re_space_char(c) ) re_add_state(pNext, x+1);
          break;
        }
        case RE_OP_NOTSPACE: {
          if( !re_space_char(c) && c!=0 ) re_add_state(pNext, x+1);
          break;
        }
        case RE_OP_BOUNDARY: {
          if( re_word_char(c)!=re_word_char(cPrev) ) re_add_state(pThis, x+1);
          break;
        }
        case RE_OP_ANYSTAR: {
          re_add_state(pNext, x);
          re_add_state(pThis, x+1);
          break;
        }
        case RE_OP_FORK: {
          re_add_state(pThis, x+pRe->aArg[x]);
          re_add_state(pThis, x+1);
          break;
        }
        case RE_OP_GOTO: {
          re_add_state(pThis, x+pRe->aArg[x]);
          break;
        }
        case RE_OP_ACCEPT: {
          rc = 1;
          goto re_match_end;
        }
        case RE_OP_CC_EXC: {
          if( c==0 ) break;
          /* fall-through */ goto re_op_cc_inc;
        }
        case RE_OP_CC_INC: re_op_cc_inc: {
          int j = 1;
          int n = pRe->aArg[x];
          int hit = 0;
          for(j=1; j>0 && j<n; j++){
            if( pRe->aOp[x+j]==RE_OP_CC_VALUE ){
              if( pRe->aArg[x+j]==c ){
                hit = 1;
                j = -1;
              }
            }else{
              if( pRe->aArg[x+j]<=c && pRe->aArg[x+j+1]>=c ){
                hit = 1;
                j = -1;
              }else{
                j++;
              }
            }
          }
          if( pRe->aOp[x]==RE_OP_CC_EXC ) hit = !hit;
          if( hit ) re_add_state(pNext, x+n);
          break;
        }
      }
    }
  }
  for(i=0; i<pNext->nState; i++){
    int x = pNext->aState[i];
    while( pRe->aOp[x]==RE_OP_GOTO ) x += pRe->aArg[x];
    if( pRe->aOp[x]==RE_OP_ACCEPT ){ rc = 1; break; }
  }
re_match_end:
  sqlite3_free(pToFree);
  return rc;
}

/* Resize the opcode and argument arrays for an RE under construction.
*/
static int re_resize(ReCompiled *p, int N){
  char *aOp;
  int *aArg;
  aOp = sqlite3_realloc64(p->aOp, N*sizeof(p->aOp[0]));
  if( aOp==0 ) return 1;
  p->aOp = aOp;
  aArg = sqlite3_realloc64(p->aArg, N*sizeof(p->aArg[0]));
  if( aArg==0 ) return 1;
  p->aArg = aArg;
  p->nAlloc = N;
  return 0;
}

/* Insert a new opcode and argument into an RE under construction.  The
** insertion point is just prior to existing opcode iBefore.
*/
static int re_insert(ReCompiled *p, int iBefore, int op, int arg){
  int i;
  if( p->nAlloc<=p->nState && re_resize(p, p->nAlloc*2) ) return 0;
  for(i=p->nState; i>iBefore; i--){
    p->aOp[i] = p->aOp[i-1];
    p->aArg[i] = p->aArg[i-1];
  }
  p->nState++;
  p->aOp[iBefore] = (char)op;
  p->aArg[iBefore] = arg;
  return iBefore;
}

/* Append a new opcode and argument to the end of the RE under construction.
*/
static int re_append(ReCompiled *p, int op, int arg){
  return re_insert(p, p->nState, op, arg);
}

/* Make a copy of N opcodes starting at iStart onto the end of the RE
** under construction.
*/
static void re_copy(ReCompiled *p, int iStart, int N){
  if( p->nState+N>=p->nAlloc && re_resize(p, p->nAlloc*2+N) ) return;
  memcpy(&p->aOp[p->nState], &p->aOp[iStart], N*sizeof(p->aOp[0]));
  memcpy(&p->aArg[p->nState], &p->aArg[iStart], N*sizeof(p->aArg[0]));
  p->nState += N;
}

/* Return true if c is a hexadecimal digit character:  [0-9a-fA-F]
** If c is a hex digit, also set *pV = (*pV)*16 + valueof(c).  If
** c is not a hex digit *pV is unchanged.
*/
static int re_hex(int c, int *pV){
  if( c>='0' && c<='9' ){
    c -= '0';
  }else if( c>='a' && c<='f' ){
    c -= 'a' - 10;
  }else if( c>='A' && c<='F' ){
    c -= 'A' - 10;
  }else{
    return 0;
  }
  *pV = (*pV)*16 + (c & 0xff);
  return 1;
}

/* A backslash character has been seen, read the next character and
** return its interpretation.
*/
static unsigned re_esc_char(ReCompiled *p){
  static const char zEsc[] = "afnrtv\\()*.+?[$^{|}]";
  static const char zTrans[] = "\a\f\n\r\t\v";
  int i, v = 0;
  char c;
  if( p->sIn.i>=p->sIn.mx ) return 0;
  c = p->sIn.z[p->sIn.i];
  if( c=='u' && p->sIn.i+4<p->sIn.mx ){
    const unsigned char *zIn = p->sIn.z + p->sIn.i;
    if( re_hex(zIn[1],&v)
     && re_hex(zIn[2],&v)
     && re_hex(zIn[3],&v)
     && re_hex(zIn[4],&v)
    ){
      p->sIn.i += 5;
      return v;
    }
  }
  if( c=='x' && p->sIn.i+2<p->sIn.mx ){
    const unsigned char *zIn = p->sIn.z + p->sIn.i;
    if( re_hex(zIn[1],&v)
     && re_hex(zIn[2],&v)
    ){
      p->sIn.i += 3;
      return v;
    }
  }
  for(i=0; zEsc[i] && zEsc[i]!=c; i++){}
  if( zEsc[i] ){
    if( i<6 ) c = zTrans[i];
    p->sIn.i++;
  }else{
    p->zErr = "unknown \\ escape";
  }
  return c;
}

/* Forward declaration */
static const char *re_subcompile_string(ReCompiled*);

/* Peek at the next byte of input */
static unsigned char rePeek(ReCompiled *p){
  return p->sIn.i<p->sIn.mx ? p->sIn.z[p->sIn.i] : 0;
}

/* Compile RE text into a sequence of opcodes.  Continue up to the
** first unmatched ")" character, then return.  If an error is found,
** return a pointer to the error message string.
*/
static const char *re_subcompile_re(ReCompiled *p){
  const char *zErr;
  int iStart, iEnd, iGoto;
  iStart = p->nState;
  zErr = re_subcompile_string(p);
  if( zErr ) return zErr;
  while( rePeek(p)=='|' ){
    iEnd = p->nState;
    re_insert(p, iStart, RE_OP_FORK, iEnd + 2 - iStart);
    iGoto = re_append(p, RE_OP_GOTO, 0);
    p->sIn.i++;
    zErr = re_subcompile_string(p);
    if( zErr ) return zErr;
    p->aArg[iGoto] = p->nState - iGoto;
  }
  return 0;
}

/* Compile an element of regular expression text (anything that can be
** an operand to the "|" operator).  Return NULL on success or a pointer
** to the error message if there is a problem.
*/
static const char *re_subcompile_string(ReCompiled *p){
  int iPrev = -1;
  int iStart;
  unsigned c;
  const char *zErr;
  while( (c = p->xNextChar(&p->sIn))!=0 ){
    iStart = p->nState;
    switch( c ){
      case '|':
      case ')': {
        p->sIn.i--;
        return 0;
      }
      case '(': {
        zErr = re_subcompile_re(p);
        if( zErr ) return zErr;
        if( rePeek(p)!=')' ) return "unmatched '('";
        p->sIn.i++;
        break;
      }
      case '.': {
        if( rePeek(p)=='*' ){
          re_append(p, RE_OP_ANYSTAR, 0);
          p->sIn.i++;
        }else{
          re_append(p, RE_OP_ANY, 0);
        }
        break;
      }
      case '*': {
        if( iPrev<0 ) return "'*' without operand";
        re_insert(p, iPrev, RE_OP_GOTO, p->nState - iPrev + 1);
        re_append(p, RE_OP_FORK, iPrev - p->nState + 1);
        break;
      }
      case '+': {
        if( iPrev<0 ) return "'+' without operand";
        re_append(p, RE_OP_FORK, iPrev - p->nState);
        break;
      }
      case '?': {
        if( iPrev<0 ) return "'?' without operand";
        re_insert(p, iPrev, RE_OP_FORK, p->nState - iPrev+1);
        break;
      }
      case '$': {
        re_append(p, RE_OP_MATCH, RE_EOF);
        break;
      }
      case '^': {
        re_append(p, RE_OP_ATSTART, 0);
        break;
      }
      case '{': {
        int m = 0, n = 0;
        int sz, j;
        if( iPrev<0 ) return "'{m,n}' without operand";
        while( (c=rePeek(p))>='0' && c<='9' ){ m = m*10 + c - '0'; p->sIn.i++; }
        n = m;
        if( c==',' ){
          p->sIn.i++;
          n = 0;
          while( (c=rePeek(p))>='0' && c<='9' ){ n = n*10 + c-'0'; p->sIn.i++; }
        }
        if( c!='}' ) return "unmatched '{'";
        if( n>0 && n<m ) return "n less than m in '{m,n}'";
        p->sIn.i++;
        sz = p->nState - iPrev;
        if( m==0 ){
          if( n==0 ) return "both m and n are zero in '{m,n}'";
          re_insert(p, iPrev, RE_OP_FORK, sz+1);
          iPrev++;
          n--;
        }else{
          for(j=1; j<m; j++) re_copy(p, iPrev, sz);
        }
        for(j=m; j<n; j++){
          re_append(p, RE_OP_FORK, sz+1);
          re_copy(p, iPrev, sz);
        }
        if( n==0 && m>0 ){
          re_append(p, RE_OP_FORK, -sz);
        }
        break;
      }
      case '[': {
        unsigned int iFirst = p->nState;
        if( rePeek(p)=='^' ){
          re_append(p, RE_OP_CC_EXC, 0);
          p->sIn.i++;
        }else{
          re_append(p, RE_OP_CC_INC, 0);
        }
        while( (c = p->xNextChar(&p->sIn))!=0 ){
          if( c=='[' && rePeek(p)==':' ){
            return "POSIX character classes not supported";
          }
          if( c=='\\' ) c = re_esc_char(p);
          if( rePeek(p)=='-' ){
            re_append(p, RE_OP_CC_RANGE, c);
            p->sIn.i++;
            c = p->xNextChar(&p->sIn);
            if( c=='\\' ) c = re_esc_char(p);
            re_append(p, RE_OP_CC_RANGE, c);
          }else{
            re_append(p, RE_OP_CC_VALUE, c);
          }
          if( rePeek(p)==']' ){ p->sIn.i++; break; }
        }
        if( c==0 ) return "unclosed '['";
        if( p->nState>iFirst ) p->aArg[iFirst] = p->nState - iFirst;
        break;
      }
      case '\\': {
        int specialOp = 0;
        switch( rePeek(p) ){
          case 'b': specialOp = RE_OP_BOUNDARY;   break;
          case 'd': specialOp = RE_OP_DIGIT;      break;
          case 'D': specialOp = RE_OP_NOTDIGIT;   break;
          case 's': specialOp = RE_OP_SPACE;      break;
          case 'S': specialOp = RE_OP_NOTSPACE;   break;
          case 'w': specialOp = RE_OP_WORD;       break;
          case 'W': specialOp = RE_OP_NOTWORD;    break;
        }
        if( specialOp ){
          p->sIn.i++;
          re_append(p, specialOp, 0);
        }else{
          c = re_esc_char(p);
          re_append(p, RE_OP_MATCH, c);
        }
        break;
      }
      default: {
        re_append(p, RE_OP_MATCH, c);
        break;
      }
    }
    iPrev = iStart;
  }
  return 0;
}

/* Free and reclaim all the memory used by a previously compiled
** regular expression.  Applications should invoke this routine once
** for every call to re_compile() to avoid memory leaks.
*/
static void re_free(ReCompiled *pRe){
  if( pRe ){
    sqlite3_free(pRe->aOp);
    sqlite3_free(pRe->aArg);
    sqlite3_free(pRe);
  }
}

/*
** Compile a textual regular expression in zIn[] into a compiled regular
** expression suitable for us by re_match() and return a pointer to the
** compiled regular expression in *ppRe.  Return NULL on success or an
** error message if something goes wrong.
*/
static const char *re_compile(ReCompiled **ppRe, const char *zIn, int noCase){
  ReCompiled *pRe;
  const char *zErr;
  int i, j;

  *ppRe = 0;
  pRe = sqlite3_malloc( sizeof(*pRe) );
  if( pRe==0 ){
    return "out of memory";
  }
  memset(pRe, 0, sizeof(*pRe));
  pRe->xNextChar = noCase ? re_next_char_nocase : re_next_char;
  if( re_resize(pRe, 30) ){
    re_free(pRe);
    return "out of memory";
  }
  if( zIn[0]=='^' ){
    zIn++;
  }else{
    re_append(pRe, RE_OP_ANYSTAR, 0);
  }
  pRe->sIn.z = (unsigned char*)zIn;
  pRe->sIn.i = 0;
  pRe->sIn.mx = (int)strlen(zIn);
  zErr = re_subcompile_re(pRe);
  if( zErr ){
    re_free(pRe);
    return zErr;
  }
  if( pRe->sIn.i>=pRe->sIn.mx ){
    re_append(pRe, RE_OP_ACCEPT, 0);
    *ppRe = pRe;
  }else{
    re_free(pRe);
    return "unrecognized character";
  }

  /* The following is a performance optimization.  If the regex begins with
  ** ".*" (if the input regex lacks an initial "^") and afterwards there are
  ** one or more matching characters, enter those matching characters into
  ** zInit[].  The re_match() routine can then search ahead in the input 
  ** string looking for the initial match without having to run the whole
  ** regex engine over the string.  Do not worry about trying to match
  ** unicode characters beyond plane 0 - those are very rare and this is
  ** just an optimization. */
  if( pRe->aOp[0]==RE_OP_ANYSTAR && !noCase ){
    for(j=0, i=1; j<(int)sizeof(pRe->zInit)-2 && pRe->aOp[i]==RE_OP_MATCH; i++){
      unsigned x = pRe->aArg[i];
      if( x<=0x7f ){
        pRe->zInit[j++] = (unsigned char)x;
      }else if( x<=0x7ff ){
        pRe->zInit[j++] = (unsigned char)(0xc0 | (x>>6));
        pRe->zInit[j++] = 0x80 | (x&0x3f);
      }else if( x<=0xffff ){
        pRe->zInit[j++] = (unsigned char)(0xe0 | (x>>12));
        pRe->zInit[j++] = 0x80 | ((x>>6)&0x3f);
        pRe->zInit[j++] = 0x80 | (x&0x3f);
      }else{
        break;
      }
    }
    if( j>0 && pRe->zInit[j-1]==0 ) j--;
    pRe->nInit = j;
  }
  return pRe->zErr;
}

/*
** Implementation of the regexp() SQL function.  This function implements
** the build-in REGEXP operator.  The first argument to the function is the
** pattern and the second argument is the string.  So, the SQL statements:
**
**       A REGEXP B
**
** is implemented as regexp(B,A).
*/
static void re_sql_func(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  ReCompiled *pRe;          /* Compiled regular expression */
  const char *zPattern;     /* The regular expression */
  const unsigned char *zStr;/* String being searched */
  const char *zErr;         /* Compile error message */
  int setAux = 0;           /* True to invoke sqlite3_set_auxdata() */

  (void)argc;  /* Unused */
  pRe = sqlite3_get_auxdata(context, 0);
  if( pRe==0 ){
    zPattern = (const char*)sqlite3_value_text(argv[0]);
    if( zPattern==0 ) return;
    zErr = re_compile(&pRe, zPattern, sqlite3_user_data(context)!=0);
    if( zErr ){
      re_free(pRe);
      sqlite3_result_error(context, zErr, -1);
      return;
    }
    if( pRe==0 ){
      sqlite3_result_error_nomem(context);
      return;
    }
    setAux = 1;
  }
  zStr = (const unsigned char*)sqlite3_value_text(argv[1]);
  if( zStr!=0 ){
    sqlite3_result_int(context, re_match(pRe, zStr, -1));
  }
  if( setAux ){
    sqlite3_set_auxdata(context, 0, pRe, (void(*)(void*))re_free);
  }
}

#if defined(SQLITE_DEBUG)
/*
** This function is used for testing and debugging only.  It is only available
** if the SQLITE_DEBUG compile-time option is used.
**
** Compile a regular expression and then convert the compiled expression into
** text and return that text.
*/
static void re_bytecode_func(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  const char *zPattern;
  const char *zErr;
  ReCompiled *pRe;
  sqlite3_str *pStr;
  int i;
  int n;
  char *z;
  (void)argc;

  zPattern = (const char*)sqlite3_value_text(argv[0]);
  if( zPattern==0 ) return;
  zErr = re_compile(&pRe, zPattern, sqlite3_user_data(context)!=0);
  if( zErr ){
    re_free(pRe);
    sqlite3_result_error(context, zErr, -1);
    return;
  }
  if( pRe==0 ){
    sqlite3_result_error_nomem(context);
    return;
  }
  pStr = sqlite3_str_new(0);
  if( pStr==0 ) goto re_bytecode_func_err;
  if( pRe->nInit>0 ){
    sqlite3_str_appendf(pStr, "INIT     ");
    for(i=0; i<pRe->nInit; i++){
      sqlite3_str_appendf(pStr, "%02x", pRe->zInit[i]);
    }
    sqlite3_str_appendf(pStr, "\n");
  }
  for(i=0; (unsigned)i<pRe->nState; i++){
    sqlite3_str_appendf(pStr, "%-8s %4d\n",
         ReOpName[(unsigned char)pRe->aOp[i]], pRe->aArg[i]);
  }
  n = sqlite3_str_length(pStr);
  z = sqlite3_str_finish(pStr);
  if( n==0 ){
    sqlite3_free(z);
  }else{
    sqlite3_result_text(context, z, n-1, sqlite3_free);
  }

re_bytecode_func_err:
  re_free(pRe);
}

#endif /* SQLITE_DEBUG */


/*
** Invoke this routine to register the regexp() function with the
** SQLite database connection.
*/
#ifdef _WIN32

#endif
int sqlite3_regexp_init(
  sqlite3 *db, 
  char **pzErrMsg, 
  const sqlite3_api_routines *pApi
){
  int rc = SQLITE_OK;
  SQLITE_EXTENSION_INIT2(pApi);
  (void)pzErrMsg;  /* Unused */
  rc = sqlite3_create_function(db, "regexp", 2, 
                            SQLITE_UTF8|SQLITE_INNOCUOUS|SQLITE_DETERMINISTIC,
                            0, re_sql_func, 0, 0);
  if( rc==SQLITE_OK ){
    /* The regexpi(PATTERN,STRING) function is a case-insensitive version
    ** of regexp(PATTERN,STRING). */
    rc = sqlite3_create_function(db, "regexpi", 2,
                            SQLITE_UTF8|SQLITE_INNOCUOUS|SQLITE_DETERMINISTIC,
                            (void*)db, re_sql_func, 0, 0);
#if defined(SQLITE_DEBUG)
    if( rc==SQLITE_OK ){
      rc = sqlite3_create_function(db, "regexp_bytecode", 1,
                            SQLITE_UTF8|SQLITE_INNOCUOUS|SQLITE_DETERMINISTIC,
                            0, re_bytecode_func, 0, 0);
    }
#endif /* SQLITE_DEBUG */
  }
  return rc;
}

/************************* End ../ext/misc/regexp.c ********************/
#ifndef SQLITE_SHELL_FIDDLE
/************************* Begin ../ext/misc/fileio.c ******************/
/*
** 2014-06-13
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
******************************************************************************
**
** This SQLite extension implements SQL functions readfile() and
** writefile(), and eponymous virtual type "fsdir".
**
** WRITEFILE(FILE, DATA [, MODE [, MTIME]]):
**
**   If neither of the optional arguments is present, then this UDF
**   function writes blob DATA to file FILE. If successful, the number
**   of bytes written is returned. If an error occurs, NULL is returned.
**
**   If the first option argument - MODE - is present, then it must
**   be passed an integer value that corresponds to a POSIX mode
**   value (file type + permissions, as returned in the stat.st_mode
**   field by the stat() system call). Three types of files may
**   be written/created:
**
**     regular files:  (mode & 0170000)==0100000
**     symbolic links: (mode & 0170000)==0120000
**     directories:    (mode & 0170000)==0040000
**
**   For a directory, the DATA is ignored. For a symbolic link, it is
**   interpreted as text and used as the target of the link. For a
**   regular file, it is interpreted as a blob and written into the
**   named file. Regardless of the type of file, its permissions are
**   set to (mode & 0777) before returning.
**
**   If the optional MTIME argument is present, then it is interpreted
**   as an integer - the number of seconds since the unix epoch. The
**   modification-time of the target file is set to this value before
**   returning.
**
**   If five or more arguments are passed to this function and an
**   error is encountered, an exception is raised.
**
** READFILE(FILE):
**
**   Read and return the contents of file FILE (type blob) from disk.
**
** FSDIR:
**
**   Used as follows:
**
**     SELECT * FROM fsdir($path [, $dir]);
**
**   Parameter $path is an absolute or relative pathname. If the file that it
**   refers to does not exist, it is an error. If the path refers to a regular
**   file or symbolic link, it returns a single row. Or, if the path refers
**   to a directory, it returns one row for the directory, and one row for each
**   file within the hierarchy rooted at $path.
**
**   Each row has the following columns:
**
**     name:  Path to file or directory (text value).
**     mode:  Value of stat.st_mode for directory entry (an integer).
**     mtime: Value of stat.st_mtime for directory entry (an integer).
**     data:  For a regular file, a blob containing the file data. For a
**            symlink, a text value containing the text of the link. For a
**            directory, NULL.
**
**   If a non-NULL value is specified for the optional $dir parameter and
**   $path is a relative path, then $path is interpreted relative to $dir. 
**   And the paths returned in the "name" column of the table are also 
**   relative to directory $dir.
**
** Notes on building this extension for Windows:
**   Unless linked statically with the SQLite library, a preprocessor
**   symbol, FILEIO_WIN32_DLL, must be #define'd to create a stand-alone
**   DLL form of this extension for WIN32. See its use below for details.
*/
/* #include "sqlite3ext.h" */
SQLITE_EXTENSION_INIT1
#include <stdio.h>
#include <string.h>
#include <assert.h>

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#if !defined(_WIN32) && !defined(WIN32)
#  include <unistd.h>
#  include <dirent.h>
#  include <utime.h>
#  include <sys/time.h>
#else
#  include "windows.h"
#  include <io.h>
#  include <direct.h>
/* #  include "test_windirent.h" */
#  define dirent DIRENT
#  ifndef chmod
#    define chmod _chmod
#  endif
#  ifndef stat
#    define stat _stat
#  endif
#  define mkdir(path,mode) _mkdir(path)
#  define lstat(path,buf) stat(path,buf)
#endif
#include <time.h>
#include <errno.h>

/* When used as part of the CLI, the sqlite3_stdio.h module will have
** been included before this one. In that case use the sqlite3_stdio.h
** #defines.  If not, create our own for fopen().
*/
#ifndef _SQLITE3_STDIO_H_
# define sqlite3_fopen fopen
#endif

/*
** Structure of the fsdir() table-valued function
*/
                 /*    0    1    2     3    4           5             */
#define FSDIR_SCHEMA "(name,mode,mtime,data,path HIDDEN,dir HIDDEN)"
#define FSDIR_COLUMN_NAME     0     /* Name of the file */
#define FSDIR_COLUMN_MODE     1     /* Access mode */
#define FSDIR_COLUMN_MTIME    2     /* Last modification time */
#define FSDIR_COLUMN_DATA     3     /* File content */
#define FSDIR_COLUMN_PATH     4     /* Path to top of search */
#define FSDIR_COLUMN_DIR      5     /* Path is relative to this directory */


/*
** Set the result stored by context ctx to a blob containing the 
** contents of file zName.  Or, leave the result unchanged (NULL)
** if the file does not exist or is unreadable.
**
** If the file exceeds the SQLite blob size limit, through an
** SQLITE_TOOBIG error.
**
** Throw an SQLITE_IOERR if there are difficulties pulling the file
** off of disk.
*/
static void readFileContents(sqlite3_context *ctx, const char *zName){
  FILE *in;
  sqlite3_int64 nIn;
  void *pBuf;
  sqlite3 *db;
  int mxBlob;

  in = sqlite3_fopen(zName, "rb");
  if( in==0 ){
    /* File does not exist or is unreadable. Leave the result set to NULL. */
    return;
  }
  fseek(in, 0, SEEK_END);
  nIn = ftell(in);
  rewind(in);
  db = sqlite3_context_db_handle(ctx);
  mxBlob = sqlite3_limit(db, SQLITE_LIMIT_LENGTH, -1);
  if( nIn>mxBlob ){
    sqlite3_result_error_code(ctx, SQLITE_TOOBIG);
    fclose(in);
    return;
  }
  pBuf = sqlite3_malloc64( nIn ? nIn : 1 );
  if( pBuf==0 ){
    sqlite3_result_error_nomem(ctx);
    fclose(in);
    return;
  }
  if( nIn==(sqlite3_int64)fread(pBuf, 1, (size_t)nIn, in) ){
    sqlite3_result_blob64(ctx, pBuf, nIn, sqlite3_free);
  }else{
    sqlite3_result_error_code(ctx, SQLITE_IOERR);
    sqlite3_free(pBuf);
  }
  fclose(in);
}

/*
** Implementation of the "readfile(X)" SQL function.  The entire content
** of the file named X is read and returned as a BLOB.  NULL is returned
** if the file does not exist or is unreadable.
*/
static void readfileFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  const char *zName;
  (void)(argc);  /* Unused parameter */
  zName = (const char*)sqlite3_value_text(argv[0]);
  if( zName==0 ) return;
  readFileContents(context, zName);
}

/*
** Set the error message contained in context ctx to the results of
** vprintf(zFmt, ...).
*/
static void ctxErrorMsg(sqlite3_context *ctx, const char *zFmt, ...){
  char *zMsg = 0;
  va_list ap;
  va_start(ap, zFmt);
  zMsg = sqlite3_vmprintf(zFmt, ap);
  sqlite3_result_error(ctx, zMsg, -1);
  sqlite3_free(zMsg);
  va_end(ap);
}

#if defined(_WIN32)
/*
** This function is designed to convert a Win32 FILETIME structure into the
** number of seconds since the Unix Epoch (1970-01-01 00:00:00 UTC).
*/
static sqlite3_uint64 fileTimeToUnixTime(
  LPFILETIME pFileTime
){
  SYSTEMTIME epochSystemTime;
  ULARGE_INTEGER epochIntervals;
  FILETIME epochFileTime;
  ULARGE_INTEGER fileIntervals;

  memset(&epochSystemTime, 0, sizeof(SYSTEMTIME));
  epochSystemTime.wYear = 1970;
  epochSystemTime.wMonth = 1;
  epochSystemTime.wDay = 1;
  SystemTimeToFileTime(&epochSystemTime, &epochFileTime);
  epochIntervals.LowPart = epochFileTime.dwLowDateTime;
  epochIntervals.HighPart = epochFileTime.dwHighDateTime;

  fileIntervals.LowPart = pFileTime->dwLowDateTime;
  fileIntervals.HighPart = pFileTime->dwHighDateTime;

  return (fileIntervals.QuadPart - epochIntervals.QuadPart) / 10000000;
}


#if defined(FILEIO_WIN32_DLL) && (defined(_WIN32) || defined(WIN32))
#  /* To allow a standalone DLL, use this next replacement function: */
#  undef sqlite3_win32_utf8_to_unicode
#  define sqlite3_win32_utf8_to_unicode utf8_to_utf16
#
LPWSTR utf8_to_utf16(const char *z){
  int nAllot = MultiByteToWideChar(CP_UTF8, 0, z, -1, NULL, 0);
  LPWSTR rv = sqlite3_malloc(nAllot * sizeof(WCHAR));
  if( rv!=0 && 0 < MultiByteToWideChar(CP_UTF8, 0, z, -1, rv, nAllot) )
    return rv;
  sqlite3_free(rv);
  return 0;
}
#endif

/*
** This function attempts to normalize the time values found in the stat()
** buffer to UTC.  This is necessary on Win32, where the runtime library
** appears to return these values as local times.
*/
static void statTimesToUtc(
  const char *zPath,
  struct stat *pStatBuf
){
  HANDLE hFindFile;
  WIN32_FIND_DATAW fd;
  LPWSTR zUnicodeName;
  extern LPWSTR sqlite3_win32_utf8_to_unicode(const char*);
  zUnicodeName = sqlite3_win32_utf8_to_unicode(zPath);
  if( zUnicodeName ){
    memset(&fd, 0, sizeof(WIN32_FIND_DATAW));
    hFindFile = FindFirstFileW(zUnicodeName, &fd);
    if( hFindFile!=NULL ){
      pStatBuf->st_ctime = (time_t)fileTimeToUnixTime(&fd.ftCreationTime);
      pStatBuf->st_atime = (time_t)fileTimeToUnixTime(&fd.ftLastAccessTime);
      pStatBuf->st_mtime = (time_t)fileTimeToUnixTime(&fd.ftLastWriteTime);
      FindClose(hFindFile);
    }
    sqlite3_free(zUnicodeName);
  }
}
#endif

/*
** This function is used in place of stat().  On Windows, special handling
** is required in order for the included time to be returned as UTC.  On all
** other systems, this function simply calls stat().
*/
static int fileStat(
  const char *zPath,
  struct stat *pStatBuf
){
#if defined(_WIN32)
  int rc = stat(zPath, pStatBuf);
  if( rc==0 ) statTimesToUtc(zPath, pStatBuf);
  return rc;
#else
  return stat(zPath, pStatBuf);
#endif
}

/*
** This function is used in place of lstat().  On Windows, special handling
** is required in order for the included time to be returned as UTC.  On all
** other systems, this function simply calls lstat().
*/
static int fileLinkStat(
  const char *zPath,
  struct stat *pStatBuf
){
#if defined(_WIN32)
  int rc = lstat(zPath, pStatBuf);
  if( rc==0 ) statTimesToUtc(zPath, pStatBuf);
  return rc;
#else
  return lstat(zPath, pStatBuf);
#endif
}

/*
** Argument zFile is the name of a file that will be created and/or written
** by SQL function writefile(). This function ensures that the directory
** zFile will be written to exists, creating it if required. The permissions
** for any path components created by this function are set in accordance
** with the current umask.
**
** If an OOM condition is encountered, SQLITE_NOMEM is returned. Otherwise,
** SQLITE_OK is returned if the directory is successfully created, or
** SQLITE_ERROR otherwise.
*/
static int makeDirectory(
  const char *zFile
){
  char *zCopy = sqlite3_mprintf("%s", zFile);
  int rc = SQLITE_OK;

  if( zCopy==0 ){
    rc = SQLITE_NOMEM;
  }else{
    int nCopy = (int)strlen(zCopy);
    int i = 1;

    while( rc==SQLITE_OK ){
      struct stat sStat;
      int rc2;

      for(; zCopy[i]!='/' && i<nCopy; i++);
      if( i==nCopy ) break;
      zCopy[i] = '\0';

      rc2 = fileStat(zCopy, &sStat);
      if( rc2!=0 ){
        if( mkdir(zCopy, 0777) ) rc = SQLITE_ERROR;
      }else{
        if( !S_ISDIR(sStat.st_mode) ) rc = SQLITE_ERROR;
      }
      zCopy[i] = '/';
      i++;
    }

    sqlite3_free(zCopy);
  }

  return rc;
}

/*
** This function does the work for the writefile() UDF. Refer to 
** header comments at the top of this file for details.
*/
static int writeFile(
  sqlite3_context *pCtx,          /* Context to return bytes written in */
  const char *zFile,              /* File to write */
  sqlite3_value *pData,           /* Data to write */
  mode_t mode,                    /* MODE parameter passed to writefile() */
  sqlite3_int64 mtime             /* MTIME parameter (or -1 to not set time) */
){
  if( zFile==0 ) return 1;
#if !defined(_WIN32) && !defined(WIN32)
  if( S_ISLNK(mode) ){
    const char *zTo = (const char*)sqlite3_value_text(pData);
    if( zTo==0 ) return 1;
    unlink(zFile);
    if( symlink(zTo, zFile)<0 ) return 1;
  }else
#endif
  {
    if( S_ISDIR(mode) ){
      if( mkdir(zFile, mode) ){
        /* The mkdir() call to create the directory failed. This might not
        ** be an error though - if there is already a directory at the same
        ** path and either the permissions already match or can be changed
        ** to do so using chmod(), it is not an error.  */
        struct stat sStat;
        if( errno!=EEXIST
         || 0!=fileStat(zFile, &sStat)
         || !S_ISDIR(sStat.st_mode)
         || ((sStat.st_mode&0777)!=(mode&0777) && 0!=chmod(zFile, mode&0777))
        ){
          return 1;
        }
      }
    }else{
      sqlite3_int64 nWrite = 0;
      const char *z;
      int rc = 0;
      FILE *out = sqlite3_fopen(zFile, "wb");
      if( out==0 ) return 1;
      z = (const char*)sqlite3_value_blob(pData);
      if( z ){
        sqlite3_int64 n = fwrite(z, 1, sqlite3_value_bytes(pData), out);
        nWrite = sqlite3_value_bytes(pData);
        if( nWrite!=n ){
          rc = 1;
        }
      }
      fclose(out);
      if( rc==0 && mode && chmod(zFile, mode & 0777) ){
        rc = 1;
      }
      if( rc ) return 2;
      sqlite3_result_int64(pCtx, nWrite);
    }
  }

  if( mtime>=0 ){
#if defined(_WIN32)
#if !SQLITE_OS_WINRT
    /* Windows */
    FILETIME lastAccess;
    FILETIME lastWrite;
    SYSTEMTIME currentTime;
    LONGLONG intervals;
    HANDLE hFile;
    LPWSTR zUnicodeName;
    extern LPWSTR sqlite3_win32_utf8_to_unicode(const char*);

    GetSystemTime(&currentTime);
    SystemTimeToFileTime(&currentTime, &lastAccess);
    intervals = Int32x32To64(mtime, 10000000) + 116444736000000000;
    lastWrite.dwLowDateTime = (DWORD)intervals;
    lastWrite.dwHighDateTime = intervals >> 32;
    zUnicodeName = sqlite3_win32_utf8_to_unicode(zFile);
    if( zUnicodeName==0 ){
      return 1;
    }
    hFile = CreateFileW(
      zUnicodeName, FILE_WRITE_ATTRIBUTES, 0, NULL, OPEN_EXISTING,
      FILE_FLAG_BACKUP_SEMANTICS, NULL
    );
    sqlite3_free(zUnicodeName);
    if( hFile!=INVALID_HANDLE_VALUE ){
      BOOL bResult = SetFileTime(hFile, NULL, &lastAccess, &lastWrite);
      CloseHandle(hFile);
      return !bResult;
    }else{
      return 1;
    }
#endif
#elif defined(AT_FDCWD) && 0 /* utimensat() is not universally available */
    /* Recent unix */
    struct timespec times[2];
    times[0].tv_nsec = times[1].tv_nsec = 0;
    times[0].tv_sec = time(0);
    times[1].tv_sec = mtime;
    if( utimensat(AT_FDCWD, zFile, times, AT_SYMLINK_NOFOLLOW) ){
      return 1;
    }
#else
    /* Legacy unix. 
    **
    ** Do not use utimes() on a symbolic link - it sees through the link and
    ** modifies the timestamps on the target. Or fails if the target does 
    ** not exist.  */
    if( 0==S_ISLNK(mode) ){
      struct timeval times[2];
      times[0].tv_usec = times[1].tv_usec = 0;
      times[0].tv_sec = time(0);
      times[1].tv_sec = mtime;
      if( utimes(zFile, times) ){
        return 1;
      }
    }
#endif
  }

  return 0;
}

/*
** Implementation of the "writefile(W,X[,Y[,Z]]])" SQL function.  
** Refer to header comments at the top of this file for details.
*/
static void writefileFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  const char *zFile;
  mode_t mode = 0;
  int res;
  sqlite3_int64 mtime = -1;

  if( argc<2 || argc>4 ){
    sqlite3_result_error(context, 
        "wrong number of arguments to function writefile()", -1
    );
    return;
  }

  zFile = (const char*)sqlite3_value_text(argv[0]);
  if( zFile==0 ) return;
  if( argc>=3 ){
    mode = (mode_t)sqlite3_value_int(argv[2]);
  }
  if( argc==4 ){
    mtime = sqlite3_value_int64(argv[3]);
  }

  res = writeFile(context, zFile, argv[1], mode, mtime);
  if( res==1 && errno==ENOENT ){
    if( makeDirectory(zFile)==SQLITE_OK ){
      res = writeFile(context, zFile, argv[1], mode, mtime);
    }
  }

  if( argc>2 && res!=0 ){
    if( S_ISLNK(mode) ){
      ctxErrorMsg(context, "failed to create symlink: %s", zFile);
    }else if( S_ISDIR(mode) ){
      ctxErrorMsg(context, "failed to create directory: %s", zFile);
    }else{
      ctxErrorMsg(context, "failed to write file: %s", zFile);
    }
  }
}

/*
** SQL function:   lsmode(MODE)
**
** Given a numberic st_mode from stat(), convert it into a human-readable
** text string in the style of "ls -l".
*/
static void lsModeFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  int i;
  int iMode = sqlite3_value_int(argv[0]);
  char z[16];
  (void)argc;
  if( S_ISLNK(iMode) ){
    z[0] = 'l';
  }else if( S_ISREG(iMode) ){
    z[0] = '-';
  }else if( S_ISDIR(iMode) ){
    z[0] = 'd';
  }else{
    z[0] = '?';
  }
  for(i=0; i<3; i++){
    int m = (iMode >> ((2-i)*3));
    char *a = &z[1 + i*3];
    a[0] = (m & 0x4) ? 'r' : '-';
    a[1] = (m & 0x2) ? 'w' : '-';
    a[2] = (m & 0x1) ? 'x' : '-';
  }
  z[10] = '\0';
  sqlite3_result_text(context, z, -1, SQLITE_TRANSIENT);
}

#ifndef SQLITE_OMIT_VIRTUALTABLE

/* 
** Cursor type for recursively iterating through a directory structure.
*/
typedef struct fsdir_cursor fsdir_cursor;
typedef struct FsdirLevel FsdirLevel;

struct FsdirLevel {
  DIR *pDir;                 /* From opendir() */
  char *zDir;                /* Name of directory (nul-terminated) */
};

struct fsdir_cursor {
  sqlite3_vtab_cursor base;  /* Base class - must be first */

  int nLvl;                  /* Number of entries in aLvl[] array */
  int iLvl;                  /* Index of current entry */
  FsdirLevel *aLvl;          /* Hierarchy of directories being traversed */

  const char *zBase;
  int nBase;

  struct stat sStat;         /* Current lstat() results */
  char *zPath;               /* Path to current entry */
  sqlite3_int64 iRowid;      /* Current rowid */
};

typedef struct fsdir_tab fsdir_tab;
struct fsdir_tab {
  sqlite3_vtab base;         /* Base class - must be first */
};

/*
** Construct a new fsdir virtual table object.
*/
static int fsdirConnect(
  sqlite3 *db,
  void *pAux,
  int argc, const char *const*argv,
  sqlite3_vtab **ppVtab,
  char **pzErr
){
  fsdir_tab *pNew = 0;
  int rc;
  (void)pAux;
  (void)argc;
  (void)argv;
  (void)pzErr;
  rc = sqlite3_declare_vtab(db, "CREATE TABLE x" FSDIR_SCHEMA);
  if( rc==SQLITE_OK ){
    pNew = (fsdir_tab*)sqlite3_malloc( sizeof(*pNew) );
    if( pNew==0 ) return SQLITE_NOMEM;
    memset(pNew, 0, sizeof(*pNew));
    sqlite3_vtab_config(db, SQLITE_VTAB_DIRECTONLY);
  }
  *ppVtab = (sqlite3_vtab*)pNew;
  return rc;
}

/*
** This method is the destructor for fsdir vtab objects.
*/
static int fsdirDisconnect(sqlite3_vtab *pVtab){
  sqlite3_free(pVtab);
  return SQLITE_OK;
}

/*
** Constructor for a new fsdir_cursor object.
*/
static int fsdirOpen(sqlite3_vtab *p, sqlite3_vtab_cursor **ppCursor){
  fsdir_cursor *pCur;
  (void)p;
  pCur = sqlite3_malloc( sizeof(*pCur) );
  if( pCur==0 ) return SQLITE_NOMEM;
  memset(pCur, 0, sizeof(*pCur));
  pCur->iLvl = -1;
  *ppCursor = &pCur->base;
  return SQLITE_OK;
}

/*
** Reset a cursor back to the state it was in when first returned
** by fsdirOpen().
*/
static void fsdirResetCursor(fsdir_cursor *pCur){
  int i;
  for(i=0; i<=pCur->iLvl; i++){
    FsdirLevel *pLvl = &pCur->aLvl[i];
    if( pLvl->pDir ) closedir(pLvl->pDir);
    sqlite3_free(pLvl->zDir);
  }
  sqlite3_free(pCur->zPath);
  sqlite3_free(pCur->aLvl);
  pCur->aLvl = 0;
  pCur->zPath = 0;
  pCur->zBase = 0;
  pCur->nBase = 0;
  pCur->nLvl = 0;
  pCur->iLvl = -1;
  pCur->iRowid = 1;
}

/*
** Destructor for an fsdir_cursor.
*/
static int fsdirClose(sqlite3_vtab_cursor *cur){
  fsdir_cursor *pCur = (fsdir_cursor*)cur;

  fsdirResetCursor(pCur);
  sqlite3_free(pCur);
  return SQLITE_OK;
}

/*
** Set the error message for the virtual table associated with cursor
** pCur to the results of vprintf(zFmt, ...).
*/
static void fsdirSetErrmsg(fsdir_cursor *pCur, const char *zFmt, ...){
  va_list ap;
  va_start(ap, zFmt);
  pCur->base.pVtab->zErrMsg = sqlite3_vmprintf(zFmt, ap);
  va_end(ap);
}


/*
** Advance an fsdir_cursor to its next row of output.
*/
static int fsdirNext(sqlite3_vtab_cursor *cur){
  fsdir_cursor *pCur = (fsdir_cursor*)cur;
  mode_t m = pCur->sStat.st_mode;

  pCur->iRowid++;
  if( S_ISDIR(m) ){
    /* Descend into this directory */
    int iNew = pCur->iLvl + 1;
    FsdirLevel *pLvl;
    if( iNew>=pCur->nLvl ){
      int nNew = iNew+1;
      sqlite3_int64 nByte = nNew*sizeof(FsdirLevel);
      FsdirLevel *aNew = (FsdirLevel*)sqlite3_realloc64(pCur->aLvl, nByte);
      if( aNew==0 ) return SQLITE_NOMEM;
      memset(&aNew[pCur->nLvl], 0, sizeof(FsdirLevel)*(nNew-pCur->nLvl));
      pCur->aLvl = aNew;
      pCur->nLvl = nNew;
    }
    pCur->iLvl = iNew;
    pLvl = &pCur->aLvl[iNew];
    
    pLvl->zDir = pCur->zPath;
    pCur->zPath = 0;
    pLvl->pDir = opendir(pLvl->zDir);
    if( pLvl->pDir==0 ){
      fsdirSetErrmsg(pCur, "cannot read directory: %s", pCur->zPath);
      return SQLITE_ERROR;
    }
  }

  while( pCur->iLvl>=0 ){
    FsdirLevel *pLvl = &pCur->aLvl[pCur->iLvl];
    struct dirent *pEntry = readdir(pLvl->pDir);
    if( pEntry ){
      if( pEntry->d_name[0]=='.' ){
       if( pEntry->d_name[1]=='.' && pEntry->d_name[2]=='\0' ) continue;
       if( pEntry->d_name[1]=='\0' ) continue;
      }
      sqlite3_free(pCur->zPath);
      pCur->zPath = sqlite3_mprintf("%s/%s", pLvl->zDir, pEntry->d_name);
      if( pCur->zPath==0 ) return SQLITE_NOMEM;
      if( fileLinkStat(pCur->zPath, &pCur->sStat) ){
        fsdirSetErrmsg(pCur, "cannot stat file: %s", pCur->zPath);
        return SQLITE_ERROR;
      }
      return SQLITE_OK;
    }
    closedir(pLvl->pDir);
    sqlite3_free(pLvl->zDir);
    pLvl->pDir = 0;
    pLvl->zDir = 0;
    pCur->iLvl--;
  }

  /* EOF */
  sqlite3_free(pCur->zPath);
  pCur->zPath = 0;
  return SQLITE_OK;
}

/*
** Return values of columns for the row at which the series_cursor
** is currently pointing.
*/
static int fsdirColumn(
  sqlite3_vtab_cursor *cur,   /* The cursor */
  sqlite3_context *ctx,       /* First argument to sqlite3_result_...() */
  int i                       /* Which column to return */
){
  fsdir_cursor *pCur = (fsdir_cursor*)cur;
  switch( i ){
    case FSDIR_COLUMN_NAME: {
      sqlite3_result_text(ctx, &pCur->zPath[pCur->nBase], -1, SQLITE_TRANSIENT);
      break;
    }

    case FSDIR_COLUMN_MODE:
      sqlite3_result_int64(ctx, pCur->sStat.st_mode);
      break;

    case FSDIR_COLUMN_MTIME:
      sqlite3_result_int64(ctx, pCur->sStat.st_mtime);
      break;

    case FSDIR_COLUMN_DATA: {
      mode_t m = pCur->sStat.st_mode;
      if( S_ISDIR(m) ){
        sqlite3_result_null(ctx);
#if !defined(_WIN32) && !defined(WIN32)
      }else if( S_ISLNK(m) ){
        char aStatic[64];
        char *aBuf = aStatic;
        sqlite3_int64 nBuf = 64;
        int n;

        while( 1 ){
          n = readlink(pCur->zPath, aBuf, nBuf);
          if( n<nBuf ) break;
          if( aBuf!=aStatic ) sqlite3_free(aBuf);
          nBuf = nBuf*2;
          aBuf = sqlite3_malloc64(nBuf);
          if( aBuf==0 ){
            sqlite3_result_error_nomem(ctx);
            return SQLITE_NOMEM;
          }
        }

        sqlite3_result_text(ctx, aBuf, n, SQLITE_TRANSIENT);
        if( aBuf!=aStatic ) sqlite3_free(aBuf);
#endif
      }else{
        readFileContents(ctx, pCur->zPath);
      }
    }
    case FSDIR_COLUMN_PATH:
    default: {
      /* The FSDIR_COLUMN_PATH and FSDIR_COLUMN_DIR are input parameters.
      ** always return their values as NULL */
      break;
    }
  }
  return SQLITE_OK;
}

/*
** Return the rowid for the current row. In this implementation, the
** first row returned is assigned rowid value 1, and each subsequent
** row a value 1 more than that of the previous.
*/
static int fsdirRowid(sqlite3_vtab_cursor *cur, sqlite_int64 *pRowid){
  fsdir_cursor *pCur = (fsdir_cursor*)cur;
  *pRowid = pCur->iRowid;
  return SQLITE_OK;
}

/*
** Return TRUE if the cursor has been moved off of the last
** row of output.
*/
static int fsdirEof(sqlite3_vtab_cursor *cur){
  fsdir_cursor *pCur = (fsdir_cursor*)cur;
  return (pCur->zPath==0);
}

/*
** xFilter callback.
**
** idxNum==1   PATH parameter only
** idxNum==2   Both PATH and DIR supplied
*/
static int fsdirFilter(
  sqlite3_vtab_cursor *cur, 
  int idxNum, const char *idxStr,
  int argc, sqlite3_value **argv
){
  const char *zDir = 0;
  fsdir_cursor *pCur = (fsdir_cursor*)cur;
  (void)idxStr;
  fsdirResetCursor(pCur);

  if( idxNum==0 ){
    fsdirSetErrmsg(pCur, "table function fsdir requires an argument");
    return SQLITE_ERROR;
  }

  assert( argc==idxNum && (argc==1 || argc==2) );
  zDir = (const char*)sqlite3_value_text(argv[0]);
  if( zDir==0 ){
    fsdirSetErrmsg(pCur, "table function fsdir requires a non-NULL argument");
    return SQLITE_ERROR;
  }
  if( argc==2 ){
    pCur->zBase = (const char*)sqlite3_value_text(argv[1]);
  }
  if( pCur->zBase ){
    pCur->nBase = (int)strlen(pCur->zBase)+1;
    pCur->zPath = sqlite3_mprintf("%s/%s", pCur->zBase, zDir);
  }else{
    pCur->zPath = sqlite3_mprintf("%s", zDir);
  }

  if( pCur->zPath==0 ){
    return SQLITE_NOMEM;
  }
  if( fileLinkStat(pCur->zPath, &pCur->sStat) ){
    fsdirSetErrmsg(pCur, "cannot stat file: %s", pCur->zPath);
    return SQLITE_ERROR;
  }

  return SQLITE_OK;
}

/*
** SQLite will invoke this method one or more times while planning a query
** that uses the generate_series virtual table.  This routine needs to create
** a query plan for each invocation and compute an estimated cost for that
** plan.
**
** In this implementation idxNum is used to represent the
** query plan.  idxStr is unused.
**
** The query plan is represented by values of idxNum:
**
**  (1)  The path value is supplied by argv[0]
**  (2)  Path is in argv[0] and dir is in argv[1]
*/
static int fsdirBestIndex(
  sqlite3_vtab *tab,
  sqlite3_index_info *pIdxInfo
){
  int i;                 /* Loop over constraints */
  int idxPath = -1;      /* Index in pIdxInfo->aConstraint of PATH= */
  int idxDir = -1;       /* Index in pIdxInfo->aConstraint of DIR= */
  int seenPath = 0;      /* True if an unusable PATH= constraint is seen */
  int seenDir = 0;       /* True if an unusable DIR= constraint is seen */
  const struct sqlite3_index_constraint *pConstraint;

  (void)tab;
  pConstraint = pIdxInfo->aConstraint;
  for(i=0; i<pIdxInfo->nConstraint; i++, pConstraint++){
    if( pConstraint->op!=SQLITE_INDEX_CONSTRAINT_EQ ) continue;
    switch( pConstraint->iColumn ){
      case FSDIR_COLUMN_PATH: {
        if( pConstraint->usable ){
          idxPath = i;
          seenPath = 0;
        }else if( idxPath<0 ){
          seenPath = 1;
        }
        break;
      }
      case FSDIR_COLUMN_DIR: {
        if( pConstraint->usable ){
          idxDir = i;
          seenDir = 0;
        }else if( idxDir<0 ){
          seenDir = 1;
        }
        break;
      }
    } 
  }
  if( seenPath || seenDir ){
    /* If input parameters are unusable, disallow this plan */
    return SQLITE_CONSTRAINT;
  }

  if( idxPath<0 ){
    pIdxInfo->idxNum = 0;
    /* The pIdxInfo->estimatedCost should have been initialized to a huge
    ** number.  Leave it unchanged. */
    pIdxInfo->estimatedRows = 0x7fffffff;
  }else{
    pIdxInfo->aConstraintUsage[idxPath].omit = 1;
    pIdxInfo->aConstraintUsage[idxPath].argvIndex = 1;
    if( idxDir>=0 ){
      pIdxInfo->aConstraintUsage[idxDir].omit = 1;
      pIdxInfo->aConstraintUsage[idxDir].argvIndex = 2;
      pIdxInfo->idxNum = 2;
      pIdxInfo->estimatedCost = 10.0;
    }else{
      pIdxInfo->idxNum = 1;
      pIdxInfo->estimatedCost = 100.0;
    }
  }

  return SQLITE_OK;
}

/*
** Register the "fsdir" virtual table.
*/
static int fsdirRegister(sqlite3 *db){
  static sqlite3_module fsdirModule = {
    0,                         /* iVersion */
    0,                         /* xCreate */
    fsdirConnect,              /* xConnect */
    fsdirBestIndex,            /* xBestIndex */
    fsdirDisconnect,           /* xDisconnect */
    0,                         /* xDestroy */
    fsdirOpen,                 /* xOpen - open a cursor */
    fsdirClose,                /* xClose - close a cursor */
    fsdirFilter,               /* xFilter - configure scan constraints */
    fsdirNext,                 /* xNext - advance a cursor */
    fsdirEof,                  /* xEof - check for end of scan */
    fsdirColumn,               /* xColumn - read data */
    fsdirRowid,                /* xRowid - read data */
    0,                         /* xUpdate */
    0,                         /* xBegin */
    0,                         /* xSync */
    0,                         /* xCommit */
    0,                         /* xRollback */
    0,                         /* xFindMethod */
    0,                         /* xRename */
    0,                         /* xSavepoint */
    0,                         /* xRelease */
    0,                         /* xRollbackTo */
    0,                         /* xShadowName */
    0                          /* xIntegrity */
  };

  int rc = sqlite3_create_module(db, "fsdir", &fsdirModule, 0);
  return rc;
}
#else         /* SQLITE_OMIT_VIRTUALTABLE */
# define fsdirRegister(x) SQLITE_OK
#endif

#ifdef _WIN32

#endif
int sqlite3_fileio_init(
  sqlite3 *db, 
  char **pzErrMsg, 
  const sqlite3_api_routines *pApi
){
  int rc = SQLITE_OK;
  SQLITE_EXTENSION_INIT2(pApi);
  (void)pzErrMsg;  /* Unused parameter */
  rc = sqlite3_create_function(db, "readfile", 1, 
                               SQLITE_UTF8|SQLITE_DIRECTONLY, 0,
                               readfileFunc, 0, 0);
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_function(db, "writefile", -1,
                                 SQLITE_UTF8|SQLITE_DIRECTONLY, 0,
                                 writefileFunc, 0, 0);
  }
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_function(db, "lsmode", 1, SQLITE_UTF8, 0,
                                 lsModeFunc, 0, 0);
  }
  if( rc==SQLITE_OK ){
    rc = fsdirRegister(db);
  }
  return rc;
}

#if defined(FILEIO_WIN32_DLL) && (defined(_WIN32) || defined(WIN32))
/* To allow a standalone DLL, make test_windirent.c use the same
 * redefined SQLite API calls as the above extension code does.
 * Just pull in this .c to accomplish this. As a beneficial side
 * effect, this extension becomes a single translation unit. */
#  include "test_windirent.c"
#endif

/************************* End ../ext/misc/fileio.c ********************/
/************************* Begin ../ext/misc/completion.c ******************/
/*
** 2017-07-10
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
**
** This file implements an eponymous virtual table that returns suggested
** completions for a partial SQL input.
**
** Suggested usage:
**
**     SELECT DISTINCT candidate COLLATE nocase
**       FROM completion($prefix,$wholeline)
**      ORDER BY 1;
**
** The two query parameters are optional.  $prefix is the text of the
** current word being typed and that is to be completed.  $wholeline is
** the complete input line, used for context.
**
** The raw completion() table might return the same candidate multiple
** times, for example if the same column name is used to two or more
** tables.  And the candidates are returned in an arbitrary order.  Hence,
** the DISTINCT and ORDER BY are recommended.
**
** This virtual table operates at the speed of human typing, and so there
** is no attempt to make it fast.  Even a slow implementation will be much
** faster than any human can type.
**
*/
/* #include "sqlite3ext.h" */
SQLITE_EXTENSION_INIT1
#include <assert.h>
#include <string.h>
#include <ctype.h>

#ifndef SQLITE_OMIT_VIRTUALTABLE

/* completion_vtab is a subclass of sqlite3_vtab which will
** serve as the underlying representation of a completion virtual table
*/
typedef struct completion_vtab completion_vtab;
struct completion_vtab {
  sqlite3_vtab base;  /* Base class - must be first */
  sqlite3 *db;        /* Database connection for this completion vtab */
};

/* completion_cursor is a subclass of sqlite3_vtab_cursor which will
** serve as the underlying representation of a cursor that scans
** over rows of the result
*/
typedef struct completion_cursor completion_cursor;
struct completion_cursor {
  sqlite3_vtab_cursor base;  /* Base class - must be first */
  sqlite3 *db;               /* Database connection for this cursor */
  int nPrefix, nLine;        /* Number of bytes in zPrefix and zLine */
  char *zPrefix;             /* The prefix for the word we want to complete */
  char *zLine;               /* The whole that we want to complete */
  const char *zCurrentRow;   /* Current output row */
  int szRow;                 /* Length of the zCurrentRow string */
  sqlite3_stmt *pStmt;       /* Current statement */
  sqlite3_int64 iRowid;      /* The rowid */
  int ePhase;                /* Current phase */
  int j;                     /* inter-phase counter */
};

/* Values for ePhase:
*/
#define COMPLETION_FIRST_PHASE   1
#define COMPLETION_KEYWORDS      1
#define COMPLETION_PRAGMAS       2
#define COMPLETION_FUNCTIONS     3
#define COMPLETION_COLLATIONS    4
#define COMPLETION_INDEXES       5
#define COMPLETION_TRIGGERS      6
#define COMPLETION_DATABASES     7
#define COMPLETION_TABLES        8    /* Also VIEWs and TRIGGERs */
#define COMPLETION_COLUMNS       9
#define COMPLETION_MODULES       10
#define COMPLETION_EOF           11

/*
** The completionConnect() method is invoked to create a new
** completion_vtab that describes the completion virtual table.
**
** Think of this routine as the constructor for completion_vtab objects.
**
** All this routine needs to do is:
**
**    (1) Allocate the completion_vtab object and initialize all fields.
**
**    (2) Tell SQLite (via the sqlite3_declare_vtab() interface) what the
**        result set of queries against completion will look like.
*/
static int completionConnect(
  sqlite3 *db,
  void *pAux,
  int argc, const char *const*argv,
  sqlite3_vtab **ppVtab,
  char **pzErr
){
  completion_vtab *pNew;
  int rc;

  (void)(pAux);    /* Unused parameter */
  (void)(argc);    /* Unused parameter */
  (void)(argv);    /* Unused parameter */
  (void)(pzErr);   /* Unused parameter */

/* Column numbers */
#define COMPLETION_COLUMN_CANDIDATE 0  /* Suggested completion of the input */
#define COMPLETION_COLUMN_PREFIX    1  /* Prefix of the word to be completed */
#define COMPLETION_COLUMN_WHOLELINE 2  /* Entire line seen so far */
#define COMPLETION_COLUMN_PHASE     3  /* ePhase - used for debugging only */

  sqlite3_vtab_config(db, SQLITE_VTAB_INNOCUOUS);
  rc = sqlite3_declare_vtab(db,
      "CREATE TABLE x("
      "  candidate TEXT,"
      "  prefix TEXT HIDDEN,"
      "  wholeline TEXT HIDDEN,"
      "  phase INT HIDDEN"        /* Used for debugging only */
      ")");
  if( rc==SQLITE_OK ){
    pNew = sqlite3_malloc( sizeof(*pNew) );
    *ppVtab = (sqlite3_vtab*)pNew;
    if( pNew==0 ) return SQLITE_NOMEM;
    memset(pNew, 0, sizeof(*pNew));
    pNew->db = db;
  }
  return rc;
}

/*
** This method is the destructor for completion_cursor objects.
*/
static int completionDisconnect(sqlite3_vtab *pVtab){
  sqlite3_free(pVtab);
  return SQLITE_OK;
}

/*
** Constructor for a new completion_cursor object.
*/
static int completionOpen(sqlite3_vtab *p, sqlite3_vtab_cursor **ppCursor){
  completion_cursor *pCur;
  pCur = sqlite3_malloc( sizeof(*pCur) );
  if( pCur==0 ) return SQLITE_NOMEM;
  memset(pCur, 0, sizeof(*pCur));
  pCur->db = ((completion_vtab*)p)->db;
  *ppCursor = &pCur->base;
  return SQLITE_OK;
}

/*
** Reset the completion_cursor.
*/
static void completionCursorReset(completion_cursor *pCur){
  sqlite3_free(pCur->zPrefix);   pCur->zPrefix = 0;  pCur->nPrefix = 0;
  sqlite3_free(pCur->zLine);     pCur->zLine = 0;    pCur->nLine = 0;
  sqlite3_finalize(pCur->pStmt); pCur->pStmt = 0;
  pCur->j = 0;
}

/*
** Destructor for a completion_cursor.
*/
static int completionClose(sqlite3_vtab_cursor *cur){
  completionCursorReset((completion_cursor*)cur);
  sqlite3_free(cur);
  return SQLITE_OK;
}

/*
** Advance a completion_cursor to its next row of output.
**
** The ->ePhase, ->j, and ->pStmt fields of the completion_cursor object
** record the current state of the scan.  This routine sets ->zCurrentRow
** to the current row of output and then returns.  If no more rows remain,
** then ->ePhase is set to COMPLETION_EOF which will signal the virtual
** table that has reached the end of its scan.
**
** The current implementation just lists potential identifiers and
** keywords and filters them by zPrefix.  Future enhancements should
** take zLine into account to try to restrict the set of identifiers and
** keywords based on what would be legal at the current point of input.
*/
static int completionNext(sqlite3_vtab_cursor *cur){
  completion_cursor *pCur = (completion_cursor*)cur;
  int eNextPhase = 0;  /* Next phase to try if current phase reaches end */
  int iCol = -1;       /* If >=0, step pCur->pStmt and use the i-th column */
  pCur->iRowid++;
  while( pCur->ePhase!=COMPLETION_EOF ){
    switch( pCur->ePhase ){
      case COMPLETION_KEYWORDS: {
        if( pCur->j >= sqlite3_keyword_count() ){
          pCur->zCurrentRow = 0;
          pCur->ePhase = COMPLETION_DATABASES;
        }else{
          sqlite3_keyword_name(pCur->j++, &pCur->zCurrentRow, &pCur->szRow);
        }
        iCol = -1;
        break;
      }
      case COMPLETION_DATABASES: {
        if( pCur->pStmt==0 ){
          sqlite3_prepare_v2(pCur->db, "PRAGMA database_list", -1,
                             &pCur->pStmt, 0);
        }
        iCol = 1;
        eNextPhase = COMPLETION_TABLES;
        break;
      }
      case COMPLETION_TABLES: {
        if( pCur->pStmt==0 ){
          sqlite3_stmt *pS2;
          char *zSql = 0;
          const char *zSep = "";
          sqlite3_prepare_v2(pCur->db, "PRAGMA database_list", -1, &pS2, 0);
          while( sqlite3_step(pS2)==SQLITE_ROW ){
            const char *zDb = (const char*)sqlite3_column_text(pS2, 1);
            zSql = sqlite3_mprintf(
               "%z%s"
               "SELECT name FROM \"%w\".sqlite_schema",
               zSql, zSep, zDb
            );
            if( zSql==0 ) return SQLITE_NOMEM;
            zSep = " UNION ";
          }
          sqlite3_finalize(pS2);
          sqlite3_prepare_v2(pCur->db, zSql, -1, &pCur->pStmt, 0);
          sqlite3_free(zSql);
        }
        iCol = 0;
        eNextPhase = COMPLETION_COLUMNS;
        break;
      }
      case COMPLETION_COLUMNS: {
        if( pCur->pStmt==0 ){
          sqlite3_stmt *pS2;
          char *zSql = 0;
          const char *zSep = "";
          sqlite3_prepare_v2(pCur->db, "PRAGMA database_list", -1, &pS2, 0);
          while( sqlite3_step(pS2)==SQLITE_ROW ){
            const char *zDb = (const char*)sqlite3_column_text(pS2, 1);
            zSql = sqlite3_mprintf(
               "%z%s"
               "SELECT pti.name FROM \"%w\".sqlite_schema AS sm"
                       " JOIN pragma_table_xinfo(sm.name,%Q) AS pti"
               " WHERE sm.type='table'",
               zSql, zSep, zDb, zDb
            );
            if( zSql==0 ) return SQLITE_NOMEM;
            zSep = " UNION ";
          }
          sqlite3_finalize(pS2);
          sqlite3_prepare_v2(pCur->db, zSql, -1, &pCur->pStmt, 0);
          sqlite3_free(zSql);
        }
        iCol = 0;
        eNextPhase = COMPLETION_EOF;
        break;
      }
    }
    if( iCol<0 ){
      /* This case is when the phase presets zCurrentRow */
      if( pCur->zCurrentRow==0 ) continue;
    }else{
      if( sqlite3_step(pCur->pStmt)==SQLITE_ROW ){
        /* Extract the next row of content */
        pCur->zCurrentRow = (const char*)sqlite3_column_text(pCur->pStmt, iCol);
        pCur->szRow = sqlite3_column_bytes(pCur->pStmt, iCol);
      }else{
        /* When all rows are finished, advance to the next phase */
        sqlite3_finalize(pCur->pStmt);
        pCur->pStmt = 0;
        pCur->ePhase = eNextPhase;
        continue;
      }
    }
    if( pCur->nPrefix==0 ) break;
    if( pCur->nPrefix<=pCur->szRow
     && sqlite3_strnicmp(pCur->zPrefix, pCur->zCurrentRow, pCur->nPrefix)==0
    ){
      break;
    }
  }

  return SQLITE_OK;
}

/*
** Return values of columns for the row at which the completion_cursor
** is currently pointing.
*/
static int completionColumn(
  sqlite3_vtab_cursor *cur,   /* The cursor */
  sqlite3_context *ctx,       /* First argument to sqlite3_result_...() */
  int i                       /* Which column to return */
){
  completion_cursor *pCur = (completion_cursor*)cur;
  switch( i ){
    case COMPLETION_COLUMN_CANDIDATE: {
      sqlite3_result_text(ctx, pCur->zCurrentRow, pCur->szRow,SQLITE_TRANSIENT);
      break;
    }
    case COMPLETION_COLUMN_PREFIX: {
      sqlite3_result_text(ctx, pCur->zPrefix, -1, SQLITE_TRANSIENT);
      break;
    }
    case COMPLETION_COLUMN_WHOLELINE: {
      sqlite3_result_text(ctx, pCur->zLine, -1, SQLITE_TRANSIENT);
      break;
    }
    case COMPLETION_COLUMN_PHASE: {
      sqlite3_result_int(ctx, pCur->ePhase);
      break;
    }
  }
  return SQLITE_OK;
}

/*
** Return the rowid for the current row.  In this implementation, the
** rowid is the same as the output value.
*/
static int completionRowid(sqlite3_vtab_cursor *cur, sqlite_int64 *pRowid){
  completion_cursor *pCur = (completion_cursor*)cur;
  *pRowid = pCur->iRowid;
  return SQLITE_OK;
}

/*
** Return TRUE if the cursor has been moved off of the last
** row of output.
*/
static int completionEof(sqlite3_vtab_cursor *cur){
  completion_cursor *pCur = (completion_cursor*)cur;
  return pCur->ePhase >= COMPLETION_EOF;
}

/*
** This method is called to "rewind" the completion_cursor object back
** to the first row of output.  This method is always called at least
** once prior to any call to completionColumn() or completionRowid() or 
** completionEof().
*/
static int completionFilter(
  sqlite3_vtab_cursor *pVtabCursor, 
  int idxNum, const char *idxStr,
  int argc, sqlite3_value **argv
){
  completion_cursor *pCur = (completion_cursor *)pVtabCursor;
  int iArg = 0;
  (void)(idxStr);   /* Unused parameter */
  (void)(argc);     /* Unused parameter */
  completionCursorReset(pCur);
  if( idxNum & 1 ){
    pCur->nPrefix = sqlite3_value_bytes(argv[iArg]);
    if( pCur->nPrefix>0 ){
      pCur->zPrefix = sqlite3_mprintf("%s", sqlite3_value_text(argv[iArg]));
      if( pCur->zPrefix==0 ) return SQLITE_NOMEM;
    }
    iArg = 1;
  }
  if( idxNum & 2 ){
    pCur->nLine = sqlite3_value_bytes(argv[iArg]);
    if( pCur->nLine>0 ){
      pCur->zLine = sqlite3_mprintf("%s", sqlite3_value_text(argv[iArg]));
      if( pCur->zLine==0 ) return SQLITE_NOMEM;
    }
  }
  if( pCur->zLine!=0 && pCur->zPrefix==0 ){
    int i = pCur->nLine;
    while( i>0 && (isalnum(pCur->zLine[i-1]) || pCur->zLine[i-1]=='_') ){
      i--;
    }
    pCur->nPrefix = pCur->nLine - i;
    if( pCur->nPrefix>0 ){
      pCur->zPrefix = sqlite3_mprintf("%.*s", pCur->nPrefix, pCur->zLine + i);
      if( pCur->zPrefix==0 ) return SQLITE_NOMEM;
    }
  }
  pCur->iRowid = 0;
  pCur->ePhase = COMPLETION_FIRST_PHASE;
  return completionNext(pVtabCursor);
}

/*
** SQLite will invoke this method one or more times while planning a query
** that uses the completion virtual table.  This routine needs to create
** a query plan for each invocation and compute an estimated cost for that
** plan.
**
** There are two hidden parameters that act as arguments to the table-valued
** function:  "prefix" and "wholeline".  Bit 0 of idxNum is set if "prefix"
** is available and bit 1 is set if "wholeline" is available.
*/
static int completionBestIndex(
  sqlite3_vtab *tab,
  sqlite3_index_info *pIdxInfo
){
  int i;                 /* Loop over constraints */
  int idxNum = 0;        /* The query plan bitmask */
  int prefixIdx = -1;    /* Index of the start= constraint, or -1 if none */
  int wholelineIdx = -1; /* Index of the stop= constraint, or -1 if none */
  int nArg = 0;          /* Number of arguments that completeFilter() expects */
  const struct sqlite3_index_constraint *pConstraint;

  (void)(tab);    /* Unused parameter */
  pConstraint = pIdxInfo->aConstraint;
  for(i=0; i<pIdxInfo->nConstraint; i++, pConstraint++){
    if( pConstraint->usable==0 ) continue;
    if( pConstraint->op!=SQLITE_INDEX_CONSTRAINT_EQ ) continue;
    switch( pConstraint->iColumn ){
      case COMPLETION_COLUMN_PREFIX:
        prefixIdx = i;
        idxNum |= 1;
        break;
      case COMPLETION_COLUMN_WHOLELINE:
        wholelineIdx = i;
        idxNum |= 2;
        break;
    }
  }
  if( prefixIdx>=0 ){
    pIdxInfo->aConstraintUsage[prefixIdx].argvIndex = ++nArg;
    pIdxInfo->aConstraintUsage[prefixIdx].omit = 1;
  }
  if( wholelineIdx>=0 ){
    pIdxInfo->aConstraintUsage[wholelineIdx].argvIndex = ++nArg;
    pIdxInfo->aConstraintUsage[wholelineIdx].omit = 1;
  }
  pIdxInfo->idxNum = idxNum;
  pIdxInfo->estimatedCost = (double)5000 - 1000*nArg;
  pIdxInfo->estimatedRows = 500 - 100*nArg;
  return SQLITE_OK;
}

/*
** This following structure defines all the methods for the 
** completion virtual table.
*/
static sqlite3_module completionModule = {
  0,                         /* iVersion */
  0,                         /* xCreate */
  completionConnect,         /* xConnect */
  completionBestIndex,       /* xBestIndex */
  completionDisconnect,      /* xDisconnect */
  0,                         /* xDestroy */
  completionOpen,            /* xOpen - open a cursor */
  completionClose,           /* xClose - close a cursor */
  completionFilter,          /* xFilter - configure scan constraints */
  completionNext,            /* xNext - advance a cursor */
  completionEof,             /* xEof - check for end of scan */
  completionColumn,          /* xColumn - read data */
  completionRowid,           /* xRowid - read data */
  0,                         /* xUpdate */
  0,                         /* xBegin */
  0,                         /* xSync */
  0,                         /* xCommit */
  0,                         /* xRollback */
  0,                         /* xFindMethod */
  0,                         /* xRename */
  0,                         /* xSavepoint */
  0,                         /* xRelease */
  0,                         /* xRollbackTo */
  0,                         /* xShadowName */
  0                          /* xIntegrity */
};

#endif /* SQLITE_OMIT_VIRTUALTABLE */

int sqlite3CompletionVtabInit(sqlite3 *db){
  int rc = SQLITE_OK;
#ifndef SQLITE_OMIT_VIRTUALTABLE
  rc = sqlite3_create_module(db, "completion", &completionModule, 0);
#endif
  return rc;
}

#ifdef _WIN32

#endif
int sqlite3_completion_init(
  sqlite3 *db, 
  char **pzErrMsg, 
  const sqlite3_api_routines *pApi
){
  int rc = SQLITE_OK;
  SQLITE_EXTENSION_INIT2(pApi);
  (void)(pzErrMsg);  /* Unused parameter */
#ifndef SQLITE_OMIT_VIRTUALTABLE
  rc = sqlite3CompletionVtabInit(db);
#endif
  return rc;
}

/************************* End ../ext/misc/completion.c ********************/
/************************* Begin ../ext/misc/appendvfs.c ******************/
/*
** 2017-10-20
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
******************************************************************************
**
** This file implements a VFS shim that allows an SQLite database to be
** appended onto the end of some other file, such as an executable.
**
** A special record must appear at the end of the file that identifies the
** file as an appended database and provides the offset to the first page
** of the exposed content. (Or, it is the length of the content prefix.)
** For best performance page 1 should be located at a disk page boundary,
** though that is not required.
**
** When opening a database using this VFS, the connection might treat
** the file as an ordinary SQLite database, or it might treat it as a
** database appended onto some other file.  The decision is made by
** applying the following rules in order:
**
**  (1)  An empty file is an ordinary database.
**
**  (2)  If the file ends with the appendvfs trailer string
**       "Start-Of-SQLite3-NNNNNNNN" that file is an appended database.
**
**  (3)  If the file begins with the standard SQLite prefix string
**       "SQLite format 3", that file is an ordinary database.
**
**  (4)  If none of the above apply and the SQLITE_OPEN_CREATE flag is
**       set, then a new database is appended to the already existing file.
**
**  (5)  Otherwise, SQLITE_CANTOPEN is returned.
**
** To avoid unnecessary complications with the PENDING_BYTE, the size of
** the file containing the database is limited to 1GiB. (1073741824 bytes)
** This VFS will not read or write past the 1GiB mark.  This restriction
** might be lifted in future versions.  For now, if you need a larger
** database, then keep it in a separate file.
**
** If the file being opened is a plain database (not an appended one), then
** this shim is a pass-through into the default underlying VFS. (rule 3)
**/
/* #include "sqlite3ext.h" */
SQLITE_EXTENSION_INIT1
#include <string.h>
#include <assert.h>

/* The append mark at the end of the database is:
**
**     Start-Of-SQLite3-NNNNNNNN
**     123456789 123456789 12345
**
** The NNNNNNNN represents a 64-bit big-endian unsigned integer which is
** the offset to page 1, and also the length of the prefix content.
*/
#define APND_MARK_PREFIX     "Start-Of-SQLite3-"
#define APND_MARK_PREFIX_SZ  17
#define APND_MARK_FOS_SZ      8
#define APND_MARK_SIZE       (APND_MARK_PREFIX_SZ+APND_MARK_FOS_SZ)

/*
** Maximum size of the combined prefix + database + append-mark.  This
** must be less than 0x40000000 to avoid locking issues on Windows.
*/
#define APND_MAX_SIZE  (0x40000000)

/*
** Try to align the database to an even multiple of APND_ROUNDUP bytes.
*/
#ifndef APND_ROUNDUP
#define APND_ROUNDUP 4096
#endif
#define APND_ALIGN_MASK         ((sqlite3_int64)(APND_ROUNDUP-1))
#define APND_START_ROUNDUP(fsz) (((fsz)+APND_ALIGN_MASK) & ~APND_ALIGN_MASK)

/*
** Forward declaration of objects used by this utility
*/
typedef struct sqlite3_vfs ApndVfs;
typedef struct ApndFile ApndFile;

/* Access to a lower-level VFS that (might) implement dynamic loading,
** access to randomness, etc.
*/
#define ORIGVFS(p)  ((sqlite3_vfs*)((p)->pAppData))
#define ORIGFILE(p) ((sqlite3_file*)(((ApndFile*)(p))+1))

/* An open appendvfs file
**
** An instance of this structure describes the appended database file.
** A separate sqlite3_file object is always appended. The appended
** sqlite3_file object (which can be accessed using ORIGFILE()) describes
** the entire file, including the prefix, the database, and the
** append-mark.
**
** The structure of an AppendVFS database is like this:
**
**   +-------------+---------+----------+-------------+
**   | prefix-file | padding | database | append-mark |
**   +-------------+---------+----------+-------------+
**                           ^          ^
**                           |          |
**                         iPgOne      iMark
**
**
** "prefix file" -  file onto which the database has been appended.
** "padding"     -  zero or more bytes inserted so that "database"
**                  starts on an APND_ROUNDUP boundary
** "database"    -  The SQLite database file
** "append-mark" -  The 25-byte "Start-Of-SQLite3-NNNNNNNN" that indicates
**                  the offset from the start of prefix-file to the start
**                  of "database".
**
** The size of the database is iMark - iPgOne.
**
** The NNNNNNNN in the "Start-Of-SQLite3-NNNNNNNN" suffix is the value
** of iPgOne stored as a big-ending 64-bit integer.
**
** iMark will be the size of the underlying file minus 25 (APND_MARKSIZE).
** Or, iMark is -1 to indicate that it has not yet been written.
*/
struct ApndFile {
  sqlite3_file base;        /* Subclass.  MUST BE FIRST! */
  sqlite3_int64 iPgOne;     /* Offset to the start of the database */
  sqlite3_int64 iMark;      /* Offset of the append mark.  -1 if unwritten */
  /* Always followed by another sqlite3_file that describes the whole file */
};

/*
** Methods for ApndFile
*/
static int apndClose(sqlite3_file*);
static int apndRead(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
static int apndWrite(sqlite3_file*,const void*,int iAmt, sqlite3_int64 iOfst);
static int apndTruncate(sqlite3_file*, sqlite3_int64 size);
static int apndSync(sqlite3_file*, int flags);
static int apndFileSize(sqlite3_file*, sqlite3_int64 *pSize);
static int apndLock(sqlite3_file*, int);
static int apndUnlock(sqlite3_file*, int);
static int apndCheckReservedLock(sqlite3_file*, int *pResOut);
static int apndFileControl(sqlite3_file*, int op, void *pArg);
static int apndSectorSize(sqlite3_file*);
static int apndDeviceCharacteristics(sqlite3_file*);
static int apndShmMap(sqlite3_file*, int iPg, int pgsz, int, void volatile**);
static int apndShmLock(sqlite3_file*, int offset, int n, int flags);
static void apndShmBarrier(sqlite3_file*);
static int apndShmUnmap(sqlite3_file*, int deleteFlag);
static int apndFetch(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp);
static int apndUnfetch(sqlite3_file*, sqlite3_int64 iOfst, void *p);

/*
** Methods for ApndVfs
*/
static int apndOpen(sqlite3_vfs*, const char *, sqlite3_file*, int , int *);
static int apndDelete(sqlite3_vfs*, const char *zName, int syncDir);
static int apndAccess(sqlite3_vfs*, const char *zName, int flags, int *);
static int apndFullPathname(sqlite3_vfs*, const char *zName, int, char *zOut);
static void *apndDlOpen(sqlite3_vfs*, const char *zFilename);
static void apndDlError(sqlite3_vfs*, int nByte, char *zErrMsg);
static void (*apndDlSym(sqlite3_vfs *pVfs, void *p, const char*zSym))(void);
static void apndDlClose(sqlite3_vfs*, void*);
static int apndRandomness(sqlite3_vfs*, int nByte, char *zOut);
static int apndSleep(sqlite3_vfs*, int microseconds);
static int apndCurrentTime(sqlite3_vfs*, double*);
static int apndGetLastError(sqlite3_vfs*, int, char *);
static int apndCurrentTimeInt64(sqlite3_vfs*, sqlite3_int64*);
static int apndSetSystemCall(sqlite3_vfs*, const char*,sqlite3_syscall_ptr);
static sqlite3_syscall_ptr apndGetSystemCall(sqlite3_vfs*, const char *z);
static const char *apndNextSystemCall(sqlite3_vfs*, const char *zName);

static sqlite3_vfs apnd_vfs = {
  3,                            /* iVersion (set when registered) */
  0,                            /* szOsFile (set when registered) */
  1024,                         /* mxPathname */
  0,                            /* pNext */
  "apndvfs",                    /* zName */
  0,                            /* pAppData (set when registered) */ 
  apndOpen,                     /* xOpen */
  apndDelete,                   /* xDelete */
  apndAccess,                   /* xAccess */
  apndFullPathname,             /* xFullPathname */
  apndDlOpen,                   /* xDlOpen */
  apndDlError,                  /* xDlError */
  apndDlSym,                    /* xDlSym */
  apndDlClose,                  /* xDlClose */
  apndRandomness,               /* xRandomness */
  apndSleep,                    /* xSleep */
  apndCurrentTime,              /* xCurrentTime */
  apndGetLastError,             /* xGetLastError */
  apndCurrentTimeInt64,         /* xCurrentTimeInt64 */
  apndSetSystemCall,            /* xSetSystemCall */
  apndGetSystemCall,            /* xGetSystemCall */
  apndNextSystemCall            /* xNextSystemCall */
};

static const sqlite3_io_methods apnd_io_methods = {
  3,                              /* iVersion */
  apndClose,                      /* xClose */
  apndRead,                       /* xRead */
  apndWrite,                      /* xWrite */
  apndTruncate,                   /* xTruncate */
  apndSync,                       /* xSync */
  apndFileSize,                   /* xFileSize */
  apndLock,                       /* xLock */
  apndUnlock,                     /* xUnlock */
  apndCheckReservedLock,          /* xCheckReservedLock */
  apndFileControl,                /* xFileControl */
  apndSectorSize,                 /* xSectorSize */
  apndDeviceCharacteristics,      /* xDeviceCharacteristics */
  apndShmMap,                     /* xShmMap */
  apndShmLock,                    /* xShmLock */
  apndShmBarrier,                 /* xShmBarrier */
  apndShmUnmap,                   /* xShmUnmap */
  apndFetch,                      /* xFetch */
  apndUnfetch                     /* xUnfetch */
};

/*
** Close an apnd-file.
*/
static int apndClose(sqlite3_file *pFile){
  pFile = ORIGFILE(pFile);
  return pFile->pMethods->xClose(pFile);
}

/*
** Read data from an apnd-file.
*/
static int apndRead(
  sqlite3_file *pFile, 
  void *zBuf, 
  int iAmt, 
  sqlite_int64 iOfst
){
  ApndFile *paf = (ApndFile *)pFile;
  pFile = ORIGFILE(pFile);
  return pFile->pMethods->xRead(pFile, zBuf, iAmt, paf->iPgOne+iOfst);
}

/*
** Add the append-mark onto what should become the end of the file.
*  If and only if this succeeds, internal ApndFile.iMark is updated.
*  Parameter iWriteEnd is the appendvfs-relative offset of the new mark.
*/
static int apndWriteMark(
  ApndFile *paf,
  sqlite3_file *pFile,
  sqlite_int64 iWriteEnd
){
  sqlite_int64 iPgOne = paf->iPgOne;
  unsigned char a[APND_MARK_SIZE];
  int i = APND_MARK_FOS_SZ;
  int rc;
  assert(pFile == ORIGFILE(paf));
  memcpy(a, APND_MARK_PREFIX, APND_MARK_PREFIX_SZ);
  while( --i >= 0 ){
    a[APND_MARK_PREFIX_SZ+i] = (unsigned char)(iPgOne & 0xff);
    iPgOne >>= 8;
  }
  iWriteEnd += paf->iPgOne;
  if( SQLITE_OK==(rc = pFile->pMethods->xWrite
                  (pFile, a, APND_MARK_SIZE, iWriteEnd)) ){
    paf->iMark = iWriteEnd;
  }
  return rc;
}

/*
** Write data to an apnd-file.
*/
static int apndWrite(
  sqlite3_file *pFile,
  const void *zBuf,
  int iAmt,
  sqlite_int64 iOfst
){
  ApndFile *paf = (ApndFile *)pFile;
  sqlite_int64 iWriteEnd = iOfst + iAmt;
  if( iWriteEnd>=APND_MAX_SIZE ) return SQLITE_FULL;
  pFile = ORIGFILE(pFile);
  /* If append-mark is absent or will be overwritten, write it. */
  if( paf->iMark < 0 || paf->iPgOne + iWriteEnd > paf->iMark ){
    int rc = apndWriteMark(paf, pFile, iWriteEnd);
    if( SQLITE_OK!=rc ) return rc;
  }
  return pFile->pMethods->xWrite(pFile, zBuf, iAmt, paf->iPgOne+iOfst);
}

/*
** Truncate an apnd-file.
*/
static int apndTruncate(sqlite3_file *pFile, sqlite_int64 size){
  ApndFile *paf = (ApndFile *)pFile;
  pFile = ORIGFILE(pFile);
  /* The append mark goes out first so truncate failure does not lose it. */
  if( SQLITE_OK!=apndWriteMark(paf, pFile, size) ) return SQLITE_IOERR;
  /* Truncate underlying file just past append mark */
  return pFile->pMethods->xTruncate(pFile, paf->iMark+APND_MARK_SIZE);
}

/*
** Sync an apnd-file.
*/
static int apndSync(sqlite3_file *pFile, int flags){
  pFile = ORIGFILE(pFile);
  return pFile->pMethods->xSync(pFile, flags);
}

/*
** Return the current file-size of an apnd-file.
** If the append mark is not yet there, the file-size is 0.
*/
static int apndFileSize(sqlite3_file *pFile, sqlite_int64 *pSize){
  ApndFile *paf = (ApndFile *)pFile;
  *pSize = ( paf->iMark >= 0 )? (paf->iMark - paf->iPgOne) : 0;
  return SQLITE_OK;
}

/*
** Lock an apnd-file.
*/
static int apndLock(sqlite3_file *pFile, int eLock){
  pFile = ORIGFILE(pFile);
  return pFile->pMethods->xLock(pFile, eLock);
}

/*
** Unlock an apnd-file.
*/
static int apndUnlock(sqlite3_file *pFile, int eLock){
  pFile = ORIGFILE(pFile);
  return pFile->pMethods->xUnlock(pFile, eLock);
}

/*
** Check if another file-handle holds a RESERVED lock on an apnd-file.
*/
static int apndCheckReservedLock(sqlite3_file *pFile, int *pResOut){
  pFile = ORIGFILE(pFile);
  return pFile->pMethods->xCheckReservedLock(pFile, pResOut);
}

/*
** File control method. For custom operations on an apnd-file.
*/
static int apndFileControl(sqlite3_file *pFile, int op, void *pArg){
  ApndFile *paf = (ApndFile *)pFile;
  int rc;
  pFile = ORIGFILE(pFile);
  if( op==SQLITE_FCNTL_SIZE_HINT ) *(sqlite3_int64*)pArg += paf->iPgOne;
  rc = pFile->pMethods->xFileControl(pFile, op, pArg);
  if( rc==SQLITE_OK && op==SQLITE_FCNTL_VFSNAME ){
    *(char**)pArg = sqlite3_mprintf("apnd(%lld)/%z", paf->iPgOne,*(char**)pArg);
  }
  return rc;
}

/*
** Return the sector-size in bytes for an apnd-file.
*/
static int apndSectorSize(sqlite3_file *pFile){
  pFile = ORIGFILE(pFile);
  return pFile->pMethods->xSectorSize(pFile);
}

/*
** Return the device characteristic flags supported by an apnd-file.
*/
static int apndDeviceCharacteristics(sqlite3_file *pFile){
  pFile = ORIGFILE(pFile);
  return pFile->pMethods->xDeviceCharacteristics(pFile);
}

/* Create a shared memory file mapping */
static int apndShmMap(
  sqlite3_file *pFile,
  int iPg,
  int pgsz,
  int bExtend,
  void volatile **pp
){
  pFile = ORIGFILE(pFile);
  return pFile->pMethods->xShmMap(pFile,iPg,pgsz,bExtend,pp);
}

/* Perform locking on a shared-memory segment */
static int apndShmLock(sqlite3_file *pFile, int offset, int n, int flags){
  pFile = ORIGFILE(pFile);
  return pFile->pMethods->xShmLock(pFile,offset,n,flags);
}

/* Memory barrier operation on shared memory */
static void apndShmBarrier(sqlite3_file *pFile){
  pFile = ORIGFILE(pFile);
  pFile->pMethods->xShmBarrier(pFile);
}

/* Unmap a shared memory segment */
static int apndShmUnmap(sqlite3_file *pFile, int deleteFlag){
  pFile = ORIGFILE(pFile);
  return pFile->pMethods->xShmUnmap(pFile,deleteFlag);
}

/* Fetch a page of a memory-mapped file */
static int apndFetch(
  sqlite3_file *pFile,
  sqlite3_int64 iOfst,
  int iAmt,
  void **pp
){
  ApndFile *p = (ApndFile *)pFile;
  if( p->iMark < 0 || iOfst+iAmt > p->iMark ){
    return SQLITE_IOERR; /* Cannot read what is not yet there. */
  }
  pFile = ORIGFILE(pFile);
  return pFile->pMethods->xFetch(pFile, iOfst+p->iPgOne, iAmt, pp);
}

/* Release a memory-mapped page */
static int apndUnfetch(sqlite3_file *pFile, sqlite3_int64 iOfst, void *pPage){
  ApndFile *p = (ApndFile *)pFile;
  pFile = ORIGFILE(pFile);
  return pFile->pMethods->xUnfetch(pFile, iOfst+p->iPgOne, pPage);
}

/*
** Try to read the append-mark off the end of a file.  Return the
** start of the appended database if the append-mark is present.
** If there is no valid append-mark, return -1;
**
** An append-mark is only valid if the NNNNNNNN start-of-database offset
** indicates that the appended database contains at least one page.  The
** start-of-database value must be a multiple of 512.
*/
static sqlite3_int64 apndReadMark(sqlite3_int64 sz, sqlite3_file *pFile){
  int rc, i;
  sqlite3_int64 iMark;
  int msbs = 8 * (APND_MARK_FOS_SZ-1);
  unsigned char a[APND_MARK_SIZE];

  if( APND_MARK_SIZE!=(sz & 0x1ff) ) return -1;
  rc = pFile->pMethods->xRead(pFile, a, APND_MARK_SIZE, sz-APND_MARK_SIZE);
  if( rc ) return -1;
  if( memcmp(a, APND_MARK_PREFIX, APND_MARK_PREFIX_SZ)!=0 ) return -1;
  iMark = ((sqlite3_int64)(a[APND_MARK_PREFIX_SZ] & 0x7f)) << msbs;
  for(i=1; i<8; i++){
    msbs -= 8;
    iMark |= (sqlite3_int64)a[APND_MARK_PREFIX_SZ+i]<<msbs;
  }
  if( iMark > (sz - APND_MARK_SIZE - 512) ) return -1;
  if( iMark & 0x1ff ) return -1;
  return iMark;
}

static const char apvfsSqliteHdr[] = "SQLite format 3";
/*
** Check to see if the file is an appendvfs SQLite database file.
** Return true iff it is such. Parameter sz is the file's size.
*/
static int apndIsAppendvfsDatabase(sqlite3_int64 sz, sqlite3_file *pFile){
  int rc;
  char zHdr[16];
  sqlite3_int64 iMark = apndReadMark(sz, pFile);
  if( iMark>=0 ){
    /* If file has the correct end-marker, the expected odd size, and the
    ** SQLite DB type marker where the end-marker puts it, then it
    ** is an appendvfs database.
    */
    rc = pFile->pMethods->xRead(pFile, zHdr, sizeof(zHdr), iMark);
    if( SQLITE_OK==rc
     && memcmp(zHdr, apvfsSqliteHdr, sizeof(zHdr))==0
     && (sz & 0x1ff) == APND_MARK_SIZE
     && sz>=512+APND_MARK_SIZE
    ){
      return 1; /* It's an appendvfs database */
    }
  }
  return 0;
}

/*
** Check to see if the file is an ordinary SQLite database file.
** Return true iff so. Parameter sz is the file's size.
*/
static int apndIsOrdinaryDatabaseFile(sqlite3_int64 sz, sqlite3_file *pFile){
  char zHdr[16];
  if( apndIsAppendvfsDatabase(sz, pFile) /* rule 2 */
   || (sz & 0x1ff) != 0
   || SQLITE_OK!=pFile->pMethods->xRead(pFile, zHdr, sizeof(zHdr), 0)
   || memcmp(zHdr, apvfsSqliteHdr, sizeof(zHdr))!=0
  ){
    return 0;
  }else{
    return 1;
  }
}

/*
** Open an apnd file handle.
*/
static int apndOpen(
  sqlite3_vfs *pApndVfs,
  const char *zName,
  sqlite3_file *pFile,
  int flags,
  int *pOutFlags
){
  ApndFile *pApndFile = (ApndFile*)pFile;
  sqlite3_file *pBaseFile = ORIGFILE(pFile);
  sqlite3_vfs *pBaseVfs = ORIGVFS(pApndVfs);
  int rc;
  sqlite3_int64 sz = 0;
  if( (flags & SQLITE_OPEN_MAIN_DB)==0 ){
    /* The appendvfs is not to be used for transient or temporary databases.
    ** Just use the base VFS open to initialize the given file object and
    ** open the underlying file. (Appendvfs is then unused for this file.)
    */
    return pBaseVfs->xOpen(pBaseVfs, zName, pFile, flags, pOutFlags);
  }
  memset(pApndFile, 0, sizeof(ApndFile));
  pFile->pMethods = &apnd_io_methods;
  pApndFile->iMark = -1;    /* Append mark not yet written */

  rc = pBaseVfs->xOpen(pBaseVfs, zName, pBaseFile, flags, pOutFlags);
  if( rc==SQLITE_OK ){
    rc = pBaseFile->pMethods->xFileSize(pBaseFile, &sz);
    if( rc ){
      pBaseFile->pMethods->xClose(pBaseFile);
    }
  }
  if( rc ){
    pFile->pMethods = 0;
    return rc;
  }
  if( apndIsOrdinaryDatabaseFile(sz, pBaseFile) ){
    /* The file being opened appears to be just an ordinary DB. Copy
    ** the base dispatch-table so this instance mimics the base VFS. 
    */
    memmove(pApndFile, pBaseFile, pBaseVfs->szOsFile);
    return SQLITE_OK;
  }
  pApndFile->iPgOne = apndReadMark(sz, pFile);
  if( pApndFile->iPgOne>=0 ){
    pApndFile->iMark = sz - APND_MARK_SIZE; /* Append mark found */
    return SQLITE_OK;
  }
  if( (flags & SQLITE_OPEN_CREATE)==0 ){
    pBaseFile->pMethods->xClose(pBaseFile);
    rc = SQLITE_CANTOPEN;
    pFile->pMethods = 0;
  }else{
    /* Round newly added appendvfs location to #define'd page boundary. 
    ** Note that nothing has yet been written to the underlying file.
    ** The append mark will be written along with first content write.
    ** Until then, paf->iMark value indicates it is not yet written.
    */
    pApndFile->iPgOne = APND_START_ROUNDUP(sz);
  }
  return rc;
}

/*
** Delete an apnd file.
** For an appendvfs, this could mean delete the appendvfs portion,
** leaving the appendee as it was before it gained an appendvfs.
** For now, this code deletes the underlying file too.
*/
static int apndDelete(sqlite3_vfs *pVfs, const char *zPath, int dirSync){
  return ORIGVFS(pVfs)->xDelete(ORIGVFS(pVfs), zPath, dirSync);
}

/*
** All other VFS methods are pass-thrus.
*/
static int apndAccess(
  sqlite3_vfs *pVfs, 
  const char *zPath, 
  int flags, 
  int *pResOut
){
  return ORIGVFS(pVfs)->xAccess(ORIGVFS(pVfs), zPath, flags, pResOut);
}
static int apndFullPathname(
  sqlite3_vfs *pVfs, 
  const char *zPath, 
  int nOut, 
  char *zOut
){
  return ORIGVFS(pVfs)->xFullPathname(ORIGVFS(pVfs),zPath,nOut,zOut);
}
static void *apndDlOpen(sqlite3_vfs *pVfs, const char *zPath){
  return ORIGVFS(pVfs)->xDlOpen(ORIGVFS(pVfs), zPath);
}
static void apndDlError(sqlite3_vfs *pVfs, int nByte, char *zErrMsg){
  ORIGVFS(pVfs)->xDlError(ORIGVFS(pVfs), nByte, zErrMsg);
}
static void (*apndDlSym(sqlite3_vfs *pVfs, void *p, const char *zSym))(void){
  return ORIGVFS(pVfs)->xDlSym(ORIGVFS(pVfs), p, zSym);
}
static void apndDlClose(sqlite3_vfs *pVfs, void *pHandle){
  ORIGVFS(pVfs)->xDlClose(ORIGVFS(pVfs), pHandle);
}
static int apndRandomness(sqlite3_vfs *pVfs, int nByte, char *zBufOut){
  return ORIGVFS(pVfs)->xRandomness(ORIGVFS(pVfs), nByte, zBufOut);
}
static int apndSleep(sqlite3_vfs *pVfs, int nMicro){
  return ORIGVFS(pVfs)->xSleep(ORIGVFS(pVfs), nMicro);
}
static int apndCurrentTime(sqlite3_vfs *pVfs, double *pTimeOut){
  return ORIGVFS(pVfs)->xCurrentTime(ORIGVFS(pVfs), pTimeOut);
}
static int apndGetLastError(sqlite3_vfs *pVfs, int a, char *b){
  return ORIGVFS(pVfs)->xGetLastError(ORIGVFS(pVfs), a, b);
}
static int apndCurrentTimeInt64(sqlite3_vfs *pVfs, sqlite3_int64 *p){
  return ORIGVFS(pVfs)->xCurrentTimeInt64(ORIGVFS(pVfs), p);
}
static int apndSetSystemCall(
  sqlite3_vfs *pVfs,
  const char *zName,
  sqlite3_syscall_ptr pCall
){
  return ORIGVFS(pVfs)->xSetSystemCall(ORIGVFS(pVfs),zName,pCall);
}
static sqlite3_syscall_ptr apndGetSystemCall(
  sqlite3_vfs *pVfs,
  const char *zName
){
  return ORIGVFS(pVfs)->xGetSystemCall(ORIGVFS(pVfs),zName);
}
static const char *apndNextSystemCall(sqlite3_vfs *pVfs, const char *zName){
  return ORIGVFS(pVfs)->xNextSystemCall(ORIGVFS(pVfs), zName);
}

  
#ifdef _WIN32

#endif
/* 
** This routine is called when the extension is loaded.
** Register the new VFS.
*/
int sqlite3_appendvfs_init(
  sqlite3 *db, 
  char **pzErrMsg, 
  const sqlite3_api_routines *pApi
){
  int rc = SQLITE_OK;
  sqlite3_vfs *pOrig;
  SQLITE_EXTENSION_INIT2(pApi);
  (void)pzErrMsg;
  (void)db;
  pOrig = sqlite3_vfs_find(0);
  if( pOrig==0 ) return SQLITE_ERROR;
  apnd_vfs.iVersion = pOrig->iVersion;
  apnd_vfs.pAppData = pOrig;
  apnd_vfs.szOsFile = pOrig->szOsFile + sizeof(ApndFile);
  rc = sqlite3_vfs_register(&apnd_vfs, 0);
#ifdef APPENDVFS_TEST
  if( rc==SQLITE_OK ){
    rc = sqlite3_auto_extension((void(*)(void))apndvfsRegister);
  }
#endif
  if( rc==SQLITE_OK ) rc = SQLITE_OK_LOAD_PERMANENTLY;
  return rc;
}

/************************* End ../ext/misc/appendvfs.c ********************/
#endif
#ifdef SQLITE_HAVE_ZLIB
/************************* Begin ../ext/misc/zipfile.c ******************/
/*
** 2017-12-26
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
******************************************************************************
**
** This file implements a virtual table for reading and writing ZIP archive
** files.
**
** Usage example:
**
**     SELECT name, sz, datetime(mtime,'unixepoch') FROM zipfile($filename);
**
** Current limitations:
**
**    *  No support for encryption
**    *  No support for ZIP archives spanning multiple files
**    *  No support for zip64 extensions
**    *  Only the "inflate/deflate" (zlib) compression method is supported
*/
/* #include "sqlite3ext.h" */
SQLITE_EXTENSION_INIT1
#include <stdio.h>
#include <string.h>
#include <assert.h>
#ifndef SQLITE_NO_STDINT
#  include <stdint.h>
#endif

#include <zlib.h>

/* When used as part of the CLI, the sqlite3_stdio.h module will have
** been included before this one. In that case use the sqlite3_stdio.h
** #defines.  If not, create our own for fopen().
*/
#ifndef _SQLITE3_STDIO_H_
# define sqlite3_fopen fopen
#endif

#ifndef SQLITE_OMIT_VIRTUALTABLE

#ifndef SQLITE_AMALGAMATION

#ifndef UINT32_TYPE
# ifdef HAVE_UINT32_T
#  define UINT32_TYPE uint32_t
# else
#  define UINT32_TYPE unsigned int
# endif
#endif
#ifndef UINT16_TYPE
# ifdef HAVE_UINT16_T
#  define UINT16_TYPE uint16_t
# else
#  define UINT16_TYPE unsigned short int
# endif
#endif
/* typedef sqlite3_int64 i64; */
/* typedef unsigned char u8; */
/* typedef UINT32_TYPE u32;           // 4-byte unsigned integer // */
/* typedef UINT16_TYPE u16;           // 2-byte unsigned integer // */
#define MIN(a,b) ((a)<(b) ? (a) : (b))

#if defined(SQLITE_COVERAGE_TEST) || defined(SQLITE_MUTATION_TEST)
# define SQLITE_OMIT_AUXILIARY_SAFETY_CHECKS 1
#endif
#if defined(SQLITE_OMIT_AUXILIARY_SAFETY_CHECKS)
# define ALWAYS(X)      (1)
# define NEVER(X)       (0)
#elif !defined(NDEBUG)
# define ALWAYS(X)      ((X)?1:(assert(0),0))
# define NEVER(X)       ((X)?(assert(0),1):0)
#else
# define ALWAYS(X)      (X)
# define NEVER(X)       (X)
#endif

#endif   /* SQLITE_AMALGAMATION */

/*
** Definitions for mode bitmasks S_IFDIR, S_IFREG and S_IFLNK.
**
** In some ways it would be better to obtain these values from system 
** header files. But, the dependency is undesirable and (a) these
** have been stable for decades, (b) the values are part of POSIX and
** are also made explicit in [man stat], and (c) are part of the 
** file format for zip archives.
*/
#ifndef S_IFDIR
# define S_IFDIR 0040000
#endif
#ifndef S_IFREG
# define S_IFREG 0100000
#endif
#ifndef S_IFLNK
# define S_IFLNK 0120000
#endif

static const char ZIPFILE_SCHEMA[] = 
  "CREATE TABLE y("
    "name PRIMARY KEY,"  /* 0: Name of file in zip archive */
    "mode,"              /* 1: POSIX mode for file */
    "mtime,"             /* 2: Last modification time (secs since 1970)*/
    "sz,"                /* 3: Size of object */
    "rawdata,"           /* 4: Raw data */
    "data,"              /* 5: Uncompressed data */
    "method,"            /* 6: Compression method (integer) */
    "z HIDDEN"           /* 7: Name of zip file */
  ") WITHOUT ROWID;";

#define ZIPFILE_F_COLUMN_IDX 7    /* Index of column "file" in the above */
#define ZIPFILE_BUFFER_SIZE (64*1024)


/*
** Magic numbers used to read and write zip files.
**
** ZIPFILE_NEWENTRY_MADEBY:
**   Use this value for the "version-made-by" field in new zip file
**   entries. The upper byte indicates "unix", and the lower byte 
**   indicates that the zip file matches pkzip specification 3.0. 
**   This is what info-zip seems to do.
**
** ZIPFILE_NEWENTRY_REQUIRED:
**   Value for "version-required-to-extract" field of new entries.
**   Version 2.0 is required to support folders and deflate compression.
**
** ZIPFILE_NEWENTRY_FLAGS:
**   Value for "general-purpose-bit-flags" field of new entries. Bit
**   11 means "utf-8 filename and comment".
**
** ZIPFILE_SIGNATURE_CDS:
**   First 4 bytes of a valid CDS record.
**
** ZIPFILE_SIGNATURE_LFH:
**   First 4 bytes of a valid LFH record.
**
** ZIPFILE_SIGNATURE_EOCD
**   First 4 bytes of a valid EOCD record.
*/
#define ZIPFILE_EXTRA_TIMESTAMP   0x5455
#define ZIPFILE_NEWENTRY_MADEBY   ((3<<8) + 30)
#define ZIPFILE_NEWENTRY_REQUIRED 20
#define ZIPFILE_NEWENTRY_FLAGS    0x800
#define ZIPFILE_SIGNATURE_CDS     0x02014b50
#define ZIPFILE_SIGNATURE_LFH     0x04034b50
#define ZIPFILE_SIGNATURE_EOCD    0x06054b50

/*
** The sizes of the fixed-size part of each of the three main data 
** structures in a zip archive.
*/
#define ZIPFILE_LFH_FIXED_SZ      30
#define ZIPFILE_EOCD_FIXED_SZ     22
#define ZIPFILE_CDS_FIXED_SZ      46

/*
*** 4.3.16  End of central directory record:
***
***   end of central dir signature    4 bytes  (0x06054b50)
***   number of this disk             2 bytes
***   number of the disk with the
***   start of the central directory  2 bytes
***   total number of entries in the
***   central directory on this disk  2 bytes
***   total number of entries in
***   the central directory           2 bytes
***   size of the central directory   4 bytes
***   offset of start of central
***   directory with respect to
***   the starting disk number        4 bytes
***   .ZIP file comment length        2 bytes
***   .ZIP file comment       (variable size)
*/
typedef struct ZipfileEOCD ZipfileEOCD;
struct ZipfileEOCD {
  u16 iDisk;
  u16 iFirstDisk;
  u16 nEntry;
  u16 nEntryTotal;
  u32 nSize;
  u32 iOffset;
};

/*
*** 4.3.12  Central directory structure:
***
*** ...
***
***   central file header signature   4 bytes  (0x02014b50)
***   version made by                 2 bytes
***   version needed to extract       2 bytes
***   general purpose bit flag        2 bytes
***   compression method              2 bytes
***   last mod file time              2 bytes
***   last mod file date              2 bytes
***   crc-32                          4 bytes
***   compressed size                 4 bytes
***   uncompressed size               4 bytes
***   file name length                2 bytes
***   extra field length              2 bytes
***   file comment length             2 bytes
***   disk number start               2 bytes
***   internal file attributes        2 bytes
***   external file attributes        4 bytes
***   relative offset of local header 4 bytes
*/
typedef struct ZipfileCDS ZipfileCDS;
struct ZipfileCDS {
  u16 iVersionMadeBy;
  u16 iVersionExtract;
  u16 flags;
  u16 iCompression;
  u16 mTime;
  u16 mDate;
  u32 crc32;
  u32 szCompressed;
  u32 szUncompressed;
  u16 nFile;
  u16 nExtra;
  u16 nComment;
  u16 iDiskStart;
  u16 iInternalAttr;
  u32 iExternalAttr;
  u32 iOffset;
  char *zFile;                    /* Filename (sqlite3_malloc()) */
};

/*
*** 4.3.7  Local file header:
***
***   local file header signature     4 bytes  (0x04034b50)
***   version needed to extract       2 bytes
***   general purpose bit flag        2 bytes
***   compression method              2 bytes
***   last mod file time              2 bytes
***   last mod file date              2 bytes
***   crc-32                          4 bytes
***   compressed size                 4 bytes
***   uncompressed size               4 bytes
***   file name length                2 bytes
***   extra field length              2 bytes
***   
*/
typedef struct ZipfileLFH ZipfileLFH;
struct ZipfileLFH {
  u16 iVersionExtract;
  u16 flags;
  u16 iCompression;
  u16 mTime;
  u16 mDate;
  u32 crc32;
  u32 szCompressed;
  u32 szUncompressed;
  u16 nFile;
  u16 nExtra;
};

typedef struct ZipfileEntry ZipfileEntry;
struct ZipfileEntry {
  ZipfileCDS cds;            /* Parsed CDS record */
  u32 mUnixTime;             /* Modification time, in UNIX format */
  u8 *aExtra;                /* cds.nExtra+cds.nComment bytes of extra data */
  i64 iDataOff;              /* Offset to data in file (if aData==0) */
  u8 *aData;                 /* cds.szCompressed bytes of compressed data */
  ZipfileEntry *pNext;       /* Next element in in-memory CDS */
};

/* 
** Cursor type for zipfile tables.
*/
typedef struct ZipfileCsr ZipfileCsr;
struct ZipfileCsr {
  sqlite3_vtab_cursor base;  /* Base class - must be first */
  i64 iId;                   /* Cursor ID */
  u8 bEof;                   /* True when at EOF */
  u8 bNoop;                  /* If next xNext() call is no-op */

  /* Used outside of write transactions */
  FILE *pFile;               /* Zip file */
  i64 iNextOff;              /* Offset of next record in central directory */
  ZipfileEOCD eocd;          /* Parse of central directory record */

  ZipfileEntry *pFreeEntry;  /* Free this list when cursor is closed or reset */
  ZipfileEntry *pCurrent;    /* Current entry */
  ZipfileCsr *pCsrNext;      /* Next cursor on same virtual table */
};

typedef struct ZipfileTab ZipfileTab;
struct ZipfileTab {
  sqlite3_vtab base;         /* Base class - must be first */
  char *zFile;               /* Zip file this table accesses (may be NULL) */
  sqlite3 *db;               /* Host database connection */
  u8 *aBuffer;               /* Temporary buffer used for various tasks */

  ZipfileCsr *pCsrList;      /* List of cursors */
  i64 iNextCsrid;

  /* The following are used by write transactions only */
  ZipfileEntry *pFirstEntry; /* Linked list of all files (if pWriteFd!=0) */
  ZipfileEntry *pLastEntry;  /* Last element in pFirstEntry list */
  FILE *pWriteFd;            /* File handle open on zip archive */
  i64 szCurrent;             /* Current size of zip archive */
  i64 szOrig;                /* Size of archive at start of transaction */
};

/*
** Set the error message contained in context ctx to the results of
** vprintf(zFmt, ...).
*/
static void zipfileCtxErrorMsg(sqlite3_context *ctx, const char *zFmt, ...){
  char *zMsg = 0;
  va_list ap;
  va_start(ap, zFmt);
  zMsg = sqlite3_vmprintf(zFmt, ap);
  sqlite3_result_error(ctx, zMsg, -1);
  sqlite3_free(zMsg);
  va_end(ap);
}

/*
** If string zIn is quoted, dequote it in place. Otherwise, if the string
** is not quoted, do nothing.
*/
static void zipfileDequote(char *zIn){
  char q = zIn[0];
  if( q=='"' || q=='\'' || q=='`' || q=='[' ){
    int iIn = 1;
    int iOut = 0;
    if( q=='[' ) q = ']';
    while( ALWAYS(zIn[iIn]) ){
      char c = zIn[iIn++];
      if( c==q && zIn[iIn++]!=q ) break;
      zIn[iOut++] = c;
    }
    zIn[iOut] = '\0';
  }
}

/*
** Construct a new ZipfileTab virtual table object.
** 
**   argv[0]   -> module name  ("zipfile")
**   argv[1]   -> database name
**   argv[2]   -> table name
**   argv[...] -> "column name" and other module argument fields.
*/
static int zipfileConnect(
  sqlite3 *db,
  void *pAux,
  int argc, const char *const*argv,
  sqlite3_vtab **ppVtab,
  char **pzErr
){
  int nByte = sizeof(ZipfileTab) + ZIPFILE_BUFFER_SIZE;
  int nFile = 0;
  const char *zFile = 0;
  ZipfileTab *pNew = 0;
  int rc;
  (void)pAux;

  /* If the table name is not "zipfile", require that the argument be
  ** specified. This stops zipfile tables from being created as:
  **
  **   CREATE VIRTUAL TABLE zzz USING zipfile();
  **
  ** It does not prevent:
  **
  **   CREATE VIRTUAL TABLE zipfile USING zipfile();
  */
  assert( 0==sqlite3_stricmp(argv[0], "zipfile") );
  if( (0!=sqlite3_stricmp(argv[2], "zipfile") && argc<4) || argc>4 ){
    *pzErr = sqlite3_mprintf("zipfile constructor requires one argument");
    return SQLITE_ERROR;
  }

  if( argc>3 ){
    zFile = argv[3];
    nFile = (int)strlen(zFile)+1;
  }

  rc = sqlite3_declare_vtab(db, ZIPFILE_SCHEMA);
  if( rc==SQLITE_OK ){
    pNew = (ZipfileTab*)sqlite3_malloc64((sqlite3_int64)nByte+nFile);
    if( pNew==0 ) return SQLITE_NOMEM;
    memset(pNew, 0, nByte+nFile);
    pNew->db = db;
    pNew->aBuffer = (u8*)&pNew[1];
    if( zFile ){
      pNew->zFile = (char*)&pNew->aBuffer[ZIPFILE_BUFFER_SIZE];
      memcpy(pNew->zFile, zFile, nFile);
      zipfileDequote(pNew->zFile);
    }
  }
  sqlite3_vtab_config(db, SQLITE_VTAB_DIRECTONLY);
  *ppVtab = (sqlite3_vtab*)pNew;
  return rc;
}

/*
** Free the ZipfileEntry structure indicated by the only argument.
*/
static void zipfileEntryFree(ZipfileEntry *p){
  if( p ){
    sqlite3_free(p->cds.zFile);
    sqlite3_free(p);
  }
}

/*
** Release resources that should be freed at the end of a write 
** transaction.
*/
static void zipfileCleanupTransaction(ZipfileTab *pTab){
  ZipfileEntry *pEntry;
  ZipfileEntry *pNext;

  if( pTab->pWriteFd ){
    fclose(pTab->pWriteFd);
    pTab->pWriteFd = 0;
  }
  for(pEntry=pTab->pFirstEntry; pEntry; pEntry=pNext){
    pNext = pEntry->pNext;
    zipfileEntryFree(pEntry);
  }
  pTab->pFirstEntry = 0;
  pTab->pLastEntry = 0;
  pTab->szCurrent = 0;
  pTab->szOrig = 0;
}

/*
** This method is the destructor for zipfile vtab objects.
*/
static int zipfileDisconnect(sqlite3_vtab *pVtab){
  zipfileCleanupTransaction((ZipfileTab*)pVtab);
  sqlite3_free(pVtab);
  return SQLITE_OK;
}

/*
** Constructor for a new ZipfileCsr object.
*/
static int zipfileOpen(sqlite3_vtab *p, sqlite3_vtab_cursor **ppCsr){
  ZipfileTab *pTab = (ZipfileTab*)p;
  ZipfileCsr *pCsr;
  pCsr = sqlite3_malloc(sizeof(*pCsr));
  *ppCsr = (sqlite3_vtab_cursor*)pCsr;
  if( pCsr==0 ){
    return SQLITE_NOMEM;
  }
  memset(pCsr, 0, sizeof(*pCsr));
  pCsr->iId = ++pTab->iNextCsrid;
  pCsr->pCsrNext = pTab->pCsrList;
  pTab->pCsrList = pCsr;
  return SQLITE_OK;
}

/*
** Reset a cursor back to the state it was in when first returned
** by zipfileOpen().
*/
static void zipfileResetCursor(ZipfileCsr *pCsr){
  ZipfileEntry *p;
  ZipfileEntry *pNext;

  pCsr->bEof = 0;
  if( pCsr->pFile ){
    fclose(pCsr->pFile);
    pCsr->pFile = 0;
    zipfileEntryFree(pCsr->pCurrent);
    pCsr->pCurrent = 0;
  }

  for(p=pCsr->pFreeEntry; p; p=pNext){
    pNext = p->pNext;
    zipfileEntryFree(p);
  }
}

/*
** Destructor for an ZipfileCsr.
*/
static int zipfileClose(sqlite3_vtab_cursor *cur){
  ZipfileCsr *pCsr = (ZipfileCsr*)cur;
  ZipfileTab *pTab = (ZipfileTab*)(pCsr->base.pVtab);
  ZipfileCsr **pp;
  zipfileResetCursor(pCsr);

  /* Remove this cursor from the ZipfileTab.pCsrList list. */
  for(pp=&pTab->pCsrList; *pp!=pCsr; pp=&((*pp)->pCsrNext));
  *pp = pCsr->pCsrNext;

  sqlite3_free(pCsr);
  return SQLITE_OK;
}

/*
** Set the error message for the virtual table associated with cursor
** pCsr to the results of vprintf(zFmt, ...).
*/
static void zipfileTableErr(ZipfileTab *pTab, const char *zFmt, ...){
  va_list ap;
  va_start(ap, zFmt);
  sqlite3_free(pTab->base.zErrMsg);
  pTab->base.zErrMsg = sqlite3_vmprintf(zFmt, ap);
  va_end(ap);
}
static void zipfileCursorErr(ZipfileCsr *pCsr, const char *zFmt, ...){
  va_list ap;
  va_start(ap, zFmt);
  sqlite3_free(pCsr->base.pVtab->zErrMsg);
  pCsr->base.pVtab->zErrMsg = sqlite3_vmprintf(zFmt, ap);
  va_end(ap);
}

/*
** Read nRead bytes of data from offset iOff of file pFile into buffer
** aRead[]. Return SQLITE_OK if successful, or an SQLite error code
** otherwise. 
**
** If an error does occur, output variable (*pzErrmsg) may be set to point
** to an English language error message. It is the responsibility of the
** caller to eventually free this buffer using
** sqlite3_free().
*/
static int zipfileReadData(
  FILE *pFile,                    /* Read from this file */
  u8 *aRead,                      /* Read into this buffer */
  int nRead,                      /* Number of bytes to read */
  i64 iOff,                       /* Offset to read from */
  char **pzErrmsg                 /* OUT: Error message (from sqlite3_malloc) */
){
  size_t n;
  fseek(pFile, (long)iOff, SEEK_SET);
  n = fread(aRead, 1, nRead, pFile);
  if( (int)n!=nRead ){
    *pzErrmsg = sqlite3_mprintf("error in fread()");
    return SQLITE_ERROR;
  }
  return SQLITE_OK;
}

static int zipfileAppendData(
  ZipfileTab *pTab,
  const u8 *aWrite,
  int nWrite
){
  if( nWrite>0 ){
    size_t n = nWrite;
    fseek(pTab->pWriteFd, (long)pTab->szCurrent, SEEK_SET);
    n = fwrite(aWrite, 1, nWrite, pTab->pWriteFd);
    if( (int)n!=nWrite ){
      pTab->base.zErrMsg = sqlite3_mprintf("error in fwrite()");
      return SQLITE_ERROR;
    }
    pTab->szCurrent += nWrite;
  }
  return SQLITE_OK;
}

/*
** Read and return a 16-bit little-endian unsigned integer from buffer aBuf.
*/
static u16 zipfileGetU16(const u8 *aBuf){
  return (aBuf[1] << 8) + aBuf[0];
}

/*
** Read and return a 32-bit little-endian unsigned integer from buffer aBuf.
*/
static u32 zipfileGetU32(const u8 *aBuf){
  if( aBuf==0 ) return 0;
  return ((u32)(aBuf[3]) << 24)
       + ((u32)(aBuf[2]) << 16)
       + ((u32)(aBuf[1]) <<  8)
       + ((u32)(aBuf[0]) <<  0);
}

/*
** Write a 16-bit little endiate integer into buffer aBuf.
*/
static void zipfilePutU16(u8 *aBuf, u16 val){
  aBuf[0] = val & 0xFF;
  aBuf[1] = (val>>8) & 0xFF;
}

/*
** Write a 32-bit little endiate integer into buffer aBuf.
*/
static void zipfilePutU32(u8 *aBuf, u32 val){
  aBuf[0] = val & 0xFF;
  aBuf[1] = (val>>8) & 0xFF;
  aBuf[2] = (val>>16) & 0xFF;
  aBuf[3] = (val>>24) & 0xFF;
}

#define zipfileRead32(aBuf) ( aBuf+=4, zipfileGetU32(aBuf-4) )
#define zipfileRead16(aBuf) ( aBuf+=2, zipfileGetU16(aBuf-2) )

#define zipfileWrite32(aBuf,val) { zipfilePutU32(aBuf,val); aBuf+=4; }
#define zipfileWrite16(aBuf,val) { zipfilePutU16(aBuf,val); aBuf+=2; }

/*
** Magic numbers used to read CDS records.
*/
#define ZIPFILE_CDS_NFILE_OFF        28
#define ZIPFILE_CDS_SZCOMPRESSED_OFF 20

/*
** Decode the CDS record in buffer aBuf into (*pCDS). Return SQLITE_ERROR
** if the record is not well-formed, or SQLITE_OK otherwise.
*/
static int zipfileReadCDS(u8 *aBuf, ZipfileCDS *pCDS){
  u8 *aRead = aBuf;
  u32 sig = zipfileRead32(aRead);
  int rc = SQLITE_OK;
  if( sig!=ZIPFILE_SIGNATURE_CDS ){
    rc = SQLITE_ERROR;
  }else{
    pCDS->iVersionMadeBy = zipfileRead16(aRead);
    pCDS->iVersionExtract = zipfileRead16(aRead);
    pCDS->flags = zipfileRead16(aRead);
    pCDS->iCompression = zipfileRead16(aRead);
    pCDS->mTime = zipfileRead16(aRead);
    pCDS->mDate = zipfileRead16(aRead);
    pCDS->crc32 = zipfileRead32(aRead);
    pCDS->szCompressed = zipfileRead32(aRead);
    pCDS->szUncompressed = zipfileRead32(aRead);
    assert( aRead==&aBuf[ZIPFILE_CDS_NFILE_OFF] );
    pCDS->nFile = zipfileRead16(aRead);
    pCDS->nExtra = zipfileRead16(aRead);
    pCDS->nComment = zipfileRead16(aRead);
    pCDS->iDiskStart = zipfileRead16(aRead);
    pCDS->iInternalAttr = zipfileRead16(aRead);
    pCDS->iExternalAttr = zipfileRead32(aRead);
    pCDS->iOffset = zipfileRead32(aRead);
    assert( aRead==&aBuf[ZIPFILE_CDS_FIXED_SZ] );
  }

  return rc;
}

/*
** Decode the LFH record in buffer aBuf into (*pLFH). Return SQLITE_ERROR
** if the record is not well-formed, or SQLITE_OK otherwise.
*/
static int zipfileReadLFH(
  u8 *aBuffer,
  ZipfileLFH *pLFH
){
  u8 *aRead = aBuffer;
  int rc = SQLITE_OK;

  u32 sig = zipfileRead32(aRead);
  if( sig!=ZIPFILE_SIGNATURE_LFH ){
    rc = SQLITE_ERROR;
  }else{
    pLFH->iVersionExtract = zipfileRead16(aRead);
    pLFH->flags = zipfileRead16(aRead);
    pLFH->iCompression = zipfileRead16(aRead);
    pLFH->mTime = zipfileRead16(aRead);
    pLFH->mDate = zipfileRead16(aRead);
    pLFH->crc32 = zipfileRead32(aRead);
    pLFH->szCompressed = zipfileRead32(aRead);
    pLFH->szUncompressed = zipfileRead32(aRead);
    pLFH->nFile = zipfileRead16(aRead);
    pLFH->nExtra = zipfileRead16(aRead);
  }
  return rc;
}


/*
** Buffer aExtra (size nExtra bytes) contains zip archive "extra" fields.
** Scan through this buffer to find an "extra-timestamp" field. If one
** exists, extract the 32-bit modification-timestamp from it and store
** the value in output parameter *pmTime.
**
** Zero is returned if no extra-timestamp record could be found (and so
** *pmTime is left unchanged), or non-zero otherwise.
**
** The general format of an extra field is:
**
**   Header ID    2 bytes
**   Data Size    2 bytes
**   Data         N bytes
*/
static int zipfileScanExtra(u8 *aExtra, int nExtra, u32 *pmTime){
  int ret = 0;
  u8 *p = aExtra;
  u8 *pEnd = &aExtra[nExtra];

  while( p<pEnd ){
    u16 id = zipfileRead16(p);
    u16 nByte = zipfileRead16(p);

    switch( id ){
      case ZIPFILE_EXTRA_TIMESTAMP: {
        u8 b = p[0];
        if( b & 0x01 ){     /* 0x01 -> modtime is present */
          *pmTime = zipfileGetU32(&p[1]);
          ret = 1;
        }
        break;
      }
    }

    p += nByte;
  }
  return ret;
}

/*
** Convert the standard MS-DOS timestamp stored in the mTime and mDate
** fields of the CDS structure passed as the only argument to a 32-bit
** UNIX seconds-since-the-epoch timestamp. Return the result.
**
** "Standard" MS-DOS time format:
**
**   File modification time:
**     Bits 00-04: seconds divided by 2
**     Bits 05-10: minute
**     Bits 11-15: hour
**   File modification date:
**     Bits 00-04: day
**     Bits 05-08: month (1-12)
**     Bits 09-15: years from 1980 
**
** https://msdn.microsoft.com/en-us/library/9kkf9tah.aspx
*/
static u32 zipfileMtime(ZipfileCDS *pCDS){
  int Y,M,D,X1,X2,A,B,sec,min,hr;
  i64 JDsec;
  Y = (1980 + ((pCDS->mDate >> 9) & 0x7F));
  M = ((pCDS->mDate >> 5) & 0x0F);
  D = (pCDS->mDate & 0x1F);
  sec = (pCDS->mTime & 0x1F)*2;
  min = (pCDS->mTime >> 5) & 0x3F;
  hr = (pCDS->mTime >> 11) & 0x1F;
  if( M<=2 ){
    Y--;
    M += 12;
  }
  X1 = 36525*(Y+4716)/100;
  X2 = 306001*(M+1)/10000;
  A = Y/100;
  B = 2 - A + (A/4);
  JDsec = (i64)((X1 + X2 + D + B - 1524.5)*86400) + hr*3600 + min*60 + sec;
  return (u32)(JDsec - (i64)24405875*(i64)8640);
}

/*
** The opposite of zipfileMtime(). This function populates the mTime and
** mDate fields of the CDS structure passed as the first argument according
** to the UNIX timestamp value passed as the second.
*/
static void zipfileMtimeToDos(ZipfileCDS *pCds, u32 mUnixTime){
  /* Convert unix timestamp to JD (2440588 is noon on 1/1/1970) */
  i64 JD = (i64)2440588 + mUnixTime / (24*60*60);

  int A, B, C, D, E;
  int yr, mon, day;
  int hr, min, sec;

  A = (int)((JD - 1867216.25)/36524.25);
  A = (int)(JD + 1 + A - (A/4));
  B = A + 1524;
  C = (int)((B - 122.1)/365.25);
  D = (36525*(C&32767))/100;
  E = (int)((B-D)/30.6001);

  day = B - D - (int)(30.6001*E);
  mon = (E<14 ? E-1 : E-13);
  yr = mon>2 ? C-4716 : C-4715;

  hr = (mUnixTime % (24*60*60)) / (60*60);
  min = (mUnixTime % (60*60)) / 60;
  sec = (mUnixTime % 60);

  if( yr>=1980 ){
    pCds->mDate = (u16)(day + (mon << 5) + ((yr-1980) << 9));
    pCds->mTime = (u16)(sec/2 + (min<<5) + (hr<<11));
  }else{
    pCds->mDate = pCds->mTime = 0;
  }

  assert( mUnixTime<315507600 
       || mUnixTime==zipfileMtime(pCds) 
       || ((mUnixTime % 2) && mUnixTime-1==zipfileMtime(pCds)) 
       /* || (mUnixTime % 2) */
  );
}

/*
** If aBlob is not NULL, then it is a pointer to a buffer (nBlob bytes in
** size) containing an entire zip archive image. Or, if aBlob is NULL,
** then pFile is a file-handle open on a zip file. In either case, this
** function creates a ZipfileEntry object based on the zip archive entry
** for which the CDS record is at offset iOff.
**
** If successful, SQLITE_OK is returned and (*ppEntry) set to point to
** the new object. Otherwise, an SQLite error code is returned and the
** final value of (*ppEntry) undefined.
*/
static int zipfileGetEntry(
  ZipfileTab *pTab,               /* Store any error message here */
  const u8 *aBlob,                /* Pointer to in-memory file image */
  int nBlob,                      /* Size of aBlob[] in bytes */
  FILE *pFile,                    /* If aBlob==0, read from this file */
  i64 iOff,                       /* Offset of CDS record */
  ZipfileEntry **ppEntry          /* OUT: Pointer to new object */
){
  u8 *aRead;
  char **pzErr = &pTab->base.zErrMsg;
  int rc = SQLITE_OK;
  (void)nBlob;

  if( aBlob==0 ){
    aRead = pTab->aBuffer;
    rc = zipfileReadData(pFile, aRead, ZIPFILE_CDS_FIXED_SZ, iOff, pzErr);
  }else{
    aRead = (u8*)&aBlob[iOff];
  }

  if( rc==SQLITE_OK ){
    sqlite3_int64 nAlloc;
    ZipfileEntry *pNew;

    int nFile = zipfileGetU16(&aRead[ZIPFILE_CDS_NFILE_OFF]);
    int nExtra = zipfileGetU16(&aRead[ZIPFILE_CDS_NFILE_OFF+2]);
    nExtra += zipfileGetU16(&aRead[ZIPFILE_CDS_NFILE_OFF+4]);

    nAlloc = sizeof(ZipfileEntry) + nExtra;
    if( aBlob ){
      nAlloc += zipfileGetU32(&aRead[ZIPFILE_CDS_SZCOMPRESSED_OFF]);
    }

    pNew = (ZipfileEntry*)sqlite3_malloc64(nAlloc);
    if( pNew==0 ){
      rc = SQLITE_NOMEM;
    }else{
      memset(pNew, 0, sizeof(ZipfileEntry));
      rc = zipfileReadCDS(aRead, &pNew->cds);
      if( rc!=SQLITE_OK ){
        *pzErr = sqlite3_mprintf("failed to read CDS at offset %lld", iOff);
      }else if( aBlob==0 ){
        rc = zipfileReadData(
            pFile, aRead, nExtra+nFile, iOff+ZIPFILE_CDS_FIXED_SZ, pzErr
        );
      }else{
        aRead = (u8*)&aBlob[iOff + ZIPFILE_CDS_FIXED_SZ];
      }
    }

    if( rc==SQLITE_OK ){
      u32 *pt = &pNew->mUnixTime;
      pNew->cds.zFile = sqlite3_mprintf("%.*s", nFile, aRead); 
      pNew->aExtra = (u8*)&pNew[1];
      memcpy(pNew->aExtra, &aRead[nFile], nExtra);
      if( pNew->cds.zFile==0 ){
        rc = SQLITE_NOMEM;
      }else if( 0==zipfileScanExtra(&aRead[nFile], pNew->cds.nExtra, pt) ){
        pNew->mUnixTime = zipfileMtime(&pNew->cds);
      }
    }

    if( rc==SQLITE_OK ){
      static const int szFix = ZIPFILE_LFH_FIXED_SZ;
      ZipfileLFH lfh;
      if( pFile ){
        rc = zipfileReadData(pFile, aRead, szFix, pNew->cds.iOffset, pzErr);
      }else{
        aRead = (u8*)&aBlob[pNew->cds.iOffset];
      }

      if( rc==SQLITE_OK ) rc = zipfileReadLFH(aRead, &lfh);
      if( rc==SQLITE_OK ){
        pNew->iDataOff =  pNew->cds.iOffset + ZIPFILE_LFH_FIXED_SZ;
        pNew->iDataOff += lfh.nFile + lfh.nExtra;
        if( aBlob && pNew->cds.szCompressed ){
          pNew->aData = &pNew->aExtra[nExtra];
          memcpy(pNew->aData, &aBlob[pNew->iDataOff], pNew->cds.szCompressed);
        }
      }else{
        *pzErr = sqlite3_mprintf("failed to read LFH at offset %d", 
            (int)pNew->cds.iOffset
        );
      }
    }

    if( rc!=SQLITE_OK ){
      zipfileEntryFree(pNew);
    }else{
      *ppEntry = pNew;
    }
  }

  return rc;
}

/*
** Advance an ZipfileCsr to its next row of output.
*/
static int zipfileNext(sqlite3_vtab_cursor *cur){
  ZipfileCsr *pCsr = (ZipfileCsr*)cur;
  int rc = SQLITE_OK;

  if( pCsr->pFile ){
    i64 iEof = pCsr->eocd.iOffset + pCsr->eocd.nSize;
    zipfileEntryFree(pCsr->pCurrent);
    pCsr->pCurrent = 0;
    if( pCsr->iNextOff>=iEof ){
      pCsr->bEof = 1;
    }else{
      ZipfileEntry *p = 0;
      ZipfileTab *pTab = (ZipfileTab*)(cur->pVtab);
      rc = zipfileGetEntry(pTab, 0, 0, pCsr->pFile, pCsr->iNextOff, &p);
      if( rc==SQLITE_OK ){
        pCsr->iNextOff += ZIPFILE_CDS_FIXED_SZ;
        pCsr->iNextOff += (int)p->cds.nExtra + p->cds.nFile + p->cds.nComment;
      }
      pCsr->pCurrent = p;
    }
  }else{
    if( !pCsr->bNoop ){
      pCsr->pCurrent = pCsr->pCurrent->pNext;
    }
    if( pCsr->pCurrent==0 ){
      pCsr->bEof = 1;
    }
  }

  pCsr->bNoop = 0;
  return rc;
}

static void zipfileFree(void *p) { 
  sqlite3_free(p); 
}

/*
** Buffer aIn (size nIn bytes) contains compressed data. Uncompressed, the
** size is nOut bytes. This function uncompresses the data and sets the
** return value in context pCtx to the result (a blob).
**
** If an error occurs, an error code is left in pCtx instead.
*/
static void zipfileInflate(
  sqlite3_context *pCtx,          /* Store result here */
  const u8 *aIn,                  /* Compressed data */
  int nIn,                        /* Size of buffer aIn[] in bytes */
  int nOut                        /* Expected output size */
){
  u8 *aRes = sqlite3_malloc(nOut);
  if( aRes==0 ){
    sqlite3_result_error_nomem(pCtx);
  }else{
    int err;
    z_stream str;
    memset(&str, 0, sizeof(str));

    str.next_in = (Byte*)aIn;
    str.avail_in = nIn;
    str.next_out = (Byte*)aRes;
    str.avail_out = nOut;

    err = inflateInit2(&str, -15);
    if( err!=Z_OK ){
      zipfileCtxErrorMsg(pCtx, "inflateInit2() failed (%d)", err);
    }else{
      err = inflate(&str, Z_NO_FLUSH);
      if( err!=Z_STREAM_END ){
        zipfileCtxErrorMsg(pCtx, "inflate() failed (%d)", err);
      }else{
        sqlite3_result_blob(pCtx, aRes, nOut, zipfileFree);
        aRes = 0;
      }
    }
    sqlite3_free(aRes);
    inflateEnd(&str);
  }
}

/*
** Buffer aIn (size nIn bytes) contains uncompressed data. This function
** compresses it and sets (*ppOut) to point to a buffer containing the
** compressed data. The caller is responsible for eventually calling
** sqlite3_free() to release buffer (*ppOut). Before returning, (*pnOut) 
** is set to the size of buffer (*ppOut) in bytes.
**
** If no error occurs, SQLITE_OK is returned. Otherwise, an SQLite error
** code is returned and an error message left in virtual-table handle
** pTab. The values of (*ppOut) and (*pnOut) are left unchanged in this
** case.
*/
static int zipfileDeflate(
  const u8 *aIn, int nIn,         /* Input */
  u8 **ppOut, int *pnOut,         /* Output */
  char **pzErr                    /* OUT: Error message */
){
  int rc = SQLITE_OK;
  sqlite3_int64 nAlloc;
  z_stream str;
  u8 *aOut;

  memset(&str, 0, sizeof(str));
  str.next_in = (Bytef*)aIn;
  str.avail_in = nIn;
  deflateInit2(&str, 9, Z_DEFLATED, -15, 8, Z_DEFAULT_STRATEGY);

  nAlloc = deflateBound(&str, nIn);
  aOut = (u8*)sqlite3_malloc64(nAlloc);
  if( aOut==0 ){
    rc = SQLITE_NOMEM;
  }else{
    int res;
    str.next_out = aOut;
    str.avail_out = nAlloc;
    res = deflate(&str, Z_FINISH);
    if( res==Z_STREAM_END ){
      *ppOut = aOut;
      *pnOut = (int)str.total_out;
    }else{
      sqlite3_free(aOut);
      *pzErr = sqlite3_mprintf("zipfile: deflate() error");
      rc = SQLITE_ERROR;
    }
    deflateEnd(&str);
  }

  return rc;
}


/*
** Return values of columns for the row at which the series_cursor
** is currently pointing.
*/
static int zipfileColumn(
  sqlite3_vtab_cursor *cur,   /* The cursor */
  sqlite3_context *ctx,       /* First argument to sqlite3_result_...() */
  int i                       /* Which column to return */
){
  ZipfileCsr *pCsr = (ZipfileCsr*)cur;
  ZipfileCDS *pCDS = &pCsr->pCurrent->cds;
  int rc = SQLITE_OK;
  switch( i ){
    case 0:   /* name */
      sqlite3_result_text(ctx, pCDS->zFile, -1, SQLITE_TRANSIENT);
      break;
    case 1:   /* mode */
      /* TODO: Whether or not the following is correct surely depends on
      ** the platform on which the archive was created.  */
      sqlite3_result_int(ctx, pCDS->iExternalAttr >> 16);
      break;
    case 2: { /* mtime */
      sqlite3_result_int64(ctx, pCsr->pCurrent->mUnixTime);
      break;
    }
    case 3: { /* sz */
      if( sqlite3_vtab_nochange(ctx)==0 ){
        sqlite3_result_int64(ctx, pCDS->szUncompressed);
      }
      break;
    }
    case 4:   /* rawdata */
      if( sqlite3_vtab_nochange(ctx) ) break;
    case 5: { /* data */
      if( i==4 || pCDS->iCompression==0 || pCDS->iCompression==8 ){
        int sz = pCDS->szCompressed;
        int szFinal = pCDS->szUncompressed;
        if( szFinal>0 ){
          u8 *aBuf;
          u8 *aFree = 0;
          if( pCsr->pCurrent->aData ){
            aBuf = pCsr->pCurrent->aData;
          }else{
            aBuf = aFree = sqlite3_malloc64(sz);
            if( aBuf==0 ){
              rc = SQLITE_NOMEM;
            }else{
              FILE *pFile = pCsr->pFile;
              if( pFile==0 ){
                pFile = ((ZipfileTab*)(pCsr->base.pVtab))->pWriteFd;
              }
              rc = zipfileReadData(pFile, aBuf, sz, pCsr->pCurrent->iDataOff,
                  &pCsr->base.pVtab->zErrMsg
              );
            }
          }
          if( rc==SQLITE_OK ){
            if( i==5 && pCDS->iCompression ){
              zipfileInflate(ctx, aBuf, sz, szFinal);
            }else{
              sqlite3_result_blob(ctx, aBuf, sz, SQLITE_TRANSIENT);
            }
          }
          sqlite3_free(aFree);
        }else{
          /* Figure out if this is a directory or a zero-sized file. Consider
          ** it to be a directory either if the mode suggests so, or if
          ** the final character in the name is '/'.  */
          u32 mode = pCDS->iExternalAttr >> 16;
          if( !(mode & S_IFDIR)
           && pCDS->nFile>=1
           && pCDS->zFile[pCDS->nFile-1]!='/'
          ){
            sqlite3_result_blob(ctx, "", 0, SQLITE_STATIC);
          }
        }
      }
      break;
    }
    case 6:   /* method */
      sqlite3_result_int(ctx, pCDS->iCompression);
      break;
    default:  /* z */
      assert( i==7 );
      sqlite3_result_int64(ctx, pCsr->iId);
      break;
  }

  return rc;
}

/*
** Return TRUE if the cursor is at EOF.
*/
static int zipfileEof(sqlite3_vtab_cursor *cur){
  ZipfileCsr *pCsr = (ZipfileCsr*)cur;
  return pCsr->bEof;
}

/*
** If aBlob is not NULL, then it points to a buffer nBlob bytes in size
** containing an entire zip archive image. Or, if aBlob is NULL, then pFile
** is guaranteed to be a file-handle open on a zip file.
**
** This function attempts to locate the EOCD record within the zip archive
** and populate *pEOCD with the results of decoding it. SQLITE_OK is
** returned if successful. Otherwise, an SQLite error code is returned and
** an English language error message may be left in virtual-table pTab.
*/
static int zipfileReadEOCD(
  ZipfileTab *pTab,               /* Return errors here */
  const u8 *aBlob,                /* Pointer to in-memory file image */
  int nBlob,                      /* Size of aBlob[] in bytes */
  FILE *pFile,                    /* Read from this file if aBlob==0 */
  ZipfileEOCD *pEOCD              /* Object to populate */
){
  u8 *aRead = pTab->aBuffer;      /* Temporary buffer */
  int nRead;                      /* Bytes to read from file */
  int rc = SQLITE_OK;

  memset(pEOCD, 0, sizeof(ZipfileEOCD));
  if( aBlob==0 ){
    i64 iOff;                     /* Offset to read from */
    i64 szFile;                   /* Total size of file in bytes */
    fseek(pFile, 0, SEEK_END);
    szFile = (i64)ftell(pFile);
    if( szFile==0 ){
      return SQLITE_OK;
    }
    nRead = (int)(MIN(szFile, ZIPFILE_BUFFER_SIZE));
    iOff = szFile - nRead;
    rc = zipfileReadData(pFile, aRead, nRead, iOff, &pTab->base.zErrMsg);
  }else{
    nRead = (int)(MIN(nBlob, ZIPFILE_BUFFER_SIZE));
    aRead = (u8*)&aBlob[nBlob-nRead];
  }

  if( rc==SQLITE_OK ){
    int i;

    /* Scan backwards looking for the signature bytes */
    for(i=nRead-20; i>=0; i--){
      if( aRead[i]==0x50 && aRead[i+1]==0x4b 
       && aRead[i+2]==0x05 && aRead[i+3]==0x06 
      ){
        break;
      }
    }
    if( i<0 ){
      pTab->base.zErrMsg = sqlite3_mprintf(
          "cannot find end of central directory record"
      );
      return SQLITE_ERROR;
    }

    aRead += i+4;
    pEOCD->iDisk = zipfileRead16(aRead);
    pEOCD->iFirstDisk = zipfileRead16(aRead);
    pEOCD->nEntry = zipfileRead16(aRead);
    pEOCD->nEntryTotal = zipfileRead16(aRead);
    pEOCD->nSize = zipfileRead32(aRead);
    pEOCD->iOffset = zipfileRead32(aRead);
  }

  return rc;
}

/*
** Add object pNew to the linked list that begins at ZipfileTab.pFirstEntry 
** and ends with pLastEntry. If argument pBefore is NULL, then pNew is added
** to the end of the list. Otherwise, it is added to the list immediately
** before pBefore (which is guaranteed to be a part of said list).
*/
static void zipfileAddEntry(
  ZipfileTab *pTab, 
  ZipfileEntry *pBefore, 
  ZipfileEntry *pNew
){
  assert( (pTab->pFirstEntry==0)==(pTab->pLastEntry==0) );
  assert( pNew->pNext==0 );
  if( pBefore==0 ){
    if( pTab->pFirstEntry==0 ){
      pTab->pFirstEntry = pTab->pLastEntry = pNew;
    }else{
      assert( pTab->pLastEntry->pNext==0 );
      pTab->pLastEntry->pNext = pNew;
      pTab->pLastEntry = pNew;
    }
  }else{
    ZipfileEntry **pp;
    for(pp=&pTab->pFirstEntry; *pp!=pBefore; pp=&((*pp)->pNext));
    pNew->pNext = pBefore;
    *pp = pNew;
  }
}

static int zipfileLoadDirectory(ZipfileTab *pTab, const u8 *aBlob, int nBlob){
  ZipfileEOCD eocd;
  int rc;
  int i;
  i64 iOff;

  rc = zipfileReadEOCD(pTab, aBlob, nBlob, pTab->pWriteFd, &eocd);
  iOff = eocd.iOffset;
  for(i=0; rc==SQLITE_OK && i<eocd.nEntry; i++){
    ZipfileEntry *pNew = 0;
    rc = zipfileGetEntry(pTab, aBlob, nBlob, pTab->pWriteFd, iOff, &pNew);

    if( rc==SQLITE_OK ){
      zipfileAddEntry(pTab, 0, pNew);
      iOff += ZIPFILE_CDS_FIXED_SZ;
      iOff += (int)pNew->cds.nExtra + pNew->cds.nFile + pNew->cds.nComment;
    }
  }
  return rc;
}

/*
** xFilter callback.
*/
static int zipfileFilter(
  sqlite3_vtab_cursor *cur, 
  int idxNum, const char *idxStr,
  int argc, sqlite3_value **argv
){
  ZipfileTab *pTab = (ZipfileTab*)cur->pVtab;
  ZipfileCsr *pCsr = (ZipfileCsr*)cur;
  const char *zFile = 0;          /* Zip file to scan */
  int rc = SQLITE_OK;             /* Return Code */
  int bInMemory = 0;              /* True for an in-memory zipfile */

  (void)idxStr;
  (void)argc;

  zipfileResetCursor(pCsr);

  if( pTab->zFile ){
    zFile = pTab->zFile;
  }else if( idxNum==0 ){
    zipfileCursorErr(pCsr, "zipfile() function requires an argument");
    return SQLITE_ERROR;
  }else if( sqlite3_value_type(argv[0])==SQLITE_BLOB ){
    static const u8 aEmptyBlob = 0;
    const u8 *aBlob = (const u8*)sqlite3_value_blob(argv[0]);
    int nBlob = sqlite3_value_bytes(argv[0]);
    assert( pTab->pFirstEntry==0 );
    if( aBlob==0 ){
      aBlob = &aEmptyBlob;
      nBlob = 0;
    }
    rc = zipfileLoadDirectory(pTab, aBlob, nBlob);
    pCsr->pFreeEntry = pTab->pFirstEntry;
    pTab->pFirstEntry = pTab->pLastEntry = 0;
    if( rc!=SQLITE_OK ) return rc;
    bInMemory = 1;
  }else{
    zFile = (const char*)sqlite3_value_text(argv[0]);
  }

  if( 0==pTab->pWriteFd && 0==bInMemory ){
    pCsr->pFile = zFile ? sqlite3_fopen(zFile, "rb") : 0;
    if( pCsr->pFile==0 ){
      zipfileCursorErr(pCsr, "cannot open file: %s", zFile);
      rc = SQLITE_ERROR;
    }else{
      rc = zipfileReadEOCD(pTab, 0, 0, pCsr->pFile, &pCsr->eocd);
      if( rc==SQLITE_OK ){
        if( pCsr->eocd.nEntry==0 ){
          pCsr->bEof = 1;
        }else{
          pCsr->iNextOff = pCsr->eocd.iOffset;
          rc = zipfileNext(cur);
        }
      }
    }
  }else{
    pCsr->bNoop = 1;
    pCsr->pCurrent = pCsr->pFreeEntry ? pCsr->pFreeEntry : pTab->pFirstEntry;
    rc = zipfileNext(cur);
  }

  return rc;
}

/*
** xBestIndex callback.
*/
static int zipfileBestIndex(
  sqlite3_vtab *tab,
  sqlite3_index_info *pIdxInfo
){
  int i;
  int idx = -1;
  int unusable = 0;
  (void)tab;

  for(i=0; i<pIdxInfo->nConstraint; i++){
    const struct sqlite3_index_constraint *pCons = &pIdxInfo->aConstraint[i];
    if( pCons->iColumn!=ZIPFILE_F_COLUMN_IDX ) continue;
    if( pCons->usable==0 ){
      unusable = 1;
    }else if( pCons->op==SQLITE_INDEX_CONSTRAINT_EQ ){
      idx = i;
    }
  }
  pIdxInfo->estimatedCost = 1000.0;
  if( idx>=0 ){
    pIdxInfo->aConstraintUsage[idx].argvIndex = 1;
    pIdxInfo->aConstraintUsage[idx].omit = 1;
    pIdxInfo->idxNum = 1;
  }else if( unusable ){
    return SQLITE_CONSTRAINT;
  }
  return SQLITE_OK;
}

static ZipfileEntry *zipfileNewEntry(const char *zPath){
  ZipfileEntry *pNew;
  pNew = sqlite3_malloc(sizeof(ZipfileEntry));
  if( pNew ){
    memset(pNew, 0, sizeof(ZipfileEntry));
    pNew->cds.zFile = sqlite3_mprintf("%s", zPath);
    if( pNew->cds.zFile==0 ){
      sqlite3_free(pNew);
      pNew = 0;
    }
  }
  return pNew;
}

static int zipfileSerializeLFH(ZipfileEntry *pEntry, u8 *aBuf){
  ZipfileCDS *pCds = &pEntry->cds;
  u8 *a = aBuf;

  pCds->nExtra = 9;

  /* Write the LFH itself */
  zipfileWrite32(a, ZIPFILE_SIGNATURE_LFH);
  zipfileWrite16(a, pCds->iVersionExtract);
  zipfileWrite16(a, pCds->flags);
  zipfileWrite16(a, pCds->iCompression);
  zipfileWrite16(a, pCds->mTime);
  zipfileWrite16(a, pCds->mDate);
  zipfileWrite32(a, pCds->crc32);
  zipfileWrite32(a, pCds->szCompressed);
  zipfileWrite32(a, pCds->szUncompressed);
  zipfileWrite16(a, (u16)pCds->nFile);
  zipfileWrite16(a, pCds->nExtra);
  assert( a==&aBuf[ZIPFILE_LFH_FIXED_SZ] );

  /* Add the file name */
  memcpy(a, pCds->zFile, (int)pCds->nFile);
  a += (int)pCds->nFile;

  /* The "extra" data */
  zipfileWrite16(a, ZIPFILE_EXTRA_TIMESTAMP);
  zipfileWrite16(a, 5);
  *a++ = 0x01;
  zipfileWrite32(a, pEntry->mUnixTime);

  return a-aBuf;
}

static int zipfileAppendEntry(
  ZipfileTab *pTab,
  ZipfileEntry *pEntry,
  const u8 *pData,
  int nData
){
  u8 *aBuf = pTab->aBuffer;
  int nBuf;
  int rc;

  nBuf = zipfileSerializeLFH(pEntry, aBuf);
  rc = zipfileAppendData(pTab, aBuf, nBuf);
  if( rc==SQLITE_OK ){
    pEntry->iDataOff = pTab->szCurrent;
    rc = zipfileAppendData(pTab, pData, nData);
  }

  return rc;
}

static int zipfileGetMode(
  sqlite3_value *pVal, 
  int bIsDir,                     /* If true, default to directory */
  u32 *pMode,                     /* OUT: Mode value */
  char **pzErr                    /* OUT: Error message */
){
  const char *z = (const char*)sqlite3_value_text(pVal);
  u32 mode = 0;
  if( z==0 ){
    mode = (bIsDir ? (S_IFDIR + 0755) : (S_IFREG + 0644));
  }else if( z[0]>='0' && z[0]<='9' ){
    mode = (unsigned int)sqlite3_value_int(pVal);
  }else{
    const char zTemplate[11] = "-rwxrwxrwx";
    int i;
    if( strlen(z)!=10 ) goto parse_error;
    switch( z[0] ){
      case '-': mode |= S_IFREG; break;
      case 'd': mode |= S_IFDIR; break;
      case 'l': mode |= S_IFLNK; break;
      default: goto parse_error;
    }
    for(i=1; i<10; i++){
      if( z[i]==zTemplate[i] ) mode |= 1 << (9-i);
      else if( z[i]!='-' ) goto parse_error;
    }
  }
  if( ((mode & S_IFDIR)==0)==bIsDir ){
    /* The "mode" attribute is a directory, but data has been specified.
    ** Or vice-versa - no data but "mode" is a file or symlink.  */
    *pzErr = sqlite3_mprintf("zipfile: mode does not match data");
    return SQLITE_CONSTRAINT;
  }
  *pMode = mode;
  return SQLITE_OK;

 parse_error:
  *pzErr = sqlite3_mprintf("zipfile: parse error in mode: %s", z);
  return SQLITE_ERROR;
}

/*
** Both (const char*) arguments point to nul-terminated strings. Argument
** nB is the value of strlen(zB). This function returns 0 if the strings are
** identical, ignoring any trailing '/' character in either path.  */
static int zipfileComparePath(const char *zA, const char *zB, int nB){
  int nA = (int)strlen(zA);
  if( nA>0 && zA[nA-1]=='/' ) nA--;
  if( nB>0 && zB[nB-1]=='/' ) nB--;
  if( nA==nB && memcmp(zA, zB, nA)==0 ) return 0;
  return 1;
}

static int zipfileBegin(sqlite3_vtab *pVtab){
  ZipfileTab *pTab = (ZipfileTab*)pVtab;
  int rc = SQLITE_OK;

  assert( pTab->pWriteFd==0 );
  if( pTab->zFile==0 || pTab->zFile[0]==0 ){
    pTab->base.zErrMsg = sqlite3_mprintf("zipfile: missing filename");
    return SQLITE_ERROR;
  }

  /* Open a write fd on the file. Also load the entire central directory
  ** structure into memory. During the transaction any new file data is 
  ** appended to the archive file, but the central directory is accumulated
  ** in main-memory until the transaction is committed.  */
  pTab->pWriteFd = sqlite3_fopen(pTab->zFile, "ab+");
  if( pTab->pWriteFd==0 ){
    pTab->base.zErrMsg = sqlite3_mprintf(
        "zipfile: failed to open file %s for writing", pTab->zFile
        );
    rc = SQLITE_ERROR;
  }else{
    fseek(pTab->pWriteFd, 0, SEEK_END);
    pTab->szCurrent = pTab->szOrig = (i64)ftell(pTab->pWriteFd);
    rc = zipfileLoadDirectory(pTab, 0, 0);
  }

  if( rc!=SQLITE_OK ){
    zipfileCleanupTransaction(pTab);
  }

  return rc;
}

/*
** Return the current time as a 32-bit timestamp in UNIX epoch format (like
** time(2)).
*/
static u32 zipfileTime(void){
  sqlite3_vfs *pVfs = sqlite3_vfs_find(0);
  u32 ret;
  if( pVfs==0 ) return 0;
  if( pVfs->iVersion>=2 && pVfs->xCurrentTimeInt64 ){
    i64 ms;
    pVfs->xCurrentTimeInt64(pVfs, &ms);
    ret = (u32)((ms/1000) - ((i64)24405875 * 8640));
  }else{
    double day;
    pVfs->xCurrentTime(pVfs, &day);
    ret = (u32)((day - 2440587.5) * 86400);
  }
  return ret;
}

/*
** Return a 32-bit timestamp in UNIX epoch format.
**
** If the value passed as the only argument is either NULL or an SQL NULL,
** return the current time. Otherwise, return the value stored in (*pVal)
** cast to a 32-bit unsigned integer.
*/
static u32 zipfileGetTime(sqlite3_value *pVal){
  if( pVal==0 || sqlite3_value_type(pVal)==SQLITE_NULL ){
    return zipfileTime();
  }
  return (u32)sqlite3_value_int64(pVal);
}

/*
** Unless it is NULL, entry pOld is currently part of the pTab->pFirstEntry
** linked list.  Remove it from the list and free the object.
*/
static void zipfileRemoveEntryFromList(ZipfileTab *pTab, ZipfileEntry *pOld){
  if( pOld ){
    if( pTab->pFirstEntry==pOld ){
      pTab->pFirstEntry = pOld->pNext;
      if( pTab->pLastEntry==pOld ) pTab->pLastEntry = 0;
    }else{
      ZipfileEntry *p;
      for(p=pTab->pFirstEntry; p; p=p->pNext){
        if( p->pNext==pOld ){
          p->pNext = pOld->pNext;
          if( pTab->pLastEntry==pOld ) pTab->pLastEntry = p;
          break;
        }
      }
    }
    zipfileEntryFree(pOld);
  }
}

/*
** xUpdate method.
*/
static int zipfileUpdate(
  sqlite3_vtab *pVtab, 
  int nVal, 
  sqlite3_value **apVal, 
  sqlite_int64 *pRowid
){
  ZipfileTab *pTab = (ZipfileTab*)pVtab;
  int rc = SQLITE_OK;             /* Return Code */
  ZipfileEntry *pNew = 0;         /* New in-memory CDS entry */

  u32 mode = 0;                   /* Mode for new entry */
  u32 mTime = 0;                  /* Modification time for new entry */
  i64 sz = 0;                     /* Uncompressed size */
  const char *zPath = 0;          /* Path for new entry */
  int nPath = 0;                  /* strlen(zPath) */
  const u8 *pData = 0;            /* Pointer to buffer containing content */
  int nData = 0;                  /* Size of pData buffer in bytes */
  int iMethod = 0;                /* Compression method for new entry */
  u8 *pFree = 0;                  /* Free this */
  char *zFree = 0;                /* Also free this */
  ZipfileEntry *pOld = 0;
  ZipfileEntry *pOld2 = 0;
  int bUpdate = 0;                /* True for an update that modifies "name" */
  int bIsDir = 0;
  u32 iCrc32 = 0;

  (void)pRowid;

  if( pTab->pWriteFd==0 ){
    rc = zipfileBegin(pVtab);
    if( rc!=SQLITE_OK ) return rc;
  }

  /* If this is a DELETE or UPDATE, find the archive entry to delete. */
  if( sqlite3_value_type(apVal[0])!=SQLITE_NULL ){
    const char *zDelete = (const char*)sqlite3_value_text(apVal[0]);
    int nDelete = (int)strlen(zDelete);
    if( nVal>1 ){
      const char *zUpdate = (const char*)sqlite3_value_text(apVal[1]);
      if( zUpdate && zipfileComparePath(zUpdate, zDelete, nDelete)!=0 ){
        bUpdate = 1;
      }
    }
    for(pOld=pTab->pFirstEntry; 1; pOld=pOld->pNext){
      if( zipfileComparePath(pOld->cds.zFile, zDelete, nDelete)==0 ){
        break;
      }
      assert( pOld->pNext );
    }
  }

  if( nVal>1 ){
    /* Check that "sz" and "rawdata" are both NULL: */
    if( sqlite3_value_type(apVal[5])!=SQLITE_NULL ){
      zipfileTableErr(pTab, "sz must be NULL");
      rc = SQLITE_CONSTRAINT;
    }
    if( sqlite3_value_type(apVal[6])!=SQLITE_NULL ){
      zipfileTableErr(pTab, "rawdata must be NULL"); 
      rc = SQLITE_CONSTRAINT;
    }

    if( rc==SQLITE_OK ){
      if( sqlite3_value_type(apVal[7])==SQLITE_NULL ){
        /* data=NULL. A directory */
        bIsDir = 1;
      }else{
        /* Value specified for "data", and possibly "method". This must be
        ** a regular file or a symlink. */
        const u8 *aIn = sqlite3_value_blob(apVal[7]);
        int nIn = sqlite3_value_bytes(apVal[7]);
        int bAuto = sqlite3_value_type(apVal[8])==SQLITE_NULL;

        iMethod = sqlite3_value_int(apVal[8]);
        sz = nIn;
        pData = aIn;
        nData = nIn;
        if( iMethod!=0 && iMethod!=8 ){
          zipfileTableErr(pTab, "unknown compression method: %d", iMethod);
          rc = SQLITE_CONSTRAINT;
        }else{
          if( bAuto || iMethod ){
            int nCmp;
            rc = zipfileDeflate(aIn, nIn, &pFree, &nCmp, &pTab->base.zErrMsg);
            if( rc==SQLITE_OK ){
              if( iMethod || nCmp<nIn ){
                iMethod = 8;
                pData = pFree;
                nData = nCmp;
              }
            }
          }
          iCrc32 = crc32(0, aIn, nIn);
        }
      }
    }

    if( rc==SQLITE_OK ){
      rc = zipfileGetMode(apVal[3], bIsDir, &mode, &pTab->base.zErrMsg);
    }

    if( rc==SQLITE_OK ){
      zPath = (const char*)sqlite3_value_text(apVal[2]);
      if( zPath==0 ) zPath = "";
      nPath = (int)strlen(zPath);
      mTime = zipfileGetTime(apVal[4]);
    }

    if( rc==SQLITE_OK && bIsDir ){
      /* For a directory, check that the last character in the path is a
      ** '/'. This appears to be required for compatibility with info-zip
      ** (the unzip command on unix). It does not create directories
      ** otherwise.  */
      if( nPath<=0 || zPath[nPath-1]!='/' ){
        zFree = sqlite3_mprintf("%s/", zPath);
        zPath = (const char*)zFree;
        if( zFree==0 ){
          rc = SQLITE_NOMEM;
          nPath = 0;
        }else{
          nPath = (int)strlen(zPath);
        }
      }
    }

    /* Check that we're not inserting a duplicate entry -OR- updating an
    ** entry with a path, thereby making it into a duplicate. */
    if( (pOld==0 || bUpdate) && rc==SQLITE_OK ){
      ZipfileEntry *p;
      for(p=pTab->pFirstEntry; p; p=p->pNext){
        if( zipfileComparePath(p->cds.zFile, zPath, nPath)==0 ){
          switch( sqlite3_vtab_on_conflict(pTab->db) ){
            case SQLITE_IGNORE: {
              goto zipfile_update_done;
            }
            case SQLITE_REPLACE: {
              pOld2 = p;
              break;
            }
            default: {
              zipfileTableErr(pTab, "duplicate name: \"%s\"", zPath);
              rc = SQLITE_CONSTRAINT;
              break;
            }
          }
          break;
        }
      }
    }

    if( rc==SQLITE_OK ){
      /* Create the new CDS record. */
      pNew = zipfileNewEntry(zPath);
      if( pNew==0 ){
        rc = SQLITE_NOMEM;
      }else{
        pNew->cds.iVersionMadeBy = ZIPFILE_NEWENTRY_MADEBY;
        pNew->cds.iVersionExtract = ZIPFILE_NEWENTRY_REQUIRED;
        pNew->cds.flags = ZIPFILE_NEWENTRY_FLAGS;
        pNew->cds.iCompression = (u16)iMethod;
        zipfileMtimeToDos(&pNew->cds, mTime);
        pNew->cds.crc32 = iCrc32;
        pNew->cds.szCompressed = nData;
        pNew->cds.szUncompressed = (u32)sz;
        pNew->cds.iExternalAttr = (mode<<16);
        pNew->cds.iOffset = (u32)pTab->szCurrent;
        pNew->cds.nFile = (u16)nPath;
        pNew->mUnixTime = (u32)mTime;
        rc = zipfileAppendEntry(pTab, pNew, pData, nData);
        zipfileAddEntry(pTab, pOld, pNew);
      }
    }
  }

  if( rc==SQLITE_OK && (pOld || pOld2) ){
    ZipfileCsr *pCsr;
    for(pCsr=pTab->pCsrList; pCsr; pCsr=pCsr->pCsrNext){
      if( pCsr->pCurrent && (pCsr->pCurrent==pOld || pCsr->pCurrent==pOld2) ){
        pCsr->pCurrent = pCsr->pCurrent->pNext;
        pCsr->bNoop = 1;
      }
    }

    zipfileRemoveEntryFromList(pTab, pOld);
    zipfileRemoveEntryFromList(pTab, pOld2);
  }

zipfile_update_done:
  sqlite3_free(pFree);
  sqlite3_free(zFree);
  return rc;
}

static int zipfileSerializeEOCD(ZipfileEOCD *p, u8 *aBuf){
  u8 *a = aBuf;
  zipfileWrite32(a, ZIPFILE_SIGNATURE_EOCD);
  zipfileWrite16(a, p->iDisk);
  zipfileWrite16(a, p->iFirstDisk);
  zipfileWrite16(a, p->nEntry);
  zipfileWrite16(a, p->nEntryTotal);
  zipfileWrite32(a, p->nSize);
  zipfileWrite32(a, p->iOffset);
  zipfileWrite16(a, 0);        /* Size of trailing comment in bytes*/

  return a-aBuf;
}

static int zipfileAppendEOCD(ZipfileTab *pTab, ZipfileEOCD *p){
  int nBuf = zipfileSerializeEOCD(p, pTab->aBuffer);
  assert( nBuf==ZIPFILE_EOCD_FIXED_SZ );
  return zipfileAppendData(pTab, pTab->aBuffer, nBuf);
}

/*
** Serialize the CDS structure into buffer aBuf[]. Return the number
** of bytes written.
*/
static int zipfileSerializeCDS(ZipfileEntry *pEntry, u8 *aBuf){
  u8 *a = aBuf;
  ZipfileCDS *pCDS = &pEntry->cds;

  if( pEntry->aExtra==0 ){
    pCDS->nExtra = 9;
  }

  zipfileWrite32(a, ZIPFILE_SIGNATURE_CDS);
  zipfileWrite16(a, pCDS->iVersionMadeBy);
  zipfileWrite16(a, pCDS->iVersionExtract);
  zipfileWrite16(a, pCDS->flags);
  zipfileWrite16(a, pCDS->iCompression);
  zipfileWrite16(a, pCDS->mTime);
  zipfileWrite16(a, pCDS->mDate);
  zipfileWrite32(a, pCDS->crc32);
  zipfileWrite32(a, pCDS->szCompressed);
  zipfileWrite32(a, pCDS->szUncompressed);
  assert( a==&aBuf[ZIPFILE_CDS_NFILE_OFF] );
  zipfileWrite16(a, pCDS->nFile);
  zipfileWrite16(a, pCDS->nExtra);
  zipfileWrite16(a, pCDS->nComment);
  zipfileWrite16(a, pCDS->iDiskStart);
  zipfileWrite16(a, pCDS->iInternalAttr);
  zipfileWrite32(a, pCDS->iExternalAttr);
  zipfileWrite32(a, pCDS->iOffset);

  memcpy(a, pCDS->zFile, pCDS->nFile);
  a += pCDS->nFile;

  if( pEntry->aExtra ){
    int n = (int)pCDS->nExtra + (int)pCDS->nComment;
    memcpy(a, pEntry->aExtra, n);
    a += n;
  }else{
    assert( pCDS->nExtra==9 );
    zipfileWrite16(a, ZIPFILE_EXTRA_TIMESTAMP);
    zipfileWrite16(a, 5);
    *a++ = 0x01;
    zipfileWrite32(a, pEntry->mUnixTime);
  }

  return a-aBuf;
}

static int zipfileCommit(sqlite3_vtab *pVtab){
  ZipfileTab *pTab = (ZipfileTab*)pVtab;
  int rc = SQLITE_OK;
  if( pTab->pWriteFd ){
    i64 iOffset = pTab->szCurrent;
    ZipfileEntry *p;
    ZipfileEOCD eocd;
    int nEntry = 0;

    /* Write out all entries */
    for(p=pTab->pFirstEntry; rc==SQLITE_OK && p; p=p->pNext){
      int n = zipfileSerializeCDS(p, pTab->aBuffer);
      rc = zipfileAppendData(pTab, pTab->aBuffer, n);
      nEntry++;
    }

    /* Write out the EOCD record */
    eocd.iDisk = 0;
    eocd.iFirstDisk = 0;
    eocd.nEntry = (u16)nEntry;
    eocd.nEntryTotal = (u16)nEntry;
    eocd.nSize = (u32)(pTab->szCurrent - iOffset);
    eocd.iOffset = (u32)iOffset;
    rc = zipfileAppendEOCD(pTab, &eocd);

    zipfileCleanupTransaction(pTab);
  }
  return rc;
}

static int zipfileRollback(sqlite3_vtab *pVtab){
  return zipfileCommit(pVtab);
}

static ZipfileCsr *zipfileFindCursor(ZipfileTab *pTab, i64 iId){
  ZipfileCsr *pCsr;
  for(pCsr=pTab->pCsrList; pCsr; pCsr=pCsr->pCsrNext){
    if( iId==pCsr->iId ) break;
  }
  return pCsr;
}

static void zipfileFunctionCds(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  ZipfileCsr *pCsr;
  ZipfileTab *pTab = (ZipfileTab*)sqlite3_user_data(context);
  assert( argc>0 );

  pCsr = zipfileFindCursor(pTab, sqlite3_value_int64(argv[0]));
  if( pCsr ){
    ZipfileCDS *p = &pCsr->pCurrent->cds;
    char *zRes = sqlite3_mprintf("{"
        "\"version-made-by\" : %u, "
        "\"version-to-extract\" : %u, "
        "\"flags\" : %u, "
        "\"compression\" : %u, "
        "\"time\" : %u, "
        "\"date\" : %u, "
        "\"crc32\" : %u, "
        "\"compressed-size\" : %u, "
        "\"uncompressed-size\" : %u, "
        "\"file-name-length\" : %u, "
        "\"extra-field-length\" : %u, "
        "\"file-comment-length\" : %u, "
        "\"disk-number-start\" : %u, "
        "\"internal-attr\" : %u, "
        "\"external-attr\" : %u, "
        "\"offset\" : %u }",
        (u32)p->iVersionMadeBy, (u32)p->iVersionExtract,
        (u32)p->flags, (u32)p->iCompression,
        (u32)p->mTime, (u32)p->mDate,
        (u32)p->crc32, (u32)p->szCompressed,
        (u32)p->szUncompressed, (u32)p->nFile,
        (u32)p->nExtra, (u32)p->nComment,
        (u32)p->iDiskStart, (u32)p->iInternalAttr,
        (u32)p->iExternalAttr, (u32)p->iOffset
    );

    if( zRes==0 ){
      sqlite3_result_error_nomem(context);
    }else{
      sqlite3_result_text(context, zRes, -1, SQLITE_TRANSIENT);
      sqlite3_free(zRes);
    }
  }
}

/*
** xFindFunction method.
*/
static int zipfileFindFunction(
  sqlite3_vtab *pVtab,            /* Virtual table handle */
  int nArg,                       /* Number of SQL function arguments */
  const char *zName,              /* Name of SQL function */
  void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), /* OUT: Result */
  void **ppArg                    /* OUT: User data for *pxFunc */
){
  (void)nArg;
  if( sqlite3_stricmp("zipfile_cds", zName)==0 ){
    *pxFunc = zipfileFunctionCds;
    *ppArg = (void*)pVtab;
    return 1;
  }
  return 0;
}

typedef struct ZipfileBuffer ZipfileBuffer;
struct ZipfileBuffer {
  u8 *a;                          /* Pointer to buffer */
  int n;                          /* Size of buffer in bytes */
  int nAlloc;                     /* Byte allocated at a[] */
};

typedef struct ZipfileCtx ZipfileCtx;
struct ZipfileCtx {
  int nEntry;
  ZipfileBuffer body;
  ZipfileBuffer cds;
};

static int zipfileBufferGrow(ZipfileBuffer *pBuf, int nByte){
  if( pBuf->n+nByte>pBuf->nAlloc ){
    u8 *aNew;
    sqlite3_int64 nNew = pBuf->n ? pBuf->n*2 : 512;
    int nReq = pBuf->n + nByte;

    while( nNew<nReq ) nNew = nNew*2;
    aNew = sqlite3_realloc64(pBuf->a, nNew);
    if( aNew==0 ) return SQLITE_NOMEM;
    pBuf->a = aNew;
    pBuf->nAlloc = (int)nNew;
  }
  return SQLITE_OK;
}

/*
** xStep() callback for the zipfile() aggregate. This can be called in
** any of the following ways:
**
**   SELECT zipfile(name,data) ...
**   SELECT zipfile(name,mode,mtime,data) ...
**   SELECT zipfile(name,mode,mtime,data,method) ...
*/
static void zipfileStep(sqlite3_context *pCtx, int nVal, sqlite3_value **apVal){
  ZipfileCtx *p;                  /* Aggregate function context */
  ZipfileEntry e;                 /* New entry to add to zip archive */

  sqlite3_value *pName = 0;
  sqlite3_value *pMode = 0;
  sqlite3_value *pMtime = 0;
  sqlite3_value *pData = 0;
  sqlite3_value *pMethod = 0;

  int bIsDir = 0;
  u32 mode;
  int rc = SQLITE_OK;
  char *zErr = 0;

  int iMethod = -1;               /* Compression method to use (0 or 8) */

  const u8 *aData = 0;            /* Possibly compressed data for new entry */
  int nData = 0;                  /* Size of aData[] in bytes */
  int szUncompressed = 0;         /* Size of data before compression */
  u8 *aFree = 0;                  /* Free this before returning */
  u32 iCrc32 = 0;                 /* crc32 of uncompressed data */

  char *zName = 0;                /* Path (name) of new entry */
  int nName = 0;                  /* Size of zName in bytes */
  char *zFree = 0;                /* Free this before returning */
  int nByte;

  memset(&e, 0, sizeof(e));
  p = (ZipfileCtx*)sqlite3_aggregate_context(pCtx, sizeof(ZipfileCtx));
  if( p==0 ) return;

  /* Martial the arguments into stack variables */
  if( nVal!=2 && nVal!=4 && nVal!=5 ){
    zErr = sqlite3_mprintf("wrong number of arguments to function zipfile()");
    rc = SQLITE_ERROR;
    goto zipfile_step_out;
  }
  pName = apVal[0];
  if( nVal==2 ){
    pData = apVal[1];
  }else{
    pMode = apVal[1];
    pMtime = apVal[2];
    pData = apVal[3];
    if( nVal==5 ){
      pMethod = apVal[4];
    }
  }

  /* Check that the 'name' parameter looks ok. */
  zName = (char*)sqlite3_value_text(pName);
  nName = sqlite3_value_bytes(pName);
  if( zName==0 ){
    zErr = sqlite3_mprintf("first argument to zipfile() must be non-NULL");
    rc = SQLITE_ERROR;
    goto zipfile_step_out;
  }

  /* Inspect the 'method' parameter. This must be either 0 (store), 8 (use
  ** deflate compression) or NULL (choose automatically).  */
  if( pMethod && SQLITE_NULL!=sqlite3_value_type(pMethod) ){
    iMethod = (int)sqlite3_value_int64(pMethod);
    if( iMethod!=0 && iMethod!=8 ){
      zErr = sqlite3_mprintf("illegal method value: %d", iMethod);
      rc = SQLITE_ERROR;
      goto zipfile_step_out;
    }
  }

  /* Now inspect the data. If this is NULL, then the new entry must be a
  ** directory.  Otherwise, figure out whether or not the data should
  ** be deflated or simply stored in the zip archive. */
  if( sqlite3_value_type(pData)==SQLITE_NULL ){
    bIsDir = 1;
    iMethod = 0;
  }else{
    aData = sqlite3_value_blob(pData);
    szUncompressed = nData = sqlite3_value_bytes(pData);
    iCrc32 = crc32(0, aData, nData);
    if( iMethod<0 || iMethod==8 ){
      int nOut = 0;
      rc = zipfileDeflate(aData, nData, &aFree, &nOut, &zErr);
      if( rc!=SQLITE_OK ){
        goto zipfile_step_out;
      }
      if( iMethod==8 || nOut<nData ){
        aData = aFree;
        nData = nOut;
        iMethod = 8;
      }else{
        iMethod = 0;
      }
    }
  }

  /* Decode the "mode" argument. */
  rc = zipfileGetMode(pMode, bIsDir, &mode, &zErr);
  if( rc ) goto zipfile_step_out;

  /* Decode the "mtime" argument. */
  e.mUnixTime = zipfileGetTime(pMtime);

  /* If this is a directory entry, ensure that there is exactly one '/'
  ** at the end of the path. Or, if this is not a directory and the path
  ** ends in '/' it is an error. */
  if( bIsDir==0 ){
    if( nName>0 && zName[nName-1]=='/' ){
      zErr = sqlite3_mprintf("non-directory name must not end with /");
      rc = SQLITE_ERROR;
      goto zipfile_step_out;
    }
  }else{
    if( nName==0 || zName[nName-1]!='/' ){
      zName = zFree = sqlite3_mprintf("%s/", zName);
      if( zName==0 ){
        rc = SQLITE_NOMEM;
        goto zipfile_step_out;
      }
      nName = (int)strlen(zName);
    }else{
      while( nName>1 && zName[nName-2]=='/' ) nName--;
    }
  }

  /* Assemble the ZipfileEntry object for the new zip archive entry */
  e.cds.iVersionMadeBy = ZIPFILE_NEWENTRY_MADEBY;
  e.cds.iVersionExtract = ZIPFILE_NEWENTRY_REQUIRED;
  e.cds.flags = ZIPFILE_NEWENTRY_FLAGS;
  e.cds.iCompression = (u16)iMethod;
  zipfileMtimeToDos(&e.cds, (u32)e.mUnixTime);
  e.cds.crc32 = iCrc32;
  e.cds.szCompressed = nData;
  e.cds.szUncompressed = szUncompressed;
  e.cds.iExternalAttr = (mode<<16);
  e.cds.iOffset = p->body.n;
  e.cds.nFile = (u16)nName;
  e.cds.zFile = zName;

  /* Append the LFH to the body of the new archive */
  nByte = ZIPFILE_LFH_FIXED_SZ + e.cds.nFile + 9;
  if( (rc = zipfileBufferGrow(&p->body, nByte)) ) goto zipfile_step_out;
  p->body.n += zipfileSerializeLFH(&e, &p->body.a[p->body.n]);

  /* Append the data to the body of the new archive */
  if( nData>0 ){
    if( (rc = zipfileBufferGrow(&p->body, nData)) ) goto zipfile_step_out;
    memcpy(&p->body.a[p->body.n], aData, nData);
    p->body.n += nData;
  }

  /* Append the CDS record to the directory of the new archive */
  nByte = ZIPFILE_CDS_FIXED_SZ + e.cds.nFile + 9;
  if( (rc = zipfileBufferGrow(&p->cds, nByte)) ) goto zipfile_step_out;
  p->cds.n += zipfileSerializeCDS(&e, &p->cds.a[p->cds.n]);

  /* Increment the count of entries in the archive */
  p->nEntry++;

 zipfile_step_out:
  sqlite3_free(aFree);
  sqlite3_free(zFree);
  if( rc ){
    if( zErr ){
      sqlite3_result_error(pCtx, zErr, -1);
    }else{
      sqlite3_result_error_code(pCtx, rc);
    }
  }
  sqlite3_free(zErr);
}

/*
** xFinalize() callback for zipfile aggregate function.
*/
static void zipfileFinal(sqlite3_context *pCtx){
  ZipfileCtx *p;
  ZipfileEOCD eocd;
  sqlite3_int64 nZip;
  u8 *aZip;

  p = (ZipfileCtx*)sqlite3_aggregate_context(pCtx, sizeof(ZipfileCtx));
  if( p==0 ) return;
  if( p->nEntry>0 ){
    memset(&eocd, 0, sizeof(eocd));
    eocd.nEntry = (u16)p->nEntry;
    eocd.nEntryTotal = (u16)p->nEntry;
    eocd.nSize = p->cds.n;
    eocd.iOffset = p->body.n;

    nZip = p->body.n + p->cds.n + ZIPFILE_EOCD_FIXED_SZ;
    aZip = (u8*)sqlite3_malloc64(nZip);
    if( aZip==0 ){
      sqlite3_result_error_nomem(pCtx);
    }else{
      memcpy(aZip, p->body.a, p->body.n);
      memcpy(&aZip[p->body.n], p->cds.a, p->cds.n);
      zipfileSerializeEOCD(&eocd, &aZip[p->body.n + p->cds.n]);
      sqlite3_result_blob(pCtx, aZip, (int)nZip, zipfileFree);
    }
  }

  sqlite3_free(p->body.a);
  sqlite3_free(p->cds.a);
}


/*
** Register the "zipfile" virtual table.
*/
static int zipfileRegister(sqlite3 *db){
  static sqlite3_module zipfileModule = {
    1,                         /* iVersion */
    zipfileConnect,            /* xCreate */
    zipfileConnect,            /* xConnect */
    zipfileBestIndex,          /* xBestIndex */
    zipfileDisconnect,         /* xDisconnect */
    zipfileDisconnect,         /* xDestroy */
    zipfileOpen,               /* xOpen - open a cursor */
    zipfileClose,              /* xClose - close a cursor */
    zipfileFilter,             /* xFilter - configure scan constraints */
    zipfileNext,               /* xNext - advance a cursor */
    zipfileEof,                /* xEof - check for end of scan */
    zipfileColumn,             /* xColumn - read data */
    0,                         /* xRowid - read data */
    zipfileUpdate,             /* xUpdate */
    zipfileBegin,              /* xBegin */
    0,                         /* xSync */
    zipfileCommit,             /* xCommit */
    zipfileRollback,           /* xRollback */
    zipfileFindFunction,       /* xFindMethod */
    0,                         /* xRename */
    0,                         /* xSavepoint */
    0,                         /* xRelease */
    0,                         /* xRollback */
    0,                         /* xShadowName */
    0                          /* xIntegrity */
  };

  int rc = sqlite3_create_module(db, "zipfile"  , &zipfileModule, 0);
  if( rc==SQLITE_OK ) rc = sqlite3_overload_function(db, "zipfile_cds", -1);
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_function(db, "zipfile", -1, SQLITE_UTF8, 0, 0, 
        zipfileStep, zipfileFinal
    );
  }
  assert( sizeof(i64)==8 );
  assert( sizeof(u32)==4 );
  assert( sizeof(u16)==2 );
  assert( sizeof(u8)==1 );
  return rc;
}
#else         /* SQLITE_OMIT_VIRTUALTABLE */
# define zipfileRegister(x) SQLITE_OK
#endif

#ifdef _WIN32

#endif
int sqlite3_zipfile_init(
  sqlite3 *db, 
  char **pzErrMsg, 
  const sqlite3_api_routines *pApi
){
  SQLITE_EXTENSION_INIT2(pApi);
  (void)pzErrMsg;  /* Unused parameter */
  return zipfileRegister(db);
}

/************************* End ../ext/misc/zipfile.c ********************/
/************************* Begin ../ext/misc/sqlar.c ******************/
/*
** 2017-12-17
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
******************************************************************************
**
** Utility functions sqlar_compress() and sqlar_uncompress(). Useful
** for working with sqlar archives and used by the shell tool's built-in
** sqlar support.
*/
/* #include "sqlite3ext.h" */
SQLITE_EXTENSION_INIT1
#include <zlib.h>
#include <assert.h>

/*
** Implementation of the "sqlar_compress(X)" SQL function.
**
** If the type of X is SQLITE_BLOB, and compressing that blob using
** zlib utility function compress() yields a smaller blob, return the
** compressed blob. Otherwise, return a copy of X.
**
** SQLar uses the "zlib format" for compressed content.  The zlib format
** contains a two-byte identification header and a four-byte checksum at
** the end.  This is different from ZIP which uses the raw deflate format.
**
** Future enhancements to SQLar might add support for new compression formats.
** If so, those new formats will be identified by alternative headers in the
** compressed data.
*/
static void sqlarCompressFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  assert( argc==1 );
  if( sqlite3_value_type(argv[0])==SQLITE_BLOB ){
    const Bytef *pData = sqlite3_value_blob(argv[0]);
    uLong nData = sqlite3_value_bytes(argv[0]);
    uLongf nOut = compressBound(nData);
    Bytef *pOut;

    pOut = (Bytef*)sqlite3_malloc(nOut);
    if( pOut==0 ){
      sqlite3_result_error_nomem(context);
      return;
    }else{
      if( Z_OK!=compress(pOut, &nOut, pData, nData) ){
        sqlite3_result_error(context, "error in compress()", -1);
      }else if( nOut<nData ){
        sqlite3_result_blob(context, pOut, nOut, SQLITE_TRANSIENT);
      }else{
        sqlite3_result_value(context, argv[0]);
      }
      sqlite3_free(pOut);
    }
  }else{
    sqlite3_result_value(context, argv[0]);
  }
}

/*
** Implementation of the "sqlar_uncompress(X,SZ)" SQL function
**
** Parameter SZ is interpreted as an integer. If it is less than or
** equal to zero, then this function returns a copy of X. Or, if
** SZ is equal to the size of X when interpreted as a blob, also
** return a copy of X. Otherwise, decompress blob X using zlib
** utility function uncompress() and return the results (another
** blob).
*/
static void sqlarUncompressFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  uLong nData;
  sqlite3_int64 sz;

  assert( argc==2 );
  sz = sqlite3_value_int(argv[1]);

  if( sz<=0 || sz==(nData = sqlite3_value_bytes(argv[0])) ){
    sqlite3_result_value(context, argv[0]);
  }else{
    uLongf szf = sz;
    const Bytef *pData= sqlite3_value_blob(argv[0]);
    Bytef *pOut = sqlite3_malloc(sz);
    if( pOut==0 ){
      sqlite3_result_error_nomem(context);
    }else if( Z_OK!=uncompress(pOut, &szf, pData, nData) ){
      sqlite3_result_error(context, "error in uncompress()", -1);
    }else{
      sqlite3_result_blob(context, pOut, szf, SQLITE_TRANSIENT);
    }
    sqlite3_free(pOut);
  }
}

#ifdef _WIN32

#endif
int sqlite3_sqlar_init(
  sqlite3 *db, 
  char **pzErrMsg, 
  const sqlite3_api_routines *pApi
){
  int rc = SQLITE_OK;
  SQLITE_EXTENSION_INIT2(pApi);
  (void)pzErrMsg;  /* Unused parameter */
  rc = sqlite3_create_function(db, "sqlar_compress", 1, 
                               SQLITE_UTF8|SQLITE_INNOCUOUS, 0,
                               sqlarCompressFunc, 0, 0);
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_function(db, "sqlar_uncompress", 2,
                                 SQLITE_UTF8|SQLITE_INNOCUOUS, 0,
                                 sqlarUncompressFunc, 0, 0);
  }
  return rc;
}

/************************* End ../ext/misc/sqlar.c ********************/
#endif
/************************* Begin ../ext/expert/sqlite3expert.h ******************/
/*
** 2017 April 07
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
*/
#if !defined(SQLITEEXPERT_H)
#define SQLITEEXPERT_H 1
/* #include "sqlite3.h" */

typedef struct sqlite3expert sqlite3expert;

/*
** Create a new sqlite3expert object.
**
** If successful, a pointer to the new object is returned and (*pzErr) set
** to NULL. Or, if an error occurs, NULL is returned and (*pzErr) set to
** an English-language error message. In this case it is the responsibility
** of the caller to eventually free the error message buffer using
** sqlite3_free().
*/
sqlite3expert *sqlite3_expert_new(sqlite3 *db, char **pzErr);

/*
** Configure an sqlite3expert object.
**
** EXPERT_CONFIG_SAMPLE:
**   By default, sqlite3_expert_analyze() generates sqlite_stat1 data for
**   each candidate index. This involves scanning and sorting the entire
**   contents of each user database table once for each candidate index
**   associated with the table. For large databases, this can be 
**   prohibitively slow. This option allows the sqlite3expert object to
**   be configured so that sqlite_stat1 data is instead generated based on a
**   subset of each table, or so that no sqlite_stat1 data is used at all.
**
**   A single integer argument is passed to this option. If the value is less
**   than or equal to zero, then no sqlite_stat1 data is generated or used by
**   the analysis - indexes are recommended based on the database schema only.
**   Or, if the value is 100 or greater, complete sqlite_stat1 data is
**   generated for each candidate index (this is the default). Finally, if the
**   value falls between 0 and 100, then it represents the percentage of user
**   table rows that should be considered when generating sqlite_stat1 data.
**
**   Examples:
**
**     // Do not generate any sqlite_stat1 data
**     sqlite3_expert_config(pExpert, EXPERT_CONFIG_SAMPLE, 0);
**
**     // Generate sqlite_stat1 data based on 10% of the rows in each table.
**     sqlite3_expert_config(pExpert, EXPERT_CONFIG_SAMPLE, 10);
*/
int sqlite3_expert_config(sqlite3expert *p, int op, ...);

#define EXPERT_CONFIG_SAMPLE 1    /* int */

/*
** Specify zero or more SQL statements to be included in the analysis.
**
** Buffer zSql must contain zero or more complete SQL statements. This
** function parses all statements contained in the buffer and adds them
** to the internal list of statements to analyze. If successful, SQLITE_OK
** is returned and (*pzErr) set to NULL. Or, if an error occurs - for example
** due to a error in the SQL - an SQLite error code is returned and (*pzErr)
** may be set to point to an English language error message. In this case
** the caller is responsible for eventually freeing the error message buffer
** using sqlite3_free().
**
** If an error does occur while processing one of the statements in the
** buffer passed as the second argument, none of the statements in the
** buffer are added to the analysis.
**
** This function must be called before sqlite3_expert_analyze(). If a call
** to this function is made on an sqlite3expert object that has already
** been passed to sqlite3_expert_analyze() SQLITE_MISUSE is returned
** immediately and no statements are added to the analysis.
*/
int sqlite3_expert_sql(
  sqlite3expert *p,               /* From a successful sqlite3_expert_new() */
  const char *zSql,               /* SQL statement(s) to add */
  char **pzErr                    /* OUT: Error message (if any) */
);


/*
** This function is called after the sqlite3expert object has been configured
** with all SQL statements using sqlite3_expert_sql() to actually perform
** the analysis. Once this function has been called, it is not possible to
** add further SQL statements to the analysis.
**
** If successful, SQLITE_OK is returned and (*pzErr) is set to NULL. Or, if
** an error occurs, an SQLite error code is returned and (*pzErr) set to 
** point to a buffer containing an English language error message. In this
** case it is the responsibility of the caller to eventually free the buffer
** using sqlite3_free().
**
** If an error does occur within this function, the sqlite3expert object
** is no longer useful for any purpose. At that point it is no longer
** possible to add further SQL statements to the object or to re-attempt
** the analysis. The sqlite3expert object must still be freed using a call
** sqlite3_expert_destroy().
*/
int sqlite3_expert_analyze(sqlite3expert *p, char **pzErr);

/*
** Return the total number of statements loaded using sqlite3_expert_sql().
** The total number of SQL statements may be different from the total number
** to calls to sqlite3_expert_sql().
*/
int sqlite3_expert_count(sqlite3expert*);

/*
** Return a component of the report.
**
** This function is called after sqlite3_expert_analyze() to extract the
** results of the analysis. Each call to this function returns either a
** NULL pointer or a pointer to a buffer containing a nul-terminated string.
** The value passed as the third argument must be one of the EXPERT_REPORT_*
** #define constants defined below.
**
** For some EXPERT_REPORT_* parameters, the buffer returned contains 
** information relating to a specific SQL statement. In these cases that
** SQL statement is identified by the value passed as the second argument.
** SQL statements are numbered from 0 in the order in which they are parsed.
** If an out-of-range value (less than zero or equal to or greater than the
** value returned by sqlite3_expert_count()) is passed as the second argument
** along with such an EXPERT_REPORT_* parameter, NULL is always returned.
**
** EXPERT_REPORT_SQL:
**   Return the text of SQL statement iStmt.
**
** EXPERT_REPORT_INDEXES:
**   Return a buffer containing the CREATE INDEX statements for all recommended
**   indexes for statement iStmt. If there are no new recommeded indexes, NULL 
**   is returned.
**
** EXPERT_REPORT_PLAN:
**   Return a buffer containing the EXPLAIN QUERY PLAN output for SQL query
**   iStmt after the proposed indexes have been added to the database schema.
**
** EXPERT_REPORT_CANDIDATES:
**   Return a pointer to a buffer containing the CREATE INDEX statements 
**   for all indexes that were tested (for all SQL statements). The iStmt
**   parameter is ignored for EXPERT_REPORT_CANDIDATES calls.
*/
const char *sqlite3_expert_report(sqlite3expert*, int iStmt, int eReport);

/*
** Values for the third argument passed to sqlite3_expert_report().
*/
#define EXPERT_REPORT_SQL        1
#define EXPERT_REPORT_INDEXES    2
#define EXPERT_REPORT_PLAN       3
#define EXPERT_REPORT_CANDIDATES 4

/*
** Free an (sqlite3expert*) handle and all associated resources. There 
** should be one call to this function for each successful call to 
** sqlite3-expert_new().
*/
void sqlite3_expert_destroy(sqlite3expert*);

#endif  /* !defined(SQLITEEXPERT_H) */

/************************* End ../ext/expert/sqlite3expert.h ********************/
/************************* Begin ../ext/expert/sqlite3expert.c ******************/
/*
** 2017 April 09
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
*/
/* #include "sqlite3expert.h" */
#include <assert.h>
#include <string.h>
#include <stdio.h>

#if !defined(SQLITE_AMALGAMATION)
#if defined(SQLITE_COVERAGE_TEST) || defined(SQLITE_MUTATION_TEST)
# define SQLITE_OMIT_AUXILIARY_SAFETY_CHECKS 1
#endif
#if defined(SQLITE_OMIT_AUXILIARY_SAFETY_CHECKS)
# define ALWAYS(X)      (1)
# define NEVER(X)       (0)
#elif !defined(NDEBUG)
# define ALWAYS(X)      ((X)?1:(assert(0),0))
# define NEVER(X)       ((X)?(assert(0),1):0)
#else
# define ALWAYS(X)      (X)
# define NEVER(X)       (X)
#endif
#endif /* !defined(SQLITE_AMALGAMATION) */


#ifndef SQLITE_OMIT_VIRTUALTABLE

/* typedef sqlite3_int64 i64; */
/* typedef sqlite3_uint64 u64; */

typedef struct IdxColumn IdxColumn;
typedef struct IdxConstraint IdxConstraint;
typedef struct IdxScan IdxScan;
typedef struct IdxStatement IdxStatement;
typedef struct IdxTable IdxTable;
typedef struct IdxWrite IdxWrite;

#define STRLEN  (int)strlen

/*
** A temp table name that we assume no user database will actually use.
** If this assumption proves incorrect triggers on the table with the
** conflicting name will be ignored.
*/
#define UNIQUE_TABLE_NAME "t592690916721053953805701627921227776"

/*
** A single constraint. Equivalent to either "col = ?" or "col < ?" (or
** any other type of single-ended range constraint on a column).
**
** pLink:
**   Used to temporarily link IdxConstraint objects into lists while
**   creating candidate indexes.
*/
struct IdxConstraint {
  char *zColl;                    /* Collation sequence */
  int bRange;                     /* True for range, false for eq */
  int iCol;                       /* Constrained table column */
  int bFlag;                      /* Used by idxFindCompatible() */
  int bDesc;                      /* True if ORDER BY <expr> DESC */
  IdxConstraint *pNext;           /* Next constraint in pEq or pRange list */
  IdxConstraint *pLink;           /* See above */
};

/*
** A single scan of a single table.
*/
struct IdxScan {
  IdxTable *pTab;                 /* Associated table object */
  int iDb;                        /* Database containing table zTable */
  i64 covering;                   /* Mask of columns required for cov. index */
  IdxConstraint *pOrder;          /* ORDER BY columns */
  IdxConstraint *pEq;             /* List of == constraints */
  IdxConstraint *pRange;          /* List of < constraints */
  IdxScan *pNextScan;             /* Next IdxScan object for same analysis */
};

/*
** Information regarding a single database table. Extracted from 
** "PRAGMA table_info" by function idxGetTableInfo().
*/
struct IdxColumn {
  char *zName;
  char *zColl;
  int iPk;
};
struct IdxTable {
  int nCol;
  char *zName;                    /* Table name */
  IdxColumn *aCol;
  IdxTable *pNext;                /* Next table in linked list of all tables */
};

/*
** An object of the following type is created for each unique table/write-op
** seen. The objects are stored in a singly-linked list beginning at
** sqlite3expert.pWrite.
*/
struct IdxWrite {
  IdxTable *pTab;
  int eOp;                        /* SQLITE_UPDATE, DELETE or INSERT */
  IdxWrite *pNext;
};

/*
** Each statement being analyzed is represented by an instance of this
** structure.
*/
struct IdxStatement {
  int iId;                        /* Statement number */
  char *zSql;                     /* SQL statement */
  char *zIdx;                     /* Indexes */
  char *zEQP;                     /* Plan */
  IdxStatement *pNext;
};


/*
** A hash table for storing strings. With space for a payload string
** with each entry. Methods are:
**
**   idxHashInit()
**   idxHashClear()
**   idxHashAdd()
**   idxHashSearch()
*/
#define IDX_HASH_SIZE 1023
typedef struct IdxHashEntry IdxHashEntry;
typedef struct IdxHash IdxHash;
struct IdxHashEntry {
  char *zKey;                     /* nul-terminated key */
  char *zVal;                     /* nul-terminated value string */
  char *zVal2;                    /* nul-terminated value string 2 */
  IdxHashEntry *pHashNext;        /* Next entry in same hash bucket */
  IdxHashEntry *pNext;            /* Next entry in hash */
};
struct IdxHash {
  IdxHashEntry *pFirst;
  IdxHashEntry *aHash[IDX_HASH_SIZE];
};

/*
** sqlite3expert object.
*/
struct sqlite3expert {
  int iSample;                    /* Percentage of tables to sample for stat1 */
  sqlite3 *db;                    /* User database */
  sqlite3 *dbm;                   /* In-memory db for this analysis */
  sqlite3 *dbv;                   /* Vtab schema for this analysis */
  IdxTable *pTable;               /* List of all IdxTable objects */
  IdxScan *pScan;                 /* List of scan objects */
  IdxWrite *pWrite;               /* List of write objects */
  IdxStatement *pStatement;       /* List of IdxStatement objects */
  int bRun;                       /* True once analysis has run */
  char **pzErrmsg;
  int rc;                         /* Error code from whereinfo hook */
  IdxHash hIdx;                   /* Hash containing all candidate indexes */
  char *zCandidates;              /* For EXPERT_REPORT_CANDIDATES */
};


/*
** Allocate and return nByte bytes of zeroed memory using sqlite3_malloc(). 
** If the allocation fails, set *pRc to SQLITE_NOMEM and return NULL.
*/
static void *idxMalloc(int *pRc, int nByte){
  void *pRet;
  assert( *pRc==SQLITE_OK );
  assert( nByte>0 );
  pRet = sqlite3_malloc(nByte);
  if( pRet ){
    memset(pRet, 0, nByte);
  }else{
    *pRc = SQLITE_NOMEM;
  }
  return pRet;
}

/*
** Initialize an IdxHash hash table.
*/
static void idxHashInit(IdxHash *pHash){
  memset(pHash, 0, sizeof(IdxHash));
}

/*
** Reset an IdxHash hash table.
*/
static void idxHashClear(IdxHash *pHash){
  int i;
  for(i=0; i<IDX_HASH_SIZE; i++){
    IdxHashEntry *pEntry;
    IdxHashEntry *pNext;
    for(pEntry=pHash->aHash[i]; pEntry; pEntry=pNext){
      pNext = pEntry->pHashNext;
      sqlite3_free(pEntry->zVal2);
      sqlite3_free(pEntry);
    }
  }
  memset(pHash, 0, sizeof(IdxHash));
}

/*
** Return the index of the hash bucket that the string specified by the
** arguments to this function belongs.
*/
static int idxHashString(const char *z, int n){
  unsigned int ret = 0;
  int i;
  for(i=0; i<n; i++){
    ret += (ret<<3) + (unsigned char)(z[i]);
  }
  return (int)(ret % IDX_HASH_SIZE);
}

/*
** If zKey is already present in the hash table, return non-zero and do
** nothing. Otherwise, add an entry with key zKey and payload string zVal to
** the hash table passed as the second argument. 
*/
static int idxHashAdd(
  int *pRc, 
  IdxHash *pHash, 
  const char *zKey,
  const char *zVal
){
  int nKey = STRLEN(zKey);
  int iHash = idxHashString(zKey, nKey);
  int nVal = (zVal ? STRLEN(zVal) : 0);
  IdxHashEntry *pEntry;
  assert( iHash>=0 );
  for(pEntry=pHash->aHash[iHash]; pEntry; pEntry=pEntry->pHashNext){
    if( STRLEN(pEntry->zKey)==nKey && 0==memcmp(pEntry->zKey, zKey, nKey) ){
      return 1;
    }
  }
  pEntry = idxMalloc(pRc, sizeof(IdxHashEntry) + nKey+1 + nVal+1);
  if( pEntry ){
    pEntry->zKey = (char*)&pEntry[1];
    memcpy(pEntry->zKey, zKey, nKey);
    if( zVal ){
      pEntry->zVal = &pEntry->zKey[nKey+1];
      memcpy(pEntry->zVal, zVal, nVal);
    }
    pEntry->pHashNext = pHash->aHash[iHash];
    pHash->aHash[iHash] = pEntry;

    pEntry->pNext = pHash->pFirst;
    pHash->pFirst = pEntry;
  }
  return 0;
}

/*
** If zKey/nKey is present in the hash table, return a pointer to the 
** hash-entry object.
*/
static IdxHashEntry *idxHashFind(IdxHash *pHash, const char *zKey, int nKey){
  int iHash;
  IdxHashEntry *pEntry;
  if( nKey<0 ) nKey = STRLEN(zKey);
  iHash = idxHashString(zKey, nKey);
  assert( iHash>=0 );
  for(pEntry=pHash->aHash[iHash]; pEntry; pEntry=pEntry->pHashNext){
    if( STRLEN(pEntry->zKey)==nKey && 0==memcmp(pEntry->zKey, zKey, nKey) ){
      return pEntry;
    }
  }
  return 0;
}

/*
** If the hash table contains an entry with a key equal to the string
** passed as the final two arguments to this function, return a pointer
** to the payload string. Otherwise, if zKey/nKey is not present in the
** hash table, return NULL.
*/
static const char *idxHashSearch(IdxHash *pHash, const char *zKey, int nKey){
  IdxHashEntry *pEntry = idxHashFind(pHash, zKey, nKey);
  if( pEntry ) return pEntry->zVal;
  return 0;
}

/*
** Allocate and return a new IdxConstraint object. Set the IdxConstraint.zColl
** variable to point to a copy of nul-terminated string zColl.
*/
static IdxConstraint *idxNewConstraint(int *pRc, const char *zColl){
  IdxConstraint *pNew;
  int nColl = STRLEN(zColl);

  assert( *pRc==SQLITE_OK );
  pNew = (IdxConstraint*)idxMalloc(pRc, sizeof(IdxConstraint) * nColl + 1);
  if( pNew ){
    pNew->zColl = (char*)&pNew[1];
    memcpy(pNew->zColl, zColl, nColl+1);
  }
  return pNew;
}

/*
** An error associated with database handle db has just occurred. Pass
** the error message to callback function xOut.
*/
static void idxDatabaseError(
  sqlite3 *db,                    /* Database handle */
  char **pzErrmsg                 /* Write error here */
){
  *pzErrmsg = sqlite3_mprintf("%s", sqlite3_errmsg(db));
}

/*
** Prepare an SQL statement.
*/
static int idxPrepareStmt(
  sqlite3 *db,                    /* Database handle to compile against */
  sqlite3_stmt **ppStmt,          /* OUT: Compiled SQL statement */
  char **pzErrmsg,                /* OUT: sqlite3_malloc()ed error message */
  const char *zSql                /* SQL statement to compile */
){
  int rc = sqlite3_prepare_v2(db, zSql, -1, ppStmt, 0);
  if( rc!=SQLITE_OK ){
    *ppStmt = 0;
    idxDatabaseError(db, pzErrmsg);
  }
  return rc;
}

/*
** Prepare an SQL statement using the results of a printf() formatting.
*/
static int idxPrintfPrepareStmt(
  sqlite3 *db,                    /* Database handle to compile against */
  sqlite3_stmt **ppStmt,          /* OUT: Compiled SQL statement */
  char **pzErrmsg,                /* OUT: sqlite3_malloc()ed error message */
  const char *zFmt,               /* printf() format of SQL statement */
  ...                             /* Trailing printf() arguments */
){
  va_list ap;
  int rc;
  char *zSql;
  va_start(ap, zFmt);
  zSql = sqlite3_vmprintf(zFmt, ap);
  if( zSql==0 ){
    rc = SQLITE_NOMEM;
  }else{
    rc = idxPrepareStmt(db, ppStmt, pzErrmsg, zSql);
    sqlite3_free(zSql);
  }
  va_end(ap);
  return rc;
}


/*************************************************************************
** Beginning of virtual table implementation.
*/
typedef struct ExpertVtab ExpertVtab;
struct ExpertVtab {
  sqlite3_vtab base;
  IdxTable *pTab;
  sqlite3expert *pExpert;
};

typedef struct ExpertCsr ExpertCsr;
struct ExpertCsr {
  sqlite3_vtab_cursor base;
  sqlite3_stmt *pData;
};

static char *expertDequote(const char *zIn){
  int n = STRLEN(zIn);
  char *zRet = sqlite3_malloc(n);

  assert( zIn[0]=='\'' );
  assert( zIn[n-1]=='\'' );

  if( zRet ){
    int iOut = 0;
    int iIn = 0;
    for(iIn=1; iIn<(n-1); iIn++){
      if( zIn[iIn]=='\'' ){
        assert( zIn[iIn+1]=='\'' );
        iIn++;
      }
      zRet[iOut++] = zIn[iIn];
    }
    zRet[iOut] = '\0';
  }

  return zRet;
}

/* 
** This function is the implementation of both the xConnect and xCreate
** methods of the r-tree virtual table.
**
**   argv[0]   -> module name
**   argv[1]   -> database name
**   argv[2]   -> table name
**   argv[...] -> column names...
*/
static int expertConnect(
  sqlite3 *db,
  void *pAux,
  int argc, const char *const*argv,
  sqlite3_vtab **ppVtab,
  char **pzErr
){
  sqlite3expert *pExpert = (sqlite3expert*)pAux;
  ExpertVtab *p = 0;
  int rc;

  if( argc!=4 ){
    *pzErr = sqlite3_mprintf("internal error!");
    rc = SQLITE_ERROR;
  }else{
    char *zCreateTable = expertDequote(argv[3]);
    if( zCreateTable ){
      rc = sqlite3_declare_vtab(db, zCreateTable);
      if( rc==SQLITE_OK ){
        p = idxMalloc(&rc, sizeof(ExpertVtab));
      }
      if( rc==SQLITE_OK ){
        p->pExpert = pExpert;
        p->pTab = pExpert->pTable;
        assert( sqlite3_stricmp(p->pTab->zName, argv[2])==0 );
      }
      sqlite3_free(zCreateTable);
    }else{
      rc = SQLITE_NOMEM;
    }
  }

  *ppVtab = (sqlite3_vtab*)p;
  return rc;
}

static int expertDisconnect(sqlite3_vtab *pVtab){
  ExpertVtab *p = (ExpertVtab*)pVtab;
  sqlite3_free(p);
  return SQLITE_OK;
}

static int expertBestIndex(sqlite3_vtab *pVtab, sqlite3_index_info *pIdxInfo){
  ExpertVtab *p = (ExpertVtab*)pVtab;
  int rc = SQLITE_OK;
  int n = 0;
  IdxScan *pScan;
  const int opmask = 
    SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_GT |
    SQLITE_INDEX_CONSTRAINT_LT | SQLITE_INDEX_CONSTRAINT_GE |
    SQLITE_INDEX_CONSTRAINT_LE;

  pScan = idxMalloc(&rc, sizeof(IdxScan));
  if( pScan ){
    int i;

    /* Link the new scan object into the list */
    pScan->pTab = p->pTab;
    pScan->pNextScan = p->pExpert->pScan;
    p->pExpert->pScan = pScan;

    /* Add the constraints to the IdxScan object */
    for(i=0; i<pIdxInfo->nConstraint; i++){
      struct sqlite3_index_constraint *pCons = &pIdxInfo->aConstraint[i];
      if( pCons->usable 
       && pCons->iColumn>=0 
       && p->pTab->aCol[pCons->iColumn].iPk==0
       && (pCons->op & opmask) 
      ){
        IdxConstraint *pNew;
        const char *zColl = sqlite3_vtab_collation(pIdxInfo, i);
        pNew = idxNewConstraint(&rc, zColl);
        if( pNew ){
          pNew->iCol = pCons->iColumn;
          if( pCons->op==SQLITE_INDEX_CONSTRAINT_EQ ){
            pNew->pNext = pScan->pEq;
            pScan->pEq = pNew;
          }else{
            pNew->bRange = 1;
            pNew->pNext = pScan->pRange;
            pScan->pRange = pNew;
          }
        }
        n++;
        pIdxInfo->aConstraintUsage[i].argvIndex = n;
      }
    }

    /* Add the ORDER BY to the IdxScan object */
    for(i=pIdxInfo->nOrderBy-1; i>=0; i--){
      int iCol = pIdxInfo->aOrderBy[i].iColumn;
      if( iCol>=0 ){
        IdxConstraint *pNew = idxNewConstraint(&rc, p->pTab->aCol[iCol].zColl);
        if( pNew ){
          pNew->iCol = iCol;
          pNew->bDesc = pIdxInfo->aOrderBy[i].desc;
          pNew->pNext = pScan->pOrder;
          pNew->pLink = pScan->pOrder;
          pScan->pOrder = pNew;
          n++;
        }
      }
    }
  }

  pIdxInfo->estimatedCost = 1000000.0 / (n+1);
  return rc;
}

static int expertUpdate(
  sqlite3_vtab *pVtab, 
  int nData, 
  sqlite3_value **azData, 
  sqlite_int64 *pRowid
){
  (void)pVtab;
  (void)nData;
  (void)azData;
  (void)pRowid;
  return SQLITE_OK;
}

/* 
** Virtual table module xOpen method.
*/
static int expertOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){
  int rc = SQLITE_OK;
  ExpertCsr *pCsr;
  (void)pVTab;
  pCsr = idxMalloc(&rc, sizeof(ExpertCsr));
  *ppCursor = (sqlite3_vtab_cursor*)pCsr;
  return rc;
}

/* 
** Virtual table module xClose method.
*/
static int expertClose(sqlite3_vtab_cursor *cur){
  ExpertCsr *pCsr = (ExpertCsr*)cur;
  sqlite3_finalize(pCsr->pData);
  sqlite3_free(pCsr);
  return SQLITE_OK;
}

/*
** Virtual table module xEof method.
**
** Return non-zero if the cursor does not currently point to a valid 
** record (i.e if the scan has finished), or zero otherwise.
*/
static int expertEof(sqlite3_vtab_cursor *cur){
  ExpertCsr *pCsr = (ExpertCsr*)cur;
  return pCsr->pData==0;
}

/* 
** Virtual table module xNext method.
*/
static int expertNext(sqlite3_vtab_cursor *cur){
  ExpertCsr *pCsr = (ExpertCsr*)cur;
  int rc = SQLITE_OK;

  assert( pCsr->pData );
  rc = sqlite3_step(pCsr->pData);
  if( rc!=SQLITE_ROW ){
    rc = sqlite3_finalize(pCsr->pData);
    pCsr->pData = 0;
  }else{
    rc = SQLITE_OK;
  }

  return rc;
}

/* 
** Virtual table module xRowid method.
*/
static int expertRowid(sqlite3_vtab_cursor *cur, sqlite_int64 *pRowid){
  (void)cur;
  *pRowid = 0;
  return SQLITE_OK;
}

/* 
** Virtual table module xColumn method.
*/
static int expertColumn(sqlite3_vtab_cursor *cur, sqlite3_context *ctx, int i){
  ExpertCsr *pCsr = (ExpertCsr*)cur;
  sqlite3_value *pVal;
  pVal = sqlite3_column_value(pCsr->pData, i);
  if( pVal ){
    sqlite3_result_value(ctx, pVal);
  }
  return SQLITE_OK;
}

/* 
** Virtual table module xFilter method.
*/
static int expertFilter(
  sqlite3_vtab_cursor *cur, 
  int idxNum, const char *idxStr,
  int argc, sqlite3_value **argv
){
  ExpertCsr *pCsr = (ExpertCsr*)cur;
  ExpertVtab *pVtab = (ExpertVtab*)(cur->pVtab);
  sqlite3expert *pExpert = pVtab->pExpert;
  int rc;

  (void)idxNum;
  (void)idxStr;
  (void)argc;
  (void)argv;
  rc = sqlite3_finalize(pCsr->pData);
  pCsr->pData = 0;
  if( rc==SQLITE_OK ){
    rc = idxPrintfPrepareStmt(pExpert->db, &pCsr->pData, &pVtab->base.zErrMsg,
        "SELECT * FROM main.%Q WHERE sqlite_expert_sample()", pVtab->pTab->zName
    );
  }

  if( rc==SQLITE_OK ){
    rc = expertNext(cur);
  }
  return rc;
}

static int idxRegisterVtab(sqlite3expert *p){
  static sqlite3_module expertModule = {
    2,                            /* iVersion */
    expertConnect,                /* xCreate - create a table */
    expertConnect,                /* xConnect - connect to an existing table */
    expertBestIndex,              /* xBestIndex - Determine search strategy */
    expertDisconnect,             /* xDisconnect - Disconnect from a table */
    expertDisconnect,             /* xDestroy - Drop a table */
    expertOpen,                   /* xOpen - open a cursor */
    expertClose,                  /* xClose - close a cursor */
    expertFilter,                 /* xFilter - configure scan constraints */
    expertNext,                   /* xNext - advance a cursor */
    expertEof,                    /* xEof */
    expertColumn,                 /* xColumn - read data */
    expertRowid,                  /* xRowid - read data */
    expertUpdate,                 /* xUpdate - write data */
    0,                            /* xBegin - begin transaction */
    0,                            /* xSync - sync transaction */
    0,                            /* xCommit - commit transaction */
    0,                            /* xRollback - rollback transaction */
    0,                            /* xFindFunction - function overloading */
    0,                            /* xRename - rename the table */
    0,                            /* xSavepoint */
    0,                            /* xRelease */
    0,                            /* xRollbackTo */
    0,                            /* xShadowName */
    0,                            /* xIntegrity */
  };

  return sqlite3_create_module(p->dbv, "expert", &expertModule, (void*)p);
}
/*
** End of virtual table implementation.
*************************************************************************/
/*
** Finalize SQL statement pStmt. If (*pRc) is SQLITE_OK when this function
** is called, set it to the return value of sqlite3_finalize() before
** returning. Otherwise, discard the sqlite3_finalize() return value.
*/
static void idxFinalize(int *pRc, sqlite3_stmt *pStmt){
  int rc = sqlite3_finalize(pStmt);
  if( *pRc==SQLITE_OK ) *pRc = rc;
}

/*
** Attempt to allocate an IdxTable structure corresponding to table zTab
** in the main database of connection db. If successful, set (*ppOut) to
** point to the new object and return SQLITE_OK. Otherwise, return an
** SQLite error code and set (*ppOut) to NULL. In this case *pzErrmsg may be
** set to point to an error string.
**
** It is the responsibility of the caller to eventually free either the
** IdxTable object or error message using sqlite3_free().
*/
static int idxGetTableInfo(
  sqlite3 *db,                    /* Database connection to read details from */
  const char *zTab,               /* Table name */
  IdxTable **ppOut,               /* OUT: New object (if successful) */
  char **pzErrmsg                 /* OUT: Error message (if not) */
){
  sqlite3_stmt *p1 = 0;
  int nCol = 0;
  int nTab;
  int nByte;
  IdxTable *pNew = 0;
  int rc, rc2;
  char *pCsr = 0;
  int nPk = 0;

  *ppOut = 0;
  if( zTab==0 ) return SQLITE_ERROR;
  nTab = STRLEN(zTab);
  nByte = sizeof(IdxTable) + nTab + 1;
  rc = idxPrintfPrepareStmt(db, &p1, pzErrmsg, "PRAGMA table_xinfo=%Q", zTab);
  while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(p1) ){
    const char *zCol = (const char*)sqlite3_column_text(p1, 1);
    const char *zColSeq = 0;
    if( zCol==0 ){
      rc = SQLITE_ERROR;
      break;
    }
    nByte += 1 + STRLEN(zCol);
    rc = sqlite3_table_column_metadata(
        db, "main", zTab, zCol, 0, &zColSeq, 0, 0, 0
    );
    if( zColSeq==0 ) zColSeq = "binary";
    nByte += 1 + STRLEN(zColSeq);
    nCol++;
    nPk += (sqlite3_column_int(p1, 5)>0);
  }
  rc2 = sqlite3_reset(p1);
  if( rc==SQLITE_OK ) rc = rc2;

  nByte += sizeof(IdxColumn) * nCol;
  if( rc==SQLITE_OK ){
    pNew = idxMalloc(&rc, nByte);
  }
  if( rc==SQLITE_OK ){
    pNew->aCol = (IdxColumn*)&pNew[1];
    pNew->nCol = nCol;
    pCsr = (char*)&pNew->aCol[nCol];
  }

  nCol = 0;
  while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(p1) ){
    const char *zCol = (const char*)sqlite3_column_text(p1, 1);
    const char *zColSeq = 0;
    int nCopy;
    if( zCol==0 ) continue;
    nCopy = STRLEN(zCol) + 1;
    pNew->aCol[nCol].zName = pCsr;
    pNew->aCol[nCol].iPk = (sqlite3_column_int(p1, 5)==1 && nPk==1);
    memcpy(pCsr, zCol, nCopy);
    pCsr += nCopy;

    rc = sqlite3_table_column_metadata(
        db, "main", zTab, zCol, 0, &zColSeq, 0, 0, 0
    );
    if( rc==SQLITE_OK ){
      if( zColSeq==0 ) zColSeq = "binary";
      nCopy = STRLEN(zColSeq) + 1;
      pNew->aCol[nCol].zColl = pCsr;
      memcpy(pCsr, zColSeq, nCopy);
      pCsr += nCopy;
    }

    nCol++;
  }
  idxFinalize(&rc, p1);

  if( rc!=SQLITE_OK ){
    sqlite3_free(pNew);
    pNew = 0;
  }else if( ALWAYS(pNew!=0) ){
    pNew->zName = pCsr;
    if( ALWAYS(pNew->zName!=0) ) memcpy(pNew->zName, zTab, nTab+1);
  }

  *ppOut = pNew;
  return rc;
}

/*
** This function is a no-op if *pRc is set to anything other than 
** SQLITE_OK when it is called.
**
** If *pRc is initially set to SQLITE_OK, then the text specified by
** the printf() style arguments is appended to zIn and the result returned
** in a buffer allocated by sqlite3_malloc(). sqlite3_free() is called on
** zIn before returning.
*/
static char *idxAppendText(int *pRc, char *zIn, const char *zFmt, ...){
  va_list ap;
  char *zAppend = 0;
  char *zRet = 0;
  int nIn = zIn ? STRLEN(zIn) : 0;
  int nAppend = 0;
  va_start(ap, zFmt);
  if( *pRc==SQLITE_OK ){
    zAppend = sqlite3_vmprintf(zFmt, ap);
    if( zAppend ){
      nAppend = STRLEN(zAppend);
      zRet = (char*)sqlite3_malloc(nIn + nAppend + 1);
    }
    if( zAppend && zRet ){
      if( nIn ) memcpy(zRet, zIn, nIn);
      memcpy(&zRet[nIn], zAppend, nAppend+1);
    }else{
      sqlite3_free(zRet);
      zRet = 0;
      *pRc = SQLITE_NOMEM;
    }
    sqlite3_free(zAppend);
    sqlite3_free(zIn);
  }
  va_end(ap);
  return zRet;
}

/*
** Return true if zId must be quoted in order to use it as an SQL
** identifier, or false otherwise.
*/
static int idxIdentifierRequiresQuotes(const char *zId){
  int i;
  int nId = STRLEN(zId);
  
  if( sqlite3_keyword_check(zId, nId) ) return 1;

  for(i=0; zId[i]; i++){
    if( !(zId[i]=='_')
     && !(zId[i]>='0' && zId[i]<='9')
     && !(zId[i]>='a' && zId[i]<='z')
     && !(zId[i]>='A' && zId[i]<='Z')
    ){
      return 1;
    }
  }
  return 0;
}

/*
** This function appends an index column definition suitable for constraint
** pCons to the string passed as zIn and returns the result.
*/
static char *idxAppendColDefn(
  int *pRc,                       /* IN/OUT: Error code */
  char *zIn,                      /* Column defn accumulated so far */
  IdxTable *pTab,                 /* Table index will be created on */
  IdxConstraint *pCons
){
  char *zRet = zIn;
  IdxColumn *p = &pTab->aCol[pCons->iCol];
  if( zRet ) zRet = idxAppendText(pRc, zRet, ", ");

  if( idxIdentifierRequiresQuotes(p->zName) ){
    zRet = idxAppendText(pRc, zRet, "%Q", p->zName);
  }else{
    zRet = idxAppendText(pRc, zRet, "%s", p->zName);
  }

  if( sqlite3_stricmp(p->zColl, pCons->zColl) ){
    if( idxIdentifierRequiresQuotes(pCons->zColl) ){
      zRet = idxAppendText(pRc, zRet, " COLLATE %Q", pCons->zColl);
    }else{
      zRet = idxAppendText(pRc, zRet, " COLLATE %s", pCons->zColl);
    }
  }

  if( pCons->bDesc ){
    zRet = idxAppendText(pRc, zRet, " DESC");
  }
  return zRet;
}

/*
** Search database dbm for an index compatible with the one idxCreateFromCons()
** would create from arguments pScan, pEq and pTail. If no error occurs and 
** such an index is found, return non-zero. Or, if no such index is found,
** return zero.
**
** If an error occurs, set *pRc to an SQLite error code and return zero.
*/
static int idxFindCompatible(
  int *pRc,                       /* OUT: Error code */
  sqlite3* dbm,                   /* Database to search */
  IdxScan *pScan,                 /* Scan for table to search for index on */
  IdxConstraint *pEq,             /* List of == constraints */
  IdxConstraint *pTail            /* List of range constraints */
){
  const char *zTbl = pScan->pTab->zName;
  sqlite3_stmt *pIdxList = 0;
  IdxConstraint *pIter;
  int nEq = 0;                    /* Number of elements in pEq */
  int rc;

  /* Count the elements in list pEq */
  for(pIter=pEq; pIter; pIter=pIter->pLink) nEq++;

  rc = idxPrintfPrepareStmt(dbm, &pIdxList, 0, "PRAGMA index_list=%Q", zTbl);
  while( rc==SQLITE_OK && sqlite3_step(pIdxList)==SQLITE_ROW ){
    int bMatch = 1;
    IdxConstraint *pT = pTail;
    sqlite3_stmt *pInfo = 0;
    const char *zIdx = (const char*)sqlite3_column_text(pIdxList, 1);
    if( zIdx==0 ) continue;

    /* Zero the IdxConstraint.bFlag values in the pEq list */
    for(pIter=pEq; pIter; pIter=pIter->pLink) pIter->bFlag = 0;

    rc = idxPrintfPrepareStmt(dbm, &pInfo, 0, "PRAGMA index_xInfo=%Q", zIdx);
    while( rc==SQLITE_OK && sqlite3_step(pInfo)==SQLITE_ROW ){
      int iIdx = sqlite3_column_int(pInfo, 0);
      int iCol = sqlite3_column_int(pInfo, 1);
      const char *zColl = (const char*)sqlite3_column_text(pInfo, 4);

      if( iIdx<nEq ){
        for(pIter=pEq; pIter; pIter=pIter->pLink){
          if( pIter->bFlag ) continue;
          if( pIter->iCol!=iCol ) continue;
          if( sqlite3_stricmp(pIter->zColl, zColl) ) continue;
          pIter->bFlag = 1;
          break;
        }
        if( pIter==0 ){
          bMatch = 0;
          break;
        }
      }else{
        if( pT ){
          if( pT->iCol!=iCol || sqlite3_stricmp(pT->zColl, zColl) ){
            bMatch = 0;
            break;
          }
          pT = pT->pLink;
        }
      }
    }
    idxFinalize(&rc, pInfo);

    if( rc==SQLITE_OK && bMatch ){
      sqlite3_finalize(pIdxList);
      return 1;
    }
  }
  idxFinalize(&rc, pIdxList);

  *pRc = rc;
  return 0;
}

/* Callback for sqlite3_exec() with query with leading count(*) column.
 * The first argument is expected to be an int*, referent to be incremented
 * if that leading column is not exactly '0'.
 */
static int countNonzeros(void* pCount, int nc,
                         char* azResults[], char* azColumns[]){
  (void)azColumns;  /* Suppress unused parameter warning */
  if( nc>0 && (azResults[0][0]!='0' || azResults[0][1]!=0) ){
    *((int *)pCount) += 1;
  }
  return 0;
}

static int idxCreateFromCons(
  sqlite3expert *p,
  IdxScan *pScan,
  IdxConstraint *pEq, 
  IdxConstraint *pTail
){
  sqlite3 *dbm = p->dbm;
  int rc = SQLITE_OK;
  if( (pEq || pTail) && 0==idxFindCompatible(&rc, dbm, pScan, pEq, pTail) ){
    IdxTable *pTab = pScan->pTab;
    char *zCols = 0;
    char *zIdx = 0;
    IdxConstraint *pCons;
    unsigned int h = 0;
    const char *zFmt;

    for(pCons=pEq; pCons; pCons=pCons->pLink){
      zCols = idxAppendColDefn(&rc, zCols, pTab, pCons);
    }
    for(pCons=pTail; pCons; pCons=pCons->pLink){
      zCols = idxAppendColDefn(&rc, zCols, pTab, pCons);
    }

    if( rc==SQLITE_OK ){
      /* Hash the list of columns to come up with a name for the index */
      const char *zTable = pScan->pTab->zName;
      int quoteTable = idxIdentifierRequiresQuotes(zTable);
      char *zName = 0;          /* Index name */
      int collisions = 0;
      do{
        int i;
        char *zFind;
        for(i=0; zCols[i]; i++){
          h += ((h<<3) + zCols[i]);
        }
        sqlite3_free(zName);
        zName = sqlite3_mprintf("%s_idx_%08x", zTable, h);
        if( zName==0 ) break;
        /* Is is unique among table, view and index names? */
        zFmt = "SELECT count(*) FROM sqlite_schema WHERE name=%Q"
          " AND type in ('index','table','view')";
        zFind = sqlite3_mprintf(zFmt, zName);
        i = 0;
        rc = sqlite3_exec(dbm, zFind, countNonzeros, &i, 0);
        assert(rc==SQLITE_OK);
        sqlite3_free(zFind);
        if( i==0 ){
          collisions = 0;
          break;
        }
        ++collisions;
      }while( collisions<50 && zName!=0 );
      if( collisions ){
        /* This return means "Gave up trying to find a unique index name." */
        rc = SQLITE_BUSY_TIMEOUT;
      }else if( zName==0 ){
        rc = SQLITE_NOMEM;
      }else{
        if( quoteTable ){
          zFmt = "CREATE INDEX \"%w\" ON \"%w\"(%s)";
        }else{
          zFmt = "CREATE INDEX %s ON %s(%s)";
        }
        zIdx = sqlite3_mprintf(zFmt, zName, zTable, zCols);
        if( !zIdx ){
          rc = SQLITE_NOMEM;
        }else{
          rc = sqlite3_exec(dbm, zIdx, 0, 0, p->pzErrmsg);
          if( rc!=SQLITE_OK ){
            rc = SQLITE_BUSY_TIMEOUT;
          }else{
            idxHashAdd(&rc, &p->hIdx, zName, zIdx);
          }
        }
        sqlite3_free(zName);
        sqlite3_free(zIdx);
      }
    }

    sqlite3_free(zCols);
  }
  return rc;
}

/*
** Return true if list pList (linked by IdxConstraint.pLink) contains
** a constraint compatible with *p. Otherwise return false.
*/
static int idxFindConstraint(IdxConstraint *pList, IdxConstraint *p){
  IdxConstraint *pCmp;
  for(pCmp=pList; pCmp; pCmp=pCmp->pLink){
    if( p->iCol==pCmp->iCol ) return 1;
  }
  return 0;
}

static int idxCreateFromWhere(
  sqlite3expert *p, 
  IdxScan *pScan,                 /* Create indexes for this scan */
  IdxConstraint *pTail            /* range/ORDER BY constraints for inclusion */
){
  IdxConstraint *p1 = 0;
  IdxConstraint *pCon;
  int rc;

  /* Gather up all the == constraints. */
  for(pCon=pScan->pEq; pCon; pCon=pCon->pNext){
    if( !idxFindConstraint(p1, pCon) && !idxFindConstraint(pTail, pCon) ){
      pCon->pLink = p1;
      p1 = pCon;
    }
  }

  /* Create an index using the == constraints collected above. And the
  ** range constraint/ORDER BY terms passed in by the caller, if any. */
  rc = idxCreateFromCons(p, pScan, p1, pTail);

  /* If no range/ORDER BY passed by the caller, create a version of the
  ** index for each range constraint.  */
  if( pTail==0 ){
    for(pCon=pScan->pRange; rc==SQLITE_OK && pCon; pCon=pCon->pNext){
      assert( pCon->pLink==0 );
      if( !idxFindConstraint(p1, pCon) && !idxFindConstraint(pTail, pCon) ){
        rc = idxCreateFromCons(p, pScan, p1, pCon);
      }
    }
  }

  return rc;
}

/*
** Create candidate indexes in database [dbm] based on the data in 
** linked-list pScan.
*/
static int idxCreateCandidates(sqlite3expert *p){
  int rc = SQLITE_OK;
  IdxScan *pIter;

  for(pIter=p->pScan; pIter && rc==SQLITE_OK; pIter=pIter->pNextScan){
    rc = idxCreateFromWhere(p, pIter, 0);
    if( rc==SQLITE_OK && pIter->pOrder ){
      rc = idxCreateFromWhere(p, pIter, pIter->pOrder);
    }
  }

  return rc;
}

/*
** Free all elements of the linked list starting at pConstraint.
*/
static void idxConstraintFree(IdxConstraint *pConstraint){
  IdxConstraint *pNext;
  IdxConstraint *p;

  for(p=pConstraint; p; p=pNext){
    pNext = p->pNext;
    sqlite3_free(p);
  }
}

/*
** Free all elements of the linked list starting from pScan up until pLast
** (pLast is not freed).
*/
static void idxScanFree(IdxScan *pScan, IdxScan *pLast){
  IdxScan *p;
  IdxScan *pNext;
  for(p=pScan; p!=pLast; p=pNext){
    pNext = p->pNextScan;
    idxConstraintFree(p->pOrder);
    idxConstraintFree(p->pEq);
    idxConstraintFree(p->pRange);
    sqlite3_free(p);
  }
}

/*
** Free all elements of the linked list starting from pStatement up 
** until pLast (pLast is not freed).
*/
static void idxStatementFree(IdxStatement *pStatement, IdxStatement *pLast){
  IdxStatement *p;
  IdxStatement *pNext;
  for(p=pStatement; p!=pLast; p=pNext){
    pNext = p->pNext;
    sqlite3_free(p->zEQP);
    sqlite3_free(p->zIdx);
    sqlite3_free(p);
  }
}

/*
** Free the linked list of IdxTable objects starting at pTab.
*/
static void idxTableFree(IdxTable *pTab){
  IdxTable *pIter;
  IdxTable *pNext;
  for(pIter=pTab; pIter; pIter=pNext){
    pNext = pIter->pNext;
    sqlite3_free(pIter);
  }
}

/*
** Free the linked list of IdxWrite objects starting at pTab.
*/
static void idxWriteFree(IdxWrite *pTab){
  IdxWrite *pIter;
  IdxWrite *pNext;
  for(pIter=pTab; pIter; pIter=pNext){
    pNext = pIter->pNext;
    sqlite3_free(pIter);
  }
}



/*
** This function is called after candidate indexes have been created. It
** runs all the queries to see which indexes they prefer, and populates
** IdxStatement.zIdx and IdxStatement.zEQP with the results.
*/
static int idxFindIndexes(
  sqlite3expert *p,
  char **pzErr                         /* OUT: Error message (sqlite3_malloc) */
){
  IdxStatement *pStmt;
  sqlite3 *dbm = p->dbm;
  int rc = SQLITE_OK;

  IdxHash hIdx;
  idxHashInit(&hIdx);

  for(pStmt=p->pStatement; rc==SQLITE_OK && pStmt; pStmt=pStmt->pNext){
    IdxHashEntry *pEntry;
    sqlite3_stmt *pExplain = 0;
    idxHashClear(&hIdx);
    rc = idxPrintfPrepareStmt(dbm, &pExplain, pzErr,
        "EXPLAIN QUERY PLAN %s", pStmt->zSql
    );
    while( rc==SQLITE_OK && sqlite3_step(pExplain)==SQLITE_ROW ){
      /* int iId = sqlite3_column_int(pExplain, 0); */
      /* int iParent = sqlite3_column_int(pExplain, 1); */
      /* int iNotUsed = sqlite3_column_int(pExplain, 2); */
      const char *zDetail = (const char*)sqlite3_column_text(pExplain, 3);
      int nDetail;
      int i;

      if( !zDetail ) continue;
      nDetail = STRLEN(zDetail);

      for(i=0; i<nDetail; i++){
        const char *zIdx = 0;
        if( i+13<nDetail && memcmp(&zDetail[i], " USING INDEX ", 13)==0 ){
          zIdx = &zDetail[i+13];
        }else if( i+22<nDetail 
            && memcmp(&zDetail[i], " USING COVERING INDEX ", 22)==0 
        ){
          zIdx = &zDetail[i+22];
        }
        if( zIdx ){
          const char *zSql;
          int nIdx = 0;
          while( zIdx[nIdx]!='\0' && (zIdx[nIdx]!=' ' || zIdx[nIdx+1]!='(') ){
            nIdx++;
          }
          zSql = idxHashSearch(&p->hIdx, zIdx, nIdx);
          if( zSql ){
            idxHashAdd(&rc, &hIdx, zSql, 0);
            if( rc ) goto find_indexes_out;
          }
          break;
        }
      }

      if( zDetail[0]!='-' ){
        pStmt->zEQP = idxAppendText(&rc, pStmt->zEQP, "%s\n", zDetail);
      }
    }

    for(pEntry=hIdx.pFirst; pEntry; pEntry=pEntry->pNext){
      pStmt->zIdx = idxAppendText(&rc, pStmt->zIdx, "%s;\n", pEntry->zKey);
    }

    idxFinalize(&rc, pExplain);
  }

 find_indexes_out:
  idxHashClear(&hIdx);
  return rc;
}

static int idxAuthCallback(
  void *pCtx,
  int eOp,
  const char *z3,
  const char *z4,
  const char *zDb,
  const char *zTrigger
){
  int rc = SQLITE_OK;
  (void)z4;
  (void)zTrigger;
  if( eOp==SQLITE_INSERT || eOp==SQLITE_UPDATE || eOp==SQLITE_DELETE ){
    if( sqlite3_stricmp(zDb, "main")==0 ){
      sqlite3expert *p = (sqlite3expert*)pCtx;
      IdxTable *pTab;
      for(pTab=p->pTable; pTab; pTab=pTab->pNext){
        if( 0==sqlite3_stricmp(z3, pTab->zName) ) break;
      }
      if( pTab ){
        IdxWrite *pWrite;
        for(pWrite=p->pWrite; pWrite; pWrite=pWrite->pNext){
          if( pWrite->pTab==pTab && pWrite->eOp==eOp ) break;
        }
        if( pWrite==0 ){
          pWrite = idxMalloc(&rc, sizeof(IdxWrite));
          if( rc==SQLITE_OK ){
            pWrite->pTab = pTab;
            pWrite->eOp = eOp;
            pWrite->pNext = p->pWrite;
            p->pWrite = pWrite;
          }
        }
      }
    }
  }
  return rc;
}

static int idxProcessOneTrigger(
  sqlite3expert *p, 
  IdxWrite *pWrite, 
  char **pzErr
){
  static const char *zInt = UNIQUE_TABLE_NAME;
  static const char *zDrop = "DROP TABLE " UNIQUE_TABLE_NAME;
  IdxTable *pTab = pWrite->pTab;
  const char *zTab = pTab->zName;
  const char *zSql = 
    "SELECT 'CREATE TEMP' || substr(sql, 7) FROM sqlite_schema "
    "WHERE tbl_name = %Q AND type IN ('table', 'trigger') "
    "ORDER BY type;";
  sqlite3_stmt *pSelect = 0;
  int rc = SQLITE_OK;
  char *zWrite = 0;

  /* Create the table and its triggers in the temp schema */
  rc = idxPrintfPrepareStmt(p->db, &pSelect, pzErr, zSql, zTab, zTab);
  while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pSelect) ){
    const char *zCreate = (const char*)sqlite3_column_text(pSelect, 0);
    if( zCreate==0 ) continue;
    rc = sqlite3_exec(p->dbv, zCreate, 0, 0, pzErr);
  }
  idxFinalize(&rc, pSelect);

  /* Rename the table in the temp schema to zInt */
  if( rc==SQLITE_OK ){
    char *z = sqlite3_mprintf("ALTER TABLE temp.%Q RENAME TO %Q", zTab, zInt);
    if( z==0 ){
      rc = SQLITE_NOMEM;
    }else{
      rc = sqlite3_exec(p->dbv, z, 0, 0, pzErr);
      sqlite3_free(z);
    }
  }

  switch( pWrite->eOp ){
    case SQLITE_INSERT: {
      int i;
      zWrite = idxAppendText(&rc, zWrite, "INSERT INTO %Q VALUES(", zInt);
      for(i=0; i<pTab->nCol; i++){
        zWrite = idxAppendText(&rc, zWrite, "%s?", i==0 ? "" : ", ");
      }
      zWrite = idxAppendText(&rc, zWrite, ")");
      break;
    }
    case SQLITE_UPDATE: {
      int i;
      zWrite = idxAppendText(&rc, zWrite, "UPDATE %Q SET ", zInt);
      for(i=0; i<pTab->nCol; i++){
        zWrite = idxAppendText(&rc, zWrite, "%s%Q=?", i==0 ? "" : ", ", 
            pTab->aCol[i].zName
        );
      }
      break;
    }
    default: {
      assert( pWrite->eOp==SQLITE_DELETE );
      if( rc==SQLITE_OK ){
        zWrite = sqlite3_mprintf("DELETE FROM %Q", zInt);
        if( zWrite==0 ) rc = SQLITE_NOMEM;
      }
    }
  }

  if( rc==SQLITE_OK ){
    sqlite3_stmt *pX = 0;
    rc = sqlite3_prepare_v2(p->dbv, zWrite, -1, &pX, 0);
    idxFinalize(&rc, pX);
    if( rc!=SQLITE_OK ){
      idxDatabaseError(p->dbv, pzErr);
    }
  }
  sqlite3_free(zWrite);

  if( rc==SQLITE_OK ){
    rc = sqlite3_exec(p->dbv, zDrop, 0, 0, pzErr);
  }

  return rc;
}

static int idxProcessTriggers(sqlite3expert *p, char **pzErr){
  int rc = SQLITE_OK;
  IdxWrite *pEnd = 0;
  IdxWrite *pFirst = p->pWrite;

  while( rc==SQLITE_OK && pFirst!=pEnd ){
    IdxWrite *pIter;
    for(pIter=pFirst; rc==SQLITE_OK && pIter!=pEnd; pIter=pIter->pNext){
      rc = idxProcessOneTrigger(p, pIter, pzErr);
    }
    pEnd = pFirst;
    pFirst = p->pWrite;
  }

  return rc;
}

/*
** This function tests if the schema of the main database of database handle
** db contains an object named zTab. Assuming no error occurs, output parameter
** (*pbContains) is set to true if zTab exists, or false if it does not.
**
** Or, if an error occurs, an SQLite error code is returned. The final value
** of (*pbContains) is undefined in this case.
*/
static int expertDbContainsObject(
  sqlite3 *db, 
  const char *zTab, 
  int *pbContains                 /* OUT: True if object exists */
){
  const char *zSql = "SELECT 1 FROM sqlite_schema WHERE name = ?";
  sqlite3_stmt *pSql = 0;
  int rc = SQLITE_OK;
  int ret = 0;

  rc = sqlite3_prepare_v2(db, zSql, -1, &pSql, 0);
  if( rc==SQLITE_OK ){
    sqlite3_bind_text(pSql, 1, zTab, -1, SQLITE_STATIC);
    if( SQLITE_ROW==sqlite3_step(pSql) ){
      ret = 1;
    }
    rc = sqlite3_finalize(pSql);
  }

  *pbContains = ret;
  return rc;
}

/*
** Execute SQL command zSql using database handle db. If no error occurs,
** set (*pzErr) to NULL and return SQLITE_OK. 
**
** If an error does occur, return an SQLite error code and set (*pzErr) to
** point to a buffer containing an English language error message. Except,
** if the error message begins with "no such module:", then ignore the
** error and return as if the SQL statement had succeeded.
**
** This is used to copy as much of the database schema as possible while 
** ignoring any errors related to missing virtual table modules.
*/
static int expertSchemaSql(sqlite3 *db, const char *zSql, char **pzErr){
  int rc = SQLITE_OK;
  char *zErr = 0;

  rc = sqlite3_exec(db, zSql, 0, 0, &zErr);
  if( rc!=SQLITE_OK && zErr ){
    int nErr = STRLEN(zErr);
    if( nErr>=15 && memcmp(zErr, "no such module:", 15)==0 ){
      sqlite3_free(zErr);
      rc = SQLITE_OK;
      zErr = 0;
    }
  }

  *pzErr = zErr;
  return rc;
}

static int idxCreateVtabSchema(sqlite3expert *p, char **pzErrmsg){
  int rc = idxRegisterVtab(p);
  sqlite3_stmt *pSchema = 0;

  /* For each table in the main db schema:
  **
  **   1) Add an entry to the p->pTable list, and
  **   2) Create the equivalent virtual table in dbv.
  */
  rc = idxPrepareStmt(p->db, &pSchema, pzErrmsg,
      "SELECT type, name, sql, 1, "
      "       substr(sql,1,14)=='create virtual' COLLATE nocase "
      "FROM sqlite_schema "
      "WHERE type IN ('table','view') AND "
      "      substr(name,1,7)!='sqlite_' COLLATE nocase "
      " UNION ALL "
      "SELECT type, name, sql, 2, 0 FROM sqlite_schema "
      "WHERE type = 'trigger'"
      "  AND tbl_name IN(SELECT name FROM sqlite_schema WHERE type = 'view') "
      "ORDER BY 4, 5 DESC, 1"
  );
  while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pSchema) ){
    const char *zType = (const char*)sqlite3_column_text(pSchema, 0);
    const char *zName = (const char*)sqlite3_column_text(pSchema, 1);
    const char *zSql = (const char*)sqlite3_column_text(pSchema, 2);
    int bVirtual = sqlite3_column_int(pSchema, 4);
    int bExists = 0;

    if( zType==0 || zName==0 ) continue;
    rc = expertDbContainsObject(p->dbv, zName, &bExists);
    if( rc || bExists ) continue;

    if( zType[0]=='v' || zType[1]=='r' || bVirtual ){
      /* A view. Or a trigger on a view. */
      if( zSql ) rc = expertSchemaSql(p->dbv, zSql, pzErrmsg);
    }else{
      IdxTable *pTab;
      rc = idxGetTableInfo(p->db, zName, &pTab, pzErrmsg);
      if( rc==SQLITE_OK && ALWAYS(pTab!=0) ){
        int i;
        char *zInner = 0;
        char *zOuter = 0;
        pTab->pNext = p->pTable;
        p->pTable = pTab;

        /* The statement the vtab will pass to sqlite3_declare_vtab() */
        zInner = idxAppendText(&rc, 0, "CREATE TABLE x(");
        for(i=0; i<pTab->nCol; i++){
          zInner = idxAppendText(&rc, zInner, "%s%Q COLLATE %s", 
              (i==0 ? "" : ", "), pTab->aCol[i].zName, pTab->aCol[i].zColl
          );
        }
        zInner = idxAppendText(&rc, zInner, ")");

        /* The CVT statement to create the vtab */
        zOuter = idxAppendText(&rc, 0, 
            "CREATE VIRTUAL TABLE %Q USING expert(%Q)", zName, zInner
        );
        if( rc==SQLITE_OK ){
          rc = sqlite3_exec(p->dbv, zOuter, 0, 0, pzErrmsg);
        }
        sqlite3_free(zInner);
        sqlite3_free(zOuter);
      }
    }
  }
  idxFinalize(&rc, pSchema);
  return rc;
}

struct IdxSampleCtx {
  int iTarget;
  double target;                  /* Target nRet/nRow value */
  double nRow;                    /* Number of rows seen */
  double nRet;                    /* Number of rows returned */
};

static void idxSampleFunc(
  sqlite3_context *pCtx,
  int argc,
  sqlite3_value **argv
){
  struct IdxSampleCtx *p = (struct IdxSampleCtx*)sqlite3_user_data(pCtx);
  int bRet;

  (void)argv;
  assert( argc==0 );
  if( p->nRow==0.0 ){
    bRet = 1;
  }else{
    bRet = (p->nRet / p->nRow) <= p->target;
    if( bRet==0 ){
      unsigned short rnd;
      sqlite3_randomness(2, (void*)&rnd);
      bRet = ((int)rnd % 100) <= p->iTarget;
    }
  }

  sqlite3_result_int(pCtx, bRet);
  p->nRow += 1.0;
  p->nRet += (double)bRet;
}

struct IdxRemCtx {
  int nSlot;
  struct IdxRemSlot {
    int eType;                    /* SQLITE_NULL, INTEGER, REAL, TEXT, BLOB */
    i64 iVal;                     /* SQLITE_INTEGER value */
    double rVal;                  /* SQLITE_FLOAT value */
    int nByte;                    /* Bytes of space allocated at z */
    int n;                        /* Size of buffer z */
    char *z;                      /* SQLITE_TEXT/BLOB value */
  } aSlot[1];
};

/*
** Implementation of scalar function sqlite_expert_rem().
*/
static void idxRemFunc(
  sqlite3_context *pCtx,
  int argc,
  sqlite3_value **argv
){
  struct IdxRemCtx *p = (struct IdxRemCtx*)sqlite3_user_data(pCtx);
  struct IdxRemSlot *pSlot;
  int iSlot;
  assert( argc==2 );

  iSlot = sqlite3_value_int(argv[0]);
  assert( iSlot<p->nSlot );
  pSlot = &p->aSlot[iSlot];

  switch( pSlot->eType ){
    case SQLITE_NULL:
      /* no-op */
      break;

    case SQLITE_INTEGER:
      sqlite3_result_int64(pCtx, pSlot->iVal);
      break;

    case SQLITE_FLOAT:
      sqlite3_result_double(pCtx, pSlot->rVal);
      break;

    case SQLITE_BLOB:
      sqlite3_result_blob(pCtx, pSlot->z, pSlot->n, SQLITE_TRANSIENT);
      break;

    case SQLITE_TEXT:
      sqlite3_result_text(pCtx, pSlot->z, pSlot->n, SQLITE_TRANSIENT);
      break;
  }

  pSlot->eType = sqlite3_value_type(argv[1]);
  switch( pSlot->eType ){
    case SQLITE_NULL:
      /* no-op */
      break;

    case SQLITE_INTEGER:
      pSlot->iVal = sqlite3_value_int64(argv[1]);
      break;

    case SQLITE_FLOAT:
      pSlot->rVal = sqlite3_value_double(argv[1]);
      break;

    case SQLITE_BLOB:
    case SQLITE_TEXT: {
      int nByte = sqlite3_value_bytes(argv[1]);
      const void *pData = 0;
      if( nByte>pSlot->nByte ){
        char *zNew = (char*)sqlite3_realloc(pSlot->z, nByte*2);
        if( zNew==0 ){
          sqlite3_result_error_nomem(pCtx);
          return;
        }
        pSlot->nByte = nByte*2;
        pSlot->z = zNew;
      }
      pSlot->n = nByte;
      if( pSlot->eType==SQLITE_BLOB ){
        pData = sqlite3_value_blob(argv[1]);
        if( pData ) memcpy(pSlot->z, pData, nByte);
      }else{
        pData = sqlite3_value_text(argv[1]);
        memcpy(pSlot->z, pData, nByte);
      }
      break;
    }
  }
}

static int idxLargestIndex(sqlite3 *db, int *pnMax, char **pzErr){
  int rc = SQLITE_OK;
  const char *zMax = 
    "SELECT max(i.seqno) FROM "
    "  sqlite_schema AS s, "
    "  pragma_index_list(s.name) AS l, "
    "  pragma_index_info(l.name) AS i "
    "WHERE s.type = 'table'";
  sqlite3_stmt *pMax = 0;

  *pnMax = 0;
  rc = idxPrepareStmt(db, &pMax, pzErr, zMax);
  if( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pMax) ){
    *pnMax = sqlite3_column_int(pMax, 0) + 1;
  }
  idxFinalize(&rc, pMax);

  return rc;
}

static int idxPopulateOneStat1(
  sqlite3expert *p,
  sqlite3_stmt *pIndexXInfo,
  sqlite3_stmt *pWriteStat,
  const char *zTab,
  const char *zIdx,
  char **pzErr
){
  char *zCols = 0;
  char *zOrder = 0;
  char *zQuery = 0;
  int nCol = 0;
  int i;
  sqlite3_stmt *pQuery = 0;
  int *aStat = 0;
  int rc = SQLITE_OK;

  assert( p->iSample>0 );

  /* Formulate the query text */
  sqlite3_bind_text(pIndexXInfo, 1, zIdx, -1, SQLITE_STATIC);
  while( SQLITE_OK==rc && SQLITE_ROW==sqlite3_step(pIndexXInfo) ){
    const char *zComma = zCols==0 ? "" : ", ";
    const char *zName = (const char*)sqlite3_column_text(pIndexXInfo, 0);
    const char *zColl = (const char*)sqlite3_column_text(pIndexXInfo, 1);
    if( zName==0 ){
      /* This index contains an expression. Ignore it. */
      sqlite3_free(zCols);
      sqlite3_free(zOrder);
      return sqlite3_reset(pIndexXInfo);
    }
    zCols = idxAppendText(&rc, zCols, 
        "%sx.%Q IS sqlite_expert_rem(%d, x.%Q) COLLATE %s", 
        zComma, zName, nCol, zName, zColl
    );
    zOrder = idxAppendText(&rc, zOrder, "%s%d", zComma, ++nCol);
  }
  sqlite3_reset(pIndexXInfo);
  if( rc==SQLITE_OK ){
    if( p->iSample==100 ){
      zQuery = sqlite3_mprintf(
          "SELECT %s FROM %Q x ORDER BY %s", zCols, zTab, zOrder
      );
    }else{
      zQuery = sqlite3_mprintf(
          "SELECT %s FROM temp."UNIQUE_TABLE_NAME" x ORDER BY %s", zCols, zOrder
      );
    }
  }
  sqlite3_free(zCols);
  sqlite3_free(zOrder);

  /* Formulate the query text */
  if( rc==SQLITE_OK ){
    sqlite3 *dbrem = (p->iSample==100 ? p->db : p->dbv);
    rc = idxPrepareStmt(dbrem, &pQuery, pzErr, zQuery);
  }
  sqlite3_free(zQuery);

  if( rc==SQLITE_OK ){
    aStat = (int*)idxMalloc(&rc, sizeof(int)*(nCol+1));
  }
  if( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pQuery) ){
    IdxHashEntry *pEntry;
    char *zStat = 0;
    for(i=0; i<=nCol; i++) aStat[i] = 1;
    while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pQuery) ){
      aStat[0]++;
      for(i=0; i<nCol; i++){
        if( sqlite3_column_int(pQuery, i)==0 ) break;
      }
      for(/*no-op*/; i<nCol; i++){
        aStat[i+1]++;
      }
    }

    if( rc==SQLITE_OK ){
      int s0 = aStat[0];
      zStat = sqlite3_mprintf("%d", s0);
      if( zStat==0 ) rc = SQLITE_NOMEM;
      for(i=1; rc==SQLITE_OK && i<=nCol; i++){
        zStat = idxAppendText(&rc, zStat, " %d", (s0+aStat[i]/2) / aStat[i]);
      }
    }

    if( rc==SQLITE_OK ){
      sqlite3_bind_text(pWriteStat, 1, zTab, -1, SQLITE_STATIC);
      sqlite3_bind_text(pWriteStat, 2, zIdx, -1, SQLITE_STATIC);
      sqlite3_bind_text(pWriteStat, 3, zStat, -1, SQLITE_STATIC);
      sqlite3_step(pWriteStat);
      rc = sqlite3_reset(pWriteStat);
    }

    pEntry = idxHashFind(&p->hIdx, zIdx, STRLEN(zIdx));
    if( pEntry ){
      assert( pEntry->zVal2==0 );
      pEntry->zVal2 = zStat;
    }else{
      sqlite3_free(zStat);
    }
  }
  sqlite3_free(aStat);
  idxFinalize(&rc, pQuery);

  return rc;
}

static int idxBuildSampleTable(sqlite3expert *p, const char *zTab){
  int rc;
  char *zSql;

  rc = sqlite3_exec(p->dbv,"DROP TABLE IF EXISTS temp."UNIQUE_TABLE_NAME,0,0,0);
  if( rc!=SQLITE_OK ) return rc;

  zSql = sqlite3_mprintf(
      "CREATE TABLE temp." UNIQUE_TABLE_NAME " AS SELECT * FROM %Q", zTab
  );
  if( zSql==0 ) return SQLITE_NOMEM;
  rc = sqlite3_exec(p->dbv, zSql, 0, 0, 0);
  sqlite3_free(zSql);

  return rc;
}

/*
** This function is called as part of sqlite3_expert_analyze(). Candidate
** indexes have already been created in database sqlite3expert.dbm, this
** function populates sqlite_stat1 table in the same database.
**
** The stat1 data is generated by querying the 
*/
static int idxPopulateStat1(sqlite3expert *p, char **pzErr){
  int rc = SQLITE_OK;
  int nMax =0;
  struct IdxRemCtx *pCtx = 0;
  struct IdxSampleCtx samplectx; 
  int i;
  i64 iPrev = -100000;
  sqlite3_stmt *pAllIndex = 0;
  sqlite3_stmt *pIndexXInfo = 0;
  sqlite3_stmt *pWrite = 0;

  const char *zAllIndex =
    "SELECT s.rowid, s.name, l.name FROM "
    "  sqlite_schema AS s, "
    "  pragma_index_list(s.name) AS l "
    "WHERE s.type = 'table'";
  const char *zIndexXInfo = 
    "SELECT name, coll FROM pragma_index_xinfo(?) WHERE key";
  const char *zWrite = "INSERT INTO sqlite_stat1 VALUES(?, ?, ?)";

  /* If iSample==0, no sqlite_stat1 data is required. */
  if( p->iSample==0 ) return SQLITE_OK;

  rc = idxLargestIndex(p->dbm, &nMax, pzErr);
  if( nMax<=0 || rc!=SQLITE_OK ) return rc;

  rc = sqlite3_exec(p->dbm, "ANALYZE; PRAGMA writable_schema=1", 0, 0, 0);

  if( rc==SQLITE_OK ){
    int nByte = sizeof(struct IdxRemCtx) + (sizeof(struct IdxRemSlot) * nMax);
    pCtx = (struct IdxRemCtx*)idxMalloc(&rc, nByte);
  }

  if( rc==SQLITE_OK ){
    sqlite3 *dbrem = (p->iSample==100 ? p->db : p->dbv);
    rc = sqlite3_create_function(dbrem, "sqlite_expert_rem", 
        2, SQLITE_UTF8, (void*)pCtx, idxRemFunc, 0, 0
    );
  }
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_function(p->db, "sqlite_expert_sample", 
        0, SQLITE_UTF8, (void*)&samplectx, idxSampleFunc, 0, 0
    );
  }

  if( rc==SQLITE_OK ){
    pCtx->nSlot = nMax+1;
    rc = idxPrepareStmt(p->dbm, &pAllIndex, pzErr, zAllIndex);
  }
  if( rc==SQLITE_OK ){
    rc = idxPrepareStmt(p->dbm, &pIndexXInfo, pzErr, zIndexXInfo);
  }
  if( rc==SQLITE_OK ){
    rc = idxPrepareStmt(p->dbm, &pWrite, pzErr, zWrite);
  }

  while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pAllIndex) ){
    i64 iRowid = sqlite3_column_int64(pAllIndex, 0);
    const char *zTab = (const char*)sqlite3_column_text(pAllIndex, 1);
    const char *zIdx = (const char*)sqlite3_column_text(pAllIndex, 2);
    if( zTab==0 || zIdx==0 ) continue;
    if( p->iSample<100 && iPrev!=iRowid ){
      samplectx.target = (double)p->iSample / 100.0;
      samplectx.iTarget = p->iSample;
      samplectx.nRow = 0.0;
      samplectx.nRet = 0.0;
      rc = idxBuildSampleTable(p, zTab);
      if( rc!=SQLITE_OK ) break;
    }
    rc = idxPopulateOneStat1(p, pIndexXInfo, pWrite, zTab, zIdx, pzErr);
    iPrev = iRowid;
  }
  if( rc==SQLITE_OK && p->iSample<100 ){
    rc = sqlite3_exec(p->dbv, 
        "DROP TABLE IF EXISTS temp." UNIQUE_TABLE_NAME, 0,0,0
    );
  }

  idxFinalize(&rc, pAllIndex);
  idxFinalize(&rc, pIndexXInfo);
  idxFinalize(&rc, pWrite);

  if( pCtx ){
    for(i=0; i<pCtx->nSlot; i++){
      sqlite3_free(pCtx->aSlot[i].z);
    }
    sqlite3_free(pCtx);
  }

  if( rc==SQLITE_OK ){
    rc = sqlite3_exec(p->dbm, "ANALYZE sqlite_schema", 0, 0, 0);
  }

  sqlite3_create_function(p->db, "sqlite_expert_rem", 2, SQLITE_UTF8, 0,0,0,0);
  sqlite3_create_function(p->db, "sqlite_expert_sample", 0,SQLITE_UTF8,0,0,0,0);

  sqlite3_exec(p->db, "DROP TABLE IF EXISTS temp."UNIQUE_TABLE_NAME,0,0,0);
  return rc;
}

/*
** Define and possibly pretend to use a useless collation sequence.
** This pretense allows expert to accept SQL using custom collations.
*/
int dummyCompare(void *up1, int up2, const void *up3, int up4, const void *up5){
  (void)up1;
  (void)up2;
  (void)up3;
  (void)up4;
  (void)up5;
  assert(0); /* VDBE should never be run. */
  return 0;
}
/* And a callback to register above upon actual need */
void useDummyCS(void *up1, sqlite3 *db, int etr, const char *zName){
  (void)up1;
  sqlite3_create_collation_v2(db, zName, etr, 0, dummyCompare, 0);
}

#if !defined(SQLITE_OMIT_SCHEMA_PRAGMAS) \
  && !defined(SQLITE_OMIT_INTROSPECTION_PRAGMAS)
/*
** dummy functions for no-op implementation of UDFs during expert's work
*/
void dummyUDF(sqlite3_context *up1, int up2, sqlite3_value **up3){
  (void)up1;
  (void)up2;
  (void)up3;
  assert(0); /* VDBE should never be run. */
}
void dummyUDFvalue(sqlite3_context *up1){
  (void)up1;
  assert(0); /* VDBE should never be run. */
}

/*
** Register UDFs from user database with another.
*/
int registerUDFs(sqlite3 *dbSrc, sqlite3 *dbDst){
  sqlite3_stmt *pStmt;
  int rc = sqlite3_prepare_v2(dbSrc,
            "SELECT name,type,enc,narg,flags "
            "FROM pragma_function_list() "
            "WHERE builtin==0", -1, &pStmt, 0);
  if( rc==SQLITE_OK ){
    while( SQLITE_ROW==(rc = sqlite3_step(pStmt)) ){
      int nargs = sqlite3_column_int(pStmt,3);
      int flags = sqlite3_column_int(pStmt,4);
      const char *name = (char*)sqlite3_column_text(pStmt,0);
      const char *type = (char*)sqlite3_column_text(pStmt,1);
      const char *enc = (char*)sqlite3_column_text(pStmt,2);
      if( name==0 || type==0 || enc==0 ){
        /* no-op.  Only happens on OOM */
      }else{
        int ienc = SQLITE_UTF8;
        int rcf = SQLITE_ERROR;
        if( strcmp(enc,"utf16le")==0 ) ienc = SQLITE_UTF16LE;
        else if( strcmp(enc,"utf16be")==0 ) ienc = SQLITE_UTF16BE;
        ienc |= (flags & (SQLITE_DETERMINISTIC|SQLITE_DIRECTONLY));
        if( strcmp(type,"w")==0 ){
          rcf = sqlite3_create_window_function(dbDst,name,nargs,ienc,0,
                                               dummyUDF,dummyUDFvalue,0,0,0);
        }else if( strcmp(type,"a")==0 ){
          rcf = sqlite3_create_function(dbDst,name,nargs,ienc,0,
                                        0,dummyUDF,dummyUDFvalue);
        }else if( strcmp(type,"s")==0 ){
          rcf = sqlite3_create_function(dbDst,name,nargs,ienc,0,
                                        dummyUDF,0,0);
        }
        if( rcf!=SQLITE_OK ){
          rc = rcf;
          break;
        }
      }
    }
    sqlite3_finalize(pStmt);
    if( rc==SQLITE_DONE ) rc = SQLITE_OK;
  }
  return rc;
}
#endif

/*
** Allocate a new sqlite3expert object.
*/
sqlite3expert *sqlite3_expert_new(sqlite3 *db, char **pzErrmsg){
  int rc = SQLITE_OK;
  sqlite3expert *pNew;

  pNew = (sqlite3expert*)idxMalloc(&rc, sizeof(sqlite3expert));

  /* Open two in-memory databases to work with. The "vtab database" (dbv)
  ** will contain a virtual table corresponding to each real table in
  ** the user database schema, and a copy of each view. It is used to
  ** collect information regarding the WHERE, ORDER BY and other clauses
  ** of the user's query.
  */
  if( rc==SQLITE_OK ){
    pNew->db = db;
    pNew->iSample = 100;
    rc = sqlite3_open(":memory:", &pNew->dbv);
  }
  if( rc==SQLITE_OK ){
    rc = sqlite3_open(":memory:", &pNew->dbm);
    if( rc==SQLITE_OK ){
      sqlite3_db_config(pNew->dbm, SQLITE_DBCONFIG_TRIGGER_EQP, 1, (int*)0);
    }
  }

  /* Allow custom collations to be dealt with through prepare. */
  if( rc==SQLITE_OK ) rc = sqlite3_collation_needed(pNew->dbm,0,useDummyCS);
  if( rc==SQLITE_OK ) rc = sqlite3_collation_needed(pNew->dbv,0,useDummyCS);

#if !defined(SQLITE_OMIT_SCHEMA_PRAGMAS) \
  && !defined(SQLITE_OMIT_INTROSPECTION_PRAGMAS)
  /* Register UDFs from database [db] with [dbm] and [dbv]. */
  if( rc==SQLITE_OK ){
    rc = registerUDFs(pNew->db, pNew->dbm);
  }
  if( rc==SQLITE_OK ){
    rc = registerUDFs(pNew->db, pNew->dbv);
  }
#endif

  /* Copy the entire schema of database [db] into [dbm]. */
  if( rc==SQLITE_OK ){
    sqlite3_stmt *pSql = 0;
    rc = idxPrintfPrepareStmt(pNew->db, &pSql, pzErrmsg, 
        "SELECT sql, name, substr(sql,1,14)=='create virtual' COLLATE nocase"
        " FROM sqlite_schema WHERE substr(name,1,7)!='sqlite_' COLLATE nocase"
        " ORDER BY 3 DESC, rowid"
    );
    while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pSql) ){
      const char *zSql = (const char*)sqlite3_column_text(pSql, 0);
      const char *zName = (const char*)sqlite3_column_text(pSql, 1);
      int bExists = 0;
      rc = expertDbContainsObject(pNew->dbm, zName, &bExists);
      if( rc==SQLITE_OK && zSql && bExists==0 ){
        rc = expertSchemaSql(pNew->dbm, zSql, pzErrmsg);
      }
    }
    idxFinalize(&rc, pSql);
  }

  /* Create the vtab schema */
  if( rc==SQLITE_OK ){
    rc = idxCreateVtabSchema(pNew, pzErrmsg);
  }

  /* Register the auth callback with dbv */
  if( rc==SQLITE_OK ){
    sqlite3_set_authorizer(pNew->dbv, idxAuthCallback, (void*)pNew);
  }

  /* If an error has occurred, free the new object and reutrn NULL. Otherwise,
  ** return the new sqlite3expert handle.  */
  if( rc!=SQLITE_OK ){
    sqlite3_expert_destroy(pNew);
    pNew = 0;
  }
  return pNew;
}

/*
** Configure an sqlite3expert object.
*/
int sqlite3_expert_config(sqlite3expert *p, int op, ...){
  int rc = SQLITE_OK;
  va_list ap;
  va_start(ap, op);
  switch( op ){
    case EXPERT_CONFIG_SAMPLE: {
      int iVal = va_arg(ap, int);
      if( iVal<0 ) iVal = 0;
      if( iVal>100 ) iVal = 100;
      p->iSample = iVal;
      break;
    }
    default:
      rc = SQLITE_NOTFOUND;
      break;
  }

  va_end(ap);
  return rc;
}

/*
** Add an SQL statement to the analysis.
*/
int sqlite3_expert_sql(
  sqlite3expert *p,               /* From sqlite3_expert_new() */
  const char *zSql,               /* SQL statement to add */
  char **pzErr                    /* OUT: Error message (if any) */
){
  IdxScan *pScanOrig = p->pScan;
  IdxStatement *pStmtOrig = p->pStatement;
  int rc = SQLITE_OK;
  const char *zStmt = zSql;

  if( p->bRun ) return SQLITE_MISUSE;

  while( rc==SQLITE_OK && zStmt && zStmt[0] ){
    sqlite3_stmt *pStmt = 0;
    /* Ensure that the provided statement compiles against user's DB. */
    rc = idxPrepareStmt(p->db, &pStmt, pzErr, zStmt);
    if( rc!=SQLITE_OK ) break;
    sqlite3_finalize(pStmt);
    rc = sqlite3_prepare_v2(p->dbv, zStmt, -1, &pStmt, &zStmt);
    if( rc==SQLITE_OK ){
      if( pStmt ){
        IdxStatement *pNew;
        const char *z = sqlite3_sql(pStmt);
        int n = STRLEN(z);
        pNew = (IdxStatement*)idxMalloc(&rc, sizeof(IdxStatement) + n+1);
        if( rc==SQLITE_OK ){
          pNew->zSql = (char*)&pNew[1];
          memcpy(pNew->zSql, z, n+1);
          pNew->pNext = p->pStatement;
          if( p->pStatement ) pNew->iId = p->pStatement->iId+1;
          p->pStatement = pNew;
        }
        sqlite3_finalize(pStmt);
      }
    }else{
      idxDatabaseError(p->dbv, pzErr);
    }
  }

  if( rc!=SQLITE_OK ){
    idxScanFree(p->pScan, pScanOrig);
    idxStatementFree(p->pStatement, pStmtOrig);
    p->pScan = pScanOrig;
    p->pStatement = pStmtOrig;
  }

  return rc;
}

int sqlite3_expert_analyze(sqlite3expert *p, char **pzErr){
  int rc;
  IdxHashEntry *pEntry;

  /* Do trigger processing to collect any extra IdxScan structures */
  rc = idxProcessTriggers(p, pzErr);

  /* Create candidate indexes within the in-memory database file */
  if( rc==SQLITE_OK ){
    rc = idxCreateCandidates(p);
  }else if ( rc==SQLITE_BUSY_TIMEOUT ){
    if( pzErr )
      *pzErr = sqlite3_mprintf("Cannot find a unique index name to propose.");
    return rc;
  }

  /* Generate the stat1 data */
  if( rc==SQLITE_OK ){
    rc = idxPopulateStat1(p, pzErr);
  }

  /* Formulate the EXPERT_REPORT_CANDIDATES text */
  for(pEntry=p->hIdx.pFirst; pEntry; pEntry=pEntry->pNext){
    p->zCandidates = idxAppendText(&rc, p->zCandidates, 
        "%s;%s%s\n", pEntry->zVal, 
        pEntry->zVal2 ? " -- stat1: " : "", pEntry->zVal2
    );
  }

  /* Figure out which of the candidate indexes are preferred by the query
  ** planner and report the results to the user.  */
  if( rc==SQLITE_OK ){
    rc = idxFindIndexes(p, pzErr);
  }

  if( rc==SQLITE_OK ){
    p->bRun = 1;
  }
  return rc;
}

/*
** Return the total number of statements that have been added to this
** sqlite3expert using sqlite3_expert_sql().
*/
int sqlite3_expert_count(sqlite3expert *p){
  int nRet = 0;
  if( p->pStatement ) nRet = p->pStatement->iId+1;
  return nRet;
}

/*
** Return a component of the report.
*/
const char *sqlite3_expert_report(sqlite3expert *p, int iStmt, int eReport){
  const char *zRet = 0;
  IdxStatement *pStmt;

  if( p->bRun==0 ) return 0;
  for(pStmt=p->pStatement; pStmt && pStmt->iId!=iStmt; pStmt=pStmt->pNext);
  switch( eReport ){
    case EXPERT_REPORT_SQL:
      if( pStmt ) zRet = pStmt->zSql;
      break;
    case EXPERT_REPORT_INDEXES:
      if( pStmt ) zRet = pStmt->zIdx;
      break;
    case EXPERT_REPORT_PLAN:
      if( pStmt ) zRet = pStmt->zEQP;
      break;
    case EXPERT_REPORT_CANDIDATES:
      zRet = p->zCandidates;
      break;
  }
  return zRet;
}

/*
** Free an sqlite3expert object.
*/
void sqlite3_expert_destroy(sqlite3expert *p){
  if( p ){
    sqlite3_close(p->dbm);
    sqlite3_close(p->dbv);
    idxScanFree(p->pScan, 0);
    idxStatementFree(p->pStatement, 0);
    idxTableFree(p->pTable);
    idxWriteFree(p->pWrite);
    idxHashClear(&p->hIdx);
    sqlite3_free(p->zCandidates);
    sqlite3_free(p);
  }
}

#endif /* ifndef SQLITE_OMIT_VIRTUALTABLE */

/************************* End ../ext/expert/sqlite3expert.c ********************/
/************************* Begin ../ext/intck/sqlite3intck.h ******************/
/*
** 2024-02-08
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
*/

/*
** Incremental Integrity-Check Extension
** -------------------------------------
**
** This module contains code to check whether or not an SQLite database
** is well-formed or corrupt. This is the same task as performed by SQLite's
** built-in "PRAGMA integrity_check" command. This module differs from
** "PRAGMA integrity_check" in that:
**
**   +  It is less thorough - this module does not detect certain types
**      of corruption that are detected by the PRAGMA command. However,
**      it does detect all kinds of corruption that are likely to cause
**      errors in SQLite applications.
**
**   +  It is slower. Sometimes up to three times slower.
**
**   +  It allows integrity-check operations to be split into multiple
**      transactions, so that the database does not need to be read-locked
**      for the duration of the integrity-check.
**
** One way to use the API to run integrity-check on the "main" database
** of handle db is:
**
**   int rc = SQLITE_OK;
**   sqlite3_intck *p = 0;
**
**   sqlite3_intck_open(db, "main", &p);
**   while( SQLITE_OK==sqlite3_intck_step(p) ){
**     const char *zMsg = sqlite3_intck_message(p);
**     if( zMsg ) printf("corruption: %s\n", zMsg);
**   }
**   rc = sqlite3_intck_error(p, &zErr);
**   if( rc!=SQLITE_OK ){
**     printf("error occured (rc=%d), (errmsg=%s)\n", rc, zErr);
**   }
**   sqlite3_intck_close(p);
**
** Usually, the sqlite3_intck object opens a read transaction within the
** first call to sqlite3_intck_step() and holds it open until the 
** integrity-check is complete. However, if sqlite3_intck_unlock() is
** called, the read transaction is ended and a new read transaction opened
** by the subsequent call to sqlite3_intck_step().
*/

#ifndef _SQLITE_INTCK_H
#define _SQLITE_INTCK_H

/* #include "sqlite3.h" */

#ifdef __cplusplus
extern "C" {
#endif

/*
** An ongoing incremental integrity-check operation is represented by an
** opaque pointer of the following type.
*/
typedef struct sqlite3_intck sqlite3_intck;

/*
** Open a new incremental integrity-check object. If successful, populate
** output variable (*ppOut) with the new object handle and return SQLITE_OK.
** Or, if an error occurs, set (*ppOut) to NULL and return an SQLite error
** code (e.g. SQLITE_NOMEM).
**
** The integrity-check will be conducted on database zDb (which must be "main",
** "temp", or the name of an attached database) of database handle db. Once
** this function has been called successfully, the caller should not use 
** database handle db until the integrity-check object has been destroyed
** using sqlite3_intck_close().
*/
int sqlite3_intck_open(
  sqlite3 *db,                    /* Database handle */
  const char *zDb,                /* Database name ("main", "temp" etc.) */
  sqlite3_intck **ppOut           /* OUT: New sqlite3_intck handle */
);

/*
** Close and release all resources associated with a handle opened by an
** earlier call to sqlite3_intck_open(). The results of using an
** integrity-check handle after it has been passed to this function are
** undefined.
*/
void sqlite3_intck_close(sqlite3_intck *pCk);

/*
** Do the next step of the integrity-check operation specified by the handle
** passed as the only argument. This function returns SQLITE_DONE if the 
** integrity-check operation is finished, or an SQLite error code if
** an error occurs, or SQLITE_OK if no error occurs but the integrity-check
** is not finished. It is not considered an error if database corruption
** is encountered.
**
** Following a successful call to sqlite3_intck_step() (one that returns
** SQLITE_OK), sqlite3_intck_message() returns a non-NULL value if 
** corruption was detected in the db.
**
** If an error occurs and a value other than SQLITE_OK or SQLITE_DONE is
** returned, then the integrity-check handle is placed in an error state.
** In this state all subsequent calls to sqlite3_intck_step() or 
** sqlite3_intck_unlock() will immediately return the same error. The 
** sqlite3_intck_error() method may be used to obtain an English language 
** error message in this case.
*/
int sqlite3_intck_step(sqlite3_intck *pCk);

/*
** If the previous call to sqlite3_intck_step() encountered corruption 
** within the database, then this function returns a pointer to a buffer
** containing a nul-terminated string describing the corruption in 
** English. If the previous call to sqlite3_intck_step() did not encounter
** corruption, or if there was no previous call, this function returns 
** NULL.
*/
const char *sqlite3_intck_message(sqlite3_intck *pCk);

/*
** Close any read-transaction opened by an earlier call to 
** sqlite3_intck_step(). Any subsequent call to sqlite3_intck_step() will
** open a new transaction. Return SQLITE_OK if successful, or an SQLite error
** code otherwise.
**
** If an error occurs, then the integrity-check handle is placed in an error
** state. In this state all subsequent calls to sqlite3_intck_step() or 
** sqlite3_intck_unlock() will immediately return the same error. The 
** sqlite3_intck_error() method may be used to obtain an English language 
** error message in this case.
*/
int sqlite3_intck_unlock(sqlite3_intck *pCk);

/*
** If an error has occurred in an earlier call to sqlite3_intck_step()
** or sqlite3_intck_unlock(), then this method returns the associated 
** SQLite error code. Additionally, if pzErr is not NULL, then (*pzErr)
** may be set to point to a nul-terminated string containing an English
** language error message. Or, if no error message is available, to
** NULL.
**
** If no error has occurred within sqlite3_intck_step() or
** sqlite_intck_unlock() calls on the handle passed as the first argument, 
** then SQLITE_OK is returned and (*pzErr) set to NULL.
*/
int sqlite3_intck_error(sqlite3_intck *pCk, const char **pzErr);

/*
** This API is used for testing only. It returns the full-text of an SQL
** statement used to test object zObj, which may be a table or index.
** The returned buffer is valid until the next call to either this function
** or sqlite3_intck_close() on the same sqlite3_intck handle.
*/
const char *sqlite3_intck_test_sql(sqlite3_intck *pCk, const char *zObj);


#ifdef __cplusplus
}  /* end of the 'extern "C"' block */
#endif

#endif /* ifndef _SQLITE_INTCK_H */

/************************* End ../ext/intck/sqlite3intck.h ********************/
/************************* Begin ../ext/intck/sqlite3intck.c ******************/
/*
** 2024-02-08
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
*/

/* #include "sqlite3intck.h" */
#include <string.h>
#include <assert.h>

#include <stdio.h>
#include <stdlib.h>

/*
** nKeyVal:
**   The number of values that make up the 'key' for the current pCheck
**   statement.
**
** rc:
**   Error code returned by most recent sqlite3_intck_step() or 
**   sqlite3_intck_unlock() call. This is set to SQLITE_DONE when
**   the integrity-check operation is finished.
**
** zErr:
**   If the object has entered the error state, this is the error message.
**   Is freed using sqlite3_free() when the object is deleted.
**
** zTestSql:
**   The value returned by the most recent call to sqlite3_intck_testsql().
**   Each call to testsql() frees the previous zTestSql value (using
**   sqlite3_free()) and replaces it with the new value it will return.
*/
struct sqlite3_intck {
  sqlite3 *db;
  const char *zDb;                /* Copy of zDb parameter to _open() */
  char *zObj;                     /* Current object. Or NULL. */

  sqlite3_stmt *pCheck;           /* Current check statement */
  char *zKey;
  int nKeyVal;

  char *zMessage;
  int bCorruptSchema;

  int rc;                         /* Error code */
  char *zErr;                     /* Error message */
  char *zTestSql;                 /* Returned by sqlite3_intck_test_sql() */
};


/*
** Some error has occurred while using database p->db. Save the error message
** and error code currently held by the database handle in p->rc and p->zErr.
*/
static void intckSaveErrmsg(sqlite3_intck *p){
  p->rc = sqlite3_errcode(p->db);
  sqlite3_free(p->zErr);
  p->zErr = sqlite3_mprintf("%s", sqlite3_errmsg(p->db));
}

/*
** If the handle passed as the first argument is already in the error state,
** then this function is a no-op (returns NULL immediately). Otherwise, if an
** error occurs within this function, it leaves an error in said handle.
**
** Otherwise, this function attempts to prepare SQL statement zSql and
** return the resulting statement handle to the user.
*/
static sqlite3_stmt *intckPrepare(sqlite3_intck *p, const char *zSql){
  sqlite3_stmt *pRet = 0;
  if( p->rc==SQLITE_OK ){
    p->rc = sqlite3_prepare_v2(p->db, zSql, -1, &pRet, 0);
    if( p->rc!=SQLITE_OK ){
      intckSaveErrmsg(p);
      assert( pRet==0 );
    }
  }
  return pRet;
}

/*
** If the handle passed as the first argument is already in the error state,
** then this function is a no-op (returns NULL immediately). Otherwise, if an
** error occurs within this function, it leaves an error in said handle.
**
** Otherwise, this function treats argument zFmt as a printf() style format
** string. It formats it according to the trailing arguments and then 
** attempts to prepare the results and return the resulting prepared
** statement.
*/
static sqlite3_stmt *intckPrepareFmt(sqlite3_intck *p, const char *zFmt, ...){
  sqlite3_stmt *pRet = 0;
  va_list ap;
  char *zSql = 0;
  va_start(ap, zFmt);
  zSql = sqlite3_vmprintf(zFmt, ap);
  if( p->rc==SQLITE_OK && zSql==0 ){
    p->rc = SQLITE_NOMEM;
  }
  pRet = intckPrepare(p, zSql);
  sqlite3_free(zSql);
  va_end(ap);
  return pRet;
}

/*
** Finalize SQL statement pStmt. If an error occurs and the handle passed
** as the first argument does not already contain an error, store the
** error in the handle.
*/
static void intckFinalize(sqlite3_intck *p, sqlite3_stmt *pStmt){
  int rc = sqlite3_finalize(pStmt);
  if( p->rc==SQLITE_OK && rc!=SQLITE_OK ){
    intckSaveErrmsg(p);
  }
}

/*
** If there is already an error in handle p, return it. Otherwise, call
** sqlite3_step() on the statement handle and return that value.
*/
static int intckStep(sqlite3_intck *p, sqlite3_stmt *pStmt){
  if( p->rc ) return p->rc;
  return sqlite3_step(pStmt);
}

/*
** Execute SQL statement zSql. There is no way to obtain any results 
** returned by the statement. This function uses the sqlite3_intck error
** code convention.
*/
static void intckExec(sqlite3_intck *p, const char *zSql){
  sqlite3_stmt *pStmt = 0;
  pStmt = intckPrepare(p, zSql);
  intckStep(p, pStmt);
  intckFinalize(p, pStmt);
}

/*
** A wrapper around sqlite3_mprintf() that uses the sqlite3_intck error
** code convention.
*/
static char *intckMprintf(sqlite3_intck *p, const char *zFmt, ...){
  va_list ap;
  char *zRet = 0;
  va_start(ap, zFmt);
  zRet = sqlite3_vmprintf(zFmt, ap);
  if( p->rc==SQLITE_OK ){
    if( zRet==0 ){
      p->rc = SQLITE_NOMEM;
    }
  }else{
    sqlite3_free(zRet);
    zRet = 0;
  }
  return zRet;
}

/*
** This is used by sqlite3_intck_unlock() to save the vector key value 
** required to restart the current pCheck query as a nul-terminated string 
** in p->zKey.
*/
static void intckSaveKey(sqlite3_intck *p){
  int ii;
  char *zSql = 0;
  sqlite3_stmt *pStmt = 0;
  sqlite3_stmt *pXinfo = 0;
  const char *zDir = 0;

  assert( p->pCheck );
  assert( p->zKey==0 );

  pXinfo = intckPrepareFmt(p, 
      "SELECT group_concat(desc, '') FROM %Q.sqlite_schema s, "
      "pragma_index_xinfo(%Q, %Q) "
      "WHERE s.type='index' AND s.name=%Q",
      p->zDb, p->zObj, p->zDb, p->zObj
  );
  if( p->rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pXinfo) ){
    zDir = (const char*)sqlite3_column_text(pXinfo, 0);
  }

  if( zDir==0 ){
    /* Object is a table, not an index. This is the easy case,as there are 
    ** no DESC columns or NULL values in a primary key.  */
    const char *zSep = "SELECT '(' || ";
    for(ii=0; ii<p->nKeyVal; ii++){
      zSql = intckMprintf(p, "%z%squote(?)", zSql, zSep);
      zSep = " || ', ' || ";
    }
    zSql = intckMprintf(p, "%z || ')'", zSql);
  }else{

    /* Object is an index. */
    assert( p->nKeyVal>1 );
    for(ii=p->nKeyVal; ii>0; ii--){
      int bLastIsDesc = zDir[ii-1]=='1';
      int bLastIsNull = sqlite3_column_type(p->pCheck, ii)==SQLITE_NULL;
      const char *zLast = sqlite3_column_name(p->pCheck, ii);
      char *zLhs = 0;
      char *zRhs = 0;
      char *zWhere = 0;

      if( bLastIsNull ){
        if( bLastIsDesc ) continue;
        zWhere = intckMprintf(p, "'%s IS NOT NULL'", zLast);
      }else{
        const char *zOp = bLastIsDesc ? "<" : ">";
        zWhere = intckMprintf(p, "'%s %s ' || quote(?%d)", zLast, zOp, ii);
      }

      if( ii>1 ){
        const char *zLhsSep = "";
        const char *zRhsSep = "";
        int jj;
        for(jj=0; jj<ii-1; jj++){
          const char *zAlias = (const char*)sqlite3_column_name(p->pCheck,jj+1);
          zLhs = intckMprintf(p, "%z%s%s", zLhs, zLhsSep, zAlias);
          zRhs = intckMprintf(p, "%z%squote(?%d)", zRhs, zRhsSep, jj+1);
          zLhsSep = ",";
          zRhsSep = " || ',' || ";
        }

        zWhere = intckMprintf(p, 
            "'(%z) IS (' || %z || ') AND ' || %z",
            zLhs, zRhs, zWhere);
      }
      zWhere = intckMprintf(p, "'WHERE ' || %z", zWhere);

      zSql = intckMprintf(p, "%z%s(quote( %z ) )",
          zSql,
          (zSql==0 ? "VALUES" : ",\n      "),
          zWhere
      );
    }
    zSql = intckMprintf(p, 
        "WITH wc(q) AS (\n%z\n)"
        "SELECT 'VALUES' || group_concat('(' || q || ')', ',\n      ') FROM wc"
        , zSql
    );
  }

  pStmt = intckPrepare(p, zSql);
  if( p->rc==SQLITE_OK ){
    for(ii=0; ii<p->nKeyVal; ii++){
      sqlite3_bind_value(pStmt, ii+1, sqlite3_column_value(p->pCheck, ii+1));
    }
    if( SQLITE_ROW==sqlite3_step(pStmt) ){
      p->zKey = intckMprintf(p,"%s",(const char*)sqlite3_column_text(pStmt, 0));
    }
    intckFinalize(p, pStmt);
  }

  sqlite3_free(zSql);
  intckFinalize(p, pXinfo);
}

/*
** Find the next database object (table or index) to check. If successful,
** set sqlite3_intck.zObj to point to a nul-terminated buffer containing
** the object's name before returning.
*/
static void intckFindObject(sqlite3_intck *p){
  sqlite3_stmt *pStmt = 0;
  char *zPrev = p->zObj;
  p->zObj = 0;

  assert( p->rc==SQLITE_OK );
  assert( p->pCheck==0 );

  pStmt = intckPrepareFmt(p, 
    "WITH tables(table_name) AS (" 
    "  SELECT name"
    "  FROM %Q.sqlite_schema WHERE (type='table' OR type='index') AND rootpage"
    "  UNION ALL "
    "  SELECT 'sqlite_schema'"
    ")"
    "SELECT table_name FROM tables "
    "WHERE ?1 IS NULL OR table_name%s?1 "
    "ORDER BY 1"
    , p->zDb, (p->zKey ? ">=" : ">")
  );

  if( p->rc==SQLITE_OK ){
    sqlite3_bind_text(pStmt, 1, zPrev, -1, SQLITE_TRANSIENT);
    if( sqlite3_step(pStmt)==SQLITE_ROW ){
      p->zObj = intckMprintf(p,"%s",(const char*)sqlite3_column_text(pStmt, 0));
    }
  }
  intckFinalize(p, pStmt);

  /* If this is a new object, ensure the previous key value is cleared. */
  if( sqlite3_stricmp(p->zObj, zPrev) ){
    sqlite3_free(p->zKey);
    p->zKey = 0;
  }

  sqlite3_free(zPrev);
}

/*
** Return the size in bytes of the first token in nul-terminated buffer z.
** For the purposes of this call, a token is either:
**
**   *  a quoted SQL string,
*    *  a contiguous series of ascii alphabet characters, or
*    *  any other single byte.
*/
static int intckGetToken(const char *z){
  char c = z[0];
  int iRet = 1;
  if( c=='\'' || c=='"' || c=='`' ){
    while( 1 ){
      if( z[iRet]==c ){
        iRet++;
        if( z[iRet]!=c ) break;
      }
      iRet++;
    }
  }
  else if( c=='[' ){
    while( z[iRet++]!=']' && z[iRet] );
  }
  else if( (c>='A' && c<='Z') || (c>='a' && c<='z') ){
    while( (z[iRet]>='A' && z[iRet]<='Z') || (z[iRet]>='a' && z[iRet]<='z') ){
      iRet++;
    }
  }

  return iRet;
}

/*
** Return true if argument c is an ascii whitespace character.
*/
static int intckIsSpace(char c){
  return (c==' ' || c=='\t' || c=='\n' || c=='\r');
}

/*
** Argument z points to the text of a CREATE INDEX statement. This function
** identifies the part of the text that contains either the index WHERE 
** clause (if iCol<0) or the iCol'th column of the index.
**
** If (iCol<0), the identified fragment does not include the "WHERE" keyword,
** only the expression that follows it. If (iCol>=0) then the identified
** fragment does not include any trailing sort-order keywords - "ASC" or 
** "DESC".
**
** If the CREATE INDEX statement does not contain the requested field or
** clause, NULL is returned and (*pnByte) is set to 0. Otherwise, a pointer to
** the identified fragment is returned and output parameter (*pnByte) set
** to its size in bytes.
*/
static const char *intckParseCreateIndex(const char *z, int iCol, int *pnByte){
  int iOff = 0;
  int iThisCol = 0;
  int iStart = 0;
  int nOpen = 0;

  const char *zRet = 0;
  int nRet = 0;

  int iEndOfCol = 0;

  /* Skip forward until the first "(" token */
  while( z[iOff]!='(' ){
    iOff += intckGetToken(&z[iOff]);
    if( z[iOff]=='\0' ) return 0;
  }
  assert( z[iOff]=='(' );

  nOpen = 1;
  iOff++;
  iStart = iOff;
  while( z[iOff] ){
    const char *zToken = &z[iOff];
    int nToken = 0;

    /* Check if this is the end of the current column - either a "," or ")"
    ** when nOpen==1.  */
    if( nOpen==1 ){
      if( z[iOff]==',' || z[iOff]==')' ){
        if( iCol==iThisCol ){
          int iEnd = iEndOfCol ? iEndOfCol : iOff;
          nRet = (iEnd - iStart);
          zRet = &z[iStart];
          break;
        }
        iStart = iOff+1;
        while( intckIsSpace(z[iStart]) ) iStart++;
        iThisCol++;
      }
      if( z[iOff]==')' ) break;
    }
    if( z[iOff]=='(' ) nOpen++;
    if( z[iOff]==')' ) nOpen--;
    nToken = intckGetToken(zToken);

    if( (nToken==3 && 0==sqlite3_strnicmp(zToken, "ASC", nToken))
     || (nToken==4 && 0==sqlite3_strnicmp(zToken, "DESC", nToken))
    ){
      iEndOfCol = iOff;
    }else if( 0==intckIsSpace(zToken[0]) ){
      iEndOfCol = 0;
    }

    iOff += nToken;
  }

  /* iStart is now the byte offset of 1 byte passed the final ')' in the
  ** CREATE INDEX statement. Try to find a WHERE clause to return.  */
  while( zRet==0 && z[iOff] ){
    int n = intckGetToken(&z[iOff]);
    if( n==5 && 0==sqlite3_strnicmp(&z[iOff], "where", 5) ){
      zRet = &z[iOff+5];
      nRet = (int)strlen(zRet);
    }
    iOff += n;
  }

  /* Trim any whitespace from the start and end of the returned string. */
  if( zRet ){
    while( intckIsSpace(zRet[0]) ){
      nRet--;
      zRet++;
    }
    while( nRet>0 && intckIsSpace(zRet[nRet-1]) ) nRet--;
  }

  *pnByte = nRet;
  return zRet;
}

/*
** User-defined SQL function wrapper for intckParseCreateIndex():
**
**     SELECT parse_create_index(<sql>, <icol>);
*/
static void intckParseCreateIndexFunc(
  sqlite3_context *pCtx, 
  int nVal, 
  sqlite3_value **apVal
){
  const char *zSql = (const char*)sqlite3_value_text(apVal[0]);
  int idx = sqlite3_value_int(apVal[1]);
  const char *zRes = 0;
  int nRes = 0;

  assert( nVal==2 );
  if( zSql ){
    zRes = intckParseCreateIndex(zSql, idx, &nRes);
  }
  sqlite3_result_text(pCtx, zRes, nRes, SQLITE_TRANSIENT);
}

/*
** Return true if sqlite3_intck.db has automatic indexes enabled, false
** otherwise.
*/
static int intckGetAutoIndex(sqlite3_intck *p){
  int bRet = 0;
  sqlite3_stmt *pStmt = 0;
  pStmt = intckPrepare(p, "PRAGMA automatic_index");
  if( SQLITE_ROW==intckStep(p, pStmt) ){
    bRet = sqlite3_column_int(pStmt, 0);
  }
  intckFinalize(p, pStmt);
  return bRet;
}

/*
** Return true if zObj is an index, or false otherwise.
*/
static int intckIsIndex(sqlite3_intck *p, const char *zObj){
  int bRet = 0;
  sqlite3_stmt *pStmt = 0;
  pStmt = intckPrepareFmt(p, 
      "SELECT 1 FROM %Q.sqlite_schema WHERE name=%Q AND type='index'",
      p->zDb, zObj
  );
  if( p->rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pStmt) ){
    bRet = 1;
  }
  intckFinalize(p, pStmt);
  return bRet;
}

/*
** Return a pointer to a nul-terminated buffer containing the SQL statement
** used to check database object zObj (a table or index) for corruption.
** If parameter zPrev is not NULL, then it must be a string containing the
** vector key required to restart the check where it left off last time.
** If pnKeyVal is not NULL, then (*pnKeyVal) is set to the number of
** columns in the vector key value for the specified object.
**
** This function uses the sqlite3_intck error code convention.
*/
static char *intckCheckObjectSql(
  sqlite3_intck *p,               /* Integrity check object */
  const char *zObj,               /* Object (table or index) to scan */
  const char *zPrev,              /* Restart key vector, if any */
  int *pnKeyVal                   /* OUT: Number of key-values for this scan */
){
  char *zRet = 0;
  sqlite3_stmt *pStmt = 0;
  int bAutoIndex = 0;
  int bIsIndex = 0;

  const char *zCommon = 
      /* Relation without_rowid also contains just one row. Column "b" is
      ** set to true if the table being examined is a WITHOUT ROWID table,
      ** or false otherwise.  */
      ", without_rowid(b) AS ("
      "  SELECT EXISTS ("
      "    SELECT 1 FROM tabname, pragma_index_list(tab, db) AS l"
      "      WHERE origin='pk' "
      "      AND NOT EXISTS (SELECT 1 FROM sqlite_schema WHERE name=l.name)"
      "  )"
      ")"
      ""
      /* Table idx_cols contains 1 row for each column in each index on the
      ** table being checked. Columns are:
      **
      **   idx_name: Name of the index.
      **   idx_ispk: True if this index is the PK of a WITHOUT ROWID table.
      **   col_name: Name of indexed column, or NULL for index on expression.
      **   col_expr: Indexed expression, including COLLATE clause.
      **   col_alias: Alias used for column in 'intck_wrapper' table.
      */
      ", idx_cols(idx_name, idx_ispk, col_name, col_expr, col_alias) AS ("
      "  SELECT l.name, (l.origin=='pk' AND w.b), i.name, COALESCE(("
      "    SELECT parse_create_index(sql, i.seqno) FROM "
      "    sqlite_schema WHERE name = l.name"
      "  ), format('\"%w\"', i.name) || ' COLLATE ' || quote(i.coll)),"
      "  'c' || row_number() OVER ()"
      "  FROM "
      "      tabname t,"
      "      without_rowid w,"
      "      pragma_index_list(t.tab, t.db) l,"
      "      pragma_index_xinfo(l.name) i"
      "      WHERE i.key"
      "  UNION ALL"
      "  SELECT '', 1, '_rowid_', '_rowid_', 'r1' FROM without_rowid WHERE b=0"
      ")"
      ""
      ""
      /*
      ** For a PK declared as "PRIMARY KEY(a, b) ... WITHOUT ROWID", where
      ** the intck_wrapper aliases of "a" and "b" are "c1" and "c2":
      **
      **   o_pk:   "o.c1, o.c2"
      **   i_pk:   "i.'a', i.'b'"
      **   ...
      **   n_pk:   2
      */ 
      ", tabpk(db, tab, idx, o_pk, i_pk, q_pk, eq_pk, ps_pk, pk_pk, n_pk) AS ("
      "    WITH pkfields(f, a) AS ("
      "      SELECT i.col_name, i.col_alias FROM idx_cols i WHERE i.idx_ispk"
      "    )"
      "    SELECT t.db, t.tab, t.idx, "
      "           group_concat(a, ', '), "
      "           group_concat('i.'||quote(f), ', '), "
      "           group_concat('quote(o.'||a||')', ' || '','' || '),  "
      "           format('(%s)==(%s)',"
      "               group_concat('o.'||a, ', '), "
      "               group_concat(format('\"%w\"', f), ', ')"
      "           ),"
      "           group_concat('%s', ','),"
      "           group_concat('quote('||a||')', ', '),  "
      "           count(*)"
      "    FROM tabname t, pkfields"
      ")"
      ""
      ", idx(name, match_expr, partial, partial_alias, idx_ps, idx_idx) AS ("
      "  SELECT idx_name,"
      "    format('(%s,%s) IS (%s,%s)', "
      "           group_concat(i.col_expr, ', '), i_pk,"
      "           group_concat('o.'||i.col_alias, ', '), o_pk"
      "    ), "
      "    parse_create_index("
      "        (SELECT sql FROM sqlite_schema WHERE name=idx_name), -1"
      "    ),"
      "    'cond' || row_number() OVER ()"
      "    , group_concat('%s', ',')"
      "    , group_concat('quote('||i.col_alias||')', ', ')"
      "  FROM tabpk t, "
      "       without_rowid w,"
      "       idx_cols i"
      "  WHERE i.idx_ispk==0 "
      "  GROUP BY idx_name"
      ")"
      ""
      ", wrapper_with(s) AS ("
      "  SELECT 'intck_wrapper AS (\n  SELECT\n    ' || ("
      "      WITH f(a, b) AS ("
      "        SELECT col_expr, col_alias FROM idx_cols"
      "          UNION ALL "
      "        SELECT partial, partial_alias FROM idx WHERE partial IS NOT NULL"
      "      )"
      "      SELECT group_concat(format('%s AS %s', a, b), ',\n    ') FROM f"
      "    )"
      "    || format('\n  FROM %Q.%Q ', t.db, t.tab)"
           /* If the object being checked is a table, append "NOT INDEXED".
           ** Otherwise, append "INDEXED BY <index>", and then, if the index 
           ** is a partial index " WHERE <condition>".  */
      "    || CASE WHEN t.idx IS NULL THEN "
      "        'NOT INDEXED'"
      "       ELSE"
      "        format('INDEXED BY %Q%s', t.idx, ' WHERE '||i.partial)"
      "       END"
      "    || '\n)'"
      "    FROM tabname t LEFT JOIN idx i ON (i.name=t.idx)"
      ")"
      ""
  ;

  bAutoIndex = intckGetAutoIndex(p);
  if( bAutoIndex ) intckExec(p, "PRAGMA automatic_index = 0");

  bIsIndex = intckIsIndex(p, zObj);
  if( bIsIndex ){
    pStmt = intckPrepareFmt(p,
      /* Table idxname contains a single row. The first column, "db", contains
      ** the name of the db containing the table (e.g. "main") and the second,
      ** "tab", the name of the table itself.  */
      "WITH tabname(db, tab, idx) AS ("
      "  SELECT %Q, (SELECT tbl_name FROM %Q.sqlite_schema WHERE name=%Q), %Q "
      ")"
      ""
      ", whereclause(w_c) AS (%s)"
      ""
      "%s" /* zCommon */
      ""
      ", case_statement(c) AS ("
      "  SELECT "
      "    'CASE WHEN (' || group_concat(col_alias, ', ') || ', 1) IS (\n' "
      "    || '      SELECT ' || group_concat(col_expr, ', ') || ', 1 FROM '"
      "    || format('%%Q.%%Q NOT INDEXED WHERE %%s\n', t.db, t.tab, p.eq_pk)"
      "    || '    )\n  THEN NULL\n    '"
      "    || 'ELSE format(''surplus entry ('"
      "    ||   group_concat('%%s', ',') || ',' || p.ps_pk"
      "    || ') in index ' || t.idx || ''', ' "
      "    ||   group_concat('quote('||i.col_alias||')', ', ') || ', ' || p.pk_pk"
      "    || ')'"
      "    || '\n  END AS error_message'"
      "  FROM tabname t, tabpk p, idx_cols i WHERE i.idx_name=t.idx"
      ")"
      ""
      ", thiskey(k, n) AS ("
      "    SELECT group_concat(i.col_alias, ', ') || ', ' || p.o_pk, "
      "           count(*) + p.n_pk "
      "    FROM tabpk p, idx_cols i WHERE i.idx_name=p.idx"
      ")"
      ""
      ", main_select(m, n) AS ("
      "  SELECT format("
      "      'WITH %%s\n' ||"
      "      ', idx_checker AS (\n' ||"
      "      '  SELECT %%s,\n' ||"
      "      '  %%s\n' || "
      "      '  FROM intck_wrapper AS o\n' ||"
      "      ')\n',"
      "      ww.s, c, t.k"
      "  ), t.n"
      "  FROM case_statement, wrapper_with ww, thiskey t"
      ")"

      "SELECT m || "
      "    group_concat('SELECT * FROM idx_checker ' || w_c, ' UNION ALL '), n"
      " FROM "
      "main_select, whereclause "
      , p->zDb, p->zDb, zObj, zObj
      , zPrev ? zPrev : "VALUES('')", zCommon
      );
  }else{
    pStmt = intckPrepareFmt(p,
      /* Table tabname contains a single row. The first column, "db", contains
      ** the name of the db containing the table (e.g. "main") and the second,
      ** "tab", the name of the table itself.  */
      "WITH tabname(db, tab, idx, prev) AS (SELECT %Q, %Q, NULL, %Q)"
      ""
      "%s" /* zCommon */

      /* expr(e) contains one row for each index on table zObj. Value e
      ** is set to an expression that evaluates to NULL if the required
      ** entry is present in the index, or an error message otherwise.  */
      ", expr(e, p) AS ("
      "  SELECT format('CASE WHEN EXISTS \n"
      "    (SELECT 1 FROM %%Q.%%Q AS i INDEXED BY %%Q WHERE %%s%%s)\n"
      "    THEN NULL\n"
      "    ELSE format(''entry (%%s,%%s) missing from index %%s'', %%s, %%s)\n"
      "  END\n'"
      "    , t.db, t.tab, i.name, i.match_expr, ' AND (' || partial || ')',"
      "      i.idx_ps, t.ps_pk, i.name, i.idx_idx, t.pk_pk),"
      "    CASE WHEN partial IS NULL THEN NULL ELSE i.partial_alias END"
      "  FROM tabpk t, idx i"
      ")"

      ", numbered(ii, cond, e) AS ("
      "  SELECT 0, 'n.ii=0', 'NULL'"
      "    UNION ALL "
      "  SELECT row_number() OVER (),"
      "      '(n.ii='||row_number() OVER ()||COALESCE(' AND '||p||')', ')'), e"
      "  FROM expr"
      ")"

      ", counter_with(w) AS ("
      "    SELECT 'WITH intck_counter(ii) AS (\n  ' || "
      "       group_concat('SELECT '||ii, ' UNION ALL\n  ') "
      "    || '\n)' FROM numbered"
      ")"
      ""
      ", case_statement(c) AS ("
      "    SELECT 'CASE ' || "
      "    group_concat(format('\n  WHEN %%s THEN (%%s)', cond, e), '') ||"
      "    '\nEND AS error_message'"
      "    FROM numbered"
      ")"
      ""

      /* This table contains a single row consisting of a single value -
      ** the text of an SQL expression that may be used by the main SQL
      ** statement to output an SQL literal that can be used to resume
      ** the scan if it is suspended. e.g. for a rowid table, an expression
      ** like:
      **
      **     format('(%d,%d)', _rowid_, n.ii)
      */
      ", thiskey(k, n) AS ("
      "    SELECT o_pk || ', ii', n_pk+1 FROM tabpk"
      ")"
      ""
      ", whereclause(w_c) AS ("
      "    SELECT CASE WHEN prev!='' THEN "
      "    '\nWHERE (' || o_pk ||', n.ii) > ' || prev"
      "    ELSE ''"
      "    END"
      "    FROM tabpk, tabname"
      ")"
      ""
      ", main_select(m, n) AS ("
      "  SELECT format("
      "      '%%s, %%s\nSELECT %%s,\n%%s\nFROM intck_wrapper AS o"
               ", intck_counter AS n%%s\nORDER BY %%s', "
      "      w, ww.s, c, thiskey.k, whereclause.w_c, t.o_pk"
      "  ), thiskey.n"
      "  FROM case_statement, tabpk t, counter_with, "
      "       wrapper_with ww, thiskey, whereclause"
      ")"

      "SELECT m, n FROM main_select",
      p->zDb, zObj, zPrev, zCommon
    );
  }

  while( p->rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pStmt) ){
    zRet = intckMprintf(p, "%s", (const char*)sqlite3_column_text(pStmt, 0));
    if( pnKeyVal ){
      *pnKeyVal = sqlite3_column_int(pStmt, 1);
    }
  }
  intckFinalize(p, pStmt);

  if( bAutoIndex ) intckExec(p, "PRAGMA automatic_index = 1");
  return zRet;
}

/*
** Open a new integrity-check object.
*/
int sqlite3_intck_open(
  sqlite3 *db,                    /* Database handle to operate on */
  const char *zDbArg,             /* "main", "temp" etc. */
  sqlite3_intck **ppOut           /* OUT: New integrity-check handle */
){
  sqlite3_intck *pNew = 0;
  int rc = SQLITE_OK;
  const char *zDb = zDbArg ? zDbArg : "main";
  int nDb = (int)strlen(zDb);

  pNew = (sqlite3_intck*)sqlite3_malloc(sizeof(*pNew) + nDb + 1);
  if( pNew==0 ){
    rc = SQLITE_NOMEM;
  }else{
    memset(pNew, 0, sizeof(*pNew));
    pNew->db = db;
    pNew->zDb = (const char*)&pNew[1];
    memcpy(&pNew[1], zDb, nDb+1);
    rc = sqlite3_create_function(db, "parse_create_index", 
        2, SQLITE_UTF8, 0, intckParseCreateIndexFunc, 0, 0
    );
    if( rc!=SQLITE_OK ){
      sqlite3_intck_close(pNew);
      pNew = 0;
    }
  }

  *ppOut = pNew;
  return rc;
}

/*
** Free the integrity-check object.
*/
void sqlite3_intck_close(sqlite3_intck *p){
  if( p ){
    sqlite3_finalize(p->pCheck);
    sqlite3_create_function(
        p->db, "parse_create_index", 1, SQLITE_UTF8, 0, 0, 0, 0
    );
    sqlite3_free(p->zObj);
    sqlite3_free(p->zKey);
    sqlite3_free(p->zTestSql);
    sqlite3_free(p->zErr);
    sqlite3_free(p->zMessage);
    sqlite3_free(p);
  }
}

/*
** Step the integrity-check object.
*/
int sqlite3_intck_step(sqlite3_intck *p){
  if( p->rc==SQLITE_OK ){

    if( p->zMessage ){
      sqlite3_free(p->zMessage);
      p->zMessage = 0;
    }

    if( p->bCorruptSchema ){
      p->rc = SQLITE_DONE;
    }else
    if( p->pCheck==0 ){
      intckFindObject(p);
      if( p->rc==SQLITE_OK ){
        if( p->zObj ){
          char *zSql = 0;
          zSql = intckCheckObjectSql(p, p->zObj, p->zKey, &p->nKeyVal);
          p->pCheck = intckPrepare(p, zSql);
          sqlite3_free(zSql);
          sqlite3_free(p->zKey);
          p->zKey = 0;
        }else{
          p->rc = SQLITE_DONE;
        }
      }else if( p->rc==SQLITE_CORRUPT ){
        p->rc = SQLITE_OK;
        p->zMessage = intckMprintf(p, "%s",
            "corruption found while reading database schema"
        );
        p->bCorruptSchema = 1;
      }
    }

    if( p->pCheck ){
      assert( p->rc==SQLITE_OK );
      if( sqlite3_step(p->pCheck)==SQLITE_ROW ){
        /* Normal case, do nothing. */
      }else{
        intckFinalize(p, p->pCheck);
        p->pCheck = 0;
        p->nKeyVal = 0;
        if( p->rc==SQLITE_CORRUPT ){
          p->rc = SQLITE_OK;
          p->zMessage = intckMprintf(p, 
              "corruption found while scanning database object %s", p->zObj
          );
        }
      }
    }
  }

  return p->rc;
}

/*
** Return a message describing the corruption encountered by the most recent
** call to sqlite3_intck_step(), or NULL if no corruption was encountered.
*/
const char *sqlite3_intck_message(sqlite3_intck *p){
  assert( p->pCheck==0 || p->zMessage==0 );
  if( p->zMessage ){
    return p->zMessage;
  }
  if( p->pCheck ){
    return (const char*)sqlite3_column_text(p->pCheck, 0);
  }
  return 0;
}

/*
** Return the error code and message.
*/
int sqlite3_intck_error(sqlite3_intck *p, const char **pzErr){
  if( pzErr ) *pzErr = p->zErr;
  return (p->rc==SQLITE_DONE ? SQLITE_OK : p->rc);
}

/*
** Close any read transaction the integrity-check object is holding open
** on the database.
*/
int sqlite3_intck_unlock(sqlite3_intck *p){
  if( p->rc==SQLITE_OK && p->pCheck ){
    assert( p->zKey==0 && p->nKeyVal>0 );
    intckSaveKey(p);
    intckFinalize(p, p->pCheck);
    p->pCheck = 0;
  }
  return p->rc;
}

/*
** Return the SQL statement used to check object zObj. Or, if zObj is 
** NULL, the current SQL statement.
*/
const char *sqlite3_intck_test_sql(sqlite3_intck *p, const char *zObj){
  sqlite3_free(p->zTestSql);
  if( zObj ){
    p->zTestSql = intckCheckObjectSql(p, zObj, 0, 0);
  }else{
    if( p->zObj ){
      p->zTestSql = intckCheckObjectSql(p, p->zObj, p->zKey, 0);
    }else{
      sqlite3_free(p->zTestSql);
      p->zTestSql = 0;
    }
  }
  return p->zTestSql;
}

/************************* End ../ext/intck/sqlite3intck.c ********************/
/************************* Begin ../ext/misc/stmtrand.c ******************/
/*
** 2024-05-24
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
******************************************************************************
**
** An SQL function that return pseudo-random non-negative integers.
**
**      SELECT stmtrand(123);
**
** A special feature of this function is that the same sequence of random
** integers is returned for each invocation of the statement.  This makes
** the results repeatable, and hence useful for testing.  The argument is
** an integer which is the seed for the random number sequence.  The seed
** is used by the first invocation of this function only and is ignored
** for all subsequent calls within the same statement.
**
** Resetting a statement (sqlite3_reset()) also resets the random number
** sequence.
*/
/* #include "sqlite3ext.h" */
SQLITE_EXTENSION_INIT1
#include <assert.h>
#include <string.h>

/* State of the pseudo-random number generator */
typedef struct Stmtrand {
  unsigned int x, y;
} Stmtrand;

/* auxdata key */
#define STMTRAND_KEY  (-4418371)

/*
** Function:     stmtrand(SEED)
**
** Return a pseudo-random number.
*/
static void stmtrandFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  Stmtrand *p;

  p = (Stmtrand*)sqlite3_get_auxdata(context, STMTRAND_KEY);
  if( p==0 ){
    unsigned int seed;
    p = sqlite3_malloc( sizeof(*p) );
    if( p==0 ){
      sqlite3_result_error_nomem(context);
      return;
    }
    if( argc>=1 ){
      seed = (unsigned int)sqlite3_value_int(argv[0]);
    }else{
      seed = 0;
    }
    p->x = seed | 1;
    p->y = seed;
    sqlite3_set_auxdata(context, STMTRAND_KEY, p, sqlite3_free);
    p = (Stmtrand*)sqlite3_get_auxdata(context, STMTRAND_KEY);
    if( p==0 ){
      sqlite3_result_error_nomem(context);
      return;
    }
  }
  p->x = (p->x>>1) ^ ((1+~(p->x&1)) & 0xd0000001);
  p->y = p->y*1103515245 + 12345;
  sqlite3_result_int(context, (int)((p->x ^ p->y)&0x7fffffff));
}

#ifdef _WIN32

#endif
int sqlite3_stmtrand_init(
  sqlite3 *db, 
  char **pzErrMsg, 
  const sqlite3_api_routines *pApi
){
  int rc = SQLITE_OK;
  SQLITE_EXTENSION_INIT2(pApi);
  (void)pzErrMsg;  /* Unused parameter */
  rc = sqlite3_create_function(db, "stmtrand", 1, SQLITE_UTF8, 0,
                               stmtrandFunc, 0, 0);
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_function(db, "stmtrand", 0, SQLITE_UTF8, 0,
                                 stmtrandFunc, 0, 0);
  }
  return rc;
}

/************************* End ../ext/misc/stmtrand.c ********************/
/************************* Begin ../ext/misc/vfstrace.c ******************/
/*
** 2011 March 16
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
******************************************************************************
**
** This file contains code implements a VFS shim that writes diagnostic
** output for each VFS call, similar to "strace".
**
** USAGE:
**
** This source file exports a single symbol which is the name of a
** function:
**
**   int vfstrace_register(
**     const char *zTraceName,         // Name of the newly constructed VFS
**     const char *zOldVfsName,        // Name of the underlying VFS
**     int (*xOut)(const char*,void*), // Output routine.  ex: fputs
**     void *pOutArg,                  // 2nd argument to xOut.  ex: stderr
**     int makeDefault                 // Make the new VFS the default
**   );
**
** Applications that want to trace their VFS usage must provide a callback
** function with this prototype:
**
**   int traceOutput(const char *zMessage, void *pAppData);
**
** This function will "output" the trace messages, where "output" can
** mean different things to different applications.  The traceOutput function
** for the command-line shell (see shell.c) is "fputs" from the standard
** library, which means that all trace output is written on the stream
** specified by the second argument.  In the case of the command-line shell
** the second argument is stderr.  Other applications might choose to output
** trace information to a file, over a socket, or write it into a buffer.
**
** The vfstrace_register() function creates a new "shim" VFS named by
** the zTraceName parameter.  A "shim" VFS is an SQLite backend that does
** not really perform the duties of a true backend, but simply filters or
** interprets VFS calls before passing them off to another VFS which does
** the actual work.  In this case the other VFS - the one that does the
** real work - is identified by the second parameter, zOldVfsName.  If
** the 2nd parameter is NULL then the default VFS is used.  The common
** case is for the 2nd parameter to be NULL.
**
** The third and fourth parameters are the pointer to the output function
** and the second argument to the output function.  For the SQLite
** command-line shell, when the -vfstrace option is used, these parameters
** are fputs and stderr, respectively.
**
** The fifth argument is true (non-zero) to cause the newly created VFS
** to become the default VFS.  The common case is for the fifth parameter
** to be true.
**
** The call to vfstrace_register() simply creates the shim VFS that does
** tracing.  The application must also arrange to use the new VFS for
** all database connections that are created and for which tracing is 
** desired.  This can be done by specifying the trace VFS using URI filename
** notation, or by specifying the trace VFS as the 4th parameter to
** sqlite3_open_v2() or by making the trace VFS be the default (by setting
** the 5th parameter of vfstrace_register() to 1).
**
**
** ENABLING VFSTRACE IN A COMMAND-LINE SHELL
**
** The SQLite command line shell implemented by the shell.c source file
** can be used with this module.  To compile in -vfstrace support, first
** gather this file (test_vfstrace.c), the shell source file (shell.c),
** and the SQLite amalgamation source files (sqlite3.c, sqlite3.h) into
** the working directory.  Then compile using a command like the following:
**
**    gcc -o sqlite3 -Os -I. -DSQLITE_ENABLE_VFSTRACE \
**        -DSQLITE_THREADSAFE=0 -DSQLITE_ENABLE_FTS3 -DSQLITE_ENABLE_RTREE \
**        -DHAVE_READLINE -DHAVE_USLEEP=1 \
**        shell.c test_vfstrace.c sqlite3.c -ldl -lreadline -lncurses
**
** The gcc command above works on Linux and provides (in addition to the
** -vfstrace option) support for FTS3 and FTS4, RTREE, and command-line
** editing using the readline library.  The command-line shell does not
** use threads so we added -DSQLITE_THREADSAFE=0 just to make the code
** run a little faster.   For compiling on a Mac, you'll probably need
** to omit the -DHAVE_READLINE, the -lreadline, and the -lncurses options.
** The compilation could be simplified to just this:
**
**    gcc -DSQLITE_ENABLE_VFSTRACE \
**         shell.c test_vfstrace.c sqlite3.c -ldl -lpthread
**
** In this second example, all unnecessary options have been removed
** Note that since the code is now threadsafe, we had to add the -lpthread
** option to pull in the pthreads library.
**
** To cross-compile for windows using MinGW, a command like this might
** work:
**
**    /opt/mingw/bin/i386-mingw32msvc-gcc -o sqlite3.exe -Os -I \
**         -DSQLITE_THREADSAFE=0 -DSQLITE_ENABLE_VFSTRACE \
**         shell.c test_vfstrace.c sqlite3.c
**
** Similar compiler commands will work on different systems.  The key
** invariants are (1) you must have -DSQLITE_ENABLE_VFSTRACE so that
** the shell.c source file will know to include the -vfstrace command-line
** option and (2) you must compile and link the three source files
** shell,c, test_vfstrace.c, and sqlite3.c.  
*/
#include <stdlib.h>
#include <string.h>
/* #include "sqlite3.h" */

/*
** An instance of this structure is attached to the each trace VFS to
** provide auxiliary information.
*/
typedef struct vfstrace_info vfstrace_info;
struct vfstrace_info {
  sqlite3_vfs *pRootVfs;              /* The underlying real VFS */
  int (*xOut)(const char*, void*);    /* Send output here */
  void *pOutArg;                      /* First argument to xOut */
  const char *zVfsName;               /* Name of this trace-VFS */
  sqlite3_vfs *pTraceVfs;             /* Pointer back to the trace VFS */
};

/*
** The sqlite3_file object for the trace VFS
*/
typedef struct vfstrace_file vfstrace_file;
struct vfstrace_file {
  sqlite3_file base;        /* Base class.  Must be first */
  vfstrace_info *pInfo;     /* The trace-VFS to which this file belongs */
  const char *zFName;       /* Base name of the file */
  sqlite3_file *pReal;      /* The real underlying file */
};

/*
** Method declarations for vfstrace_file.
*/
static int vfstraceClose(sqlite3_file*);
static int vfstraceRead(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
static int vfstraceWrite(sqlite3_file*,const void*,int iAmt, sqlite3_int64);
static int vfstraceTruncate(sqlite3_file*, sqlite3_int64 size);
static int vfstraceSync(sqlite3_file*, int flags);
static int vfstraceFileSize(sqlite3_file*, sqlite3_int64 *pSize);
static int vfstraceLock(sqlite3_file*, int);
static int vfstraceUnlock(sqlite3_file*, int);
static int vfstraceCheckReservedLock(sqlite3_file*, int *);
static int vfstraceFileControl(sqlite3_file*, int op, void *pArg);
static int vfstraceSectorSize(sqlite3_file*);
static int vfstraceDeviceCharacteristics(sqlite3_file*);
static int vfstraceShmLock(sqlite3_file*,int,int,int);
static int vfstraceShmMap(sqlite3_file*,int,int,int, void volatile **);
static void vfstraceShmBarrier(sqlite3_file*);
static int vfstraceShmUnmap(sqlite3_file*,int);

/*
** Method declarations for vfstrace_vfs.
*/
static int vfstraceOpen(sqlite3_vfs*, const char *, sqlite3_file*, int , int *);
static int vfstraceDelete(sqlite3_vfs*, const char *zName, int syncDir);
static int vfstraceAccess(sqlite3_vfs*, const char *zName, int flags, int *);
static int vfstraceFullPathname(sqlite3_vfs*, const char *zName, int, char *);
static void *vfstraceDlOpen(sqlite3_vfs*, const char *zFilename);
static void vfstraceDlError(sqlite3_vfs*, int nByte, char *zErrMsg);
static void (*vfstraceDlSym(sqlite3_vfs*,void*, const char *zSymbol))(void);
static void vfstraceDlClose(sqlite3_vfs*, void*);
static int vfstraceRandomness(sqlite3_vfs*, int nByte, char *zOut);
static int vfstraceSleep(sqlite3_vfs*, int microseconds);
static int vfstraceCurrentTime(sqlite3_vfs*, double*);
static int vfstraceGetLastError(sqlite3_vfs*, int, char*);
static int vfstraceCurrentTimeInt64(sqlite3_vfs*, sqlite3_int64*);
static int vfstraceSetSystemCall(sqlite3_vfs*,const char*, sqlite3_syscall_ptr);
static sqlite3_syscall_ptr vfstraceGetSystemCall(sqlite3_vfs*, const char *);
static const char *vfstraceNextSystemCall(sqlite3_vfs*, const char *zName);

/*
** Return a pointer to the tail of the pathname.  Examples:
**
**     /home/drh/xyzzy.txt -> xyzzy.txt
**     xyzzy.txt           -> xyzzy.txt
*/
static const char *fileTail(const char *z){
  size_t i;
  if( z==0 ) return 0;
  i = strlen(z)-1;
  while( i>0 && z[i-1]!='/' ){ i--; }
  return &z[i];
}

/*
** Send trace output defined by zFormat and subsequent arguments.
*/
static void vfstrace_printf(
  vfstrace_info *pInfo,
  const char *zFormat,
  ...
){
  va_list ap;
  char *zMsg;
  va_start(ap, zFormat);
  zMsg = sqlite3_vmprintf(zFormat, ap);
  va_end(ap);
  pInfo->xOut(zMsg, pInfo->pOutArg);
  sqlite3_free(zMsg);
}

/*
** Try to convert an error code into a symbolic name for that error code.
*/
static const char *vfstrace_errcode_name(int rc ){
  const char *zVal = 0;
  switch( rc ){
    case SQLITE_OK:                 zVal = "SQLITE_OK";                 break;
    case SQLITE_INTERNAL:           zVal = "SQLITE_INTERNAL";           break;
    case SQLITE_ERROR:              zVal = "SQLITE_ERROR";              break;
    case SQLITE_PERM:               zVal = "SQLITE_PERM";               break;
    case SQLITE_ABORT:              zVal = "SQLITE_ABORT";              break;
    case SQLITE_BUSY:               zVal = "SQLITE_BUSY";               break;
    case SQLITE_LOCKED:             zVal = "SQLITE_LOCKED";             break;
    case SQLITE_NOMEM:              zVal = "SQLITE_NOMEM";              break;
    case SQLITE_READONLY:           zVal = "SQLITE_READONLY";           break;
    case SQLITE_INTERRUPT:          zVal = "SQLITE_INTERRUPT";          break;
    case SQLITE_IOERR:              zVal = "SQLITE_IOERR";              break;
    case SQLITE_CORRUPT:            zVal = "SQLITE_CORRUPT";            break;
    case SQLITE_NOTFOUND:           zVal = "SQLITE_NOTFOUND";           break;
    case SQLITE_FULL:               zVal = "SQLITE_FULL";               break;
    case SQLITE_CANTOPEN:           zVal = "SQLITE_CANTOPEN";           break;
    case SQLITE_PROTOCOL:           zVal = "SQLITE_PROTOCOL";           break;
    case SQLITE_EMPTY:              zVal = "SQLITE_EMPTY";              break;
    case SQLITE_SCHEMA:             zVal = "SQLITE_SCHEMA";             break;
    case SQLITE_TOOBIG:             zVal = "SQLITE_TOOBIG";             break;
    case SQLITE_CONSTRAINT:         zVal = "SQLITE_CONSTRAINT";         break;
    case SQLITE_MISMATCH:           zVal = "SQLITE_MISMATCH";           break;
    case SQLITE_MISUSE:             zVal = "SQLITE_MISUSE";             break;
    case SQLITE_NOLFS:              zVal = "SQLITE_NOLFS";              break;
    case SQLITE_IOERR_READ:         zVal = "SQLITE_IOERR_READ";         break;
    case SQLITE_IOERR_SHORT_READ:   zVal = "SQLITE_IOERR_SHORT_READ";   break;
    case SQLITE_IOERR_WRITE:        zVal = "SQLITE_IOERR_WRITE";        break;
    case SQLITE_IOERR_FSYNC:        zVal = "SQLITE_IOERR_FSYNC";        break;
    case SQLITE_IOERR_DIR_FSYNC:    zVal = "SQLITE_IOERR_DIR_FSYNC";    break;
    case SQLITE_IOERR_TRUNCATE:     zVal = "SQLITE_IOERR_TRUNCATE";     break;
    case SQLITE_IOERR_FSTAT:        zVal = "SQLITE_IOERR_FSTAT";        break;
    case SQLITE_IOERR_UNLOCK:       zVal = "SQLITE_IOERR_UNLOCK";       break;
    case SQLITE_IOERR_RDLOCK:       zVal = "SQLITE_IOERR_RDLOCK";       break;
    case SQLITE_IOERR_DELETE:       zVal = "SQLITE_IOERR_DELETE";       break;
    case SQLITE_IOERR_BLOCKED:      zVal = "SQLITE_IOERR_BLOCKED";      break;
    case SQLITE_IOERR_NOMEM:        zVal = "SQLITE_IOERR_NOMEM";        break;
    case SQLITE_IOERR_ACCESS:       zVal = "SQLITE_IOERR_ACCESS";       break;
    case SQLITE_IOERR_CHECKRESERVEDLOCK:
                               zVal = "SQLITE_IOERR_CHECKRESERVEDLOCK"; break;
    case SQLITE_IOERR_LOCK:         zVal = "SQLITE_IOERR_LOCK";         break;
    case SQLITE_IOERR_CLOSE:        zVal = "SQLITE_IOERR_CLOSE";        break;
    case SQLITE_IOERR_DIR_CLOSE:    zVal = "SQLITE_IOERR_DIR_CLOSE";    break;
    case SQLITE_IOERR_SHMOPEN:      zVal = "SQLITE_IOERR_SHMOPEN";      break;
    case SQLITE_IOERR_SHMSIZE:      zVal = "SQLITE_IOERR_SHMSIZE";      break;
    case SQLITE_IOERR_SHMLOCK:      zVal = "SQLITE_IOERR_SHMLOCK";      break;
    case SQLITE_IOERR_SHMMAP:       zVal = "SQLITE_IOERR_SHMMAP";       break;
    case SQLITE_IOERR_SEEK:         zVal = "SQLITE_IOERR_SEEK";         break;
    case SQLITE_IOERR_GETTEMPPATH:  zVal = "SQLITE_IOERR_GETTEMPPATH";  break;
    case SQLITE_IOERR_CONVPATH:     zVal = "SQLITE_IOERR_CONVPATH";     break;
    case SQLITE_READONLY_DBMOVED:   zVal = "SQLITE_READONLY_DBMOVED";   break;
    case SQLITE_LOCKED_SHAREDCACHE: zVal = "SQLITE_LOCKED_SHAREDCACHE"; break;
    case SQLITE_BUSY_RECOVERY:      zVal = "SQLITE_BUSY_RECOVERY";      break;
    case SQLITE_CANTOPEN_NOTEMPDIR: zVal = "SQLITE_CANTOPEN_NOTEMPDIR"; break;
  }
  return zVal;
}

/*
** Convert value rc into a string and print it using zFormat.  zFormat
** should have exactly one %s
*/
static void vfstrace_print_errcode(
  vfstrace_info *pInfo,
  const char *zFormat,
  int rc
){
  const char *zVal;
  char zBuf[50];
  zVal = vfstrace_errcode_name(rc);
  if( zVal==0 ){
    zVal = vfstrace_errcode_name(rc&0xff);
    if( zVal ){
      sqlite3_snprintf(sizeof(zBuf), zBuf, "%s | 0x%x", zVal, rc&0xffff00);
    }else{
      sqlite3_snprintf(sizeof(zBuf), zBuf, "%d (0x%x)", rc, rc);
    }
    zVal = zBuf;
  }
  vfstrace_printf(pInfo, zFormat, zVal);
}

/*
** Append to a buffer.
*/
static void strappend(char *z, int *pI, const char *zAppend){
  int i = *pI;
  while( zAppend[0] ){ z[i++] = *(zAppend++); }
  z[i] = 0;
  *pI = i;
}

/*
** Close an vfstrace-file.
*/
static int vfstraceClose(sqlite3_file *pFile){
  vfstrace_file *p = (vfstrace_file *)pFile;
  vfstrace_info *pInfo = p->pInfo;
  int rc;
  vfstrace_printf(pInfo, "%s.xClose(%s)", pInfo->zVfsName, p->zFName);
  rc = p->pReal->pMethods->xClose(p->pReal);
  vfstrace_print_errcode(pInfo, " -> %s\n", rc);
  if( rc==SQLITE_OK ){
    sqlite3_free((void*)p->base.pMethods);
    p->base.pMethods = 0;
  }
  return rc;
}

/*
** Read data from an vfstrace-file.
*/
static int vfstraceRead(
  sqlite3_file *pFile, 
  void *zBuf, 
  int iAmt, 
  sqlite_int64 iOfst
){
  vfstrace_file *p = (vfstrace_file *)pFile;
  vfstrace_info *pInfo = p->pInfo;
  int rc;
  vfstrace_printf(pInfo, "%s.xRead(%s,n=%d,ofst=%lld)",
                  pInfo->zVfsName, p->zFName, iAmt, iOfst);
  rc = p->pReal->pMethods->xRead(p->pReal, zBuf, iAmt, iOfst);
  vfstrace_print_errcode(pInfo, " -> %s\n", rc);
  return rc;
}

/*
** Write data to an vfstrace-file.
*/
static int vfstraceWrite(
  sqlite3_file *pFile, 
  const void *zBuf, 
  int iAmt, 
  sqlite_int64 iOfst
){
  vfstrace_file *p = (vfstrace_file *)pFile;
  vfstrace_info *pInfo = p->pInfo;
  int rc;
  vfstrace_printf(pInfo, "%s.xWrite(%s,n=%d,ofst=%lld)",
                  pInfo->zVfsName, p->zFName, iAmt, iOfst);
  rc = p->pReal->pMethods->xWrite(p->pReal, zBuf, iAmt, iOfst);
  vfstrace_print_errcode(pInfo, " -> %s\n", rc);
  return rc;
}

/*
** Truncate an vfstrace-file.
*/
static int vfstraceTruncate(sqlite3_file *pFile, sqlite_int64 size){
  vfstrace_file *p = (vfstrace_file *)pFile;
  vfstrace_info *pInfo = p->pInfo;
  int rc;
  vfstrace_printf(pInfo, "%s.xTruncate(%s,%lld)", pInfo->zVfsName, p->zFName,
                  size);
  rc = p->pReal->pMethods->xTruncate(p->pReal, size);
  vfstrace_printf(pInfo, " -> %d\n", rc);
  return rc;
}

/*
** Sync an vfstrace-file.
*/
static int vfstraceSync(sqlite3_file *pFile, int flags){
  vfstrace_file *p = (vfstrace_file *)pFile;
  vfstrace_info *pInfo = p->pInfo;
  int rc;
  int i;
  char zBuf[100];
  memcpy(zBuf, "|0", 3);
  i = 0;
  if( flags & SQLITE_SYNC_FULL )        strappend(zBuf, &i, "|FULL");
  else if( flags & SQLITE_SYNC_NORMAL ) strappend(zBuf, &i, "|NORMAL");
  if( flags & SQLITE_SYNC_DATAONLY )    strappend(zBuf, &i, "|DATAONLY");
  if( flags & ~(SQLITE_SYNC_FULL|SQLITE_SYNC_DATAONLY) ){
    sqlite3_snprintf(sizeof(zBuf)-i, &zBuf[i], "|0x%x", flags);
  }
  vfstrace_printf(pInfo, "%s.xSync(%s,%s)", pInfo->zVfsName, p->zFName,
                  &zBuf[1]);
  rc = p->pReal->pMethods->xSync(p->pReal, flags);
  vfstrace_printf(pInfo, " -> %d\n", rc);
  return rc;
}

/*
** Return the current file-size of an vfstrace-file.
*/
static int vfstraceFileSize(sqlite3_file *pFile, sqlite_int64 *pSize){
  vfstrace_file *p = (vfstrace_file *)pFile;
  vfstrace_info *pInfo = p->pInfo;
  int rc;
  vfstrace_printf(pInfo, "%s.xFileSize(%s)", pInfo->zVfsName, p->zFName);
  rc = p->pReal->pMethods->xFileSize(p->pReal, pSize);
  vfstrace_print_errcode(pInfo, " -> %s,", rc);
  vfstrace_printf(pInfo, " size=%lld\n", *pSize);
  return rc;
}

/*
** Return the name of a lock.
*/
static const char *lockName(int eLock){
  const char *azLockNames[] = {
     "NONE", "SHARED", "RESERVED", "PENDING", "EXCLUSIVE"
  };
  if( eLock<0 || eLock>=(int)(sizeof(azLockNames)/sizeof(azLockNames[0])) ){
    return "???";
  }else{
    return azLockNames[eLock];
  }
}

/*
** Lock an vfstrace-file.
*/
static int vfstraceLock(sqlite3_file *pFile, int eLock){
  vfstrace_file *p = (vfstrace_file *)pFile;
  vfstrace_info *pInfo = p->pInfo;
  int rc;
  vfstrace_printf(pInfo, "%s.xLock(%s,%s)", pInfo->zVfsName, p->zFName,
                  lockName(eLock));
  rc = p->pReal->pMethods->xLock(p->pReal, eLock);
  vfstrace_print_errcode(pInfo, " -> %s\n", rc);
  return rc;
}

/*
** Unlock an vfstrace-file.
*/
static int vfstraceUnlock(sqlite3_file *pFile, int eLock){
  vfstrace_file *p = (vfstrace_file *)pFile;
  vfstrace_info *pInfo = p->pInfo;
  int rc;
  vfstrace_printf(pInfo, "%s.xUnlock(%s,%s)", pInfo->zVfsName, p->zFName,
                  lockName(eLock));
  rc = p->pReal->pMethods->xUnlock(p->pReal, eLock);
  vfstrace_print_errcode(pInfo, " -> %s\n", rc);
  return rc;
}

/*
** Check if another file-handle holds a RESERVED lock on an vfstrace-file.
*/
static int vfstraceCheckReservedLock(sqlite3_file *pFile, int *pResOut){
  vfstrace_file *p = (vfstrace_file *)pFile;
  vfstrace_info *pInfo = p->pInfo;
  int rc;
  vfstrace_printf(pInfo, "%s.xCheckReservedLock(%s,%d)", 
                  pInfo->zVfsName, p->zFName);
  rc = p->pReal->pMethods->xCheckReservedLock(p->pReal, pResOut);
  vfstrace_print_errcode(pInfo, " -> %s", rc);
  vfstrace_printf(pInfo, ", out=%d\n", *pResOut);
  return rc;
}

/*
** File control method. For custom operations on an vfstrace-file.
*/
static int vfstraceFileControl(sqlite3_file *pFile, int op, void *pArg){
  vfstrace_file *p = (vfstrace_file *)pFile;
  vfstrace_info *pInfo = p->pInfo;
  int rc;
  char zBuf[100];
  char zBuf2[100];
  char *zOp;
  char *zRVal = 0;
  switch( op ){
    case SQLITE_FCNTL_LOCKSTATE:           zOp = "LOCKSTATE";           break;
    case SQLITE_GET_LOCKPROXYFILE:         zOp = "GET_LOCKPROXYFILE";   break;
    case SQLITE_SET_LOCKPROXYFILE:         zOp = "SET_LOCKPROXYFILE";   break;
    case SQLITE_LAST_ERRNO:                zOp = "LAST_ERRNO";          break;
    case SQLITE_FCNTL_SIZE_HINT: {
      sqlite3_snprintf(sizeof(zBuf), zBuf, "SIZE_HINT,%lld",
                       *(sqlite3_int64*)pArg);
      zOp = zBuf;
      break;
    }
    case SQLITE_FCNTL_CHUNK_SIZE: {
      sqlite3_snprintf(sizeof(zBuf), zBuf, "CHUNK_SIZE,%d", *(int*)pArg);
      zOp = zBuf;
      break;
    }
    case SQLITE_FCNTL_FILE_POINTER:        zOp = "FILE_POINTER";        break;
    case SQLITE_FCNTL_WIN32_AV_RETRY:      zOp = "WIN32_AV_RETRY";      break;
    case SQLITE_FCNTL_PERSIST_WAL: {
       sqlite3_snprintf(sizeof(zBuf), zBuf, "PERSIST_WAL,%d", *(int*)pArg);
       zOp = zBuf;
       break;
    }
    case SQLITE_FCNTL_OVERWRITE:           zOp = "OVERWRITE";           break;
    case SQLITE_FCNTL_VFSNAME:             zOp = "VFSNAME";             break;
    case SQLITE_FCNTL_POWERSAFE_OVERWRITE: zOp = "POWERSAFE_OVERWRITE"; break;
    case SQLITE_FCNTL_PRAGMA: {
      const char *const* a = (const char*const*)pArg;
      sqlite3_snprintf(sizeof(zBuf), zBuf, "PRAGMA,[%s,%s]",a[1],a[2]);
      zOp = zBuf;
      break;
    }
    case SQLITE_FCNTL_BUSYHANDLER:         zOp = "BUSYHANDLER";         break;
    case SQLITE_FCNTL_TEMPFILENAME:        zOp = "TEMPFILENAME";        break;
    case SQLITE_FCNTL_MMAP_SIZE: {
      sqlite3_int64 iMMap = *(sqlite3_int64*)pArg;
      sqlite3_snprintf(sizeof(zBuf), zBuf, "MMAP_SIZE,%lld",iMMap);
      zOp = zBuf;
      break;
    }
    case SQLITE_FCNTL_TRACE:               zOp = "TRACE";               break;
    case SQLITE_FCNTL_HAS_MOVED:           zOp = "HAS_MOVED";           break;
    case SQLITE_FCNTL_SYNC:                zOp = "SYNC";                break;
    case SQLITE_FCNTL_COMMIT_PHASETWO:     zOp = "COMMIT_PHASETWO";     break;
    case SQLITE_FCNTL_WIN32_SET_HANDLE:    zOp = "WIN32_SET_HANDLE";    break;
    case SQLITE_FCNTL_WAL_BLOCK:           zOp = "WAL_BLOCK";           break;
    case SQLITE_FCNTL_ZIPVFS:              zOp = "ZIPVFS";              break; 
    case SQLITE_FCNTL_RBU:                 zOp = "RBU";                 break;
    case SQLITE_FCNTL_VFS_POINTER:         zOp = "VFS_POINTER";         break;
    case SQLITE_FCNTL_JOURNAL_POINTER:     zOp = "JOURNAL_POINTER";     break;
    case SQLITE_FCNTL_WIN32_GET_HANDLE:    zOp = "WIN32_GET_HANDLE";    break;
    case SQLITE_FCNTL_PDB:                 zOp = "PDB";                 break;
    case SQLITE_FCNTL_BEGIN_ATOMIC_WRITE:  zOp = "BEGIN_ATOMIC_WRITE";  break;
    case SQLITE_FCNTL_COMMIT_ATOMIC_WRITE: zOp = "COMMIT_ATOMIC_WRITE"; break;
    case SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE: {
       zOp = "ROLLBACK_ATOMIC_WRITE";
       break;
    }
    case SQLITE_FCNTL_LOCK_TIMEOUT: {
       sqlite3_snprintf(sizeof(zBuf), zBuf, "LOCK_TIMEOUT,%d", *(int*)pArg);
       zOp = zBuf;
       break;
    }
    case SQLITE_FCNTL_DATA_VERSION:        zOp = "DATA_VERSION";        break;
    case SQLITE_FCNTL_SIZE_LIMIT:          zOp = "SIZE_LIMIT";          break;
    case SQLITE_FCNTL_CKPT_DONE:           zOp = "CKPT_DONE";           break;
    case SQLITE_FCNTL_RESERVE_BYTES:       zOp = "RESERVED_BYTES";      break;
    case SQLITE_FCNTL_CKPT_START:          zOp = "CKPT_START";          break;
    case SQLITE_FCNTL_EXTERNAL_READER:     zOp = "EXTERNAL_READER";     break;
    case SQLITE_FCNTL_CKSM_FILE:           zOp = "CKSM_FILE";           break;
    case SQLITE_FCNTL_RESET_CACHE:         zOp = "RESET_CACHE";         break;
    case 0xca093fa0:                       zOp = "DB_UNCHANGED";        break;
    default: {
      sqlite3_snprintf(sizeof zBuf, zBuf, "%d", op);
      zOp = zBuf;
      break;
    }
  }
  vfstrace_printf(pInfo, "%s.xFileControl(%s,%s)",
                  pInfo->zVfsName, p->zFName, zOp);
  rc = p->pReal->pMethods->xFileControl(p->pReal, op, pArg);
  if( rc==SQLITE_OK ){
    switch( op ){
      case SQLITE_FCNTL_VFSNAME: {
        *(char**)pArg = sqlite3_mprintf("vfstrace.%s/%z",
                                    pInfo->zVfsName, *(char**)pArg);
        zRVal = *(char**)pArg;
        break;
      }
      case SQLITE_FCNTL_MMAP_SIZE: {
        sqlite3_snprintf(sizeof(zBuf2), zBuf2, "%lld", *(sqlite3_int64*)pArg);
        zRVal = zBuf2;
        break;
      }
      case SQLITE_FCNTL_HAS_MOVED:
      case SQLITE_FCNTL_PERSIST_WAL: {
        sqlite3_snprintf(sizeof(zBuf2), zBuf2, "%d", *(int*)pArg);
        zRVal = zBuf2;
        break;
      }
      case SQLITE_FCNTL_PRAGMA:
      case SQLITE_FCNTL_TEMPFILENAME: {
        zRVal = *(char**)pArg;
        break;
      }
    }
  }
  if( zRVal ){
    vfstrace_print_errcode(pInfo, " -> %s", rc);
    vfstrace_printf(pInfo, ", %s\n", zRVal);
  }else{
    vfstrace_print_errcode(pInfo, " -> %s\n", rc);
  }
  return rc;
}

/*
** Return the sector-size in bytes for an vfstrace-file.
*/
static int vfstraceSectorSize(sqlite3_file *pFile){
  vfstrace_file *p = (vfstrace_file *)pFile;
  vfstrace_info *pInfo = p->pInfo;
  int rc;
  vfstrace_printf(pInfo, "%s.xSectorSize(%s)", pInfo->zVfsName, p->zFName);
  rc = p->pReal->pMethods->xSectorSize(p->pReal);
  vfstrace_printf(pInfo, " -> %d\n", rc);
  return rc;
}

/*
** Return the device characteristic flags supported by an vfstrace-file.
*/
static int vfstraceDeviceCharacteristics(sqlite3_file *pFile){
  vfstrace_file *p = (vfstrace_file *)pFile;
  vfstrace_info *pInfo = p->pInfo;
  int rc;
  vfstrace_printf(pInfo, "%s.xDeviceCharacteristics(%s)",
                  pInfo->zVfsName, p->zFName);
  rc = p->pReal->pMethods->xDeviceCharacteristics(p->pReal);
  vfstrace_printf(pInfo, " -> 0x%08x\n", rc);
  return rc;
}

/*
** Shared-memory operations.
*/
static int vfstraceShmLock(sqlite3_file *pFile, int ofst, int n, int flags){
  vfstrace_file *p = (vfstrace_file *)pFile;
  vfstrace_info *pInfo = p->pInfo;
  int rc;
  char zLck[100];
  int i = 0;
  memcpy(zLck, "|0", 3);
  if( flags & SQLITE_SHM_UNLOCK )    strappend(zLck, &i, "|UNLOCK");
  if( flags & SQLITE_SHM_LOCK )      strappend(zLck, &i, "|LOCK");
  if( flags & SQLITE_SHM_SHARED )    strappend(zLck, &i, "|SHARED");
  if( flags & SQLITE_SHM_EXCLUSIVE ) strappend(zLck, &i, "|EXCLUSIVE");
  if( flags & ~(0xf) ){
     sqlite3_snprintf(sizeof(zLck)-i, &zLck[i], "|0x%x", flags);
  }
  vfstrace_printf(pInfo, "%s.xShmLock(%s,ofst=%d,n=%d,%s)",
                  pInfo->zVfsName, p->zFName, ofst, n, &zLck[1]);
  rc = p->pReal->pMethods->xShmLock(p->pReal, ofst, n, flags);
  vfstrace_print_errcode(pInfo, " -> %s\n", rc);
  return rc;
}
static int vfstraceShmMap(
  sqlite3_file *pFile, 
  int iRegion, 
  int szRegion, 
  int isWrite, 
  void volatile **pp
){
  vfstrace_file *p = (vfstrace_file *)pFile;
  vfstrace_info *pInfo = p->pInfo;
  int rc;
  vfstrace_printf(pInfo, "%s.xShmMap(%s,iRegion=%d,szRegion=%d,isWrite=%d,*)",
                  pInfo->zVfsName, p->zFName, iRegion, szRegion, isWrite);
  rc = p->pReal->pMethods->xShmMap(p->pReal, iRegion, szRegion, isWrite, pp);
  vfstrace_print_errcode(pInfo, " -> %s\n", rc);
  return rc;
}
static void vfstraceShmBarrier(sqlite3_file *pFile){
  vfstrace_file *p = (vfstrace_file *)pFile;
  vfstrace_info *pInfo = p->pInfo;
  vfstrace_printf(pInfo, "%s.xShmBarrier(%s)\n", pInfo->zVfsName, p->zFName);
  p->pReal->pMethods->xShmBarrier(p->pReal);
}
static int vfstraceShmUnmap(sqlite3_file *pFile, int delFlag){
  vfstrace_file *p = (vfstrace_file *)pFile;
  vfstrace_info *pInfo = p->pInfo;
  int rc;
  vfstrace_printf(pInfo, "%s.xShmUnmap(%s,delFlag=%d)",
                  pInfo->zVfsName, p->zFName, delFlag);
  rc = p->pReal->pMethods->xShmUnmap(p->pReal, delFlag);
  vfstrace_print_errcode(pInfo, " -> %s\n", rc);
  return rc;
}



/*
** Open an vfstrace file handle.
*/
static int vfstraceOpen(
  sqlite3_vfs *pVfs,
  const char *zName,
  sqlite3_file *pFile,
  int flags,
  int *pOutFlags
){
  int rc;
  vfstrace_file *p = (vfstrace_file *)pFile;
  vfstrace_info *pInfo = (vfstrace_info*)pVfs->pAppData;
  sqlite3_vfs *pRoot = pInfo->pRootVfs;
  p->pInfo = pInfo;
  p->zFName = zName ? fileTail(zName) : "<temp>";
  p->pReal = (sqlite3_file *)&p[1];
  rc = pRoot->xOpen(pRoot, zName, p->pReal, flags, pOutFlags);
  vfstrace_printf(pInfo, "%s.xOpen(%s,flags=0x%x)",
                  pInfo->zVfsName, p->zFName, flags);
  if( p->pReal->pMethods ){
    sqlite3_io_methods *pNew = sqlite3_malloc( sizeof(*pNew) );
    const sqlite3_io_methods *pSub = p->pReal->pMethods;
    memset(pNew, 0, sizeof(*pNew));
    pNew->iVersion = pSub->iVersion;
    pNew->xClose = vfstraceClose;
    pNew->xRead = vfstraceRead;
    pNew->xWrite = vfstraceWrite;
    pNew->xTruncate = vfstraceTruncate;
    pNew->xSync = vfstraceSync;
    pNew->xFileSize = vfstraceFileSize;
    pNew->xLock = vfstraceLock;
    pNew->xUnlock = vfstraceUnlock;
    pNew->xCheckReservedLock = vfstraceCheckReservedLock;
    pNew->xFileControl = vfstraceFileControl;
    pNew->xSectorSize = vfstraceSectorSize;
    pNew->xDeviceCharacteristics = vfstraceDeviceCharacteristics;
    if( pNew->iVersion>=2 ){
      pNew->xShmMap = pSub->xShmMap ? vfstraceShmMap : 0;
      pNew->xShmLock = pSub->xShmLock ? vfstraceShmLock : 0;
      pNew->xShmBarrier = pSub->xShmBarrier ? vfstraceShmBarrier : 0;
      pNew->xShmUnmap = pSub->xShmUnmap ? vfstraceShmUnmap : 0;
    }
    pFile->pMethods = pNew;
  }
  vfstrace_print_errcode(pInfo, " -> %s", rc);
  if( pOutFlags ){
    vfstrace_printf(pInfo, ", outFlags=0x%x\n", *pOutFlags);
  }else{
    vfstrace_printf(pInfo, "\n");
  }
  return rc;
}

/*
** Delete the file located at zPath. If the dirSync argument is true,
** ensure the file-system modifications are synced to disk before
** returning.
*/
static int vfstraceDelete(sqlite3_vfs *pVfs, const char *zPath, int dirSync){
  vfstrace_info *pInfo = (vfstrace_info*)pVfs->pAppData;
  sqlite3_vfs *pRoot = pInfo->pRootVfs;
  int rc;
  vfstrace_printf(pInfo, "%s.xDelete(\"%s\",%d)",
                  pInfo->zVfsName, zPath, dirSync);
  rc = pRoot->xDelete(pRoot, zPath, dirSync);
  vfstrace_print_errcode(pInfo, " -> %s\n", rc);
  return rc;
}

/*
** Test for access permissions. Return true if the requested permission
** is available, or false otherwise.
*/
static int vfstraceAccess(
  sqlite3_vfs *pVfs, 
  const char *zPath, 
  int flags, 
  int *pResOut
){
  vfstrace_info *pInfo = (vfstrace_info*)pVfs->pAppData;
  sqlite3_vfs *pRoot = pInfo->pRootVfs;
  int rc;
  vfstrace_printf(pInfo, "%s.xAccess(\"%s\",%d)",
                  pInfo->zVfsName, zPath, flags);
  rc = pRoot->xAccess(pRoot, zPath, flags, pResOut);
  vfstrace_print_errcode(pInfo, " -> %s", rc);
  vfstrace_printf(pInfo, ", out=%d\n", *pResOut);
  return rc;
}

/*
** Populate buffer zOut with the full canonical pathname corresponding
** to the pathname in zPath. zOut is guaranteed to point to a buffer
** of at least (DEVSYM_MAX_PATHNAME+1) bytes.
*/
static int vfstraceFullPathname(
  sqlite3_vfs *pVfs, 
  const char *zPath, 
  int nOut, 
  char *zOut
){
  vfstrace_info *pInfo = (vfstrace_info*)pVfs->pAppData;
  sqlite3_vfs *pRoot = pInfo->pRootVfs;
  int rc;
  vfstrace_printf(pInfo, "%s.xFullPathname(\"%s\")",
                  pInfo->zVfsName, zPath);
  rc = pRoot->xFullPathname(pRoot, zPath, nOut, zOut);
  vfstrace_print_errcode(pInfo, " -> %s", rc);
  vfstrace_printf(pInfo, ", out=\"%.*s\"\n", nOut, zOut);
  return rc;
}

/*
** Open the dynamic library located at zPath and return a handle.
*/
static void *vfstraceDlOpen(sqlite3_vfs *pVfs, const char *zPath){
  vfstrace_info *pInfo = (vfstrace_info*)pVfs->pAppData;
  sqlite3_vfs *pRoot = pInfo->pRootVfs;
  vfstrace_printf(pInfo, "%s.xDlOpen(\"%s\")\n", pInfo->zVfsName, zPath);
  return pRoot->xDlOpen(pRoot, zPath);
}

/*
** Populate the buffer zErrMsg (size nByte bytes) with a human readable
** utf-8 string describing the most recent error encountered associated 
** with dynamic libraries.
*/
static void vfstraceDlError(sqlite3_vfs *pVfs, int nByte, char *zErrMsg){
  vfstrace_info *pInfo = (vfstrace_info*)pVfs->pAppData;
  sqlite3_vfs *pRoot = pInfo->pRootVfs;
  vfstrace_printf(pInfo, "%s.xDlError(%d)", pInfo->zVfsName, nByte);
  pRoot->xDlError(pRoot, nByte, zErrMsg);
  vfstrace_printf(pInfo, " -> \"%s\"", zErrMsg);
}

/*
** Return a pointer to the symbol zSymbol in the dynamic library pHandle.
*/
static void (*vfstraceDlSym(sqlite3_vfs *pVfs,void *p,const char *zSym))(void){
  vfstrace_info *pInfo = (vfstrace_info*)pVfs->pAppData;
  sqlite3_vfs *pRoot = pInfo->pRootVfs;
  vfstrace_printf(pInfo, "%s.xDlSym(\"%s\")\n", pInfo->zVfsName, zSym);
  return pRoot->xDlSym(pRoot, p, zSym);
}

/*
** Close the dynamic library handle pHandle.
*/
static void vfstraceDlClose(sqlite3_vfs *pVfs, void *pHandle){
  vfstrace_info *pInfo = (vfstrace_info*)pVfs->pAppData;
  sqlite3_vfs *pRoot = pInfo->pRootVfs;
  vfstrace_printf(pInfo, "%s.xDlOpen()\n", pInfo->zVfsName);
  pRoot->xDlClose(pRoot, pHandle);
}

/*
** Populate the buffer pointed to by zBufOut with nByte bytes of 
** random data.
*/
static int vfstraceRandomness(sqlite3_vfs *pVfs, int nByte, char *zBufOut){
  vfstrace_info *pInfo = (vfstrace_info*)pVfs->pAppData;
  sqlite3_vfs *pRoot = pInfo->pRootVfs;
  vfstrace_printf(pInfo, "%s.xRandomness(%d)\n", pInfo->zVfsName, nByte);
  return pRoot->xRandomness(pRoot, nByte, zBufOut);
}

/*
** Sleep for nMicro microseconds. Return the number of microseconds 
** actually slept.
*/
static int vfstraceSleep(sqlite3_vfs *pVfs, int nMicro){
  vfstrace_info *pInfo = (vfstrace_info*)pVfs->pAppData;
  sqlite3_vfs *pRoot = pInfo->pRootVfs;
  return pRoot->xSleep(pRoot, nMicro);
}

/*
** Return the current time as a Julian Day number in *pTimeOut.
*/
static int vfstraceCurrentTime(sqlite3_vfs *pVfs, double *pTimeOut){
  vfstrace_info *pInfo = (vfstrace_info*)pVfs->pAppData;
  sqlite3_vfs *pRoot = pInfo->pRootVfs;
  return pRoot->xCurrentTime(pRoot, pTimeOut);
}
static int vfstraceCurrentTimeInt64(sqlite3_vfs *pVfs, sqlite3_int64 *pTimeOut){
  vfstrace_info *pInfo = (vfstrace_info*)pVfs->pAppData;
  sqlite3_vfs *pRoot = pInfo->pRootVfs;
  return pRoot->xCurrentTimeInt64(pRoot, pTimeOut);
}

/*
** Return th3 most recent error code and message
*/
static int vfstraceGetLastError(sqlite3_vfs *pVfs, int iErr, char *zErr){
  vfstrace_info *pInfo = (vfstrace_info*)pVfs->pAppData;
  sqlite3_vfs *pRoot = pInfo->pRootVfs;
  return pRoot->xGetLastError(pRoot, iErr, zErr);
}

/*
** Override system calls.
*/
static int vfstraceSetSystemCall(
  sqlite3_vfs *pVfs,
  const char *zName,
  sqlite3_syscall_ptr pFunc
){
  vfstrace_info *pInfo = (vfstrace_info*)pVfs->pAppData;
  sqlite3_vfs *pRoot = pInfo->pRootVfs;
  return pRoot->xSetSystemCall(pRoot, zName, pFunc);
}
static sqlite3_syscall_ptr vfstraceGetSystemCall(
  sqlite3_vfs *pVfs,
  const char *zName
){
  vfstrace_info *pInfo = (vfstrace_info*)pVfs->pAppData;
  sqlite3_vfs *pRoot = pInfo->pRootVfs;
  return pRoot->xGetSystemCall(pRoot, zName);
}
static const char *vfstraceNextSystemCall(sqlite3_vfs *pVfs, const char *zName){
  vfstrace_info *pInfo = (vfstrace_info*)pVfs->pAppData;
  sqlite3_vfs *pRoot = pInfo->pRootVfs;
  return pRoot->xNextSystemCall(pRoot, zName);
}


/*
** Clients invoke this routine to construct a new trace-vfs shim.
**
** Return SQLITE_OK on success.  
**
** SQLITE_NOMEM is returned in the case of a memory allocation error.
** SQLITE_NOTFOUND is returned if zOldVfsName does not exist.
*/
int vfstrace_register(
   const char *zTraceName,           /* Name of the newly constructed VFS */
   const char *zOldVfsName,          /* Name of the underlying VFS */
   int (*xOut)(const char*,void*),   /* Output routine.  ex: fputs */
   void *pOutArg,                    /* 2nd argument to xOut.  ex: stderr */
   int makeDefault                   /* True to make the new VFS the default */
){
  sqlite3_vfs *pNew;
  sqlite3_vfs *pRoot;
  vfstrace_info *pInfo;
  size_t nName;
  size_t nByte;

  pRoot = sqlite3_vfs_find(zOldVfsName);
  if( pRoot==0 ) return SQLITE_NOTFOUND;
  nName = strlen(zTraceName);
  nByte = sizeof(*pNew) + sizeof(*pInfo) + nName + 1;
  pNew = sqlite3_malloc64( nByte );
  if( pNew==0 ) return SQLITE_NOMEM;
  memset(pNew, 0, nByte);
  pInfo = (vfstrace_info*)&pNew[1];
  pNew->iVersion = pRoot->iVersion;
  pNew->szOsFile = pRoot->szOsFile + sizeof(vfstrace_file);
  pNew->mxPathname = pRoot->mxPathname;
  pNew->zName = (char*)&pInfo[1];
  memcpy((char*)&pInfo[1], zTraceName, nName+1);
  pNew->pAppData = pInfo;
  pNew->xOpen = vfstraceOpen;
  pNew->xDelete = vfstraceDelete;
  pNew->xAccess = vfstraceAccess;
  pNew->xFullPathname = vfstraceFullPathname;
  pNew->xDlOpen = pRoot->xDlOpen==0 ? 0 : vfstraceDlOpen;
  pNew->xDlError = pRoot->xDlError==0 ? 0 : vfstraceDlError;
  pNew->xDlSym = pRoot->xDlSym==0 ? 0 : vfstraceDlSym;
  pNew->xDlClose = pRoot->xDlClose==0 ? 0 : vfstraceDlClose;
  pNew->xRandomness = vfstraceRandomness;
  pNew->xSleep = vfstraceSleep;
  pNew->xCurrentTime = vfstraceCurrentTime;
  pNew->xGetLastError = pRoot->xGetLastError==0 ? 0 : vfstraceGetLastError;
  if( pNew->iVersion>=2 ){
    pNew->xCurrentTimeInt64 = pRoot->xCurrentTimeInt64==0 ? 0 :
                                   vfstraceCurrentTimeInt64;
    if( pNew->iVersion>=3 ){
      pNew->xSetSystemCall = pRoot->xSetSystemCall==0 ? 0 : 
                                   vfstraceSetSystemCall;
      pNew->xGetSystemCall = pRoot->xGetSystemCall==0 ? 0 : 
                                   vfstraceGetSystemCall;
      pNew->xNextSystemCall = pRoot->xNextSystemCall==0 ? 0 : 
                                   vfstraceNextSystemCall;
    }
  }
  pInfo->pRootVfs = pRoot;
  pInfo->xOut = xOut;
  pInfo->pOutArg = pOutArg;
  pInfo->zVfsName = pNew->zName;
  pInfo->pTraceVfs = pNew;
  vfstrace_printf(pInfo, "%s.enabled_for(\"%s\")\n",
       pInfo->zVfsName, pRoot->zName);
  return sqlite3_vfs_register(pNew, makeDefault);
}

/*
** Look for the named VFS.  If it is a TRACEVFS, then unregister it
** and delete it.
*/
void vfstrace_unregister(const char *zTraceName){
  sqlite3_vfs *pVfs = sqlite3_vfs_find(zTraceName);
  if( pVfs==0 ) return;
  if( pVfs->xOpen!=vfstraceOpen ) return;
  sqlite3_vfs_unregister(pVfs);
  sqlite3_free(pVfs);
}

/************************* End ../ext/misc/vfstrace.c ********************/

#if !defined(SQLITE_OMIT_VIRTUALTABLE) && defined(SQLITE_ENABLE_DBPAGE_VTAB)
#define SQLITE_SHELL_HAVE_RECOVER 1
#else
#define SQLITE_SHELL_HAVE_RECOVER 0
#endif
#if SQLITE_SHELL_HAVE_RECOVER
/************************* Begin ../ext/recover/sqlite3recover.h ******************/
/*
** 2022-08-27
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
**
** This file contains the public interface to the "recover" extension -
** an SQLite extension designed to recover data from corrupted database
** files.
*/

/*
** OVERVIEW:
**
** To use the API to recover data from a corrupted database, an
** application:
**
**   1) Creates an sqlite3_recover handle by calling either
**      sqlite3_recover_init() or sqlite3_recover_init_sql().
**
**   2) Configures the new handle using one or more calls to
**      sqlite3_recover_config().
**
**   3) Executes the recovery by repeatedly calling sqlite3_recover_step() on
**      the handle until it returns something other than SQLITE_OK. If it
**      returns SQLITE_DONE, then the recovery operation completed without 
**      error. If it returns some other non-SQLITE_OK value, then an error 
**      has occurred.
**
**   4) Retrieves any error code and English language error message using the
**      sqlite3_recover_errcode() and sqlite3_recover_errmsg() APIs,
**      respectively.
**
**   5) Destroys the sqlite3_recover handle and frees all resources
**      using sqlite3_recover_finish().
**
** The application may abandon the recovery operation at any point 
** before it is finished by passing the sqlite3_recover handle to
** sqlite3_recover_finish(). This is not an error, but the final state
** of the output database, or the results of running the partial script
** delivered to the SQL callback, are undefined.
*/

#ifndef _SQLITE_RECOVER_H
#define _SQLITE_RECOVER_H

/* #include "sqlite3.h" */

#ifdef __cplusplus
extern "C" {
#endif

/*
** An instance of the sqlite3_recover object represents a recovery
** operation in progress.
**
** Constructors:
**
**    sqlite3_recover_init()
**    sqlite3_recover_init_sql()
**
** Destructor:
**
**    sqlite3_recover_finish()
**
** Methods:
**
**    sqlite3_recover_config()
**    sqlite3_recover_errcode()
**    sqlite3_recover_errmsg()
**    sqlite3_recover_run()
**    sqlite3_recover_step()
*/
typedef struct sqlite3_recover sqlite3_recover;

/* 
** These two APIs attempt to create and return a new sqlite3_recover object.
** In both cases the first two arguments identify the (possibly
** corrupt) database to recover data from. The first argument is an open
** database handle and the second the name of a database attached to that
** handle (i.e. "main", "temp" or the name of an attached database).
**
** If sqlite3_recover_init() is used to create the new sqlite3_recover
** handle, then data is recovered into a new database, identified by
** string parameter zUri. zUri may be an absolute or relative file path,
** or may be an SQLite URI. If the identified database file already exists,
** it is overwritten.
**
** If sqlite3_recover_init_sql() is invoked, then any recovered data will
** be returned to the user as a series of SQL statements. Executing these
** SQL statements results in the same database as would have been created
** had sqlite3_recover_init() been used. For each SQL statement in the
** output, the callback function passed as the third argument (xSql) is 
** invoked once. The first parameter is a passed a copy of the fourth argument
** to this function (pCtx) as its first parameter, and a pointer to a
** nul-terminated buffer containing the SQL statement formated as UTF-8 as 
** the second. If the xSql callback returns any value other than SQLITE_OK,
** then processing is immediately abandoned and the value returned used as
** the recover handle error code (see below).
**
** If an out-of-memory error occurs, NULL may be returned instead of
** a valid handle. In all other cases, it is the responsibility of the
** application to avoid resource leaks by ensuring that
** sqlite3_recover_finish() is called on all allocated handles.
*/
sqlite3_recover *sqlite3_recover_init(
  sqlite3* db, 
  const char *zDb, 
  const char *zUri
);
sqlite3_recover *sqlite3_recover_init_sql(
  sqlite3* db, 
  const char *zDb, 
  int (*xSql)(void*, const char*),
  void *pCtx
);

/*
** Configure an sqlite3_recover object that has just been created using
** sqlite3_recover_init() or sqlite3_recover_init_sql(). This function
** may only be called before the first call to sqlite3_recover_step()
** or sqlite3_recover_run() on the object.
**
** The second argument passed to this function must be one of the
** SQLITE_RECOVER_* symbols defined below. Valid values for the third argument
** depend on the specific SQLITE_RECOVER_* symbol in use.
**
** SQLITE_OK is returned if the configuration operation was successful,
** or an SQLite error code otherwise.
*/
int sqlite3_recover_config(sqlite3_recover*, int op, void *pArg);

/*
** SQLITE_RECOVER_LOST_AND_FOUND:
**   The pArg argument points to a string buffer containing the name
**   of a "lost-and-found" table in the output database, or NULL. If
**   the argument is non-NULL and the database contains seemingly
**   valid pages that cannot be associated with any table in the
**   recovered part of the schema, data is extracted from these
**   pages to add to the lost-and-found table.
**
** SQLITE_RECOVER_FREELIST_CORRUPT:
**   The pArg value must actually be a pointer to a value of type
**   int containing value 0 or 1 cast as a (void*). If this option is set
**   (argument is 1) and a lost-and-found table has been configured using
**   SQLITE_RECOVER_LOST_AND_FOUND, then is assumed that the freelist is 
**   corrupt and an attempt is made to recover records from pages that
**   appear to be linked into the freelist. Otherwise, pages on the freelist
**   are ignored. Setting this option can recover more data from the
**   database, but often ends up "recovering" deleted records. The default 
**   value is 0 (clear).
**
** SQLITE_RECOVER_ROWIDS:
**   The pArg value must actually be a pointer to a value of type
**   int containing value 0 or 1 cast as a (void*). If this option is set
**   (argument is 1), then an attempt is made to recover rowid values
**   that are not also INTEGER PRIMARY KEY values. If this option is
**   clear, then new rowids are assigned to all recovered rows. The
**   default value is 1 (set).
**
** SQLITE_RECOVER_SLOWINDEXES:
**   The pArg value must actually be a pointer to a value of type
**   int containing value 0 or 1 cast as a (void*). If this option is clear
**   (argument is 0), then when creating an output database, the recover 
**   module creates and populates non-UNIQUE indexes right at the end of the
**   recovery operation - after all recoverable data has been inserted
**   into the new database. This is faster overall, but means that the
**   final call to sqlite3_recover_step() for a recovery operation may
**   be need to create a large number of indexes, which may be very slow.
**
**   Or, if this option is set (argument is 1), then non-UNIQUE indexes
**   are created in the output database before it is populated with 
**   recovered data. This is slower overall, but avoids the slow call
**   to sqlite3_recover_step() at the end of the recovery operation.
**
**   The default option value is 0.
*/
#define SQLITE_RECOVER_LOST_AND_FOUND   1
#define SQLITE_RECOVER_FREELIST_CORRUPT 2
#define SQLITE_RECOVER_ROWIDS           3
#define SQLITE_RECOVER_SLOWINDEXES      4

/*
** Perform a unit of work towards the recovery operation. This function 
** must normally be called multiple times to complete database recovery.
**
** If no error occurs but the recovery operation is not completed, this
** function returns SQLITE_OK. If recovery has been completed successfully
** then SQLITE_DONE is returned. If an error has occurred, then an SQLite
** error code (e.g. SQLITE_IOERR or SQLITE_NOMEM) is returned. It is not
** considered an error if some or all of the data cannot be recovered
** due to database corruption.
**
** Once sqlite3_recover_step() has returned a value other than SQLITE_OK,
** all further such calls on the same recover handle are no-ops that return
** the same non-SQLITE_OK value.
*/
int sqlite3_recover_step(sqlite3_recover*);

/* 
** Run the recovery operation to completion. Return SQLITE_OK if successful,
** or an SQLite error code otherwise. Calling this function is the same
** as executing:
**
**     while( SQLITE_OK==sqlite3_recover_step(p) );
**     return sqlite3_recover_errcode(p);
*/
int sqlite3_recover_run(sqlite3_recover*);

/*
** If an error has been encountered during a prior call to
** sqlite3_recover_step(), then this function attempts to return a 
** pointer to a buffer containing an English language explanation of 
** the error. If no error message is available, or if an out-of memory 
** error occurs while attempting to allocate a buffer in which to format
** the error message, NULL is returned.
**
** The returned buffer remains valid until the sqlite3_recover handle is
** destroyed using sqlite3_recover_finish().
*/
const char *sqlite3_recover_errmsg(sqlite3_recover*);

/*
** If this function is called on an sqlite3_recover handle after
** an error occurs, an SQLite error code is returned. Otherwise, SQLITE_OK.
*/
int sqlite3_recover_errcode(sqlite3_recover*);

/* 
** Clean up a recovery object created by a call to sqlite3_recover_init().
** The results of using a recovery object with any API after it has been
** passed to this function are undefined.
**
** This function returns the same value as sqlite3_recover_errcode().
*/
int sqlite3_recover_finish(sqlite3_recover*);


#ifdef __cplusplus
}  /* end of the 'extern "C"' block */
#endif

#endif /* ifndef _SQLITE_RECOVER_H */

/************************* End ../ext/recover/sqlite3recover.h ********************/
# ifndef SQLITE_HAVE_SQLITE3R
/************************* Begin ../ext/recover/dbdata.c ******************/
/*
** 2019-04-17
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
******************************************************************************
**
** This file contains an implementation of two eponymous virtual tables,
** "sqlite_dbdata" and "sqlite_dbptr". Both modules require that the
** "sqlite_dbpage" eponymous virtual table be available.
**
** SQLITE_DBDATA:
**   sqlite_dbdata is used to extract data directly from a database b-tree
**   page and its associated overflow pages, bypassing the b-tree layer.
**   The table schema is equivalent to:
**
**     CREATE TABLE sqlite_dbdata(
**       pgno INTEGER,
**       cell INTEGER,
**       field INTEGER,
**       value ANY,
**       schema TEXT HIDDEN
**     );
**
**   IMPORTANT: THE VIRTUAL TABLE SCHEMA ABOVE IS SUBJECT TO CHANGE. IN THE
**   FUTURE NEW NON-HIDDEN COLUMNS MAY BE ADDED BETWEEN "value" AND
**   "schema".
**
**   Each page of the database is inspected. If it cannot be interpreted as
**   a b-tree page, or if it is a b-tree page containing 0 entries, the
**   sqlite_dbdata table contains no rows for that page.  Otherwise, the
**   table contains one row for each field in the record associated with
**   each cell on the page. For intkey b-trees, the key value is stored in
**   field -1.
**
**   For example, for the database:
**
**     CREATE TABLE t1(a, b);     -- root page is page 2
**     INSERT INTO t1(rowid, a, b) VALUES(5, 'v', 'five');
**     INSERT INTO t1(rowid, a, b) VALUES(10, 'x', 'ten');
**
**   the sqlite_dbdata table contains, as well as from entries related to 
**   page 1, content equivalent to:
**
**     INSERT INTO sqlite_dbdata(pgno, cell, field, value) VALUES
**         (2, 0, -1, 5     ),
**         (2, 0,  0, 'v'   ),
**         (2, 0,  1, 'five'),
**         (2, 1, -1, 10    ),
**         (2, 1,  0, 'x'   ),
**         (2, 1,  1, 'ten' );
**
**   If database corruption is encountered, this module does not report an
**   error. Instead, it attempts to extract as much data as possible and
**   ignores the corruption.
**
** SQLITE_DBPTR:
**   The sqlite_dbptr table has the following schema:
**
**     CREATE TABLE sqlite_dbptr(
**       pgno INTEGER,
**       child INTEGER,
**       schema TEXT HIDDEN
**     );
**
**   It contains one entry for each b-tree pointer between a parent and
**   child page in the database.
*/

#if !defined(SQLITEINT_H) 
/* #include "sqlite3.h" */

/* typedef unsigned char u8; */
/* typedef unsigned int u32; */

#endif
#include <string.h>
#include <assert.h>

#ifndef SQLITE_OMIT_VIRTUALTABLE

#define DBDATA_PADDING_BYTES 100 

typedef struct DbdataTable DbdataTable;
typedef struct DbdataCursor DbdataCursor;
typedef struct DbdataBuffer DbdataBuffer;

/*
** Buffer type.
*/
struct DbdataBuffer {
  u8 *aBuf;
  sqlite3_int64 nBuf;
};

/* Cursor object */
struct DbdataCursor {
  sqlite3_vtab_cursor base;       /* Base class.  Must be first */
  sqlite3_stmt *pStmt;            /* For fetching database pages */

  int iPgno;                      /* Current page number */
  u8 *aPage;                      /* Buffer containing page */
  int nPage;                      /* Size of aPage[] in bytes */
  int nCell;                      /* Number of cells on aPage[] */
  int iCell;                      /* Current cell number */
  int bOnePage;                   /* True to stop after one page */
  int szDb;
  sqlite3_int64 iRowid;

  /* Only for the sqlite_dbdata table */
  DbdataBuffer rec;
  sqlite3_int64 nRec;             /* Size of pRec[] in bytes */
  sqlite3_int64 nHdr;             /* Size of header in bytes */
  int iField;                     /* Current field number */
  u8 *pHdrPtr;
  u8 *pPtr;
  u32 enc;                        /* Text encoding */
  
  sqlite3_int64 iIntkey;          /* Integer key value */
};

/* Table object */
struct DbdataTable {
  sqlite3_vtab base;              /* Base class.  Must be first */
  sqlite3 *db;                    /* The database connection */
  sqlite3_stmt *pStmt;            /* For fetching database pages */
  int bPtr;                       /* True for sqlite3_dbptr table */
};

/* Column and schema definitions for sqlite_dbdata */
#define DBDATA_COLUMN_PGNO        0
#define DBDATA_COLUMN_CELL        1
#define DBDATA_COLUMN_FIELD       2
#define DBDATA_COLUMN_VALUE       3
#define DBDATA_COLUMN_SCHEMA      4
#define DBDATA_SCHEMA             \
      "CREATE TABLE x("           \
      "  pgno INTEGER,"           \
      "  cell INTEGER,"           \
      "  field INTEGER,"          \
      "  value ANY,"              \
      "  schema TEXT HIDDEN"      \
      ")"

/* Column and schema definitions for sqlite_dbptr */
#define DBPTR_COLUMN_PGNO         0
#define DBPTR_COLUMN_CHILD        1
#define DBPTR_COLUMN_SCHEMA       2
#define DBPTR_SCHEMA              \
      "CREATE TABLE x("           \
      "  pgno INTEGER,"           \
      "  child INTEGER,"          \
      "  schema TEXT HIDDEN"      \
      ")"

/*
** Ensure the buffer passed as the first argument is at least nMin bytes
** in size. If an error occurs while attempting to resize the buffer,
** SQLITE_NOMEM is returned. Otherwise, SQLITE_OK.
*/
static int dbdataBufferSize(DbdataBuffer *pBuf, sqlite3_int64 nMin){
  if( nMin>pBuf->nBuf ){
    sqlite3_int64 nNew = nMin+16384;
    u8 *aNew = (u8*)sqlite3_realloc64(pBuf->aBuf, nNew);

    if( aNew==0 ) return SQLITE_NOMEM;
    pBuf->aBuf = aNew;
    pBuf->nBuf = nNew;
  }
  return SQLITE_OK;
}

/*
** Release the allocation managed by buffer pBuf.
*/
static void dbdataBufferFree(DbdataBuffer *pBuf){
  sqlite3_free(pBuf->aBuf);
  memset(pBuf, 0, sizeof(*pBuf));
}

/*
** Connect to an sqlite_dbdata (pAux==0) or sqlite_dbptr (pAux!=0) virtual 
** table.
*/
static int dbdataConnect(
  sqlite3 *db,
  void *pAux,
  int argc, const char *const*argv,
  sqlite3_vtab **ppVtab,
  char **pzErr
){
  DbdataTable *pTab = 0;
  int rc = sqlite3_declare_vtab(db, pAux ? DBPTR_SCHEMA : DBDATA_SCHEMA);

  (void)argc;
  (void)argv;
  (void)pzErr;
  sqlite3_vtab_config(db, SQLITE_VTAB_USES_ALL_SCHEMAS);
  if( rc==SQLITE_OK ){
    pTab = (DbdataTable*)sqlite3_malloc64(sizeof(DbdataTable));
    if( pTab==0 ){
      rc = SQLITE_NOMEM;
    }else{
      memset(pTab, 0, sizeof(DbdataTable));
      pTab->db = db;
      pTab->bPtr = (pAux!=0);
    }
  }

  *ppVtab = (sqlite3_vtab*)pTab;
  return rc;
}

/*
** Disconnect from or destroy a sqlite_dbdata or sqlite_dbptr virtual table.
*/
static int dbdataDisconnect(sqlite3_vtab *pVtab){
  DbdataTable *pTab = (DbdataTable*)pVtab;
  if( pTab ){
    sqlite3_finalize(pTab->pStmt);
    sqlite3_free(pVtab);
  }
  return SQLITE_OK;
}

/*
** This function interprets two types of constraints:
**
**       schema=?
**       pgno=?
**
** If neither are present, idxNum is set to 0. If schema=? is present,
** the 0x01 bit in idxNum is set. If pgno=? is present, the 0x02 bit
** in idxNum is set.
**
** If both parameters are present, schema is in position 0 and pgno in
** position 1.
*/
static int dbdataBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdx){
  DbdataTable *pTab = (DbdataTable*)tab;
  int i;
  int iSchema = -1;
  int iPgno = -1;
  int colSchema = (pTab->bPtr ? DBPTR_COLUMN_SCHEMA : DBDATA_COLUMN_SCHEMA);

  for(i=0; i<pIdx->nConstraint; i++){
    struct sqlite3_index_constraint *p = &pIdx->aConstraint[i];
    if( p->op==SQLITE_INDEX_CONSTRAINT_EQ ){
      if( p->iColumn==colSchema ){
        if( p->usable==0 ) return SQLITE_CONSTRAINT;
        iSchema = i;
      }
      if( p->iColumn==DBDATA_COLUMN_PGNO && p->usable ){
        iPgno = i;
      }
    }
  }

  if( iSchema>=0 ){
    pIdx->aConstraintUsage[iSchema].argvIndex = 1;
    pIdx->aConstraintUsage[iSchema].omit = 1;
  }
  if( iPgno>=0 ){
    pIdx->aConstraintUsage[iPgno].argvIndex = 1 + (iSchema>=0);
    pIdx->aConstraintUsage[iPgno].omit = 1;
    pIdx->estimatedCost = 100;
    pIdx->estimatedRows =  50;

    if( pTab->bPtr==0 && pIdx->nOrderBy && pIdx->aOrderBy[0].desc==0 ){
      int iCol = pIdx->aOrderBy[0].iColumn;
      if( pIdx->nOrderBy==1 ){
        pIdx->orderByConsumed = (iCol==0 || iCol==1);
      }else if( pIdx->nOrderBy==2 && pIdx->aOrderBy[1].desc==0 && iCol==0 ){
        pIdx->orderByConsumed = (pIdx->aOrderBy[1].iColumn==1);
      }
    }

  }else{
    pIdx->estimatedCost = 100000000;
    pIdx->estimatedRows = 1000000000;
  }
  pIdx->idxNum = (iSchema>=0 ? 0x01 : 0x00) | (iPgno>=0 ? 0x02 : 0x00);
  return SQLITE_OK;
}

/*
** Open a new sqlite_dbdata or sqlite_dbptr cursor.
*/
static int dbdataOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){
  DbdataCursor *pCsr;

  pCsr = (DbdataCursor*)sqlite3_malloc64(sizeof(DbdataCursor));
  if( pCsr==0 ){
    return SQLITE_NOMEM;
  }else{
    memset(pCsr, 0, sizeof(DbdataCursor));
    pCsr->base.pVtab = pVTab;
  }

  *ppCursor = (sqlite3_vtab_cursor *)pCsr;
  return SQLITE_OK;
}

/*
** Restore a cursor object to the state it was in when first allocated 
** by dbdataOpen().
*/
static void dbdataResetCursor(DbdataCursor *pCsr){
  DbdataTable *pTab = (DbdataTable*)(pCsr->base.pVtab);
  if( pTab->pStmt==0 ){
    pTab->pStmt = pCsr->pStmt;
  }else{
    sqlite3_finalize(pCsr->pStmt);
  }
  pCsr->pStmt = 0;
  pCsr->iPgno = 1;
  pCsr->iCell = 0;
  pCsr->iField = 0;
  pCsr->bOnePage = 0;
  sqlite3_free(pCsr->aPage);
  dbdataBufferFree(&pCsr->rec);
  pCsr->aPage = 0;
  pCsr->nRec = 0;
}

/*
** Close an sqlite_dbdata or sqlite_dbptr cursor.
*/
static int dbdataClose(sqlite3_vtab_cursor *pCursor){
  DbdataCursor *pCsr = (DbdataCursor*)pCursor;
  dbdataResetCursor(pCsr);
  sqlite3_free(pCsr);
  return SQLITE_OK;
}

/* 
** Utility methods to decode 16 and 32-bit big-endian unsigned integers. 
*/
static u32 get_uint16(unsigned char *a){
  return (a[0]<<8)|a[1];
}
static u32 get_uint32(unsigned char *a){
  return ((u32)a[0]<<24)
       | ((u32)a[1]<<16)
       | ((u32)a[2]<<8)
       | ((u32)a[3]);
}

/*
** Load page pgno from the database via the sqlite_dbpage virtual table.
** If successful, set (*ppPage) to point to a buffer containing the page
** data, (*pnPage) to the size of that buffer in bytes and return
** SQLITE_OK. In this case it is the responsibility of the caller to
** eventually free the buffer using sqlite3_free().
**
** Or, if an error occurs, set both (*ppPage) and (*pnPage) to 0 and
** return an SQLite error code.
*/
static int dbdataLoadPage(
  DbdataCursor *pCsr,             /* Cursor object */
  u32 pgno,                       /* Page number of page to load */
  u8 **ppPage,                    /* OUT: pointer to page buffer */
  int *pnPage                     /* OUT: Size of (*ppPage) in bytes */
){
  int rc2;
  int rc = SQLITE_OK;
  sqlite3_stmt *pStmt = pCsr->pStmt;

  *ppPage = 0;
  *pnPage = 0;
  if( pgno>0 ){
    sqlite3_bind_int64(pStmt, 2, pgno);
    if( SQLITE_ROW==sqlite3_step(pStmt) ){
      int nCopy = sqlite3_column_bytes(pStmt, 0);
      if( nCopy>0 ){
        u8 *pPage;
        pPage = (u8*)sqlite3_malloc64(nCopy + DBDATA_PADDING_BYTES);
        if( pPage==0 ){
          rc = SQLITE_NOMEM;
        }else{
          const u8 *pCopy = sqlite3_column_blob(pStmt, 0);
          memcpy(pPage, pCopy, nCopy);
          memset(&pPage[nCopy], 0, DBDATA_PADDING_BYTES);
        }
        *ppPage = pPage;
        *pnPage = nCopy;
      }
    }
    rc2 = sqlite3_reset(pStmt);
    if( rc==SQLITE_OK ) rc = rc2;
  }

  return rc;
}

/*
** Read a varint.  Put the value in *pVal and return the number of bytes.
*/
static int dbdataGetVarint(const u8 *z, sqlite3_int64 *pVal){
  sqlite3_uint64 u = 0;
  int i;
  for(i=0; i<8; i++){
    u = (u<<7) + (z[i]&0x7f);
    if( (z[i]&0x80)==0 ){ *pVal = (sqlite3_int64)u; return i+1; }
  }
  u = (u<<8) + (z[i]&0xff);
  *pVal = (sqlite3_int64)u;
  return 9;
}

/*
** Like dbdataGetVarint(), but set the output to 0 if it is less than 0
** or greater than 0xFFFFFFFF. This can be used for all varints in an
** SQLite database except for key values in intkey tables.
*/
static int dbdataGetVarintU32(const u8 *z, sqlite3_int64 *pVal){
  sqlite3_int64 val;
  int nRet = dbdataGetVarint(z, &val);
  if( val<0 || val>0xFFFFFFFF ) val = 0;
  *pVal = val;
  return nRet;
}

/*
** Return the number of bytes of space used by an SQLite value of type
** eType.
*/
static int dbdataValueBytes(int eType){
  switch( eType ){
    case 0: case 8: case 9:
    case 10: case 11:
      return 0;
    case 1:
      return 1;
    case 2:
      return 2;
    case 3:
      return 3;
    case 4:
      return 4;
    case 5:
      return 6;
    case 6:
    case 7:
      return 8;
    default:
      if( eType>0 ){
        return ((eType-12) / 2);
      }
      return 0;
  }
}

/*
** Load a value of type eType from buffer pData and use it to set the
** result of context object pCtx.
*/
static void dbdataValue(
  sqlite3_context *pCtx, 
  u32 enc,
  int eType, 
  u8 *pData,
  sqlite3_int64 nData
){
  if( eType>=0 ){
    if( dbdataValueBytes(eType)<=nData ){
      switch( eType ){
        case 0: 
        case 10: 
        case 11: 
          sqlite3_result_null(pCtx);
          break;
        
        case 8: 
          sqlite3_result_int(pCtx, 0);
          break;
        case 9:
          sqlite3_result_int(pCtx, 1);
          break;
    
        case 1: case 2: case 3: case 4: case 5: case 6: case 7: {
          sqlite3_uint64 v = (signed char)pData[0];
          pData++;
          switch( eType ){
            case 7:
            case 6:  v = (v<<16) + (pData[0]<<8) + pData[1];  pData += 2;
            case 5:  v = (v<<16) + (pData[0]<<8) + pData[1];  pData += 2;
            case 4:  v = (v<<8) + pData[0];  pData++;
            case 3:  v = (v<<8) + pData[0];  pData++;
            case 2:  v = (v<<8) + pData[0];  pData++;
          }
    
          if( eType==7 ){
            double r;
            memcpy(&r, &v, sizeof(r));
            sqlite3_result_double(pCtx, r);
          }else{
            sqlite3_result_int64(pCtx, (sqlite3_int64)v);
          }
          break;
        }
    
        default: {
          int n = ((eType-12) / 2);
          if( eType % 2 ){
            switch( enc ){
  #ifndef SQLITE_OMIT_UTF16
              case SQLITE_UTF16BE:
                sqlite3_result_text16be(pCtx, (void*)pData, n, SQLITE_TRANSIENT);
                break;
              case SQLITE_UTF16LE:
                sqlite3_result_text16le(pCtx, (void*)pData, n, SQLITE_TRANSIENT);
                break;
  #endif
              default:
                sqlite3_result_text(pCtx, (char*)pData, n, SQLITE_TRANSIENT);
                break;
            }
          }else{
            sqlite3_result_blob(pCtx, pData, n, SQLITE_TRANSIENT);
          }
        }
      }
    }else{
      if( eType==7 ){
        sqlite3_result_double(pCtx, 0.0);
      }else if( eType<7 ){
        sqlite3_result_int(pCtx, 0);
      }else if( eType%2 ){
        sqlite3_result_text(pCtx, "", 0, SQLITE_STATIC);
      }else{
        sqlite3_result_blob(pCtx, "", 0, SQLITE_STATIC);
      }
    }
  }
}

/* This macro is a copy of the MX_CELL() macro in the SQLite core. Given
** a page-size, it returns the maximum number of cells that may be present
** on the page.  */
#define DBDATA_MX_CELL(pgsz) ((pgsz-8)/6)

/* Maximum number of fields that may appear in a single record. This is
** the "hard-limit", according to comments in sqliteLimit.h. */
#define DBDATA_MX_FIELD 32676

/*
** Move an sqlite_dbdata or sqlite_dbptr cursor to the next entry.
*/
static int dbdataNext(sqlite3_vtab_cursor *pCursor){
  DbdataCursor *pCsr = (DbdataCursor*)pCursor;
  DbdataTable *pTab = (DbdataTable*)pCursor->pVtab;

  pCsr->iRowid++;
  while( 1 ){
    int rc;
    int iOff = (pCsr->iPgno==1 ? 100 : 0);
    int bNextPage = 0;

    if( pCsr->aPage==0 ){
      while( 1 ){
        if( pCsr->bOnePage==0 && pCsr->iPgno>pCsr->szDb ) return SQLITE_OK;
        rc = dbdataLoadPage(pCsr, pCsr->iPgno, &pCsr->aPage, &pCsr->nPage);
        if( rc!=SQLITE_OK ) return rc;
        if( pCsr->aPage && pCsr->nPage>=256 ) break;
        sqlite3_free(pCsr->aPage);
        pCsr->aPage = 0;
        if( pCsr->bOnePage ) return SQLITE_OK;
        pCsr->iPgno++;
      }

      assert( iOff+3+2<=pCsr->nPage );
      pCsr->iCell = pTab->bPtr ? -2 : 0;
      pCsr->nCell = get_uint16(&pCsr->aPage[iOff+3]);
      if( pCsr->nCell>DBDATA_MX_CELL(pCsr->nPage) ){
        pCsr->nCell = DBDATA_MX_CELL(pCsr->nPage);
      }
    }

    if( pTab->bPtr ){
      if( pCsr->aPage[iOff]!=0x02 && pCsr->aPage[iOff]!=0x05 ){
        pCsr->iCell = pCsr->nCell;
      }
      pCsr->iCell++;
      if( pCsr->iCell>=pCsr->nCell ){
        sqlite3_free(pCsr->aPage);
        pCsr->aPage = 0;
        if( pCsr->bOnePage ) return SQLITE_OK;
        pCsr->iPgno++;
      }else{
        return SQLITE_OK;
      }
    }else{
      /* If there is no record loaded, load it now. */
      assert( pCsr->rec.aBuf!=0 || pCsr->nRec==0 );
      if( pCsr->nRec==0 ){
        int bHasRowid = 0;
        int nPointer = 0;
        sqlite3_int64 nPayload = 0;
        sqlite3_int64 nHdr = 0;
        int iHdr;
        int U, X;
        int nLocal;
  
        switch( pCsr->aPage[iOff] ){
          case 0x02:
            nPointer = 4;
            break;
          case 0x0a:
            break;
          case 0x0d:
            bHasRowid = 1;
            break;
          default:
            /* This is not a b-tree page with records on it. Continue. */
            pCsr->iCell = pCsr->nCell;
            break;
        }

        if( pCsr->iCell>=pCsr->nCell ){
          bNextPage = 1;
        }else{
          int iCellPtr = iOff + 8 + nPointer + pCsr->iCell*2;
  
          if( iCellPtr>pCsr->nPage ){
            bNextPage = 1;
          }else{
            iOff = get_uint16(&pCsr->aPage[iCellPtr]);
          }
    
          /* For an interior node cell, skip past the child-page number */
          iOff += nPointer;
    
          /* Load the "byte of payload including overflow" field */
          if( bNextPage || iOff>pCsr->nPage || iOff<=iCellPtr ){
            bNextPage = 1;
          }else{
            iOff += dbdataGetVarintU32(&pCsr->aPage[iOff], &nPayload);
            if( nPayload>0x7fffff00 ) nPayload &= 0x3fff;
            if( nPayload==0 ) nPayload = 1;
          }
    
          /* If this is a leaf intkey cell, load the rowid */
          if( bHasRowid && !bNextPage && iOff<pCsr->nPage ){
            iOff += dbdataGetVarint(&pCsr->aPage[iOff], &pCsr->iIntkey);
          }
    
          /* Figure out how much data to read from the local page */
          U = pCsr->nPage;
          if( bHasRowid ){
            X = U-35;
          }else{
            X = ((U-12)*64/255)-23;
          }
          if( nPayload<=X ){
            nLocal = nPayload;
          }else{
            int M, K;
            M = ((U-12)*32/255)-23;
            K = M+((nPayload-M)%(U-4));
            if( K<=X ){
              nLocal = K;
            }else{
              nLocal = M;
            }
          }

          if( bNextPage || nLocal+iOff>pCsr->nPage ){
            bNextPage = 1;
          }else{

            /* Allocate space for payload. And a bit more to catch small buffer
            ** overruns caused by attempting to read a varint or similar from 
            ** near the end of a corrupt record.  */
            rc = dbdataBufferSize(&pCsr->rec, nPayload+DBDATA_PADDING_BYTES);
            if( rc!=SQLITE_OK ) return rc;
            assert( pCsr->rec.aBuf!=0 );
            assert( nPayload!=0 );

            /* Load the nLocal bytes of payload */
            memcpy(pCsr->rec.aBuf, &pCsr->aPage[iOff], nLocal);
            iOff += nLocal;

            /* Load content from overflow pages */
            if( nPayload>nLocal ){
              sqlite3_int64 nRem = nPayload - nLocal;
              u32 pgnoOvfl = get_uint32(&pCsr->aPage[iOff]);
              while( nRem>0 ){
                u8 *aOvfl = 0;
                int nOvfl = 0;
                int nCopy;
                rc = dbdataLoadPage(pCsr, pgnoOvfl, &aOvfl, &nOvfl);
                assert( rc!=SQLITE_OK || aOvfl==0 || nOvfl==pCsr->nPage );
                if( rc!=SQLITE_OK ) return rc;
                if( aOvfl==0 ) break;

                nCopy = U-4;
                if( nCopy>nRem ) nCopy = nRem;
                memcpy(&pCsr->rec.aBuf[nPayload-nRem], &aOvfl[4], nCopy);
                nRem -= nCopy;

                pgnoOvfl = get_uint32(aOvfl);
                sqlite3_free(aOvfl);
              }
              nPayload -= nRem;
            }
            memset(&pCsr->rec.aBuf[nPayload], 0, DBDATA_PADDING_BYTES);
            pCsr->nRec = nPayload;
    
            iHdr = dbdataGetVarintU32(pCsr->rec.aBuf, &nHdr);
            if( nHdr>nPayload ) nHdr = 0;
            pCsr->nHdr = nHdr;
            pCsr->pHdrPtr = &pCsr->rec.aBuf[iHdr];
            pCsr->pPtr = &pCsr->rec.aBuf[pCsr->nHdr];
            pCsr->iField = (bHasRowid ? -1 : 0);
          }
        }
      }else{
        pCsr->iField++;
        if( pCsr->iField>0 ){
          sqlite3_int64 iType;
          if( pCsr->pHdrPtr>=&pCsr->rec.aBuf[pCsr->nRec] 
           || pCsr->iField>=DBDATA_MX_FIELD
          ){
            bNextPage = 1;
          }else{
            int szField = 0;
            pCsr->pHdrPtr += dbdataGetVarintU32(pCsr->pHdrPtr, &iType);
            szField = dbdataValueBytes(iType);
            if( (pCsr->nRec - (pCsr->pPtr - pCsr->rec.aBuf))<szField ){
              pCsr->pPtr = &pCsr->rec.aBuf[pCsr->nRec];
            }else{
              pCsr->pPtr += szField;
            }
          }
        }
      }

      if( bNextPage ){
        sqlite3_free(pCsr->aPage);
        pCsr->aPage = 0;
        pCsr->nRec = 0;
        if( pCsr->bOnePage ) return SQLITE_OK;
        pCsr->iPgno++;
      }else{
        if( pCsr->iField<0 || pCsr->pHdrPtr<&pCsr->rec.aBuf[pCsr->nHdr] ){
          return SQLITE_OK;
        }

        /* Advance to the next cell. The next iteration of the loop will load
        ** the record and so on. */
        pCsr->nRec = 0;
        pCsr->iCell++;
      }
    }
  }

  assert( !"can't get here" );
  return SQLITE_OK;
}

/* 
** Return true if the cursor is at EOF.
*/
static int dbdataEof(sqlite3_vtab_cursor *pCursor){
  DbdataCursor *pCsr = (DbdataCursor*)pCursor;
  return pCsr->aPage==0;
}

/*
** Return true if nul-terminated string zSchema ends in "()". Or false
** otherwise.
*/
static int dbdataIsFunction(const char *zSchema){
  size_t n = strlen(zSchema);
  if( n>2 && zSchema[n-2]=='(' && zSchema[n-1]==')' ){
    return (int)n-2;
  }
  return 0;
}

/* 
** Determine the size in pages of database zSchema (where zSchema is
** "main", "temp" or the name of an attached database) and set 
** pCsr->szDb accordingly. If successful, return SQLITE_OK. Otherwise,
** an SQLite error code.
*/
static int dbdataDbsize(DbdataCursor *pCsr, const char *zSchema){
  DbdataTable *pTab = (DbdataTable*)pCsr->base.pVtab;
  char *zSql = 0;
  int rc, rc2;
  int nFunc = 0;
  sqlite3_stmt *pStmt = 0;

  if( (nFunc = dbdataIsFunction(zSchema))>0 ){
    zSql = sqlite3_mprintf("SELECT %.*s(0)", nFunc, zSchema);
  }else{
    zSql = sqlite3_mprintf("PRAGMA %Q.page_count", zSchema);
  }
  if( zSql==0 ) return SQLITE_NOMEM;

  rc = sqlite3_prepare_v2(pTab->db, zSql, -1, &pStmt, 0);
  sqlite3_free(zSql);
  if( rc==SQLITE_OK && sqlite3_step(pStmt)==SQLITE_ROW ){
    pCsr->szDb = sqlite3_column_int(pStmt, 0);
  }
  rc2 = sqlite3_finalize(pStmt);
  if( rc==SQLITE_OK ) rc = rc2;
  return rc;
}

/*
** Attempt to figure out the encoding of the database by retrieving page 1
** and inspecting the header field. If successful, set the pCsr->enc variable
** and return SQLITE_OK. Otherwise, return an SQLite error code.
*/
static int dbdataGetEncoding(DbdataCursor *pCsr){
  int rc = SQLITE_OK;
  int nPg1 = 0;
  u8 *aPg1 = 0;
  rc = dbdataLoadPage(pCsr, 1, &aPg1, &nPg1);
  if( rc==SQLITE_OK && nPg1>=(56+4) ){
    pCsr->enc = get_uint32(&aPg1[56]);
  }
  sqlite3_free(aPg1);
  return rc;
}


/* 
** xFilter method for sqlite_dbdata and sqlite_dbptr.
*/
static int dbdataFilter(
  sqlite3_vtab_cursor *pCursor, 
  int idxNum, const char *idxStr,
  int argc, sqlite3_value **argv
){
  DbdataCursor *pCsr = (DbdataCursor*)pCursor;
  DbdataTable *pTab = (DbdataTable*)pCursor->pVtab;
  int rc = SQLITE_OK;
  const char *zSchema = "main";
  (void)idxStr;
  (void)argc;

  dbdataResetCursor(pCsr);
  assert( pCsr->iPgno==1 );
  if( idxNum & 0x01 ){
    zSchema = (const char*)sqlite3_value_text(argv[0]);
    if( zSchema==0 ) zSchema = "";
  }
  if( idxNum & 0x02 ){
    pCsr->iPgno = sqlite3_value_int(argv[(idxNum & 0x01)]);
    pCsr->bOnePage = 1;
  }else{
    rc = dbdataDbsize(pCsr, zSchema);
  }

  if( rc==SQLITE_OK ){
    int nFunc = 0;
    if( pTab->pStmt ){
      pCsr->pStmt = pTab->pStmt;
      pTab->pStmt = 0;
    }else if( (nFunc = dbdataIsFunction(zSchema))>0 ){
      char *zSql = sqlite3_mprintf("SELECT %.*s(?2)", nFunc, zSchema);
      if( zSql==0 ){
        rc = SQLITE_NOMEM;
      }else{
        rc = sqlite3_prepare_v2(pTab->db, zSql, -1, &pCsr->pStmt, 0);
        sqlite3_free(zSql);
      }
    }else{
      rc = sqlite3_prepare_v2(pTab->db, 
          "SELECT data FROM sqlite_dbpage(?) WHERE pgno=?", -1,
          &pCsr->pStmt, 0
      );
    }
  }
  if( rc==SQLITE_OK ){
    rc = sqlite3_bind_text(pCsr->pStmt, 1, zSchema, -1, SQLITE_TRANSIENT);
  }

  /* Try to determine the encoding of the db by inspecting the header
  ** field on page 1. */
  if( rc==SQLITE_OK ){
    rc = dbdataGetEncoding(pCsr);
  }

  if( rc!=SQLITE_OK ){
    pTab->base.zErrMsg = sqlite3_mprintf("%s", sqlite3_errmsg(pTab->db));
  }

  if( rc==SQLITE_OK ){
    rc = dbdataNext(pCursor);
  }
  return rc;
}

/*
** Return a column for the sqlite_dbdata or sqlite_dbptr table.
*/
static int dbdataColumn(
  sqlite3_vtab_cursor *pCursor, 
  sqlite3_context *ctx, 
  int i
){
  DbdataCursor *pCsr = (DbdataCursor*)pCursor;
  DbdataTable *pTab = (DbdataTable*)pCursor->pVtab;
  if( pTab->bPtr ){
    switch( i ){
      case DBPTR_COLUMN_PGNO:
        sqlite3_result_int64(ctx, pCsr->iPgno);
        break;
      case DBPTR_COLUMN_CHILD: {
        int iOff = pCsr->iPgno==1 ? 100 : 0;
        if( pCsr->iCell<0 ){
          iOff += 8;
        }else{
          iOff += 12 + pCsr->iCell*2;
          if( iOff>pCsr->nPage ) return SQLITE_OK;
          iOff = get_uint16(&pCsr->aPage[iOff]);
        }
        if( iOff<=pCsr->nPage ){
          sqlite3_result_int64(ctx, get_uint32(&pCsr->aPage[iOff]));
        }
        break;
      }
    }
  }else{
    switch( i ){
      case DBDATA_COLUMN_PGNO:
        sqlite3_result_int64(ctx, pCsr->iPgno);
        break;
      case DBDATA_COLUMN_CELL:
        sqlite3_result_int(ctx, pCsr->iCell);
        break;
      case DBDATA_COLUMN_FIELD:
        sqlite3_result_int(ctx, pCsr->iField);
        break;
      case DBDATA_COLUMN_VALUE: {
        if( pCsr->iField<0 ){
          sqlite3_result_int64(ctx, pCsr->iIntkey);
        }else if( &pCsr->rec.aBuf[pCsr->nRec] >= pCsr->pPtr ){
          sqlite3_int64 iType;
          dbdataGetVarintU32(pCsr->pHdrPtr, &iType);
          dbdataValue(
              ctx, pCsr->enc, iType, pCsr->pPtr, 
              &pCsr->rec.aBuf[pCsr->nRec] - pCsr->pPtr
          );
        }
        break;
      }
    }
  }
  return SQLITE_OK;
}

/* 
** Return the rowid for an sqlite_dbdata or sqlite_dptr table.
*/
static int dbdataRowid(sqlite3_vtab_cursor *pCursor, sqlite_int64 *pRowid){
  DbdataCursor *pCsr = (DbdataCursor*)pCursor;
  *pRowid = pCsr->iRowid;
  return SQLITE_OK;
}


/*
** Invoke this routine to register the "sqlite_dbdata" virtual table module
*/
static int sqlite3DbdataRegister(sqlite3 *db){
  static sqlite3_module dbdata_module = {
    0,                            /* iVersion */
    0,                            /* xCreate */
    dbdataConnect,                /* xConnect */
    dbdataBestIndex,              /* xBestIndex */
    dbdataDisconnect,             /* xDisconnect */
    0,                            /* xDestroy */
    dbdataOpen,                   /* xOpen - open a cursor */
    dbdataClose,                  /* xClose - close a cursor */
    dbdataFilter,                 /* xFilter - configure scan constraints */
    dbdataNext,                   /* xNext - advance a cursor */
    dbdataEof,                    /* xEof - check for end of scan */
    dbdataColumn,                 /* xColumn - read data */
    dbdataRowid,                  /* xRowid - read data */
    0,                            /* xUpdate */
    0,                            /* xBegin */
    0,                            /* xSync */
    0,                            /* xCommit */
    0,                            /* xRollback */
    0,                            /* xFindMethod */
    0,                            /* xRename */
    0,                            /* xSavepoint */
    0,                            /* xRelease */
    0,                            /* xRollbackTo */
    0,                            /* xShadowName */
    0                             /* xIntegrity */
  };

  int rc = sqlite3_create_module(db, "sqlite_dbdata", &dbdata_module, 0);
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_module(db, "sqlite_dbptr", &dbdata_module, (void*)1);
  }
  return rc;
}

int sqlite3_dbdata_init(
  sqlite3 *db, 
  char **pzErrMsg, 
  const sqlite3_api_routines *pApi
){
  (void)pzErrMsg;
  return sqlite3DbdataRegister(db);
}

#endif /* ifndef SQLITE_OMIT_VIRTUALTABLE */

/************************* End ../ext/recover/dbdata.c ********************/
/************************* Begin ../ext/recover/sqlite3recover.c ******************/
/*
** 2022-08-27
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
**
*/


/* #include "sqlite3recover.h" */
#include <assert.h>
#include <string.h>

#ifndef SQLITE_OMIT_VIRTUALTABLE

/*
** Declaration for public API function in file dbdata.c. This may be called
** with NULL as the final two arguments to register the sqlite_dbptr and
** sqlite_dbdata virtual tables with a database handle.
*/
#ifdef _WIN32

#endif
int sqlite3_dbdata_init(sqlite3*, char**, const sqlite3_api_routines*);

/* typedef unsigned int u32; */
/* typedef unsigned char u8; */
/* typedef sqlite3_int64 i64; */

typedef struct RecoverTable RecoverTable;
typedef struct RecoverColumn RecoverColumn;

/*
** When recovering rows of data that can be associated with table
** definitions recovered from the sqlite_schema table, each table is
** represented by an instance of the following object.
**
** iRoot:
**   The root page in the original database. Not necessarily (and usually
**   not) the same in the recovered database.
**
** zTab:
**   Name of the table.
**
** nCol/aCol[]:
**   aCol[] is an array of nCol columns. In the order in which they appear 
**   in the table.
**
** bIntkey:
**   Set to true for intkey tables, false for WITHOUT ROWID.
**
** iRowidBind:
**   Each column in the aCol[] array has associated with it the index of
**   the bind parameter its values will be bound to in the INSERT statement
**   used to construct the output database. If the table does has a rowid
**   but not an INTEGER PRIMARY KEY column, then iRowidBind contains the
**   index of the bind paramater to which the rowid value should be bound.
**   Otherwise, it contains -1. If the table does contain an INTEGER PRIMARY 
**   KEY column, then the rowid value should be bound to the index associated
**   with the column.
**
** pNext:
**   All RecoverTable objects used by the recovery operation are allocated
**   and populated as part of creating the recovered database schema in
**   the output database, before any non-schema data are recovered. They
**   are then stored in a singly-linked list linked by this variable beginning
**   at sqlite3_recover.pTblList.
*/
struct RecoverTable {
  u32 iRoot;                      /* Root page in original database */
  char *zTab;                     /* Name of table */
  int nCol;                       /* Number of columns in table */
  RecoverColumn *aCol;            /* Array of columns */
  int bIntkey;                    /* True for intkey, false for without rowid */
  int iRowidBind;                 /* If >0, bind rowid to INSERT here */
  RecoverTable *pNext;
};

/*
** Each database column is represented by an instance of the following object
** stored in the RecoverTable.aCol[] array of the associated table.
**
** iField:
**   The index of the associated field within database records. Or -1 if
**   there is no associated field (e.g. for virtual generated columns).
**
** iBind:
**   The bind index of the INSERT statement to bind this columns values
**   to. Or 0 if there is no such index (iff (iField<0)).
**
** bIPK:
**   True if this is the INTEGER PRIMARY KEY column.
**
** zCol:
**   Name of column.
**
** eHidden:
**   A RECOVER_EHIDDEN_* constant value (see below for interpretation of each).
*/
struct RecoverColumn {
  int iField;                     /* Field in record on disk */
  int iBind;                      /* Binding to use in INSERT */
  int bIPK;                       /* True for IPK column */
  char *zCol;
  int eHidden;
};

#define RECOVER_EHIDDEN_NONE    0      /* Normal database column */
#define RECOVER_EHIDDEN_HIDDEN  1      /* Column is __HIDDEN__ */
#define RECOVER_EHIDDEN_VIRTUAL 2      /* Virtual generated column */
#define RECOVER_EHIDDEN_STORED  3      /* Stored generated column */

/*
** Bitmap object used to track pages in the input database. Allocated
** and manipulated only by the following functions:
**
**     recoverBitmapAlloc()
**     recoverBitmapFree()
**     recoverBitmapSet()
**     recoverBitmapQuery()
**
** nPg:
**   Largest page number that may be stored in the bitmap. The range
**   of valid keys is 1 to nPg, inclusive.
**
** aElem[]:
**   Array large enough to contain a bit for each key. For key value
**   iKey, the associated bit is the bit (iKey%32) of aElem[iKey/32].
**   In other words, the following is true if bit iKey is set, or 
**   false if it is clear:
**
**       (aElem[iKey/32] & (1 << (iKey%32))) ? 1 : 0
*/
typedef struct RecoverBitmap RecoverBitmap;
struct RecoverBitmap {
  i64 nPg;                        /* Size of bitmap */
  u32 aElem[1];                   /* Array of 32-bit bitmasks */
};

/*
** State variables (part of the sqlite3_recover structure) used while
** recovering data for tables identified in the recovered schema (state
** RECOVER_STATE_WRITING).
*/
typedef struct RecoverStateW1 RecoverStateW1;
struct RecoverStateW1 {
  sqlite3_stmt *pTbls;
  sqlite3_stmt *pSel;
  sqlite3_stmt *pInsert;
  int nInsert;

  RecoverTable *pTab;             /* Table currently being written */
  int nMax;                       /* Max column count in any schema table */
  sqlite3_value **apVal;          /* Array of nMax values */
  int nVal;                       /* Number of valid entries in apVal[] */
  int bHaveRowid;
  i64 iRowid;
  i64 iPrevPage;
  int iPrevCell;
};

/*
** State variables (part of the sqlite3_recover structure) used while
** recovering data destined for the lost and found table (states
** RECOVER_STATE_LOSTANDFOUND[123]).
*/
typedef struct RecoverStateLAF RecoverStateLAF;
struct RecoverStateLAF {
  RecoverBitmap *pUsed;
  i64 nPg;                        /* Size of db in pages */
  sqlite3_stmt *pAllAndParent;
  sqlite3_stmt *pMapInsert;
  sqlite3_stmt *pMaxField;
  sqlite3_stmt *pUsedPages;
  sqlite3_stmt *pFindRoot;
  sqlite3_stmt *pInsert;          /* INSERT INTO lost_and_found ... */
  sqlite3_stmt *pAllPage;
  sqlite3_stmt *pPageData;
  sqlite3_value **apVal;
  int nMaxField;
};

/*
** Main recover handle structure.
*/
struct sqlite3_recover {
  /* Copies of sqlite3_recover_init[_sql]() parameters */
  sqlite3 *dbIn;                  /* Input database */
  char *zDb;                      /* Name of input db ("main" etc.) */
  char *zUri;                     /* URI for output database */
  void *pSqlCtx;                  /* SQL callback context */
  int (*xSql)(void*,const char*); /* Pointer to SQL callback function */

  /* Values configured by sqlite3_recover_config() */
  char *zStateDb;                 /* State database to use (or NULL) */
  char *zLostAndFound;            /* Name of lost-and-found table (or NULL) */
  int bFreelistCorrupt;           /* SQLITE_RECOVER_FREELIST_CORRUPT setting */
  int bRecoverRowid;              /* SQLITE_RECOVER_ROWIDS setting */
  int bSlowIndexes;               /* SQLITE_RECOVER_SLOWINDEXES setting */

  int pgsz;
  int detected_pgsz;
  int nReserve;
  u8 *pPage1Disk;
  u8 *pPage1Cache;

  /* Error code and error message */
  int errCode;                    /* For sqlite3_recover_errcode() */
  char *zErrMsg;                  /* For sqlite3_recover_errmsg() */

  int eState;
  int bCloseTransaction;

  /* Variables used with eState==RECOVER_STATE_WRITING */
  RecoverStateW1 w1;

  /* Variables used with states RECOVER_STATE_LOSTANDFOUND[123] */
  RecoverStateLAF laf;

  /* Fields used within sqlite3_recover_run() */
  sqlite3 *dbOut;                 /* Output database */
  sqlite3_stmt *pGetPage;         /* SELECT against input db sqlite_dbdata */
  RecoverTable *pTblList;         /* List of tables recovered from schema */
};

/*
** The various states in which an sqlite3_recover object may exist:
**
**   RECOVER_STATE_INIT:
**    The object is initially created in this state. sqlite3_recover_step()
**    has yet to be called. This is the only state in which it is permitted
**    to call sqlite3_recover_config().
**
**   RECOVER_STATE_WRITING:
**
**   RECOVER_STATE_LOSTANDFOUND1:
**    State to populate the bitmap of pages used by other tables or the
**    database freelist.
**
**   RECOVER_STATE_LOSTANDFOUND2:
**    Populate the recovery.map table - used to figure out a "root" page
**    for each lost page from in the database from which records are
**    extracted.
**
**   RECOVER_STATE_LOSTANDFOUND3:
**    Populate the lost-and-found table itself.
*/
#define RECOVER_STATE_INIT           0
#define RECOVER_STATE_WRITING        1
#define RECOVER_STATE_LOSTANDFOUND1  2
#define RECOVER_STATE_LOSTANDFOUND2  3
#define RECOVER_STATE_LOSTANDFOUND3  4
#define RECOVER_STATE_SCHEMA2        5
#define RECOVER_STATE_DONE           6


/*
** Global variables used by this extension.
*/
typedef struct RecoverGlobal RecoverGlobal;
struct RecoverGlobal {
  const sqlite3_io_methods *pMethods;
  sqlite3_recover *p;
};
static RecoverGlobal recover_g;

/*
** Use this static SQLite mutex to protect the globals during the
** first call to sqlite3_recover_step().
*/ 
#define RECOVER_MUTEX_ID SQLITE_MUTEX_STATIC_APP2


/* 
** Default value for SQLITE_RECOVER_ROWIDS (sqlite3_recover.bRecoverRowid).
*/
#define RECOVER_ROWID_DEFAULT 1

/*
** Mutex handling:
**
**    recoverEnterMutex()       -   Enter the recovery mutex
**    recoverLeaveMutex()       -   Leave the recovery mutex
**    recoverAssertMutexHeld()  -   Assert that the recovery mutex is held
*/
#if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE==0
# define recoverEnterMutex()
# define recoverLeaveMutex()
#else
static void recoverEnterMutex(void){
  sqlite3_mutex_enter(sqlite3_mutex_alloc(RECOVER_MUTEX_ID));
}
static void recoverLeaveMutex(void){
  sqlite3_mutex_leave(sqlite3_mutex_alloc(RECOVER_MUTEX_ID));
}
#endif
#if SQLITE_THREADSAFE+0>=1 && defined(SQLITE_DEBUG)
static void recoverAssertMutexHeld(void){
  assert( sqlite3_mutex_held(sqlite3_mutex_alloc(RECOVER_MUTEX_ID)) );
}
#else
# define recoverAssertMutexHeld()
#endif


/*
** Like strlen(). But handles NULL pointer arguments.
*/
static int recoverStrlen(const char *zStr){
  if( zStr==0 ) return 0;
  return (int)(strlen(zStr)&0x7fffffff);
}

/*
** This function is a no-op if the recover handle passed as the first 
** argument already contains an error (if p->errCode!=SQLITE_OK). 
**
** Otherwise, an attempt is made to allocate, zero and return a buffer nByte
** bytes in size. If successful, a pointer to the new buffer is returned. Or,
** if an OOM error occurs, NULL is returned and the handle error code
** (p->errCode) set to SQLITE_NOMEM.
*/
static void *recoverMalloc(sqlite3_recover *p, i64 nByte){
  void *pRet = 0;
  assert( nByte>0 );
  if( p->errCode==SQLITE_OK ){
    pRet = sqlite3_malloc64(nByte);
    if( pRet ){
      memset(pRet, 0, nByte);
    }else{
      p->errCode = SQLITE_NOMEM;
    }
  }
  return pRet;
}

/*
** Set the error code and error message for the recover handle passed as
** the first argument. The error code is set to the value of parameter
** errCode.
**
** Parameter zFmt must be a printf() style formatting string. The handle 
** error message is set to the result of using any trailing arguments for 
** parameter substitutions in the formatting string.
**
** For example:
**
**   recoverError(p, SQLITE_ERROR, "no such table: %s", zTablename);
*/
static int recoverError(
  sqlite3_recover *p, 
  int errCode, 
  const char *zFmt, ...
){
  char *z = 0;
  va_list ap;
  va_start(ap, zFmt);
  if( zFmt ){
    z = sqlite3_vmprintf(zFmt, ap);
  }
  va_end(ap);
  sqlite3_free(p->zErrMsg);
  p->zErrMsg = z;
  p->errCode = errCode;
  return errCode;
}


/*
** This function is a no-op if p->errCode is initially other than SQLITE_OK.
** In this case it returns NULL.
**
** Otherwise, an attempt is made to allocate and return a bitmap object
** large enough to store a bit for all page numbers between 1 and nPg,
** inclusive. The bitmap is initially zeroed.
*/
static RecoverBitmap *recoverBitmapAlloc(sqlite3_recover *p, i64 nPg){
  int nElem = (nPg+1+31) / 32;
  int nByte = sizeof(RecoverBitmap) + nElem*sizeof(u32);
  RecoverBitmap *pRet = (RecoverBitmap*)recoverMalloc(p, nByte);

  if( pRet ){
    pRet->nPg = nPg;
  }
  return pRet;
}

/*
** Free a bitmap object allocated by recoverBitmapAlloc().
*/
static void recoverBitmapFree(RecoverBitmap *pMap){
  sqlite3_free(pMap);
}

/*
** Set the bit associated with page iPg in bitvec pMap.
*/
static void recoverBitmapSet(RecoverBitmap *pMap, i64 iPg){
  if( iPg<=pMap->nPg ){
    int iElem = (iPg / 32);
    int iBit = (iPg % 32);
    pMap->aElem[iElem] |= (((u32)1) << iBit);
  }
}

/*
** Query bitmap object pMap for the state of the bit associated with page
** iPg. Return 1 if it is set, or 0 otherwise.
*/
static int recoverBitmapQuery(RecoverBitmap *pMap, i64 iPg){
  int ret = 1;
  if( iPg<=pMap->nPg && iPg>0 ){
    int iElem = (iPg / 32);
    int iBit = (iPg % 32);
    ret = (pMap->aElem[iElem] & (((u32)1) << iBit)) ? 1 : 0;
  }
  return ret;
}

/*
** Set the recover handle error to the error code and message returned by
** calling sqlite3_errcode() and sqlite3_errmsg(), respectively, on database
** handle db.
*/
static int recoverDbError(sqlite3_recover *p, sqlite3 *db){
  return recoverError(p, sqlite3_errcode(db), "%s", sqlite3_errmsg(db));
}

/*
** This function is a no-op if recover handle p already contains an error
** (if p->errCode!=SQLITE_OK). 
**
** Otherwise, it attempts to prepare the SQL statement in zSql against
** database handle db. If successful, the statement handle is returned.
** Or, if an error occurs, NULL is returned and an error left in the
** recover handle.
*/
static sqlite3_stmt *recoverPrepare(
  sqlite3_recover *p,
  sqlite3 *db, 
  const char *zSql
){
  sqlite3_stmt *pStmt = 0;
  if( p->errCode==SQLITE_OK ){
    if( sqlite3_prepare_v2(db, zSql, -1, &pStmt, 0) ){
      recoverDbError(p, db);
    }
  }
  return pStmt;
}

/*
** This function is a no-op if recover handle p already contains an error
** (if p->errCode!=SQLITE_OK). 
**
** Otherwise, argument zFmt is used as a printf() style format string,
** along with any trailing arguments, to create an SQL statement. This
** SQL statement is prepared against database handle db and, if successful,
** the statment handle returned. Or, if an error occurs - either during
** the printf() formatting or when preparing the resulting SQL - an
** error code and message are left in the recover handle.
*/
static sqlite3_stmt *recoverPreparePrintf(
  sqlite3_recover *p,
  sqlite3 *db, 
  const char *zFmt, ...
){
  sqlite3_stmt *pStmt = 0;
  if( p->errCode==SQLITE_OK ){
    va_list ap;
    char *z;
    va_start(ap, zFmt);
    z = sqlite3_vmprintf(zFmt, ap);
    va_end(ap);
    if( z==0 ){
      p->errCode = SQLITE_NOMEM;
    }else{
      pStmt = recoverPrepare(p, db, z);
      sqlite3_free(z);
    }
  }
  return pStmt;
}

/*
** Reset SQLite statement handle pStmt. If the call to sqlite3_reset() 
** indicates that an error occurred, and there is not already an error
** in the recover handle passed as the first argument, set the error
** code and error message appropriately.
**
** This function returns a copy of the statement handle pointer passed
** as the second argument.
*/
static sqlite3_stmt *recoverReset(sqlite3_recover *p, sqlite3_stmt *pStmt){
  int rc = sqlite3_reset(pStmt);
  if( rc!=SQLITE_OK && rc!=SQLITE_CONSTRAINT && p->errCode==SQLITE_OK ){
    recoverDbError(p, sqlite3_db_handle(pStmt));
  }
  return pStmt;
}

/*
** Finalize SQLite statement handle pStmt. If the call to sqlite3_reset() 
** indicates that an error occurred, and there is not already an error
** in the recover handle passed as the first argument, set the error
** code and error message appropriately.
*/
static void recoverFinalize(sqlite3_recover *p, sqlite3_stmt *pStmt){
  sqlite3 *db = sqlite3_db_handle(pStmt);
  int rc = sqlite3_finalize(pStmt);
  if( rc!=SQLITE_OK && p->errCode==SQLITE_OK ){
    recoverDbError(p, db);
  }
}

/*
** This function is a no-op if recover handle p already contains an error
** (if p->errCode!=SQLITE_OK). A copy of p->errCode is returned in this 
** case.
**
** Otherwise, execute SQL script zSql. If successful, return SQLITE_OK.
** Or, if an error occurs, leave an error code and message in the recover
** handle and return a copy of the error code.
*/
static int recoverExec(sqlite3_recover *p, sqlite3 *db, const char *zSql){
  if( p->errCode==SQLITE_OK ){
    int rc = sqlite3_exec(db, zSql, 0, 0, 0);
    if( rc ){
      recoverDbError(p, db);
    }
  }
  return p->errCode;
}

/*
** Bind the value pVal to parameter iBind of statement pStmt. Leave an
** error in the recover handle passed as the first argument if an error
** (e.g. an OOM) occurs.
*/
static void recoverBindValue(
  sqlite3_recover *p, 
  sqlite3_stmt *pStmt, 
  int iBind, 
  sqlite3_value *pVal
){
  if( p->errCode==SQLITE_OK ){
    int rc = sqlite3_bind_value(pStmt, iBind, pVal);
    if( rc ) recoverError(p, rc, 0);
  }
}

/*
** This function is a no-op if recover handle p already contains an error
** (if p->errCode!=SQLITE_OK). NULL is returned in this case.
**
** Otherwise, an attempt is made to interpret zFmt as a printf() style
** formatting string and the result of using the trailing arguments for
** parameter substitution with it written into a buffer obtained from
** sqlite3_malloc(). If successful, a pointer to the buffer is returned.
** It is the responsibility of the caller to eventually free the buffer
** using sqlite3_free().
**
** Or, if an error occurs, an error code and message is left in the recover
** handle and NULL returned.
*/
static char *recoverMPrintf(sqlite3_recover *p, const char *zFmt, ...){
  va_list ap;
  char *z;
  va_start(ap, zFmt);
  z = sqlite3_vmprintf(zFmt, ap);
  va_end(ap);
  if( p->errCode==SQLITE_OK ){
    if( z==0 ) p->errCode = SQLITE_NOMEM;
  }else{
    sqlite3_free(z);
    z = 0;
  }
  return z;
}

/*
** This function is a no-op if recover handle p already contains an error
** (if p->errCode!=SQLITE_OK). Zero is returned in this case.
**
** Otherwise, execute "PRAGMA page_count" against the input database. If
** successful, return the integer result. Or, if an error occurs, leave an
** error code and error message in the sqlite3_recover handle and return
** zero.
*/
static i64 recoverPageCount(sqlite3_recover *p){
  i64 nPg = 0;
  if( p->errCode==SQLITE_OK ){
    sqlite3_stmt *pStmt = 0;
    pStmt = recoverPreparePrintf(p, p->dbIn, "PRAGMA %Q.page_count", p->zDb);
    if( pStmt ){
      sqlite3_step(pStmt);
      nPg = sqlite3_column_int64(pStmt, 0);
    }
    recoverFinalize(p, pStmt);
  }
  return nPg;
}

/*
** Implementation of SQL scalar function "read_i32". The first argument to 
** this function must be a blob. The second a non-negative integer. This 
** function reads and returns a 32-bit big-endian integer from byte
** offset (4*<arg2>) of the blob.
**
**     SELECT read_i32(<blob>, <idx>)
*/
static void recoverReadI32(
  sqlite3_context *context, 
  int argc, 
  sqlite3_value **argv
){
  const unsigned char *pBlob;
  int nBlob;
  int iInt;

  assert( argc==2 );
  nBlob = sqlite3_value_bytes(argv[0]);
  pBlob = (const unsigned char*)sqlite3_value_blob(argv[0]);
  iInt = sqlite3_value_int(argv[1]) & 0xFFFF;

  if( (iInt+1)*4<=nBlob ){
    const unsigned char *a = &pBlob[iInt*4];
    i64 iVal = ((i64)a[0]<<24)
             + ((i64)a[1]<<16)
             + ((i64)a[2]<< 8)
             + ((i64)a[3]<< 0);
    sqlite3_result_int64(context, iVal);
  }
}

/*
** Implementation of SQL scalar function "page_is_used". This function
** is used as part of the procedure for locating orphan rows for the
** lost-and-found table, and it depends on those routines having populated
** the sqlite3_recover.laf.pUsed variable.
**
** The only argument to this function is a page-number. It returns true 
** if the page has already been used somehow during data recovery, or false
** otherwise.
**
**     SELECT page_is_used(<pgno>);
*/
static void recoverPageIsUsed(
  sqlite3_context *pCtx,
  int nArg,
  sqlite3_value **apArg
){
  sqlite3_recover *p = (sqlite3_recover*)sqlite3_user_data(pCtx);
  i64 pgno = sqlite3_value_int64(apArg[0]);
  assert( nArg==1 );
  sqlite3_result_int(pCtx, recoverBitmapQuery(p->laf.pUsed, pgno));
}

/*
** The implementation of a user-defined SQL function invoked by the 
** sqlite_dbdata and sqlite_dbptr virtual table modules to access pages
** of the database being recovered.
**
** This function always takes a single integer argument. If the argument
** is zero, then the value returned is the number of pages in the db being
** recovered. If the argument is greater than zero, it is a page number. 
** The value returned in this case is an SQL blob containing the data for 
** the identified page of the db being recovered. e.g.
**
**     SELECT getpage(0);       -- return number of pages in db
**     SELECT getpage(4);       -- return page 4 of db as a blob of data 
*/
static void recoverGetPage(
  sqlite3_context *pCtx,
  int nArg,
  sqlite3_value **apArg
){
  sqlite3_recover *p = (sqlite3_recover*)sqlite3_user_data(pCtx);
  i64 pgno = sqlite3_value_int64(apArg[0]);
  sqlite3_stmt *pStmt = 0;

  assert( nArg==1 );
  if( pgno==0 ){
    i64 nPg = recoverPageCount(p);
    sqlite3_result_int64(pCtx, nPg);
    return;
  }else{
    if( p->pGetPage==0 ){
      pStmt = p->pGetPage = recoverPreparePrintf(
          p, p->dbIn, "SELECT data FROM sqlite_dbpage(%Q) WHERE pgno=?", p->zDb
      );
    }else if( p->errCode==SQLITE_OK ){
      pStmt = p->pGetPage;
    }

    if( pStmt ){
      sqlite3_bind_int64(pStmt, 1, pgno);
      if( SQLITE_ROW==sqlite3_step(pStmt) ){
        const u8 *aPg;
        int nPg;
        assert( p->errCode==SQLITE_OK );
        aPg = sqlite3_column_blob(pStmt, 0);
        nPg = sqlite3_column_bytes(pStmt, 0);
        if( pgno==1 && nPg==p->pgsz && 0==memcmp(p->pPage1Cache, aPg, nPg) ){
          aPg = p->pPage1Disk;
        }
        sqlite3_result_blob(pCtx, aPg, nPg-p->nReserve, SQLITE_TRANSIENT);
      }
      recoverReset(p, pStmt);
    }
  }

  if( p->errCode ){
    if( p->zErrMsg ) sqlite3_result_error(pCtx, p->zErrMsg, -1);
    sqlite3_result_error_code(pCtx, p->errCode);
  }
}

/*
** Find a string that is not found anywhere in z[].  Return a pointer
** to that string.
**
** Try to use zA and zB first.  If both of those are already found in z[]
** then make up some string and store it in the buffer zBuf.
*/
static const char *recoverUnusedString(
  const char *z,                    /* Result must not appear anywhere in z */
  const char *zA, const char *zB,   /* Try these first */
  char *zBuf                        /* Space to store a generated string */
){
  unsigned i = 0;
  if( strstr(z, zA)==0 ) return zA;
  if( strstr(z, zB)==0 ) return zB;
  do{
    sqlite3_snprintf(20,zBuf,"(%s%u)", zA, i++);
  }while( strstr(z,zBuf)!=0 );
  return zBuf;
}

/*
** Implementation of scalar SQL function "escape_crlf".  The argument passed to
** this function is the output of built-in function quote(). If the first
** character of the input is "'", indicating that the value passed to quote()
** was a text value, then this function searches the input for "\n" and "\r"
** characters and adds a wrapper similar to the following:
**
**   replace(replace(<input>, '\n', char(10), '\r', char(13));
**
** Or, if the first character of the input is not "'", then a copy of the input
** is returned.
*/
static void recoverEscapeCrlf(
  sqlite3_context *context, 
  int argc, 
  sqlite3_value **argv
){
  const char *zText = (const char*)sqlite3_value_text(argv[0]);
  (void)argc;
  if( zText && zText[0]=='\'' ){
    int nText = sqlite3_value_bytes(argv[0]);
    int i;
    char zBuf1[20];
    char zBuf2[20];
    const char *zNL = 0;
    const char *zCR = 0;
    int nCR = 0;
    int nNL = 0;

    for(i=0; zText[i]; i++){
      if( zNL==0 && zText[i]=='\n' ){
        zNL = recoverUnusedString(zText, "\\n", "\\012", zBuf1);
        nNL = (int)strlen(zNL);
      }
      if( zCR==0 && zText[i]=='\r' ){
        zCR = recoverUnusedString(zText, "\\r", "\\015", zBuf2);
        nCR = (int)strlen(zCR);
      }
    }

    if( zNL || zCR ){
      int iOut = 0;
      i64 nMax = (nNL > nCR) ? nNL : nCR;
      i64 nAlloc = nMax * nText + (nMax+64)*2;
      char *zOut = (char*)sqlite3_malloc64(nAlloc);
      if( zOut==0 ){
        sqlite3_result_error_nomem(context);
        return;
      }

      if( zNL && zCR ){
        memcpy(&zOut[iOut], "replace(replace(", 16);
        iOut += 16;
      }else{
        memcpy(&zOut[iOut], "replace(", 8);
        iOut += 8;
      }
      for(i=0; zText[i]; i++){
        if( zText[i]=='\n' ){
          memcpy(&zOut[iOut], zNL, nNL);
          iOut += nNL;
        }else if( zText[i]=='\r' ){
          memcpy(&zOut[iOut], zCR, nCR);
          iOut += nCR;
        }else{
          zOut[iOut] = zText[i];
          iOut++;
        }
      }

      if( zNL ){
        memcpy(&zOut[iOut], ",'", 2); iOut += 2;
        memcpy(&zOut[iOut], zNL, nNL); iOut += nNL;
        memcpy(&zOut[iOut], "', char(10))", 12); iOut += 12;
      }
      if( zCR ){
        memcpy(&zOut[iOut], ",'", 2); iOut += 2;
        memcpy(&zOut[iOut], zCR, nCR); iOut += nCR;
        memcpy(&zOut[iOut], "', char(13))", 12); iOut += 12;
      }

      sqlite3_result_text(context, zOut, iOut, SQLITE_TRANSIENT);
      sqlite3_free(zOut);
      return;
    }
  }

  sqlite3_result_value(context, argv[0]);
}

/*
** This function is a no-op if recover handle p already contains an error
** (if p->errCode!=SQLITE_OK). A copy of the error code is returned in
** this case. 
**
** Otherwise, attempt to populate temporary table "recovery.schema" with the
** parts of the database schema that can be extracted from the input database.
**
** If no error occurs, SQLITE_OK is returned. Otherwise, an error code
** and error message are left in the recover handle and a copy of the
** error code returned. It is not considered an error if part of all of
** the database schema cannot be recovered due to corruption.
*/
static int recoverCacheSchema(sqlite3_recover *p){
  return recoverExec(p, p->dbOut,
    "WITH RECURSIVE pages(p) AS ("
    "  SELECT 1"
    "    UNION"
    "  SELECT child FROM sqlite_dbptr('getpage()'), pages WHERE pgno=p"
    ")"
    "INSERT INTO recovery.schema SELECT"
    "  max(CASE WHEN field=0 THEN value ELSE NULL END),"
    "  max(CASE WHEN field=1 THEN value ELSE NULL END),"
    "  max(CASE WHEN field=2 THEN value ELSE NULL END),"
    "  max(CASE WHEN field=3 THEN value ELSE NULL END),"
    "  max(CASE WHEN field=4 THEN value ELSE NULL END)"
    "FROM sqlite_dbdata('getpage()') WHERE pgno IN ("
    "  SELECT p FROM pages"
    ") GROUP BY pgno, cell"
  );
}

/*
** If this recover handle is not in SQL callback mode (i.e. was not created 
** using sqlite3_recover_init_sql()) of if an error has already occurred, 
** this function is a no-op. Otherwise, issue a callback with SQL statement
** zSql as the parameter. 
**
** If the callback returns non-zero, set the recover handle error code to
** the value returned (so that the caller will abandon processing).
*/
static void recoverSqlCallback(sqlite3_recover *p, const char *zSql){
  if( p->errCode==SQLITE_OK && p->xSql ){
    int res = p->xSql(p->pSqlCtx, zSql);
    if( res ){
      recoverError(p, SQLITE_ERROR, "callback returned an error - %d", res);
    }
  }
}

/*
** Transfer the following settings from the input database to the output
** database:
**
**   + page-size,
**   + auto-vacuum settings,
**   + database encoding,
**   + user-version (PRAGMA user_version), and
**   + application-id (PRAGMA application_id), and
*/
static void recoverTransferSettings(sqlite3_recover *p){
  const char *aPragma[] = {
    "encoding",
    "page_size",
    "auto_vacuum",
    "user_version",
    "application_id"
  };
  int ii;

  /* Truncate the output database to 0 pages in size. This is done by 
  ** opening a new, empty, temp db, then using the backup API to clobber 
  ** any existing output db with a copy of it. */
  if( p->errCode==SQLITE_OK ){
    sqlite3 *db2 = 0;
    int rc = sqlite3_open("", &db2);
    if( rc!=SQLITE_OK ){
      recoverDbError(p, db2);
      return;
    }

    for(ii=0; ii<(int)(sizeof(aPragma)/sizeof(aPragma[0])); ii++){
      const char *zPrag = aPragma[ii];
      sqlite3_stmt *p1 = 0;
      p1 = recoverPreparePrintf(p, p->dbIn, "PRAGMA %Q.%s", p->zDb, zPrag);
      if( p->errCode==SQLITE_OK && sqlite3_step(p1)==SQLITE_ROW ){
        const char *zArg = (const char*)sqlite3_column_text(p1, 0);
        char *z2 = recoverMPrintf(p, "PRAGMA %s = %Q", zPrag, zArg);
        recoverSqlCallback(p, z2);
        recoverExec(p, db2, z2);
        sqlite3_free(z2);
        if( zArg==0 ){
          recoverError(p, SQLITE_NOMEM, 0);
        }
      }
      recoverFinalize(p, p1);
    }
    recoverExec(p, db2, "CREATE TABLE t1(a); DROP TABLE t1;");

    if( p->errCode==SQLITE_OK ){
      sqlite3 *db = p->dbOut;
      sqlite3_backup *pBackup = sqlite3_backup_init(db, "main", db2, "main");
      if( pBackup ){
        sqlite3_backup_step(pBackup, -1);
        p->errCode = sqlite3_backup_finish(pBackup);
      }else{
        recoverDbError(p, db);
      }
    }

    sqlite3_close(db2);
  }
}

/*
** This function is a no-op if recover handle p already contains an error
** (if p->errCode!=SQLITE_OK). A copy of the error code is returned in
** this case. 
**
** Otherwise, an attempt is made to open the output database, attach
** and create the schema of the temporary database used to store
** intermediate data, and to register all required user functions and
** virtual table modules with the output handle.
**
** If no error occurs, SQLITE_OK is returned. Otherwise, an error code
** and error message are left in the recover handle and a copy of the
** error code returned.
*/
static int recoverOpenOutput(sqlite3_recover *p){
  struct Func {
    const char *zName;
    int nArg;
    void (*xFunc)(sqlite3_context*,int,sqlite3_value **);
  } aFunc[] = {
    { "getpage", 1, recoverGetPage },
    { "page_is_used", 1, recoverPageIsUsed },
    { "read_i32", 2, recoverReadI32 },
    { "escape_crlf", 1, recoverEscapeCrlf },
  };

  const int flags = SQLITE_OPEN_URI|SQLITE_OPEN_CREATE|SQLITE_OPEN_READWRITE;
  sqlite3 *db = 0;                /* New database handle */
  int ii;                         /* For iterating through aFunc[] */

  assert( p->dbOut==0 );

  if( sqlite3_open_v2(p->zUri, &db, flags, 0) ){
    recoverDbError(p, db);
  }

  /* Register the sqlite_dbdata and sqlite_dbptr virtual table modules.
  ** These two are registered with the output database handle - this
  ** module depends on the input handle supporting the sqlite_dbpage
  ** virtual table only.  */
  if( p->errCode==SQLITE_OK ){
    p->errCode = sqlite3_dbdata_init(db, 0, 0);
  }

  /* Register the custom user-functions with the output handle. */
  for(ii=0;
      p->errCode==SQLITE_OK && ii<(int)(sizeof(aFunc)/sizeof(aFunc[0]));
      ii++){
    p->errCode = sqlite3_create_function(db, aFunc[ii].zName, 
        aFunc[ii].nArg, SQLITE_UTF8, (void*)p, aFunc[ii].xFunc, 0, 0
    );
  }

  p->dbOut = db;
  return p->errCode;
}

/*
** Attach the auxiliary database 'recovery' to the output database handle.
** This temporary database is used during the recovery process and then 
** discarded.
*/
static void recoverOpenRecovery(sqlite3_recover *p){
  char *zSql = recoverMPrintf(p, "ATTACH %Q AS recovery;", p->zStateDb);
  recoverExec(p, p->dbOut, zSql);
  recoverExec(p, p->dbOut,
      "PRAGMA writable_schema = 1;"
      "CREATE TABLE recovery.map(pgno INTEGER PRIMARY KEY, parent INT);" 
      "CREATE TABLE recovery.schema(type, name, tbl_name, rootpage, sql);"
  );
  sqlite3_free(zSql);
}


/*
** This function is a no-op if recover handle p already contains an error
** (if p->errCode!=SQLITE_OK).
**
** Otherwise, argument zName must be the name of a table that has just been
** created in the output database. This function queries the output db
** for the schema of said table, and creates a RecoverTable object to
** store the schema in memory. The new RecoverTable object is linked into
** the list at sqlite3_recover.pTblList.
**
** Parameter iRoot must be the root page of table zName in the INPUT 
** database.
*/
static void recoverAddTable(
  sqlite3_recover *p, 
  const char *zName,              /* Name of table created in output db */
  i64 iRoot                       /* Root page of same table in INPUT db */
){
  sqlite3_stmt *pStmt = recoverPreparePrintf(p, p->dbOut, 
      "PRAGMA table_xinfo(%Q)", zName
  );

  if( pStmt ){
    int iPk = -1;
    int iBind = 1;
    RecoverTable *pNew = 0;
    int nCol = 0;
    int nName = recoverStrlen(zName);
    int nByte = 0;
    while( sqlite3_step(pStmt)==SQLITE_ROW ){
      nCol++;
      nByte += (sqlite3_column_bytes(pStmt, 1)+1);
    }
    nByte += sizeof(RecoverTable) + nCol*sizeof(RecoverColumn) + nName+1;
    recoverReset(p, pStmt);

    pNew = recoverMalloc(p, nByte);
    if( pNew ){
      int i = 0;
      int iField = 0;
      char *csr = 0;
      pNew->aCol = (RecoverColumn*)&pNew[1];
      pNew->zTab = csr = (char*)&pNew->aCol[nCol];
      pNew->nCol = nCol;
      pNew->iRoot = iRoot;
      memcpy(csr, zName, nName);
      csr += nName+1;

      for(i=0; sqlite3_step(pStmt)==SQLITE_ROW; i++){
        int iPKF = sqlite3_column_int(pStmt, 5);
        int n = sqlite3_column_bytes(pStmt, 1);
        const char *z = (const char*)sqlite3_column_text(pStmt, 1);
        const char *zType = (const char*)sqlite3_column_text(pStmt, 2);
        int eHidden = sqlite3_column_int(pStmt, 6);

        if( iPk==-1 && iPKF==1 && !sqlite3_stricmp("integer", zType) ) iPk = i;
        if( iPKF>1 ) iPk = -2;
        pNew->aCol[i].zCol = csr;
        pNew->aCol[i].eHidden = eHidden;
        if( eHidden==RECOVER_EHIDDEN_VIRTUAL ){
          pNew->aCol[i].iField = -1;
        }else{
          pNew->aCol[i].iField = iField++;
        }
        if( eHidden!=RECOVER_EHIDDEN_VIRTUAL
         && eHidden!=RECOVER_EHIDDEN_STORED
        ){
          pNew->aCol[i].iBind = iBind++;
        }
        memcpy(csr, z, n);
        csr += (n+1);
      }

      pNew->pNext = p->pTblList;
      p->pTblList = pNew;
      pNew->bIntkey = 1;
    }

    recoverFinalize(p, pStmt);

    pStmt = recoverPreparePrintf(p, p->dbOut, "PRAGMA index_xinfo(%Q)", zName);
    while( pStmt && sqlite3_step(pStmt)==SQLITE_ROW ){
      int iField = sqlite3_column_int(pStmt, 0);
      int iCol = sqlite3_column_int(pStmt, 1);

      assert( iCol<pNew->nCol );
      pNew->aCol[iCol].iField = iField;

      pNew->bIntkey = 0;
      iPk = -2;
    }
    recoverFinalize(p, pStmt);

    if( p->errCode==SQLITE_OK ){
      if( iPk>=0 ){
        pNew->aCol[iPk].bIPK = 1;
      }else if( pNew->bIntkey ){
        pNew->iRowidBind = iBind++;
      }
    }
  }
}

/*
** This function is called after recoverCacheSchema() has cached those parts
** of the input database schema that could be recovered in temporary table
** "recovery.schema". This function creates in the output database copies
** of all parts of that schema that must be created before the tables can
** be populated. Specifically, this means:
**
**     * all tables that are not VIRTUAL, and
**     * UNIQUE indexes.
**
** If the recovery handle uses SQL callbacks, then callbacks containing
** the associated "CREATE TABLE" and "CREATE INDEX" statements are made.
**
** Additionally, records are added to the sqlite_schema table of the
** output database for any VIRTUAL tables. The CREATE VIRTUAL TABLE
** records are written directly to sqlite_schema, not actually executed.
** If the handle is in SQL callback mode, then callbacks are invoked 
** with equivalent SQL statements.
*/
static int recoverWriteSchema1(sqlite3_recover *p){
  sqlite3_stmt *pSelect = 0;
  sqlite3_stmt *pTblname = 0;

  pSelect = recoverPrepare(p, p->dbOut,
      "WITH dbschema(rootpage, name, sql, tbl, isVirtual, isIndex) AS ("
      "  SELECT rootpage, name, sql, "
      "    type='table', "
      "    sql LIKE 'create virtual%',"
      "    (type='index' AND (sql LIKE '%unique%' OR ?1))"
      "  FROM recovery.schema"
      ")"
      "SELECT rootpage, tbl, isVirtual, name, sql"
      " FROM dbschema "
      "  WHERE tbl OR isIndex"
      "  ORDER BY tbl DESC, name=='sqlite_sequence' DESC"
  );

  pTblname = recoverPrepare(p, p->dbOut,
      "SELECT name FROM sqlite_schema "
      "WHERE type='table' ORDER BY rowid DESC LIMIT 1"
  );

  if( pSelect ){
    sqlite3_bind_int(pSelect, 1, p->bSlowIndexes);
    while( sqlite3_step(pSelect)==SQLITE_ROW ){
      i64 iRoot = sqlite3_column_int64(pSelect, 0);
      int bTable = sqlite3_column_int(pSelect, 1);
      int bVirtual = sqlite3_column_int(pSelect, 2);
      const char *zName = (const char*)sqlite3_column_text(pSelect, 3);
      const char *zSql = (const char*)sqlite3_column_text(pSelect, 4);
      char *zFree = 0;
      int rc = SQLITE_OK;

      if( bVirtual ){
        zSql = (const char*)(zFree = recoverMPrintf(p,
            "INSERT INTO sqlite_schema VALUES('table', %Q, %Q, 0, %Q)",
            zName, zName, zSql
        ));
      }
      rc = sqlite3_exec(p->dbOut, zSql, 0, 0, 0);
      if( rc==SQLITE_OK ){
        recoverSqlCallback(p, zSql);
        if( bTable && !bVirtual ){
          if( SQLITE_ROW==sqlite3_step(pTblname) ){
            const char *zTbl = (const char*)sqlite3_column_text(pTblname, 0);
            if( zTbl ) recoverAddTable(p, zTbl, iRoot);
          }
          recoverReset(p, pTblname);
        }
      }else if( rc!=SQLITE_ERROR ){
        recoverDbError(p, p->dbOut);
      }
      sqlite3_free(zFree);
    }
  }
  recoverFinalize(p, pSelect);
  recoverFinalize(p, pTblname);

  return p->errCode;
}

/*
** This function is called after the output database has been populated. It
** adds all recovered schema elements that were not created in the output
** database by recoverWriteSchema1() - everything except for tables and
** UNIQUE indexes. Specifically:
**
**     * views,
**     * triggers,
**     * non-UNIQUE indexes.
**
** If the recover handle is in SQL callback mode, then equivalent callbacks
** are issued to create the schema elements.
*/
static int recoverWriteSchema2(sqlite3_recover *p){
  sqlite3_stmt *pSelect = 0;

  pSelect = recoverPrepare(p, p->dbOut,
      p->bSlowIndexes ?
      "SELECT rootpage, sql FROM recovery.schema "
      "  WHERE type!='table' AND type!='index'"
      :
      "SELECT rootpage, sql FROM recovery.schema "
      "  WHERE type!='table' AND (type!='index' OR sql NOT LIKE '%unique%')"
  );

  if( pSelect ){
    while( sqlite3_step(pSelect)==SQLITE_ROW ){
      const char *zSql = (const char*)sqlite3_column_text(pSelect, 1);
      int rc = sqlite3_exec(p->dbOut, zSql, 0, 0, 0);
      if( rc==SQLITE_OK ){
        recoverSqlCallback(p, zSql);
      }else if( rc!=SQLITE_ERROR ){
        recoverDbError(p, p->dbOut);
      }
    }
  }
  recoverFinalize(p, pSelect);

  return p->errCode;
}

/*
** This function is a no-op if recover handle p already contains an error
** (if p->errCode!=SQLITE_OK). In this case it returns NULL.
**
** Otherwise, if the recover handle is configured to create an output
** database (was created by sqlite3_recover_init()), then this function
** prepares and returns an SQL statement to INSERT a new record into table
** pTab, assuming the first nField fields of a record extracted from disk
** are valid.
**
** For example, if table pTab is:
**
**     CREATE TABLE name(a, b GENERATED ALWAYS AS (a+1) STORED, c, d, e);
**
** And nField is 4, then the SQL statement prepared and returned is:
**
**     INSERT INTO (a, c, d) VALUES (?1, ?2, ?3);
**
** In this case even though 4 values were extracted from the input db,
** only 3 are written to the output, as the generated STORED column 
** cannot be written.
**
** If the recover handle is in SQL callback mode, then the SQL statement
** prepared is such that evaluating it returns a single row containing
** a single text value - itself an SQL statement similar to the above,
** except with SQL literals in place of the variables. For example:
**
**     SELECT 'INSERT INTO (a, c, d) VALUES (' 
**          || quote(?1) || ', '
**          || quote(?2) || ', '
**          || quote(?3) || ')';
**
** In either case, it is the responsibility of the caller to eventually
** free the statement handle using sqlite3_finalize().
*/
static sqlite3_stmt *recoverInsertStmt(
  sqlite3_recover *p, 
  RecoverTable *pTab,
  int nField
){
  sqlite3_stmt *pRet = 0;
  const char *zSep = "";
  const char *zSqlSep = "";
  char *zSql = 0;
  char *zFinal = 0;
  char *zBind = 0;
  int ii;
  int bSql = p->xSql ? 1 : 0;

  if( nField<=0 ) return 0;

  assert( nField<=pTab->nCol );

  zSql = recoverMPrintf(p, "INSERT OR IGNORE INTO %Q(", pTab->zTab);

  if( pTab->iRowidBind ){
    assert( pTab->bIntkey );
    zSql = recoverMPrintf(p, "%z_rowid_", zSql);
    if( bSql ){
      zBind = recoverMPrintf(p, "%zquote(?%d)", zBind, pTab->iRowidBind);
    }else{
      zBind = recoverMPrintf(p, "%z?%d", zBind, pTab->iRowidBind);
    }
    zSqlSep = "||', '||";
    zSep = ", ";
  }

  for(ii=0; ii<nField; ii++){
    int eHidden = pTab->aCol[ii].eHidden;
    if( eHidden!=RECOVER_EHIDDEN_VIRTUAL
     && eHidden!=RECOVER_EHIDDEN_STORED
    ){
      assert( pTab->aCol[ii].iField>=0 && pTab->aCol[ii].iBind>=1 );
      zSql = recoverMPrintf(p, "%z%s%Q", zSql, zSep, pTab->aCol[ii].zCol);

      if( bSql ){
        zBind = recoverMPrintf(p, 
            "%z%sescape_crlf(quote(?%d))", zBind, zSqlSep, pTab->aCol[ii].iBind
        );
        zSqlSep = "||', '||";
      }else{
        zBind = recoverMPrintf(p, "%z%s?%d", zBind, zSep, pTab->aCol[ii].iBind);
      }
      zSep = ", ";
    }
  }

  if( bSql ){
    zFinal = recoverMPrintf(p, "SELECT %Q || ') VALUES (' || %s || ')'", 
        zSql, zBind
    );
  }else{
    zFinal = recoverMPrintf(p, "%s) VALUES (%s)", zSql, zBind);
  }

  pRet = recoverPrepare(p, p->dbOut, zFinal);
  sqlite3_free(zSql);
  sqlite3_free(zBind);
  sqlite3_free(zFinal);
  
  return pRet;
}


/*
** Search the list of RecoverTable objects at p->pTblList for one that
** has root page iRoot in the input database. If such an object is found,
** return a pointer to it. Otherwise, return NULL.
*/
static RecoverTable *recoverFindTable(sqlite3_recover *p, u32 iRoot){
  RecoverTable *pRet = 0;
  for(pRet=p->pTblList; pRet && pRet->iRoot!=iRoot; pRet=pRet->pNext);
  return pRet;
}

/*
** This function attempts to create a lost and found table within the 
** output db. If successful, it returns a pointer to a buffer containing
** the name of the new table. It is the responsibility of the caller to
** eventually free this buffer using sqlite3_free().
**
** If an error occurs, NULL is returned and an error code and error 
** message left in the recover handle.
*/
static char *recoverLostAndFoundCreate(
  sqlite3_recover *p,             /* Recover object */
  int nField                      /* Number of column fields in new table */
){
  char *zTbl = 0;
  sqlite3_stmt *pProbe = 0;
  int ii = 0;

  pProbe = recoverPrepare(p, p->dbOut,
    "SELECT 1 FROM sqlite_schema WHERE name=?"
  );
  for(ii=-1; zTbl==0 && p->errCode==SQLITE_OK && ii<1000; ii++){
    int bFail = 0;
    if( ii<0 ){
      zTbl = recoverMPrintf(p, "%s", p->zLostAndFound);
    }else{
      zTbl = recoverMPrintf(p, "%s_%d", p->zLostAndFound, ii);
    }

    if( p->errCode==SQLITE_OK ){
      sqlite3_bind_text(pProbe, 1, zTbl, -1, SQLITE_STATIC);
      if( SQLITE_ROW==sqlite3_step(pProbe) ){
        bFail = 1;
      }
      recoverReset(p, pProbe);
    }

    if( bFail ){
      sqlite3_clear_bindings(pProbe);
      sqlite3_free(zTbl);
      zTbl = 0;
    }
  }
  recoverFinalize(p, pProbe);

  if( zTbl ){
    const char *zSep = 0;
    char *zField = 0;
    char *zSql = 0;

    zSep = "rootpgno INTEGER, pgno INTEGER, nfield INTEGER, id INTEGER, ";
    for(ii=0; p->errCode==SQLITE_OK && ii<nField; ii++){
      zField = recoverMPrintf(p, "%z%sc%d", zField, zSep, ii);
      zSep = ", ";
    }

    zSql = recoverMPrintf(p, "CREATE TABLE %s(%s)", zTbl, zField);
    sqlite3_free(zField);

    recoverExec(p, p->dbOut, zSql);
    recoverSqlCallback(p, zSql);
    sqlite3_free(zSql);
  }else if( p->errCode==SQLITE_OK ){
    recoverError(
        p, SQLITE_ERROR, "failed to create %s output table", p->zLostAndFound
    );
  }

  return zTbl;
}

/*
** Synthesize and prepare an INSERT statement to write to the lost_and_found
** table in the output database. The name of the table is zTab, and it has
** nField c* fields.
*/
static sqlite3_stmt *recoverLostAndFoundInsert(
  sqlite3_recover *p,
  const char *zTab,
  int nField
){
  int nTotal = nField + 4;
  int ii;
  char *zBind = 0;
  sqlite3_stmt *pRet = 0;

  if( p->xSql==0 ){
    for(ii=0; ii<nTotal; ii++){
      zBind = recoverMPrintf(p, "%z%s?", zBind, zBind?", ":"", ii);
    }
    pRet = recoverPreparePrintf(
        p, p->dbOut, "INSERT INTO %s VALUES(%s)", zTab, zBind
    );
  }else{
    const char *zSep = "";
    for(ii=0; ii<nTotal; ii++){
      zBind = recoverMPrintf(p, "%z%squote(?)", zBind, zSep);
      zSep = "|| ', ' ||";
    }
    pRet = recoverPreparePrintf(
        p, p->dbOut, "SELECT 'INSERT INTO %s VALUES(' || %s || ')'", zTab, zBind
    );
  }

  sqlite3_free(zBind);
  return pRet;
}

/*
** Input database page iPg contains data that will be written to the
** lost-and-found table of the output database. This function attempts
** to identify the root page of the tree that page iPg belonged to.
** If successful, it sets output variable (*piRoot) to the page number
** of the root page and returns SQLITE_OK. Otherwise, if an error occurs,
** an SQLite error code is returned and the final value of *piRoot 
** undefined.
*/
static int recoverLostAndFoundFindRoot(
  sqlite3_recover *p, 
  i64 iPg,
  i64 *piRoot
){
  RecoverStateLAF *pLaf = &p->laf;

  if( pLaf->pFindRoot==0 ){
    pLaf->pFindRoot = recoverPrepare(p, p->dbOut,
        "WITH RECURSIVE p(pgno) AS ("
        "  SELECT ?"
        "    UNION"
        "  SELECT parent FROM recovery.map AS m, p WHERE m.pgno=p.pgno"
        ") "
        "SELECT p.pgno FROM p, recovery.map m WHERE m.pgno=p.pgno "
        "    AND m.parent IS NULL"
    );
  }
  if( p->errCode==SQLITE_OK ){
    sqlite3_bind_int64(pLaf->pFindRoot, 1, iPg);
    if( sqlite3_step(pLaf->pFindRoot)==SQLITE_ROW ){
      *piRoot = sqlite3_column_int64(pLaf->pFindRoot, 0);
    }else{
      *piRoot = iPg;
    }
    recoverReset(p, pLaf->pFindRoot);
  }
  return p->errCode;
}

/*
** Recover data from page iPage of the input database and write it to
** the lost-and-found table in the output database.
*/
static void recoverLostAndFoundOnePage(sqlite3_recover *p, i64 iPage){
  RecoverStateLAF *pLaf = &p->laf;
  sqlite3_value **apVal = pLaf->apVal;
  sqlite3_stmt *pPageData = pLaf->pPageData;
  sqlite3_stmt *pInsert = pLaf->pInsert;

  int nVal = -1;
  int iPrevCell = 0;
  i64 iRoot = 0;
  int bHaveRowid = 0;
  i64 iRowid = 0;
  int ii = 0;

  if( recoverLostAndFoundFindRoot(p, iPage, &iRoot) ) return;
  sqlite3_bind_int64(pPageData, 1, iPage);
  while( p->errCode==SQLITE_OK && SQLITE_ROW==sqlite3_step(pPageData) ){
    int iCell = sqlite3_column_int64(pPageData, 0);
    int iField = sqlite3_column_int64(pPageData, 1);

    if( iPrevCell!=iCell && nVal>=0 ){
      /* Insert the new row */
      sqlite3_bind_int64(pInsert, 1, iRoot);      /* rootpgno */
      sqlite3_bind_int64(pInsert, 2, iPage);      /* pgno */
      sqlite3_bind_int(pInsert, 3, nVal);         /* nfield */
      if( bHaveRowid ){
        sqlite3_bind_int64(pInsert, 4, iRowid);   /* id */
      }
      for(ii=0; ii<nVal; ii++){
        recoverBindValue(p, pInsert, 5+ii, apVal[ii]);
      }
      if( sqlite3_step(pInsert)==SQLITE_ROW ){
        recoverSqlCallback(p, (const char*)sqlite3_column_text(pInsert, 0));
      }
      recoverReset(p, pInsert);

      /* Discard the accumulated row data */
      for(ii=0; ii<nVal; ii++){
        sqlite3_value_free(apVal[ii]);
        apVal[ii] = 0;
      }
      sqlite3_clear_bindings(pInsert);
      bHaveRowid = 0;
      nVal = -1;
    }

    if( iCell<0 ) break;

    if( iField<0 ){
      assert( nVal==-1 );
      iRowid = sqlite3_column_int64(pPageData, 2);
      bHaveRowid = 1;
      nVal = 0;
    }else if( iField<pLaf->nMaxField ){
      sqlite3_value *pVal = sqlite3_column_value(pPageData, 2);
      apVal[iField] = sqlite3_value_dup(pVal);
      assert( iField==nVal || (nVal==-1 && iField==0) );
      nVal = iField+1;
      if( apVal[iField]==0 ){
        recoverError(p, SQLITE_NOMEM, 0);
      }
    }

    iPrevCell = iCell;
  }
  recoverReset(p, pPageData);

  for(ii=0; ii<nVal; ii++){
    sqlite3_value_free(apVal[ii]);
    apVal[ii] = 0;
  }
}

/*
** Perform one step (sqlite3_recover_step()) of work for the connection 
** passed as the only argument, which is guaranteed to be in
** RECOVER_STATE_LOSTANDFOUND3 state - during which the lost-and-found 
** table of the output database is populated with recovered data that can 
** not be assigned to any recovered schema object.
*/ 
static int recoverLostAndFound3Step(sqlite3_recover *p){
  RecoverStateLAF *pLaf = &p->laf;
  if( p->errCode==SQLITE_OK ){
    if( pLaf->pInsert==0 ){
      return SQLITE_DONE;
    }else{
      if( p->errCode==SQLITE_OK ){
        int res = sqlite3_step(pLaf->pAllPage);
        if( res==SQLITE_ROW ){
          i64 iPage = sqlite3_column_int64(pLaf->pAllPage, 0);
          if( recoverBitmapQuery(pLaf->pUsed, iPage)==0 ){
            recoverLostAndFoundOnePage(p, iPage);
          }
        }else{
          recoverReset(p, pLaf->pAllPage);
          return SQLITE_DONE;
        }
      }
    }
  }
  return SQLITE_OK;
}

/*
** Initialize resources required in RECOVER_STATE_LOSTANDFOUND3 
** state - during which the lost-and-found table of the output database 
** is populated with recovered data that can not be assigned to any 
** recovered schema object.
*/ 
static void recoverLostAndFound3Init(sqlite3_recover *p){
  RecoverStateLAF *pLaf = &p->laf;

  if( pLaf->nMaxField>0 ){
    char *zTab = 0;               /* Name of lost_and_found table */

    zTab = recoverLostAndFoundCreate(p, pLaf->nMaxField);
    pLaf->pInsert = recoverLostAndFoundInsert(p, zTab, pLaf->nMaxField);
    sqlite3_free(zTab);

    pLaf->pAllPage = recoverPreparePrintf(p, p->dbOut,
        "WITH RECURSIVE seq(ii) AS ("
        "  SELECT 1 UNION ALL SELECT ii+1 FROM seq WHERE ii<%lld"
        ")"
        "SELECT ii FROM seq" , p->laf.nPg
    );
    pLaf->pPageData = recoverPrepare(p, p->dbOut,
        "SELECT cell, field, value "
        "FROM sqlite_dbdata('getpage()') d WHERE d.pgno=? "
        "UNION ALL "
        "SELECT -1, -1, -1"
    );

    pLaf->apVal = (sqlite3_value**)recoverMalloc(p, 
        pLaf->nMaxField*sizeof(sqlite3_value*)
    );
  }
}

/*
** Initialize resources required in RECOVER_STATE_WRITING state - during which
** tables recovered from the schema of the input database are populated with
** recovered data.
*/ 
static int recoverWriteDataInit(sqlite3_recover *p){
  RecoverStateW1 *p1 = &p->w1;
  RecoverTable *pTbl = 0;
  int nByte = 0;

  /* Figure out the maximum number of columns for any table in the schema */
  assert( p1->nMax==0 );
  for(pTbl=p->pTblList; pTbl; pTbl=pTbl->pNext){
    if( pTbl->nCol>p1->nMax ) p1->nMax = pTbl->nCol;
  }

  /* Allocate an array of (sqlite3_value*) in which to accumulate the values
  ** that will be written to the output database in a single row. */
  nByte = sizeof(sqlite3_value*) * (p1->nMax+1);
  p1->apVal = (sqlite3_value**)recoverMalloc(p, nByte);
  if( p1->apVal==0 ) return p->errCode;

  /* Prepare the SELECT to loop through schema tables (pTbls) and the SELECT
  ** to loop through cells that appear to belong to a single table (pSel). */
  p1->pTbls = recoverPrepare(p, p->dbOut,
      "SELECT rootpage FROM recovery.schema "
      "  WHERE type='table' AND (sql NOT LIKE 'create virtual%')"
      "  ORDER BY (tbl_name='sqlite_sequence') ASC"
  );
  p1->pSel = recoverPrepare(p, p->dbOut, 
      "WITH RECURSIVE pages(page) AS ("
      "  SELECT ?1"
      "    UNION"
      "  SELECT child FROM sqlite_dbptr('getpage()'), pages "
      "    WHERE pgno=page"
      ") "
      "SELECT page, cell, field, value "
      "FROM sqlite_dbdata('getpage()') d, pages p WHERE p.page=d.pgno "
      "UNION ALL "
      "SELECT 0, 0, 0, 0"
  );

  return p->errCode;
}

/*
** Clean up resources allocated by recoverWriteDataInit() (stuff in 
** sqlite3_recover.w1).
*/
static void recoverWriteDataCleanup(sqlite3_recover *p){
  RecoverStateW1 *p1 = &p->w1;
  int ii;
  for(ii=0; ii<p1->nVal; ii++){
    sqlite3_value_free(p1->apVal[ii]);
  }
  sqlite3_free(p1->apVal);
  recoverFinalize(p, p1->pInsert);
  recoverFinalize(p, p1->pTbls);
  recoverFinalize(p, p1->pSel);
  memset(p1, 0, sizeof(*p1));
}

/*
** Perform one step (sqlite3_recover_step()) of work for the connection 
** passed as the only argument, which is guaranteed to be in
** RECOVER_STATE_WRITING state - during which tables recovered from the
** schema of the input database are populated with recovered data.
*/ 
static int recoverWriteDataStep(sqlite3_recover *p){
  RecoverStateW1 *p1 = &p->w1;
  sqlite3_stmt *pSel = p1->pSel;
  sqlite3_value **apVal = p1->apVal;

  if( p->errCode==SQLITE_OK && p1->pTab==0 ){
    if( sqlite3_step(p1->pTbls)==SQLITE_ROW ){
      i64 iRoot = sqlite3_column_int64(p1->pTbls, 0);
      p1->pTab = recoverFindTable(p, iRoot);

      recoverFinalize(p, p1->pInsert);
      p1->pInsert = 0;

      /* If this table is unknown, return early. The caller will invoke this
      ** function again and it will move on to the next table.  */
      if( p1->pTab==0 ) return p->errCode;

      /* If this is the sqlite_sequence table, delete any rows added by
      ** earlier INSERT statements on tables with AUTOINCREMENT primary
      ** keys before recovering its contents. The p1->pTbls SELECT statement
      ** is rigged to deliver "sqlite_sequence" last of all, so we don't
      ** worry about it being modified after it is recovered. */
      if( sqlite3_stricmp("sqlite_sequence", p1->pTab->zTab)==0 ){
        recoverExec(p, p->dbOut, "DELETE FROM sqlite_sequence");
        recoverSqlCallback(p, "DELETE FROM sqlite_sequence");
      }

      /* Bind the root page of this table within the original database to 
      ** SELECT statement p1->pSel. The SELECT statement will then iterate
      ** through cells that look like they belong to table pTab.  */
      sqlite3_bind_int64(pSel, 1, iRoot);

      p1->nVal = 0;
      p1->bHaveRowid = 0;
      p1->iPrevPage = -1;
      p1->iPrevCell = -1;
    }else{
      return SQLITE_DONE;
    }
  }
  assert( p->errCode!=SQLITE_OK || p1->pTab );

  if( p->errCode==SQLITE_OK && sqlite3_step(pSel)==SQLITE_ROW ){
    RecoverTable *pTab = p1->pTab;

    i64 iPage = sqlite3_column_int64(pSel, 0);
    int iCell = sqlite3_column_int(pSel, 1);
    int iField = sqlite3_column_int(pSel, 2);
    sqlite3_value *pVal = sqlite3_column_value(pSel, 3);
    int bNewCell = (p1->iPrevPage!=iPage || p1->iPrevCell!=iCell);

    assert( bNewCell==0 || (iField==-1 || iField==0) );
    assert( bNewCell || iField==p1->nVal || p1->nVal==pTab->nCol );

    if( bNewCell ){
      int ii = 0;
      if( p1->nVal>=0 ){
        if( p1->pInsert==0 || p1->nVal!=p1->nInsert ){
          recoverFinalize(p, p1->pInsert);
          p1->pInsert = recoverInsertStmt(p, pTab, p1->nVal);
          p1->nInsert = p1->nVal;
        }
        if( p1->nVal>0 ){
          sqlite3_stmt *pInsert = p1->pInsert;
          for(ii=0; ii<pTab->nCol; ii++){
            RecoverColumn *pCol = &pTab->aCol[ii];
            int iBind = pCol->iBind;
            if( iBind>0 ){
              if( pCol->bIPK ){
                sqlite3_bind_int64(pInsert, iBind, p1->iRowid);
              }else if( pCol->iField<p1->nVal ){
                recoverBindValue(p, pInsert, iBind, apVal[pCol->iField]);
              }
            }
          }
          if( p->bRecoverRowid && pTab->iRowidBind>0 && p1->bHaveRowid ){
            sqlite3_bind_int64(pInsert, pTab->iRowidBind, p1->iRowid);
          }
          if( SQLITE_ROW==sqlite3_step(pInsert) ){
            const char *z = (const char*)sqlite3_column_text(pInsert, 0);
            recoverSqlCallback(p, z);
          }
          recoverReset(p, pInsert);
          assert( p->errCode || pInsert );
          if( pInsert ) sqlite3_clear_bindings(pInsert);
        }
      }

      for(ii=0; ii<p1->nVal; ii++){
        sqlite3_value_free(apVal[ii]);
        apVal[ii] = 0;
      }
      p1->nVal = -1;
      p1->bHaveRowid = 0;
    }

    if( iPage!=0 ){
      if( iField<0 ){
        p1->iRowid = sqlite3_column_int64(pSel, 3);
        assert( p1->nVal==-1 );
        p1->nVal = 0;
        p1->bHaveRowid = 1;
      }else if( iField<pTab->nCol ){
        assert( apVal[iField]==0 );
        apVal[iField] = sqlite3_value_dup( pVal );
        if( apVal[iField]==0 ){
          recoverError(p, SQLITE_NOMEM, 0);
        }
        p1->nVal = iField+1;
      }
      p1->iPrevCell = iCell;
      p1->iPrevPage = iPage;
    }
  }else{
    recoverReset(p, pSel);
    p1->pTab = 0;
  }

  return p->errCode;
}

/*
** Initialize resources required by sqlite3_recover_step() in
** RECOVER_STATE_LOSTANDFOUND1 state - during which the set of pages not
** already allocated to a recovered schema element is determined.
*/ 
static void recoverLostAndFound1Init(sqlite3_recover *p){
  RecoverStateLAF *pLaf = &p->laf;
  sqlite3_stmt *pStmt = 0;

  assert( p->laf.pUsed==0 );
  pLaf->nPg = recoverPageCount(p);
  pLaf->pUsed = recoverBitmapAlloc(p, pLaf->nPg);

  /* Prepare a statement to iterate through all pages that are part of any tree
  ** in the recoverable part of the input database schema to the bitmap. And,
  ** if !p->bFreelistCorrupt, add all pages that appear to be part of the
  ** freelist.  */
  pStmt = recoverPrepare(
      p, p->dbOut,
      "WITH trunk(pgno) AS ("
      "  SELECT read_i32(getpage(1), 8) AS x WHERE x>0"
      "    UNION"
      "  SELECT read_i32(getpage(trunk.pgno), 0) AS x FROM trunk WHERE x>0"
      "),"
      "trunkdata(pgno, data) AS ("
      "  SELECT pgno, getpage(pgno) FROM trunk"
      "),"
      "freelist(data, n, freepgno) AS ("
      "  SELECT data, min(16384, read_i32(data, 1)-1), pgno FROM trunkdata"
      "    UNION ALL"
      "  SELECT data, n-1, read_i32(data, 2+n) FROM freelist WHERE n>=0"
      "),"
      ""
      "roots(r) AS ("
      "  SELECT 1 UNION ALL"
      "  SELECT rootpage FROM recovery.schema WHERE rootpage>0"
      "),"
      "used(page) AS ("
      "  SELECT r FROM roots"
      "    UNION"
      "  SELECT child FROM sqlite_dbptr('getpage()'), used "
      "    WHERE pgno=page"
      ") "
      "SELECT page FROM used"
      " UNION ALL "
      "SELECT freepgno FROM freelist WHERE NOT ?"
  );
  if( pStmt ) sqlite3_bind_int(pStmt, 1, p->bFreelistCorrupt);
  pLaf->pUsedPages = pStmt;
}

/*
** Perform one step (sqlite3_recover_step()) of work for the connection 
** passed as the only argument, which is guaranteed to be in
** RECOVER_STATE_LOSTANDFOUND1 state - during which the set of pages not
** already allocated to a recovered schema element is determined.
*/ 
static int recoverLostAndFound1Step(sqlite3_recover *p){
  RecoverStateLAF *pLaf = &p->laf;
  int rc = p->errCode;
  if( rc==SQLITE_OK ){
    rc = sqlite3_step(pLaf->pUsedPages);
    if( rc==SQLITE_ROW ){
      i64 iPg = sqlite3_column_int64(pLaf->pUsedPages, 0);
      recoverBitmapSet(pLaf->pUsed, iPg);
      rc = SQLITE_OK;
    }else{
      recoverFinalize(p, pLaf->pUsedPages);
      pLaf->pUsedPages = 0;
    }
  }
  return rc;
}

/*
** Initialize resources required by RECOVER_STATE_LOSTANDFOUND2 
** state - during which the pages identified in RECOVER_STATE_LOSTANDFOUND1
** are sorted into sets that likely belonged to the same database tree.
*/ 
static void recoverLostAndFound2Init(sqlite3_recover *p){
  RecoverStateLAF *pLaf = &p->laf;

  assert( p->laf.pAllAndParent==0 );
  assert( p->laf.pMapInsert==0 );
  assert( p->laf.pMaxField==0 );
  assert( p->laf.nMaxField==0 );

  pLaf->pMapInsert = recoverPrepare(p, p->dbOut,
      "INSERT OR IGNORE INTO recovery.map(pgno, parent) VALUES(?, ?)"
  );
  pLaf->pAllAndParent = recoverPreparePrintf(p, p->dbOut,
      "WITH RECURSIVE seq(ii) AS ("
      "  SELECT 1 UNION ALL SELECT ii+1 FROM seq WHERE ii<%lld"
      ")"
      "SELECT pgno, child FROM sqlite_dbptr('getpage()') "
      " UNION ALL "
      "SELECT NULL, ii FROM seq", p->laf.nPg
  );
  pLaf->pMaxField = recoverPreparePrintf(p, p->dbOut,
      "SELECT max(field)+1 FROM sqlite_dbdata('getpage') WHERE pgno = ?"
  );
}

/*
** Perform one step (sqlite3_recover_step()) of work for the connection 
** passed as the only argument, which is guaranteed to be in
** RECOVER_STATE_LOSTANDFOUND2 state - during which the pages identified 
** in RECOVER_STATE_LOSTANDFOUND1 are sorted into sets that likely belonged 
** to the same database tree.
*/ 
static int recoverLostAndFound2Step(sqlite3_recover *p){
  RecoverStateLAF *pLaf = &p->laf;
  if( p->errCode==SQLITE_OK ){
    int res = sqlite3_step(pLaf->pAllAndParent);
    if( res==SQLITE_ROW ){
      i64 iChild = sqlite3_column_int(pLaf->pAllAndParent, 1);
      if( recoverBitmapQuery(pLaf->pUsed, iChild)==0 ){
        sqlite3_bind_int64(pLaf->pMapInsert, 1, iChild);
        sqlite3_bind_value(pLaf->pMapInsert, 2, 
            sqlite3_column_value(pLaf->pAllAndParent, 0)
        );
        sqlite3_step(pLaf->pMapInsert);
        recoverReset(p, pLaf->pMapInsert);
        sqlite3_bind_int64(pLaf->pMaxField, 1, iChild);
        if( SQLITE_ROW==sqlite3_step(pLaf->pMaxField) ){
          int nMax = sqlite3_column_int(pLaf->pMaxField, 0);
          if( nMax>pLaf->nMaxField ) pLaf->nMaxField = nMax;
        }
        recoverReset(p, pLaf->pMaxField);
      }
    }else{
      recoverFinalize(p, pLaf->pAllAndParent);
      pLaf->pAllAndParent =0;
      return SQLITE_DONE;
    }
  }
  return p->errCode;
}

/*
** Free all resources allocated as part of sqlite3_recover_step() calls
** in one of the RECOVER_STATE_LOSTANDFOUND[123] states.
*/
static void recoverLostAndFoundCleanup(sqlite3_recover *p){
  recoverBitmapFree(p->laf.pUsed);
  p->laf.pUsed = 0;
  sqlite3_finalize(p->laf.pUsedPages);
  sqlite3_finalize(p->laf.pAllAndParent);
  sqlite3_finalize(p->laf.pMapInsert);
  sqlite3_finalize(p->laf.pMaxField);
  sqlite3_finalize(p->laf.pFindRoot);
  sqlite3_finalize(p->laf.pInsert);
  sqlite3_finalize(p->laf.pAllPage);
  sqlite3_finalize(p->laf.pPageData);
  p->laf.pUsedPages = 0;
  p->laf.pAllAndParent = 0;
  p->laf.pMapInsert = 0;
  p->laf.pMaxField = 0;
  p->laf.pFindRoot = 0;
  p->laf.pInsert = 0;
  p->laf.pAllPage = 0;
  p->laf.pPageData = 0;
  sqlite3_free(p->laf.apVal);
  p->laf.apVal = 0;
}

/*
** Free all resources allocated as part of sqlite3_recover_step() calls.
*/
static void recoverFinalCleanup(sqlite3_recover *p){
  RecoverTable *pTab = 0;
  RecoverTable *pNext = 0;

  recoverWriteDataCleanup(p);
  recoverLostAndFoundCleanup(p);

  for(pTab=p->pTblList; pTab; pTab=pNext){
    pNext = pTab->pNext;
    sqlite3_free(pTab);
  }
  p->pTblList = 0;
  sqlite3_finalize(p->pGetPage);
  p->pGetPage = 0;
  sqlite3_file_control(p->dbIn, p->zDb, SQLITE_FCNTL_RESET_CACHE, 0);

  {
#ifndef NDEBUG
    int res = 
#endif
       sqlite3_close(p->dbOut);
    assert( res==SQLITE_OK );
  }
  p->dbOut = 0;
}

/*
** Decode and return an unsigned 16-bit big-endian integer value from 
** buffer a[].
*/
static u32 recoverGetU16(const u8 *a){
  return (((u32)a[0])<<8) + ((u32)a[1]);
}

/*
** Decode and return an unsigned 32-bit big-endian integer value from 
** buffer a[].
*/
static u32 recoverGetU32(const u8 *a){
  return (((u32)a[0])<<24) + (((u32)a[1])<<16) + (((u32)a[2])<<8) + ((u32)a[3]);
}

/*
** Decode an SQLite varint from buffer a[]. Write the decoded value to (*pVal)
** and return the number of bytes consumed.
*/
static int recoverGetVarint(const u8 *a, i64 *pVal){
  sqlite3_uint64 u = 0;
  int i;
  for(i=0; i<8; i++){
    u = (u<<7) + (a[i]&0x7f);
    if( (a[i]&0x80)==0 ){ *pVal = (sqlite3_int64)u; return i+1; }
  }
  u = (u<<8) + (a[i]&0xff);
  *pVal = (sqlite3_int64)u;
  return 9;
}

/*
** The second argument points to a buffer n bytes in size. If this buffer
** or a prefix thereof appears to contain a well-formed SQLite b-tree page, 
** return the page-size in bytes. Otherwise, if the buffer does not 
** appear to contain a well-formed b-tree page, return 0.
*/
static int recoverIsValidPage(u8 *aTmp, const u8 *a, int n){
  u8 *aUsed = aTmp;
  int nFrag = 0;
  int nActual = 0;
  int iFree = 0;
  int nCell = 0;                  /* Number of cells on page */
  int iCellOff = 0;               /* Offset of cell array in page */
  int iContent = 0;
  int eType = 0;
  int ii = 0;

  eType = (int)a[0];
  if( eType!=0x02 && eType!=0x05 && eType!=0x0A && eType!=0x0D ) return 0;

  iFree = (int)recoverGetU16(&a[1]);
  nCell = (int)recoverGetU16(&a[3]);
  iContent = (int)recoverGetU16(&a[5]);
  if( iContent==0 ) iContent = 65536;
  nFrag = (int)a[7];

  if( iContent>n ) return 0;

  memset(aUsed, 0, n);
  memset(aUsed, 0xFF, iContent);

  /* Follow the free-list. This is the same format for all b-tree pages. */
  if( iFree && iFree<=iContent ) return 0;
  while( iFree ){
    int iNext = 0;
    int nByte = 0;
    if( iFree>(n-4) ) return 0;
    iNext = recoverGetU16(&a[iFree]);
    nByte = recoverGetU16(&a[iFree+2]);
    if( iFree+nByte>n || nByte<4 ) return 0;
    if( iNext && iNext<iFree+nByte ) return 0;
    memset(&aUsed[iFree], 0xFF, nByte);
    iFree = iNext;
  }

  /* Run through the cells */
  if( eType==0x02 || eType==0x05 ){
    iCellOff = 12;
  }else{
    iCellOff = 8;
  }
  if( (iCellOff + 2*nCell)>iContent ) return 0;
  for(ii=0; ii<nCell; ii++){
    int iByte;
    i64 nPayload = 0;
    int nByte = 0;
    int iOff = recoverGetU16(&a[iCellOff + 2*ii]);
    if( iOff<iContent || iOff>n ){
      return 0;
    }
    if( eType==0x05 || eType==0x02 ) nByte += 4;
    nByte += recoverGetVarint(&a[iOff+nByte], &nPayload);
    if( eType==0x0D ){
      i64 dummy = 0;
      nByte += recoverGetVarint(&a[iOff+nByte], &dummy);
    }
    if( eType!=0x05 ){
      int X = (eType==0x0D) ? n-35 : (((n-12)*64/255)-23);
      int M = ((n-12)*32/255)-23;
      int K = M+((nPayload-M)%(n-4));

      if( nPayload<X ){
        nByte += nPayload;
      }else if( K<=X ){
        nByte += K+4;
      }else{
        nByte += M+4;
      }
    }

    if( iOff+nByte>n ){
      return 0;
    }
    for(iByte=iOff; iByte<(iOff+nByte); iByte++){
      if( aUsed[iByte]!=0 ){
        return 0;
      }
      aUsed[iByte] = 0xFF;
    }
  }

  nActual = 0;
  for(ii=0; ii<n; ii++){
    if( aUsed[ii]==0 ) nActual++;
  }
  return (nActual==nFrag);
}


static int recoverVfsClose(sqlite3_file*);
static int recoverVfsRead(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
static int recoverVfsWrite(sqlite3_file*, const void*, int, sqlite3_int64);
static int recoverVfsTruncate(sqlite3_file*, sqlite3_int64 size);
static int recoverVfsSync(sqlite3_file*, int flags);
static int recoverVfsFileSize(sqlite3_file*, sqlite3_int64 *pSize);
static int recoverVfsLock(sqlite3_file*, int);
static int recoverVfsUnlock(sqlite3_file*, int);
static int recoverVfsCheckReservedLock(sqlite3_file*, int *pResOut);
static int recoverVfsFileControl(sqlite3_file*, int op, void *pArg);
static int recoverVfsSectorSize(sqlite3_file*);
static int recoverVfsDeviceCharacteristics(sqlite3_file*);
static int recoverVfsShmMap(sqlite3_file*, int, int, int, void volatile**);
static int recoverVfsShmLock(sqlite3_file*, int offset, int n, int flags);
static void recoverVfsShmBarrier(sqlite3_file*);
static int recoverVfsShmUnmap(sqlite3_file*, int deleteFlag);
static int recoverVfsFetch(sqlite3_file*, sqlite3_int64, int, void**);
static int recoverVfsUnfetch(sqlite3_file *pFd, sqlite3_int64 iOff, void *p);

static sqlite3_io_methods recover_methods = {
  2, /* iVersion */
  recoverVfsClose,
  recoverVfsRead,
  recoverVfsWrite,
  recoverVfsTruncate,
  recoverVfsSync,
  recoverVfsFileSize,
  recoverVfsLock,
  recoverVfsUnlock,
  recoverVfsCheckReservedLock,
  recoverVfsFileControl,
  recoverVfsSectorSize,
  recoverVfsDeviceCharacteristics,
  recoverVfsShmMap,
  recoverVfsShmLock,
  recoverVfsShmBarrier,
  recoverVfsShmUnmap,
  recoverVfsFetch,
  recoverVfsUnfetch
};

static int recoverVfsClose(sqlite3_file *pFd){
  assert( pFd->pMethods!=&recover_methods );
  return pFd->pMethods->xClose(pFd);
}

/*
** Write value v to buffer a[] as a 16-bit big-endian unsigned integer.
*/
static void recoverPutU16(u8 *a, u32 v){
  a[0] = (v>>8) & 0x00FF;
  a[1] = (v>>0) & 0x00FF;
}

/*
** Write value v to buffer a[] as a 32-bit big-endian unsigned integer.
*/
static void recoverPutU32(u8 *a, u32 v){
  a[0] = (v>>24) & 0x00FF;
  a[1] = (v>>16) & 0x00FF;
  a[2] = (v>>8) & 0x00FF;
  a[3] = (v>>0) & 0x00FF;
}

/*
** Detect the page-size of the database opened by file-handle pFd by 
** searching the first part of the file for a well-formed SQLite b-tree 
** page. If parameter nReserve is non-zero, then as well as searching for
** a b-tree page with zero reserved bytes, this function searches for one
** with nReserve reserved bytes at the end of it.
**
** If successful, set variable p->detected_pgsz to the detected page-size
** in bytes and return SQLITE_OK. Or, if no error occurs but no valid page
** can be found, return SQLITE_OK but leave p->detected_pgsz set to 0. Or,
** if an error occurs (e.g. an IO or OOM error), then an SQLite error code
** is returned. The final value of p->detected_pgsz is undefined in this
** case.
*/
static int recoverVfsDetectPagesize(
  sqlite3_recover *p,             /* Recover handle */
  sqlite3_file *pFd,              /* File-handle open on input database */
  u32 nReserve,                   /* Possible nReserve value */
  i64 nSz                         /* Size of database file in bytes */
){
  int rc = SQLITE_OK;
  const int nMin = 512;
  const int nMax = 65536;
  const int nMaxBlk = 4;
  u32 pgsz = 0;
  int iBlk = 0;
  u8 *aPg = 0;
  u8 *aTmp = 0;
  int nBlk = 0;

  aPg = (u8*)sqlite3_malloc(2*nMax);
  if( aPg==0 ) return SQLITE_NOMEM;
  aTmp = &aPg[nMax];

  nBlk = (nSz+nMax-1)/nMax;
  if( nBlk>nMaxBlk ) nBlk = nMaxBlk;

  do {
    for(iBlk=0; rc==SQLITE_OK && iBlk<nBlk; iBlk++){
      int nByte = (nSz>=((iBlk+1)*nMax)) ? nMax : (nSz % nMax);
      memset(aPg, 0, nMax);
      rc = pFd->pMethods->xRead(pFd, aPg, nByte, iBlk*nMax);
      if( rc==SQLITE_OK ){
        int pgsz2;
        for(pgsz2=(pgsz ? pgsz*2 : nMin); pgsz2<=nMax; pgsz2=pgsz2*2){
          int iOff;
          for(iOff=0; iOff<nMax; iOff+=pgsz2){
            if( recoverIsValidPage(aTmp, &aPg[iOff], pgsz2-nReserve) ){
              pgsz = pgsz2;
              break;
            }
          }
        }
      }
    }
    if( pgsz>(u32)p->detected_pgsz ){
      p->detected_pgsz = pgsz;
      p->nReserve = nReserve;
    }
    if( nReserve==0 ) break;
    nReserve = 0;
  }while( 1 );

  p->detected_pgsz = pgsz;
  sqlite3_free(aPg);
  return rc;
}

/*
** The xRead() method of the wrapper VFS. This is used to intercept calls
** to read page 1 of the input database.
*/
static int recoverVfsRead(sqlite3_file *pFd, void *aBuf, int nByte, i64 iOff){
  int rc = SQLITE_OK;
  if( pFd->pMethods==&recover_methods ){
    pFd->pMethods = recover_g.pMethods;
    rc = pFd->pMethods->xRead(pFd, aBuf, nByte, iOff);
    if( nByte==16 ){
      sqlite3_randomness(16, aBuf);
    }else
    if( rc==SQLITE_OK && iOff==0 && nByte>=108 ){
      /* Ensure that the database has a valid header file. The only fields
      ** that really matter to recovery are:
      **
      **   + Database page size (16-bits at offset 16)
      **   + Size of db in pages (32-bits at offset 28)
      **   + Database encoding (32-bits at offset 56)
      **
      ** Also preserved are:
      **
      **   + first freelist page (32-bits at offset 32)
      **   + size of freelist (32-bits at offset 36)
      **   + the wal-mode flags (16-bits at offset 18)
      **
      ** We also try to preserve the auto-vacuum, incr-value, user-version
      ** and application-id fields - all 32 bit quantities at offsets 
      ** 52, 60, 64 and 68. All other fields are set to known good values.
      **
      ** Byte offset 105 should also contain the page-size as a 16-bit 
      ** integer.
      */
      const int aPreserve[] = {32, 36, 52, 60, 64, 68};
      u8 aHdr[108] = {
        0x53, 0x51, 0x4c, 0x69, 0x74, 0x65, 0x20, 0x66, 
        0x6f, 0x72, 0x6d, 0x61, 0x74, 0x20, 0x33, 0x00,
        0xFF, 0xFF, 0x01, 0x01, 0x00, 0x40, 0x20, 0x20,
        0x00, 0x00, 0x00, 0x00, 0xFF, 0xFF, 0xFF, 0xFF,
        0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x04,
        0x00, 0x00, 0x10, 0x00, 0xFF, 0xFF, 0xFF, 0xFF,
        0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
        0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x2e, 0x5b, 0x30,

        0x0D, 0x00, 0x00, 0x00, 0x00, 0xFF, 0xFF, 0x00
      };
      u8 *a = (u8*)aBuf;

      u32 pgsz = recoverGetU16(&a[16]);
      u32 nReserve = a[20];
      u32 enc = recoverGetU32(&a[56]);
      u32 dbsz = 0;
      i64 dbFileSize = 0;
      int ii;
      sqlite3_recover *p = recover_g.p;

      if( pgsz==0x01 ) pgsz = 65536;
      rc = pFd->pMethods->xFileSize(pFd, &dbFileSize);

      if( rc==SQLITE_OK && p->detected_pgsz==0 ){
        rc = recoverVfsDetectPagesize(p, pFd, nReserve, dbFileSize);
      }
      if( p->detected_pgsz ){
        pgsz = p->detected_pgsz;
        nReserve = p->nReserve;
      }

      if( pgsz ){
        dbsz = dbFileSize / pgsz;
      }
      if( enc!=SQLITE_UTF8 && enc!=SQLITE_UTF16BE && enc!=SQLITE_UTF16LE ){
        enc = SQLITE_UTF8;
      }

      sqlite3_free(p->pPage1Cache);
      p->pPage1Cache = 0;
      p->pPage1Disk = 0;

      p->pgsz = nByte;
      p->pPage1Cache = (u8*)recoverMalloc(p, nByte*2);
      if( p->pPage1Cache ){
        p->pPage1Disk = &p->pPage1Cache[nByte];
        memcpy(p->pPage1Disk, aBuf, nByte);
        aHdr[18] = a[18];
        aHdr[19] = a[19];
        recoverPutU32(&aHdr[28], dbsz);
        recoverPutU32(&aHdr[56], enc);
        recoverPutU16(&aHdr[105], pgsz-nReserve);
        if( pgsz==65536 ) pgsz = 1;
        recoverPutU16(&aHdr[16], pgsz);
        aHdr[20] = nReserve;
        for(ii=0; ii<(int)(sizeof(aPreserve)/sizeof(aPreserve[0])); ii++){
          memcpy(&aHdr[aPreserve[ii]], &a[aPreserve[ii]], 4);
        }
        memcpy(aBuf, aHdr, sizeof(aHdr));
        memset(&((u8*)aBuf)[sizeof(aHdr)], 0, nByte-sizeof(aHdr));

        memcpy(p->pPage1Cache, aBuf, nByte);
      }else{
        rc = p->errCode;
      }

    }
    pFd->pMethods = &recover_methods;
  }else{
    rc = pFd->pMethods->xRead(pFd, aBuf, nByte, iOff);
  }
  return rc;
}

/*
** Used to make sqlite3_io_methods wrapper methods less verbose.
*/
#define RECOVER_VFS_WRAPPER(code)                         \
  int rc = SQLITE_OK;                                     \
  if( pFd->pMethods==&recover_methods ){                  \
    pFd->pMethods = recover_g.pMethods;                   \
    rc = code;                                            \
    pFd->pMethods = &recover_methods;                     \
  }else{                                                  \
    rc = code;                                            \
  }                                                       \
  return rc;                                              

/*
** Methods of the wrapper VFS. All methods except for xRead() and xClose()
** simply uninstall the sqlite3_io_methods wrapper, invoke the equivalent
** method on the lower level VFS, then reinstall the wrapper before returning.
** Those that return an integer value use the RECOVER_VFS_WRAPPER macro.
*/
static int recoverVfsWrite(
  sqlite3_file *pFd, const void *aBuf, int nByte, i64 iOff
){
  RECOVER_VFS_WRAPPER (
      pFd->pMethods->xWrite(pFd, aBuf, nByte, iOff)
  );
}
static int recoverVfsTruncate(sqlite3_file *pFd, sqlite3_int64 size){
  RECOVER_VFS_WRAPPER (
      pFd->pMethods->xTruncate(pFd, size)
  );
}
static int recoverVfsSync(sqlite3_file *pFd, int flags){
  RECOVER_VFS_WRAPPER (
      pFd->pMethods->xSync(pFd, flags)
  );
}
static int recoverVfsFileSize(sqlite3_file *pFd, sqlite3_int64 *pSize){
  RECOVER_VFS_WRAPPER (
      pFd->pMethods->xFileSize(pFd, pSize)
  );
}
static int recoverVfsLock(sqlite3_file *pFd, int eLock){
  RECOVER_VFS_WRAPPER (
      pFd->pMethods->xLock(pFd, eLock)
  );
}
static int recoverVfsUnlock(sqlite3_file *pFd, int eLock){
  RECOVER_VFS_WRAPPER (
      pFd->pMethods->xUnlock(pFd, eLock)
  );
}
static int recoverVfsCheckReservedLock(sqlite3_file *pFd, int *pResOut){
  RECOVER_VFS_WRAPPER (
      pFd->pMethods->xCheckReservedLock(pFd, pResOut)
  );
}
static int recoverVfsFileControl(sqlite3_file *pFd, int op, void *pArg){
  RECOVER_VFS_WRAPPER (
    (pFd->pMethods ?  pFd->pMethods->xFileControl(pFd, op, pArg) : SQLITE_NOTFOUND)
  );
}
static int recoverVfsSectorSize(sqlite3_file *pFd){
  RECOVER_VFS_WRAPPER (
      pFd->pMethods->xSectorSize(pFd)
  );
}
static int recoverVfsDeviceCharacteristics(sqlite3_file *pFd){
  RECOVER_VFS_WRAPPER (
      pFd->pMethods->xDeviceCharacteristics(pFd)
  );
}
static int recoverVfsShmMap(
  sqlite3_file *pFd, int iPg, int pgsz, int bExtend, void volatile **pp
){
  RECOVER_VFS_WRAPPER (
      pFd->pMethods->xShmMap(pFd, iPg, pgsz, bExtend, pp)
  );
}
static int recoverVfsShmLock(sqlite3_file *pFd, int offset, int n, int flags){
  RECOVER_VFS_WRAPPER (
      pFd->pMethods->xShmLock(pFd, offset, n, flags)
  );
}
static void recoverVfsShmBarrier(sqlite3_file *pFd){
  if( pFd->pMethods==&recover_methods ){
    pFd->pMethods = recover_g.pMethods;
    pFd->pMethods->xShmBarrier(pFd);
    pFd->pMethods = &recover_methods;
  }else{
    pFd->pMethods->xShmBarrier(pFd);
  }
}
static int recoverVfsShmUnmap(sqlite3_file *pFd, int deleteFlag){
  RECOVER_VFS_WRAPPER (
      pFd->pMethods->xShmUnmap(pFd, deleteFlag)
  );
}

static int recoverVfsFetch(
  sqlite3_file *pFd, 
  sqlite3_int64 iOff, 
  int iAmt, 
  void **pp
){
  (void)pFd;
  (void)iOff;
  (void)iAmt;
  *pp = 0;
  return SQLITE_OK;
}
static int recoverVfsUnfetch(sqlite3_file *pFd, sqlite3_int64 iOff, void *p){
  (void)pFd;
  (void)iOff;
  (void)p;
  return SQLITE_OK;
}

/*
** Install the VFS wrapper around the file-descriptor open on the input
** database for recover handle p. Mutex RECOVER_MUTEX_ID must be held
** when this function is called.
*/
static void recoverInstallWrapper(sqlite3_recover *p){
  sqlite3_file *pFd = 0;
  assert( recover_g.pMethods==0 );
  recoverAssertMutexHeld();
  sqlite3_file_control(p->dbIn, p->zDb, SQLITE_FCNTL_FILE_POINTER, (void*)&pFd);
  assert( pFd==0 || pFd->pMethods!=&recover_methods );
  if( pFd && pFd->pMethods ){
    int iVersion = 1 + (pFd->pMethods->iVersion>1 && pFd->pMethods->xShmMap!=0);
    recover_g.pMethods = pFd->pMethods;
    recover_g.p = p;
    recover_methods.iVersion = iVersion;
    pFd->pMethods = &recover_methods;
  }
}

/*
** Uninstall the VFS wrapper that was installed around the file-descriptor open
** on the input database for recover handle p. Mutex RECOVER_MUTEX_ID must be
** held when this function is called.
*/
static void recoverUninstallWrapper(sqlite3_recover *p){
  sqlite3_file *pFd = 0;
  recoverAssertMutexHeld();
  sqlite3_file_control(p->dbIn, p->zDb,SQLITE_FCNTL_FILE_POINTER,(void*)&pFd);
  if( pFd && pFd->pMethods ){
    pFd->pMethods = recover_g.pMethods;
    recover_g.pMethods = 0;
    recover_g.p = 0;
  }
}

/*
** This function does the work of a single sqlite3_recover_step() call. It
** is guaranteed that the handle is not in an error state when this
** function is called.
*/
static void recoverStep(sqlite3_recover *p){
  assert( p && p->errCode==SQLITE_OK );
  switch( p->eState ){
    case RECOVER_STATE_INIT:
      /* This is the very first call to sqlite3_recover_step() on this object.
      */
      recoverSqlCallback(p, "BEGIN");
      recoverSqlCallback(p, "PRAGMA writable_schema = on");

      recoverEnterMutex();
      recoverInstallWrapper(p);

      /* Open the output database. And register required virtual tables and 
      ** user functions with the new handle. */
      recoverOpenOutput(p);

      /* Open transactions on both the input and output databases. */
      sqlite3_file_control(p->dbIn, p->zDb, SQLITE_FCNTL_RESET_CACHE, 0);
      recoverExec(p, p->dbIn, "PRAGMA writable_schema = on");
      recoverExec(p, p->dbIn, "BEGIN");
      if( p->errCode==SQLITE_OK ) p->bCloseTransaction = 1;
      recoverExec(p, p->dbIn, "SELECT 1 FROM sqlite_schema");
      recoverTransferSettings(p);
      recoverOpenRecovery(p);
      recoverCacheSchema(p);

      recoverUninstallWrapper(p);
      recoverLeaveMutex();

      recoverExec(p, p->dbOut, "BEGIN");

      recoverWriteSchema1(p);
      p->eState = RECOVER_STATE_WRITING;
      break;
      
    case RECOVER_STATE_WRITING: {
      if( p->w1.pTbls==0 ){
        recoverWriteDataInit(p);
      }
      if( SQLITE_DONE==recoverWriteDataStep(p) ){
        recoverWriteDataCleanup(p);
        if( p->zLostAndFound ){
          p->eState = RECOVER_STATE_LOSTANDFOUND1;
        }else{
          p->eState = RECOVER_STATE_SCHEMA2;
        }
      }
      break;
    }

    case RECOVER_STATE_LOSTANDFOUND1: {
      if( p->laf.pUsed==0 ){
        recoverLostAndFound1Init(p);
      }
      if( SQLITE_DONE==recoverLostAndFound1Step(p) ){
        p->eState = RECOVER_STATE_LOSTANDFOUND2;
      }
      break;
    }
    case RECOVER_STATE_LOSTANDFOUND2: {
      if( p->laf.pAllAndParent==0 ){
        recoverLostAndFound2Init(p);
      }
      if( SQLITE_DONE==recoverLostAndFound2Step(p) ){
        p->eState = RECOVER_STATE_LOSTANDFOUND3;
      }
      break;
    }

    case RECOVER_STATE_LOSTANDFOUND3: {
      if( p->laf.pInsert==0 ){
        recoverLostAndFound3Init(p);
      }
      if( SQLITE_DONE==recoverLostAndFound3Step(p) ){
        p->eState = RECOVER_STATE_SCHEMA2;
      }
      break;
    }

    case RECOVER_STATE_SCHEMA2: {
      int rc = SQLITE_OK;

      recoverWriteSchema2(p);
      p->eState = RECOVER_STATE_DONE;

      /* If no error has occurred, commit the write transaction on the output
      ** database. Regardless of whether or not an error has occurred, make
      ** an attempt to end the read transaction on the input database.  */
      recoverExec(p, p->dbOut, "COMMIT");
      rc = sqlite3_exec(p->dbIn, "END", 0, 0, 0);
      if( p->errCode==SQLITE_OK ) p->errCode = rc;

      recoverSqlCallback(p, "PRAGMA writable_schema = off");
      recoverSqlCallback(p, "COMMIT");
      p->eState = RECOVER_STATE_DONE;
      recoverFinalCleanup(p);
      break;
    };

    case RECOVER_STATE_DONE: {
      /* no-op */
      break;
    };
  }
}


/*
** This is a worker function that does the heavy lifting for both init
** functions:
**
**     sqlite3_recover_init()
**     sqlite3_recover_init_sql()
**
** All this function does is allocate space for the recover handle and
** take copies of the input parameters. All the real work is done within
** sqlite3_recover_run().
*/
sqlite3_recover *recoverInit(
  sqlite3* db, 
  const char *zDb, 
  const char *zUri,               /* Output URI for _recover_init() */
  int (*xSql)(void*, const char*),/* SQL callback for _recover_init_sql() */
  void *pSqlCtx                   /* Context arg for _recover_init_sql() */
){
  sqlite3_recover *pRet = 0;
  int nDb = 0;
  int nUri = 0;
  int nByte = 0;

  if( zDb==0 ){ zDb = "main"; }

  nDb = recoverStrlen(zDb);
  nUri = recoverStrlen(zUri);

  nByte = sizeof(sqlite3_recover) + nDb+1 + nUri+1;
  pRet = (sqlite3_recover*)sqlite3_malloc(nByte);
  if( pRet ){
    memset(pRet, 0, nByte);
    pRet->dbIn = db;
    pRet->zDb = (char*)&pRet[1];
    pRet->zUri = &pRet->zDb[nDb+1];
    memcpy(pRet->zDb, zDb, nDb);
    if( nUri>0 && zUri ) memcpy(pRet->zUri, zUri, nUri);
    pRet->xSql = xSql;
    pRet->pSqlCtx = pSqlCtx;
    pRet->bRecoverRowid = RECOVER_ROWID_DEFAULT;
  }

  return pRet;
}

/*
** Initialize a recovery handle that creates a new database containing
** the recovered data.
*/
sqlite3_recover *sqlite3_recover_init(
  sqlite3* db, 
  const char *zDb, 
  const char *zUri
){
  return recoverInit(db, zDb, zUri, 0, 0);
}

/*
** Initialize a recovery handle that returns recovered data in the
** form of SQL statements via a callback.
*/
sqlite3_recover *sqlite3_recover_init_sql(
  sqlite3* db, 
  const char *zDb, 
  int (*xSql)(void*, const char*),
  void *pSqlCtx
){
  return recoverInit(db, zDb, 0, xSql, pSqlCtx);
}

/*
** Return the handle error message, if any.
*/
const char *sqlite3_recover_errmsg(sqlite3_recover *p){
  return (p && p->errCode!=SQLITE_NOMEM) ? p->zErrMsg : "out of memory";
}

/*
** Return the handle error code.
*/
int sqlite3_recover_errcode(sqlite3_recover *p){
  return p ? p->errCode : SQLITE_NOMEM;
}

/*
** Configure the handle.
*/
int sqlite3_recover_config(sqlite3_recover *p, int op, void *pArg){
  int rc = SQLITE_OK;
  if( p==0 ){
    rc = SQLITE_NOMEM;
  }else if( p->eState!=RECOVER_STATE_INIT ){
    rc = SQLITE_MISUSE;
  }else{
    switch( op ){
      case 789:
        /* This undocumented magic configuration option is used to set the
        ** name of the auxiliary database that is ATTACH-ed to the database
        ** connection and used to hold state information during the
        ** recovery process.  This option is for debugging use only and
        ** is subject to change or removal at any time. */
        sqlite3_free(p->zStateDb);
        p->zStateDb = recoverMPrintf(p, "%s", (char*)pArg);
        break;

      case SQLITE_RECOVER_LOST_AND_FOUND: {
        const char *zArg = (const char*)pArg;
        sqlite3_free(p->zLostAndFound);
        if( zArg ){
          p->zLostAndFound = recoverMPrintf(p, "%s", zArg);
        }else{
          p->zLostAndFound = 0;
        }
        break;
      }

      case SQLITE_RECOVER_FREELIST_CORRUPT:
        p->bFreelistCorrupt = *(int*)pArg;
        break;

      case SQLITE_RECOVER_ROWIDS:
        p->bRecoverRowid = *(int*)pArg;
        break;

      case SQLITE_RECOVER_SLOWINDEXES:
        p->bSlowIndexes = *(int*)pArg;
        break;

      default:
        rc = SQLITE_NOTFOUND;
        break;
    }
  }

  return rc;
}

/*
** Do a unit of work towards the recovery job. Return SQLITE_OK if
** no error has occurred but database recovery is not finished, SQLITE_DONE
** if database recovery has been successfully completed, or an SQLite
** error code if an error has occurred.
*/
int sqlite3_recover_step(sqlite3_recover *p){
  if( p==0 ) return SQLITE_NOMEM;
  if( p->errCode==SQLITE_OK ) recoverStep(p);
  if( p->eState==RECOVER_STATE_DONE && p->errCode==SQLITE_OK ){
    return SQLITE_DONE;
  }
  return p->errCode;
}

/*
** Do the configured recovery operation. Return SQLITE_OK if successful, or
** else an SQLite error code.
*/
int sqlite3_recover_run(sqlite3_recover *p){
  while( SQLITE_OK==sqlite3_recover_step(p) );
  return sqlite3_recover_errcode(p);
}


/*
** Free all resources associated with the recover handle passed as the only
** argument. The results of using a handle with any sqlite3_recover_**
** API function after it has been passed to this function are undefined.
**
** A copy of the value returned by the first call made to sqlite3_recover_run()
** on this handle is returned, or SQLITE_OK if sqlite3_recover_run() has
** not been called on this handle.
*/
int sqlite3_recover_finish(sqlite3_recover *p){
  int rc;
  if( p==0 ){
    rc = SQLITE_NOMEM;
  }else{
    recoverFinalCleanup(p);
    if( p->bCloseTransaction && sqlite3_get_autocommit(p->dbIn)==0 ){
      rc = sqlite3_exec(p->dbIn, "END", 0, 0, 0);
      if( p->errCode==SQLITE_OK ) p->errCode = rc;
    }
    rc = p->errCode;
    sqlite3_free(p->zErrMsg);
    sqlite3_free(p->zStateDb);
    sqlite3_free(p->zLostAndFound);
    sqlite3_free(p->pPage1Cache);
    sqlite3_free(p);
  }
  return rc;
}

#endif /* ifndef SQLITE_OMIT_VIRTUALTABLE */

/************************* End ../ext/recover/sqlite3recover.c ********************/
# endif /* SQLITE_HAVE_SQLITE3R */
#endif
#ifdef SQLITE_SHELL_EXTSRC
# include SHELL_STRINGIFY(SQLITE_SHELL_EXTSRC)
#endif

#if defined(SQLITE_ENABLE_SESSION)
/*
** State information for a single open session
*/
typedef struct OpenSession OpenSession;
struct OpenSession {
  char *zName;             /* Symbolic name for this session */
  int nFilter;             /* Number of xFilter rejection GLOB patterns */
  char **azFilter;         /* Array of xFilter rejection GLOB patterns */
  sqlite3_session *p;      /* The open session */
};
#endif

typedef struct ExpertInfo ExpertInfo;
struct ExpertInfo {
  sqlite3expert *pExpert;
  int bVerbose;
};

/* A single line in the EQP output */
typedef struct EQPGraphRow EQPGraphRow;
struct EQPGraphRow {
  int iEqpId;           /* ID for this row */
  int iParentId;        /* ID of the parent row */
  EQPGraphRow *pNext;   /* Next row in sequence */
  char zText[1];        /* Text to display for this row */
};

/* All EQP output is collected into an instance of the following */
typedef struct EQPGraph EQPGraph;
struct EQPGraph {
  EQPGraphRow *pRow;    /* Linked list of all rows of the EQP output */
  EQPGraphRow *pLast;   /* Last element of the pRow list */
  char zPrefix[100];    /* Graph prefix */
};

/* Parameters affecting columnar mode result display (defaulting together) */
typedef struct ColModeOpts {
  int iWrap;            /* In columnar modes, wrap lines reaching this limit */
  u8 bQuote;            /* Quote results for .mode box and table */
  u8 bWordWrap;         /* In columnar modes, wrap at word boundaries  */
} ColModeOpts;
#define ColModeOpts_default { 60, 0, 0 }
#define ColModeOpts_default_qbox { 60, 1, 0 }

/*
** State information about the database connection is contained in an
** instance of the following structure.
*/
typedef struct ShellState ShellState;
struct ShellState {
  sqlite3 *db;           /* The database */
  u8 autoExplain;        /* Automatically turn on .explain mode */
  u8 autoEQP;            /* Run EXPLAIN QUERY PLAN prior to each SQL stmt */
  u8 autoEQPtest;        /* autoEQP is in test mode */
  u8 autoEQPtrace;       /* autoEQP is in trace mode */
  u8 scanstatsOn;        /* True to display scan stats before each finalize */
  u8 openMode;           /* SHELL_OPEN_NORMAL, _APPENDVFS, or _ZIPFILE */
  u8 doXdgOpen;          /* Invoke start/open/xdg-open in output_reset() */
  u8 nEqpLevel;          /* Depth of the EQP output graph */
  u8 eTraceType;         /* SHELL_TRACE_* value for type of trace */
  u8 bSafeMode;          /* True to prohibit unsafe operations */
  u8 bSafeModePersist;   /* The long-term value of bSafeMode */
  u8 eRestoreState;      /* See comments above doAutoDetectRestore() */
  u8 crlfMode;           /* Do NL-to-CRLF translations when enabled (maybe) */
  ColModeOpts cmOpts;    /* Option values affecting columnar mode output */
  unsigned statsOn;      /* True to display memory stats before each finalize */
  unsigned mEqpLines;    /* Mask of vertical lines in the EQP output graph */
  int inputNesting;      /* Track nesting level of .read and other redirects */
  int outCount;          /* Revert to stdout when reaching zero */
  int cnt;               /* Number of records displayed so far */
  int lineno;            /* Line number of last line read from in */
  int openFlags;         /* Additional flags to open.  (SQLITE_OPEN_NOFOLLOW) */
  FILE *in;              /* Read commands from this stream */
  FILE *out;             /* Write results here */
  FILE *traceOut;        /* Output for sqlite3_trace() */
  int nErr;              /* Number of errors seen */
  int mode;              /* An output mode setting */
  int modePrior;         /* Saved mode */
  int cMode;             /* temporary output mode for the current query */
  int normalMode;        /* Output mode before ".explain on" */
  int writableSchema;    /* True if PRAGMA writable_schema=ON */
  int showHeader;        /* True to show column names in List or Column mode */
  int nCheck;            /* Number of ".check" commands run */
  unsigned nProgress;    /* Number of progress callbacks encountered */
  unsigned mxProgress;   /* Maximum progress callbacks before failing */
  unsigned flgProgress;  /* Flags for the progress callback */
  unsigned shellFlgs;    /* Various flags */
  unsigned priorShFlgs;  /* Saved copy of flags */
  sqlite3_int64 szMax;   /* --maxsize argument to .open */
  char *zDestTable;      /* Name of destination table when MODE_Insert */
  char *zTempFile;       /* Temporary file that might need deleting */
  char zTestcase[30];    /* Name of current test case */
  char colSeparator[20]; /* Column separator character for several modes */
  char rowSeparator[20]; /* Row separator character for MODE_Ascii */
  char colSepPrior[20];  /* Saved column separator */
  char rowSepPrior[20];  /* Saved row separator */
  int *colWidth;         /* Requested width of each column in columnar modes */
  int *actualWidth;      /* Actual width of each column */
  int nWidth;            /* Number of slots in colWidth[] and actualWidth[] */
  char nullValue[20];    /* The text to print when a NULL comes back from
                         ** the database */
  char outfile[FILENAME_MAX]; /* Filename for *out */
  sqlite3_stmt *pStmt;   /* Current statement if any. */
  FILE *pLog;            /* Write log output here */
  struct AuxDb {         /* Storage space for auxiliary database connections */
    sqlite3 *db;               /* Connection pointer */
    const char *zDbFilename;   /* Filename used to open the connection */
    char *zFreeOnClose;        /* Free this memory allocation on close */
#if defined(SQLITE_ENABLE_SESSION)
    int nSession;              /* Number of active sessions */
    OpenSession aSession[4];   /* Array of sessions.  [0] is in focus. */
#endif
  } aAuxDb[5],           /* Array of all database connections */
    *pAuxDb;             /* Currently active database connection */
  int *aiIndent;         /* Array of indents used in MODE_Explain */
  int nIndent;           /* Size of array aiIndent[] */
  int iIndent;           /* Index of current op in aiIndent[] */
  char *zNonce;          /* Nonce for temporary safe-mode escapes */
  EQPGraph sGraph;       /* Information for the graphical EXPLAIN QUERY PLAN */
  ExpertInfo expert;     /* Valid if previous command was ".expert OPT..." */
#ifdef SQLITE_SHELL_FIDDLE
  struct {
    const char * zInput; /* Input string from wasm/JS proxy */
    const char * zPos;   /* Cursor pos into zInput */
    const char * zDefaultDbName; /* Default name for db file */
  } wasm;
#endif
};

#ifdef SQLITE_SHELL_FIDDLE
static ShellState shellState;
#endif


/* Allowed values for ShellState.autoEQP
*/
#define AUTOEQP_off      0           /* Automatic EXPLAIN QUERY PLAN is off */
#define AUTOEQP_on       1           /* Automatic EQP is on */
#define AUTOEQP_trigger  2           /* On and also show plans for triggers */
#define AUTOEQP_full     3           /* Show full EXPLAIN */

/* Allowed values for ShellState.openMode
*/
#define SHELL_OPEN_UNSPEC      0      /* No open-mode specified */
#define SHELL_OPEN_NORMAL      1      /* Normal database file */
#define SHELL_OPEN_APPENDVFS   2      /* Use appendvfs */
#define SHELL_OPEN_ZIPFILE     3      /* Use the zipfile virtual table */
#define SHELL_OPEN_READONLY    4      /* Open a normal database read-only */
#define SHELL_OPEN_DESERIALIZE 5      /* Open using sqlite3_deserialize() */
#define SHELL_OPEN_HEXDB       6      /* Use "dbtotxt" output as data source */

/* Allowed values for ShellState.eTraceType
*/
#define SHELL_TRACE_PLAIN      0      /* Show input SQL text */
#define SHELL_TRACE_EXPANDED   1      /* Show expanded SQL text */
#define SHELL_TRACE_NORMALIZED 2      /* Show normalized SQL text */

/* Bits in the ShellState.flgProgress variable */
#define SHELL_PROGRESS_QUIET 0x01  /* Omit announcing every progress callback */
#define SHELL_PROGRESS_RESET 0x02  /* Reset the count when the progress
                                   ** callback limit is reached, and for each
                                   ** top-level SQL statement */
#define SHELL_PROGRESS_ONCE  0x04  /* Cancel the --limit after firing once */

/*
** These are the allowed shellFlgs values
*/
#define SHFLG_Pagecache      0x00000001 /* The --pagecache option is used */
#define SHFLG_Lookaside      0x00000002 /* Lookaside memory is used */
#define SHFLG_Backslash      0x00000004 /* The --backslash option is used */
#define SHFLG_PreserveRowid  0x00000008 /* .dump preserves rowid values */
#define SHFLG_Newlines       0x00000010 /* .dump --newline flag */
#define SHFLG_CountChanges   0x00000020 /* .changes setting */
#define SHFLG_Echo           0x00000040 /* .echo on/off, or --echo setting */
#define SHFLG_HeaderSet      0x00000080 /* showHeader has been specified */
#define SHFLG_DumpDataOnly   0x00000100 /* .dump show data only */
#define SHFLG_DumpNoSys      0x00000200 /* .dump omits system tables */
#define SHFLG_TestingMode    0x00000400 /* allow unsafe testing features */

/*
** Macros for testing and setting shellFlgs
*/
#define ShellHasFlag(P,X)    (((P)->shellFlgs & (X))!=0)
#define ShellSetFlag(P,X)    ((P)->shellFlgs|=(X))
#define ShellClearFlag(P,X)  ((P)->shellFlgs&=(~(X)))

/*
** These are the allowed modes.
*/
#define MODE_Line     0  /* One column per line.  Blank line between records */
#define MODE_Column   1  /* One record per line in neat columns */
#define MODE_List     2  /* One record per line with a separator */
#define MODE_Semi     3  /* Same as MODE_List but append ";" to each line */
#define MODE_Html     4  /* Generate an XHTML table */
#define MODE_Insert   5  /* Generate SQL "insert" statements */
#define MODE_Quote    6  /* Quote values as for SQL */
#define MODE_Tcl      7  /* Generate ANSI-C or TCL quoted elements */
#define MODE_Csv      8  /* Quote strings, numbers are plain */
#define MODE_Explain  9  /* Like MODE_Column, but do not truncate data */
#define MODE_Ascii   10  /* Use ASCII unit and record separators (0x1F/0x1E) */
#define MODE_Pretty  11  /* Pretty-print schemas */
#define MODE_EQP     12  /* Converts EXPLAIN QUERY PLAN output into a graph */
#define MODE_Json    13  /* Output JSON */
#define MODE_Markdown 14 /* Markdown formatting */
#define MODE_Table   15  /* MySQL-style table formatting */
#define MODE_Box     16  /* Unicode box-drawing characters */
#define MODE_Count   17  /* Output only a count of the rows of output */
#define MODE_Off     18  /* No query output shown */
#define MODE_ScanExp 19  /* Like MODE_Explain, but for ".scanstats vm" */
#define MODE_Www     20  /* Full web-page output */

static const char *modeDescr[] = {
  "line",
  "column",
  "list",
  "semi",
  "html",
  "insert",
  "quote",
  "tcl",
  "csv",
  "explain",
  "ascii",
  "prettyprint",
  "eqp",
  "json",
  "markdown",
  "table",
  "box",
  "count",
  "off",
  "scanexp",
  "www",
};

/*
** These are the column/row/line separators used by the various
** import/export modes.
*/
#define SEP_Column    "|"
#define SEP_Row       "\n"
#define SEP_Tab       "\t"
#define SEP_Space     " "
#define SEP_Comma     ","
#define SEP_CrLf      "\r\n"
#define SEP_Unit      "\x1F"
#define SEP_Record    "\x1E"

/*
** Limit input nesting via .read or any other input redirect.
** It's not too expensive, so a generous allowance can be made.
*/
#define MAX_INPUT_NESTING 25

/*
** A callback for the sqlite3_log() interface.
*/
static void shellLog(void *pArg, int iErrCode, const char *zMsg){
  ShellState *p = (ShellState*)pArg;
  if( p->pLog==0 ) return;
  sqlite3_fprintf(p->pLog, "(%d) %s\n", iErrCode, zMsg);
  fflush(p->pLog);
}

/*
** SQL function:  shell_putsnl(X)
**
** Write the text X to the screen (or whatever output is being directed)
** adding a newline at the end, and then return X.
*/
static void shellPutsFunc(
  sqlite3_context *pCtx,
  int nVal,
  sqlite3_value **apVal
){
  ShellState *p = (ShellState*)sqlite3_user_data(pCtx);
  (void)nVal;
  sqlite3_fprintf(p->out, "%s\n", sqlite3_value_text(apVal[0]));
  sqlite3_result_value(pCtx, apVal[0]);
}

/*
** If in safe mode, print an error message described by the arguments
** and exit immediately.
*/
static void failIfSafeMode(
  ShellState *p,
  const char *zErrMsg,
  ...
){
  if( p->bSafeMode ){
    va_list ap;
    char *zMsg;
    va_start(ap, zErrMsg);
    zMsg = sqlite3_vmprintf(zErrMsg, ap);
    va_end(ap);
    sqlite3_fprintf(stderr, "line %d: %s\n", p->lineno, zMsg);
    exit(1);
  }
}

/*
** SQL function:   edit(VALUE)
**                 edit(VALUE,EDITOR)
**
** These steps:
**
**     (1) Write VALUE into a temporary file.
**     (2) Run program EDITOR on that temporary file.
**     (3) Read the temporary file back and return its content as the result.
**     (4) Delete the temporary file
**
** If the EDITOR argument is omitted, use the value in the VISUAL
** environment variable.  If still there is no EDITOR, through an error.
**
** Also throw an error if the EDITOR program returns a non-zero exit code.
*/
#ifndef SQLITE_NOHAVE_SYSTEM
static void editFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  const char *zEditor;
  char *zTempFile = 0;
  sqlite3 *db;
  char *zCmd = 0;
  int bBin;
  int rc;
  int hasCRLF = 0;
  FILE *f = 0;
  sqlite3_int64 sz;
  sqlite3_int64 x;
  unsigned char *p = 0;

  if( argc==2 ){
    zEditor = (const char*)sqlite3_value_text(argv[1]);
  }else{
    zEditor = getenv("VISUAL");
  }
  if( zEditor==0 ){
    sqlite3_result_error(context, "no editor for edit()", -1);
    return;
  }
  if( sqlite3_value_type(argv[0])==SQLITE_NULL ){
    sqlite3_result_error(context, "NULL input to edit()", -1);
    return;
  }
  db = sqlite3_context_db_handle(context);
  zTempFile = 0;
  sqlite3_file_control(db, 0, SQLITE_FCNTL_TEMPFILENAME, &zTempFile);
  if( zTempFile==0 ){
    sqlite3_uint64 r = 0;
    sqlite3_randomness(sizeof(r), &r);
    zTempFile = sqlite3_mprintf("temp%llx", r);
    if( zTempFile==0 ){
      sqlite3_result_error_nomem(context);
      return;
    }
  }
  bBin = sqlite3_value_type(argv[0])==SQLITE_BLOB;
  /* When writing the file to be edited, do \n to \r\n conversions on systems
  ** that want \r\n line endings */
  f = sqlite3_fopen(zTempFile, bBin ? "wb" : "w");
  if( f==0 ){
    sqlite3_result_error(context, "edit() cannot open temp file", -1);
    goto edit_func_end;
  }
  sz = sqlite3_value_bytes(argv[0]);
  if( bBin ){
    x = fwrite(sqlite3_value_blob(argv[0]), 1, (size_t)sz, f);
  }else{
    const char *z = (const char*)sqlite3_value_text(argv[0]);
    /* Remember whether or not the value originally contained \r\n */
    if( z && strstr(z,"\r\n")!=0 ) hasCRLF = 1;
    x = fwrite(sqlite3_value_text(argv[0]), 1, (size_t)sz, f);
  }
  fclose(f);
  f = 0;
  if( x!=sz ){
    sqlite3_result_error(context, "edit() could not write the whole file", -1);
    goto edit_func_end;
  }
  zCmd = sqlite3_mprintf("%s \"%s\"", zEditor, zTempFile);
  if( zCmd==0 ){
    sqlite3_result_error_nomem(context);
    goto edit_func_end;
  }
  rc = system(zCmd);
  sqlite3_free(zCmd);
  if( rc ){
    sqlite3_result_error(context, "EDITOR returned non-zero", -1);
    goto edit_func_end;
  }
  f = sqlite3_fopen(zTempFile, "rb");
  if( f==0 ){
    sqlite3_result_error(context,
      "edit() cannot reopen temp file after edit", -1);
    goto edit_func_end;
  }
  fseek(f, 0, SEEK_END);
  sz = ftell(f);
  rewind(f);
  p = sqlite3_malloc64( sz+1 );
  if( p==0 ){
    sqlite3_result_error_nomem(context);
    goto edit_func_end;
  }
  x = fread(p, 1, (size_t)sz, f);
  fclose(f);
  f = 0;
  if( x!=sz ){
    sqlite3_result_error(context, "could not read back the whole file", -1);
    goto edit_func_end;
  }
  if( bBin ){
    sqlite3_result_blob64(context, p, sz, sqlite3_free);
  }else{
    sqlite3_int64 i, j;
    if( hasCRLF ){
      /* If the original contains \r\n then do no conversions back to \n */
    }else{
      /* If the file did not originally contain \r\n then convert any new
      ** \r\n back into \n */
      p[sz] = 0;
      for(i=j=0; i<sz; i++){
        if( p[i]=='\r' && p[i+1]=='\n' ) i++;
        p[j++] = p[i];
      }
      sz = j;
      p[sz] = 0;
    }
    sqlite3_result_text64(context, (const char*)p, sz,
                          sqlite3_free, SQLITE_UTF8);
  }
  p = 0;

edit_func_end:
  if( f ) fclose(f);
  unlink(zTempFile);
  sqlite3_free(zTempFile);
  sqlite3_free(p);
}
#endif /* SQLITE_NOHAVE_SYSTEM */

/*
** Save or restore the current output mode
*/
static void outputModePush(ShellState *p){
  p->modePrior = p->mode;
  p->priorShFlgs = p->shellFlgs;
  memcpy(p->colSepPrior, p->colSeparator, sizeof(p->colSeparator));
  memcpy(p->rowSepPrior, p->rowSeparator, sizeof(p->rowSeparator));
}
static void outputModePop(ShellState *p){
  p->mode = p->modePrior;
  p->shellFlgs = p->priorShFlgs;
  memcpy(p->colSeparator, p->colSepPrior, sizeof(p->colSeparator));
  memcpy(p->rowSeparator, p->rowSepPrior, sizeof(p->rowSeparator));
}

/*
** Set output mode to text or binary for Windows.
*/
static void setCrlfMode(ShellState *p){
#ifdef _WIN32
  if( p->crlfMode ){
    sqlite3_fsetmode(p->out, _O_TEXT);
  }else{
    sqlite3_fsetmode(p->out, _O_BINARY);
  }
#else
  UNUSED_PARAMETER(p);
#endif    
}

/*
** Output the given string as a hex-encoded blob (eg. X'1234' )
*/
static void output_hex_blob(FILE *out, const void *pBlob, int nBlob){
  int i;
  unsigned char *aBlob = (unsigned char*)pBlob;

  char *zStr = sqlite3_malloc(nBlob*2 + 1);
  shell_check_oom(zStr);

  for(i=0; i<nBlob; i++){
    static const char aHex[] = {
        '0', '1', '2', '3', '4', '5', '6', '7',
        '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'
    };
    zStr[i*2] = aHex[ (aBlob[i] >> 4) ];
    zStr[i*2+1] = aHex[ (aBlob[i] & 0x0F) ];
  }
  zStr[i*2] = '\0';

  sqlite3_fprintf(out, "X'%s'", zStr);
  sqlite3_free(zStr);
}

/*
** Find a string that is not found anywhere in z[].  Return a pointer
** to that string.
**
** Try to use zA and zB first.  If both of those are already found in z[]
** then make up some string and store it in the buffer zBuf.
*/
static const char *unused_string(
  const char *z,                    /* Result must not appear anywhere in z */
  const char *zA, const char *zB,   /* Try these first */
  char *zBuf                        /* Space to store a generated string */
){
  unsigned i = 0;
  if( strstr(z, zA)==0 ) return zA;
  if( strstr(z, zB)==0 ) return zB;
  do{
    sqlite3_snprintf(20,zBuf,"(%s%u)", zA, i++);
  }while( strstr(z,zBuf)!=0 );
  return zBuf;
}

/*
** Output the given string as a quoted string using SQL quoting conventions.
**
** See also: output_quoted_escaped_string()
*/
static void output_quoted_string(ShellState *p, const char *z){
  int i;
  char c;
  FILE *out = p->out;
  sqlite3_fsetmode(out, _O_BINARY);
  if( z==0 ) return;
  for(i=0; (c = z[i])!=0 && c!='\''; i++){}
  if( c==0 ){
    sqlite3_fprintf(out, "'%s'",z);
  }else{
    sqlite3_fputs("'", out);
    while( *z ){
      for(i=0; (c = z[i])!=0 && c!='\''; i++){}
      if( c=='\'' ) i++;
      if( i ){
        sqlite3_fprintf(out, "%.*s", i, z);
        z += i;
      }
      if( c=='\'' ){
        sqlite3_fputs("'", out);
        continue;
      }
      if( c==0 ){
        break;
      }
      z++;
    }
    sqlite3_fputs("'", out);
  }
  setCrlfMode(p);
}

/*
** Output the given string as a quoted string using SQL quoting conventions.
** Additionallly , escape the "\n" and "\r" characters so that they do not
** get corrupted by end-of-line translation facilities in some operating
** systems.
**
** This is like output_quoted_string() but with the addition of the \r\n
** escape mechanism.
*/
static void output_quoted_escaped_string(ShellState *p, const char *z){
  int i;
  char c;
  FILE *out = p->out;
  sqlite3_fsetmode(out, _O_BINARY);
  for(i=0; (c = z[i])!=0 && c!='\'' && c!='\n' && c!='\r'; i++){}
  if( c==0 ){
    sqlite3_fprintf(out, "'%s'",z);
  }else{
    const char *zNL = 0;
    const char *zCR = 0;
    int nNL = 0;
    int nCR = 0;
    char zBuf1[20], zBuf2[20];
    for(i=0; z[i]; i++){
      if( z[i]=='\n' ) nNL++;
      if( z[i]=='\r' ) nCR++;
    }
    if( nNL ){
      sqlite3_fputs("replace(", out);
      zNL = unused_string(z, "\\n", "\\012", zBuf1);
    }
    if( nCR ){
      sqlite3_fputs("replace(", out);
      zCR = unused_string(z, "\\r", "\\015", zBuf2);
    }
    sqlite3_fputs("'", out);
    while( *z ){
      for(i=0; (c = z[i])!=0 && c!='\n' && c!='\r' && c!='\''; i++){}
      if( c=='\'' ) i++;
      if( i ){
        sqlite3_fprintf(out, "%.*s", i, z);
        z += i;
      }
      if( c=='\'' ){
        sqlite3_fputs("'", out);
        continue;
      }
      if( c==0 ){
        break;
      }
      z++;
      if( c=='\n' ){
        sqlite3_fputs(zNL, out);
        continue;
      }
      sqlite3_fputs(zCR, out);
    }
    sqlite3_fputs("'", out);
    if( nCR ){
      sqlite3_fprintf(out, ",'%s',char(13))", zCR);
    }
    if( nNL ){
      sqlite3_fprintf(out, ",'%s',char(10))", zNL);
    }
  }
  setCrlfMode(p);
}

/*
** Find earliest of chars within s specified in zAny.
** With ns == ~0, is like strpbrk(s,zAny) and s must be 0-terminated.
*/
static const char *anyOfInStr(const char *s, const char *zAny, size_t ns){
  const char *pcFirst = 0;
  if( ns == ~(size_t)0 ) ns = strlen(s);
  while(*zAny){
    const char *pc = (const char*)memchr(s, *zAny&0xff, ns);
    if( pc ){
      pcFirst = pc;
      ns = pcFirst - s;
    }
    ++zAny;
  }
  return pcFirst;
}

/* Skip over as much z[] input char sequence as is valid UTF-8,
** limited per nAccept char's or whole characters and containing
** no char cn such that ((1<<cn) & ccm)!=0. On return, the
** sequence z:return (inclusive:exclusive) is validated UTF-8.
** Limit: nAccept>=0 => char count, nAccept<0 => character
 */
const char *zSkipValidUtf8(const char *z, int nAccept, long ccm){
  int ng = (nAccept<0)? -nAccept : 0;
  const char *pcLimit = (nAccept>=0)? z+nAccept : 0;
  assert(z!=0);
  while( (pcLimit)? (z<pcLimit) : (ng-- != 0) ){
    char c = *z;
    if( (c & 0x80) == 0 ){
      if( ccm != 0L && c < 0x20 && ((1L<<c) & ccm) != 0 ) return z;
      ++z; /* ASCII */
    }else if( (c & 0xC0) != 0xC0 ) return z; /* not a lead byte */
    else{
      const char *zt = z+1; /* Got lead byte, look at trail bytes.*/
      do{
        if( pcLimit && zt >= pcLimit ) return z;
        else{
          char ct = *zt++;
          if( ct==0 || (zt-z)>4 || (ct & 0xC0)!=0x80 ){
            /* Trailing bytes are too few, too many, or invalid. */
            return z;
          }
        }
      } while( ((c <<= 1) & 0x40) == 0x40 ); /* Eat lead byte's count. */
      z = zt;
    }
  }
  return z;
}


/*
** Output the given string as a quoted according to C or TCL quoting rules.
*/
static void output_c_string(FILE *out, const char *z){
  char c;
  static const char *zq = "\"";
  static long ctrlMask = ~0L;
  static const char *zDQBSRO = "\"\\\x7f"; /* double-quote, backslash, rubout */
  char ace[3] = "\\?";
  char cbsSay;
  sqlite3_fputs(zq, out);
  while( *z!=0 ){
    const char *pcDQBSRO = anyOfInStr(z, zDQBSRO, ~(size_t)0);
    const char *pcPast = zSkipValidUtf8(z, INT_MAX, ctrlMask);
    const char *pcEnd = (pcDQBSRO && pcDQBSRO < pcPast)? pcDQBSRO : pcPast;
    if( pcEnd > z ){
      sqlite3_fprintf(out, "%.*s", (int)(pcEnd-z), z);
    }
    if( (c = *pcEnd)==0 ) break;
    ++pcEnd;
    switch( c ){
    case '\\': case '"':
      cbsSay = (char)c;
      break;
    case '\t': cbsSay = 't'; break;
    case '\n': cbsSay = 'n'; break;
    case '\r': cbsSay = 'r'; break;
    case '\f': cbsSay = 'f'; break;
    default: cbsSay = 0; break;
    }
    if( cbsSay ){
      ace[1] = cbsSay;
      sqlite3_fputs(ace, out);
    }else if( !isprint(c&0xff) ){
      sqlite3_fprintf(out, "\\%03o", c&0xff);
    }else{
      ace[1] = (char)c;
      sqlite3_fputs(ace+1, out);
    }
    z = pcEnd;
  }
  sqlite3_fputs(zq, out);
}

/*
** Output the given string as a quoted according to JSON quoting rules.
*/
static void output_json_string(FILE *out, const char *z, i64 n){
  char c;
  static const char *zq = "\"";
  static long ctrlMask = ~0L;
  static const char *zDQBS = "\"\\";
  const char *pcLimit;
  char ace[3] = "\\?";
  char cbsSay;

  if( z==0 ) z = "";
  pcLimit = z + ((n<0)? strlen(z) : (size_t)n);
  sqlite3_fputs(zq, out);
  while( z < pcLimit ){
    const char *pcDQBS = anyOfInStr(z, zDQBS, pcLimit-z);
    const char *pcPast = zSkipValidUtf8(z, (int)(pcLimit-z), ctrlMask);
    const char *pcEnd = (pcDQBS && pcDQBS < pcPast)? pcDQBS : pcPast;
    if( pcEnd > z ){
      sqlite3_fprintf(out, "%.*s", (int)(pcEnd-z), z);
      z = pcEnd;
    }
    if( z >= pcLimit ) break;
    c = *(z++);
    switch( c ){
    case '"': case '\\':
      cbsSay = (char)c;
      break;
    case '\b': cbsSay = 'b'; break;
    case '\f': cbsSay = 'f'; break;
    case '\n': cbsSay = 'n'; break;
    case '\r': cbsSay = 'r'; break;
    case '\t': cbsSay = 't'; break;
    default: cbsSay = 0; break;
    }
    if( cbsSay ){
      ace[1] = cbsSay;
      sqlite3_fputs(ace, out);
    }else if( c<=0x1f ){
      sqlite3_fprintf(out, "u%04x", c);
    }else{
      ace[1] = (char)c;
      sqlite3_fputs(ace+1, out);
    }
  }
  sqlite3_fputs(zq, out);
}

/*
** Output the given string with characters that are special to
** HTML escaped.
*/
static void output_html_string(FILE *out, const char *z){
  int i;
  if( z==0 ) z = "";
  while( *z ){
    for(i=0;   z[i]
            && z[i]!='<'
            && z[i]!='&'
            && z[i]!='>'
            && z[i]!='\"'
            && z[i]!='\'';
        i++){}
    if( i>0 ){
      sqlite3_fprintf(out, "%.*s",i,z);
    }
    if( z[i]=='<' ){
      sqlite3_fputs("&lt;", out);
    }else if( z[i]=='&' ){
      sqlite3_fputs("&amp;", out);
    }else if( z[i]=='>' ){
      sqlite3_fputs("&gt;", out);
    }else if( z[i]=='\"' ){
      sqlite3_fputs("&quot;", out);
    }else if( z[i]=='\'' ){
      sqlite3_fputs("&#39;", out);
    }else{
      break;
    }
    z += i + 1;
  }
}

/*
** If a field contains any character identified by a 1 in the following
** array, then the string must be quoted for CSV.
*/
static const char needCsvQuote[] = {
  1, 1, 1, 1, 1, 1, 1, 1,   1, 1, 1, 1, 1, 1, 1, 1,
  1, 1, 1, 1, 1, 1, 1, 1,   1, 1, 1, 1, 1, 1, 1, 1,
  1, 0, 1, 0, 0, 0, 0, 1,   0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0,   0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0,   0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0,   0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0,   0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0,   0, 0, 0, 0, 0, 0, 0, 1,
  1, 1, 1, 1, 1, 1, 1, 1,   1, 1, 1, 1, 1, 1, 1, 1,
  1, 1, 1, 1, 1, 1, 1, 1,   1, 1, 1, 1, 1, 1, 1, 1,
  1, 1, 1, 1, 1, 1, 1, 1,   1, 1, 1, 1, 1, 1, 1, 1,
  1, 1, 1, 1, 1, 1, 1, 1,   1, 1, 1, 1, 1, 1, 1, 1,
  1, 1, 1, 1, 1, 1, 1, 1,   1, 1, 1, 1, 1, 1, 1, 1,
  1, 1, 1, 1, 1, 1, 1, 1,   1, 1, 1, 1, 1, 1, 1, 1,
  1, 1, 1, 1, 1, 1, 1, 1,   1, 1, 1, 1, 1, 1, 1, 1,
  1, 1, 1, 1, 1, 1, 1, 1,   1, 1, 1, 1, 1, 1, 1, 1,
};

/*
** Output a single term of CSV.  Actually, p->colSeparator is used for
** the separator, which may or may not be a comma.  p->nullValue is
** the null value.  Strings are quoted if necessary.  The separator
** is only issued if bSep is true.
*/
static void output_csv(ShellState *p, const char *z, int bSep){
  if( z==0 ){
    sqlite3_fprintf(p->out, "%s",p->nullValue);
  }else{
    unsigned i;
    for(i=0; z[i]; i++){
      if( needCsvQuote[((unsigned char*)z)[i]] ){
        i = 0;
        break;
      }
    }
    if( i==0 || strstr(z, p->colSeparator)!=0 ){
      char *zQuoted = sqlite3_mprintf("\"%w\"", z);
      shell_check_oom(zQuoted);
      sqlite3_fputs(zQuoted, p->out);
      sqlite3_free(zQuoted);
    }else{
      sqlite3_fputs(z, p->out);
    }
  }
  if( bSep ){
    sqlite3_fputs(p->colSeparator, p->out);
  }
}

/*
** This routine runs when the user presses Ctrl-C
*/
static void interrupt_handler(int NotUsed){
  UNUSED_PARAMETER(NotUsed);
  if( ++seenInterrupt>1 ) exit(1);
  if( globalDb ) sqlite3_interrupt(globalDb);
}

#if (defined(_WIN32) || defined(WIN32)) && !defined(_WIN32_WCE)
/*
** This routine runs for console events (e.g. Ctrl-C) on Win32
*/
static BOOL WINAPI ConsoleCtrlHandler(
  DWORD dwCtrlType /* One of the CTRL_*_EVENT constants */
){
  if( dwCtrlType==CTRL_C_EVENT ){
    interrupt_handler(0);
    return TRUE;
  }
  return FALSE;
}
#endif

#ifndef SQLITE_OMIT_AUTHORIZATION
/*
** This authorizer runs in safe mode.
*/
static int safeModeAuth(
  void *pClientData,
  int op,
  const char *zA1,
  const char *zA2,
  const char *zA3,
  const char *zA4
){
  ShellState *p = (ShellState*)pClientData;
  static const char *azProhibitedFunctions[] = {
    "edit",
    "fts3_tokenizer",
    "load_extension",
    "readfile",
    "writefile",
    "zipfile",
    "zipfile_cds",
  };
  UNUSED_PARAMETER(zA1);
  UNUSED_PARAMETER(zA3);
  UNUSED_PARAMETER(zA4);
  switch( op ){
    case SQLITE_ATTACH: {
#ifndef SQLITE_SHELL_FIDDLE
      /* In WASM builds the filesystem is a virtual sandbox, so
      ** there's no harm in using ATTACH. */
      failIfSafeMode(p, "cannot run ATTACH in safe mode");
#endif
      break;
    }
    case SQLITE_FUNCTION: {
      int i;
      for(i=0; i<ArraySize(azProhibitedFunctions); i++){
        if( sqlite3_stricmp(zA2, azProhibitedFunctions[i])==0 ){
          failIfSafeMode(p, "cannot use the %s() function in safe mode",
                         azProhibitedFunctions[i]);
        }
      }
      break;
    }
  }
  return SQLITE_OK;
}

/*
** When the ".auth ON" is set, the following authorizer callback is
** invoked.  It always returns SQLITE_OK.
*/
static int shellAuth(
  void *pClientData,
  int op,
  const char *zA1,
  const char *zA2,
  const char *zA3,
  const char *zA4
){
  ShellState *p = (ShellState*)pClientData;
  static const char *azAction[] = { 0,
     "CREATE_INDEX",         "CREATE_TABLE",         "CREATE_TEMP_INDEX",
     "CREATE_TEMP_TABLE",    "CREATE_TEMP_TRIGGER",  "CREATE_TEMP_VIEW",
     "CREATE_TRIGGER",       "CREATE_VIEW",          "DELETE",
     "DROP_INDEX",           "DROP_TABLE",           "DROP_TEMP_INDEX",
     "DROP_TEMP_TABLE",      "DROP_TEMP_TRIGGER",    "DROP_TEMP_VIEW",
     "DROP_TRIGGER",         "DROP_VIEW",            "INSERT",
     "PRAGMA",               "READ",                 "SELECT",
     "TRANSACTION",          "UPDATE",               "ATTACH",
     "DETACH",               "ALTER_TABLE",          "REINDEX",
     "ANALYZE",              "CREATE_VTABLE",        "DROP_VTABLE",
     "FUNCTION",             "SAVEPOINT",            "RECURSIVE"
  };
  int i;
  const char *az[4];
  az[0] = zA1;
  az[1] = zA2;
  az[2] = zA3;
  az[3] = zA4;
  sqlite3_fprintf(p->out, "authorizer: %s", azAction[op]);
  for(i=0; i<4; i++){
    sqlite3_fputs(" ", p->out);
    if( az[i] ){
      output_c_string(p->out, az[i]);
    }else{
      sqlite3_fputs("NULL", p->out);
    }
  }
  sqlite3_fputs("\n", p->out);
  if( p->bSafeMode ) (void)safeModeAuth(pClientData, op, zA1, zA2, zA3, zA4);
  return SQLITE_OK;
}
#endif

/*
** Print a schema statement.  Part of MODE_Semi and MODE_Pretty output.
**
** This routine converts some CREATE TABLE statements for shadow tables
** in FTS3/4/5 into CREATE TABLE IF NOT EXISTS statements.
**
** If the schema statement in z[] contains a start-of-comment and if
** sqlite3_complete() returns false, try to terminate the comment before
** printing the result.  https://sqlite.org/forum/forumpost/d7be961c5c
*/
static void printSchemaLine(FILE *out, const char *z, const char *zTail){
  char *zToFree = 0;
  if( z==0 ) return;
  if( zTail==0 ) return;
  if( zTail[0]==';' && (strstr(z, "/*")!=0 || strstr(z,"--")!=0) ){
    const char *zOrig = z;
    static const char *azTerm[] = { "", "*/", "\n" };
    int i;
    for(i=0; i<ArraySize(azTerm); i++){
      char *zNew = sqlite3_mprintf("%s%s;", zOrig, azTerm[i]);
      shell_check_oom(zNew);
      if( sqlite3_complete(zNew) ){
        size_t n = strlen(zNew);
        zNew[n-1] = 0;
        zToFree = zNew;
        z = zNew;
        break;
      }
      sqlite3_free(zNew);
    }
  }
  if( sqlite3_strglob("CREATE TABLE ['\"]*", z)==0 ){
    sqlite3_fprintf(out, "CREATE TABLE IF NOT EXISTS %s%s", z+13, zTail);
  }else{
    sqlite3_fprintf(out, "%s%s", z, zTail);
  }
  sqlite3_free(zToFree);
}
static void printSchemaLineN(FILE *out, char *z, int n, const char *zTail){
  char c = z[n];
  z[n] = 0;
  printSchemaLine(out, z, zTail);
  z[n] = c;
}

/*
** Return true if string z[] has nothing but whitespace and comments to the
** end of the first line.
*/
static int wsToEol(const char *z){
  int i;
  for(i=0; z[i]; i++){
    if( z[i]=='\n' ) return 1;
    if( IsSpace(z[i]) ) continue;
    if( z[i]=='-' && z[i+1]=='-' ) return 1;
    return 0;
  }
  return 1;
}

/*
** Add a new entry to the EXPLAIN QUERY PLAN data
*/
static void eqp_append(ShellState *p, int iEqpId, int p2, const char *zText){
  EQPGraphRow *pNew;
  i64 nText;
  if( zText==0 ) return;
  nText = strlen(zText);
  if( p->autoEQPtest ){
    sqlite3_fprintf(p->out, "%d,%d,%s\n", iEqpId, p2, zText);
  }
  pNew = sqlite3_malloc64( sizeof(*pNew) + nText );
  shell_check_oom(pNew);
  pNew->iEqpId = iEqpId;
  pNew->iParentId = p2;
  memcpy(pNew->zText, zText, nText+1);
  pNew->pNext = 0;
  if( p->sGraph.pLast ){
    p->sGraph.pLast->pNext = pNew;
  }else{
    p->sGraph.pRow = pNew;
  }
  p->sGraph.pLast = pNew;
}

/*
** Free and reset the EXPLAIN QUERY PLAN data that has been collected
** in p->sGraph.
*/
static void eqp_reset(ShellState *p){
  EQPGraphRow *pRow, *pNext;
  for(pRow = p->sGraph.pRow; pRow; pRow = pNext){
    pNext = pRow->pNext;
    sqlite3_free(pRow);
  }
  memset(&p->sGraph, 0, sizeof(p->sGraph));
}

/* Return the next EXPLAIN QUERY PLAN line with iEqpId that occurs after
** pOld, or return the first such line if pOld is NULL
*/
static EQPGraphRow *eqp_next_row(ShellState *p, int iEqpId, EQPGraphRow *pOld){
  EQPGraphRow *pRow = pOld ? pOld->pNext : p->sGraph.pRow;
  while( pRow && pRow->iParentId!=iEqpId ) pRow = pRow->pNext;
  return pRow;
}

/* Render a single level of the graph that has iEqpId as its parent.  Called
** recursively to render sublevels.
*/
static void eqp_render_level(ShellState *p, int iEqpId){
  EQPGraphRow *pRow, *pNext;
  i64 n = strlen(p->sGraph.zPrefix);
  char *z;
  for(pRow = eqp_next_row(p, iEqpId, 0); pRow; pRow = pNext){
    pNext = eqp_next_row(p, iEqpId, pRow);
    z = pRow->zText;
    sqlite3_fprintf(p->out, "%s%s%s\n", p->sGraph.zPrefix,
                            pNext ? "|--" : "`--", z);
    if( n<(i64)sizeof(p->sGraph.zPrefix)-7 ){
      memcpy(&p->sGraph.zPrefix[n], pNext ? "|  " : "   ", 4);
      eqp_render_level(p, pRow->iEqpId);
      p->sGraph.zPrefix[n] = 0;
    }
  }
}

/*
** Display and reset the EXPLAIN QUERY PLAN data
*/
static void eqp_render(ShellState *p, i64 nCycle){
  EQPGraphRow *pRow = p->sGraph.pRow;
  if( pRow ){
    if( pRow->zText[0]=='-' ){
      if( pRow->pNext==0 ){
        eqp_reset(p);
        return;
      }
      sqlite3_fprintf(p->out, "%s\n", pRow->zText+3);
      p->sGraph.pRow = pRow->pNext;
      sqlite3_free(pRow);
    }else if( nCycle>0 ){
      sqlite3_fprintf(p->out, "QUERY PLAN (cycles=%lld [100%%])\n", nCycle);
    }else{
      sqlite3_fputs("QUERY PLAN\n", p->out);
    }
    p->sGraph.zPrefix[0] = 0;
    eqp_render_level(p, 0);
    eqp_reset(p);
  }
}

#ifndef SQLITE_OMIT_PROGRESS_CALLBACK
/*
** Progress handler callback.
*/
static int progress_handler(void *pClientData) {
  ShellState *p = (ShellState*)pClientData;
  p->nProgress++;
  if( p->nProgress>=p->mxProgress && p->mxProgress>0 ){
    sqlite3_fprintf(p->out, "Progress limit reached (%u)\n", p->nProgress);
    if( p->flgProgress & SHELL_PROGRESS_RESET ) p->nProgress = 0;
    if( p->flgProgress & SHELL_PROGRESS_ONCE ) p->mxProgress = 0;
    return 1;
  }
  if( (p->flgProgress & SHELL_PROGRESS_QUIET)==0 ){
    sqlite3_fprintf(p->out, "Progress %u\n", p->nProgress);
  }
  return 0;
}
#endif /* SQLITE_OMIT_PROGRESS_CALLBACK */

/*
** Print N dashes
*/
static void print_dashes(FILE *out, int N){
  const char zDash[] = "--------------------------------------------------";
  const int nDash = sizeof(zDash) - 1;
  while( N>nDash ){
    sqlite3_fputs(zDash, out);
    N -= nDash;
  }
  sqlite3_fprintf(out, "%.*s", N, zDash);
}

/*
** Print a markdown or table-style row separator using ascii-art
*/
static void print_row_separator(
  ShellState *p,
  int nArg,
  const char *zSep
){
  int i;
  if( nArg>0 ){
    sqlite3_fputs(zSep, p->out);
    print_dashes(p->out, p->actualWidth[0]+2);
    for(i=1; i<nArg; i++){
      sqlite3_fputs(zSep, p->out);
      print_dashes(p->out, p->actualWidth[i]+2);
    }
    sqlite3_fputs(zSep, p->out);
  }
  sqlite3_fputs("\n", p->out);
}

/*
** This is the callback routine that the shell
** invokes for each row of a query result.
*/
static int shell_callback(
  void *pArg,
  int nArg,        /* Number of result columns */
  char **azArg,    /* Text of each result column */
  char **azCol,    /* Column names */
  int *aiType      /* Column types.  Might be NULL */
){
  int i;
  ShellState *p = (ShellState*)pArg;

  if( azArg==0 ) return 0;
  switch( p->cMode ){
    case MODE_Count:
    case MODE_Off: {
      break;
    }
    case MODE_Line: {
      int w = 5;
      if( azArg==0 ) break;
      for(i=0; i<nArg; i++){
        int len = strlen30(azCol[i] ? azCol[i] : "");
        if( len>w ) w = len;
      }
      if( p->cnt++>0 ) sqlite3_fputs(p->rowSeparator, p->out);
      for(i=0; i<nArg; i++){
        sqlite3_fprintf(p->out, "%*s = %s%s", w, azCol[i],
              azArg[i] ? azArg[i] : p->nullValue, p->rowSeparator);
      }
      break;
    }
    case MODE_ScanExp:
    case MODE_Explain: {
      static const int aExplainWidth[] = {4,       13, 4, 4, 4, 13, 2, 13};
      static const int aExplainMap[] =   {0,       1,  2, 3, 4, 5,  6, 7 };
      static const int aScanExpWidth[] = {4, 15, 6, 13, 4, 4, 4, 13, 2, 13};
      static const int aScanExpMap[] =   {0, 9, 8, 1,  2, 3, 4, 5,  6, 7 };

      const int *aWidth = aExplainWidth;
      const int *aMap = aExplainMap;
      int nWidth = ArraySize(aExplainWidth);
      int iIndent = 1;

      if( p->cMode==MODE_ScanExp ){
        aWidth = aScanExpWidth;
        aMap = aScanExpMap;
        nWidth = ArraySize(aScanExpWidth);
        iIndent = 3;
      }
      if( nArg>nWidth ) nArg = nWidth;

      /* If this is the first row seen, print out the headers */
      if( p->cnt++==0 ){
        for(i=0; i<nArg; i++){
          utf8_width_print(p->out, aWidth[i], azCol[ aMap[i] ]);
          sqlite3_fputs(i==nArg-1 ? "\n" : "  ", p->out);
        }
        for(i=0; i<nArg; i++){
          print_dashes(p->out, aWidth[i]);
          sqlite3_fputs(i==nArg-1 ? "\n" : "  ", p->out);
        }
      }

      /* If there is no data, exit early. */
      if( azArg==0 ) break;

      for(i=0; i<nArg; i++){
        const char *zSep = "  ";
        int w = aWidth[i];
        const char *zVal = azArg[ aMap[i] ];
        if( i==nArg-1 ) w = 0;
        if( zVal && strlenChar(zVal)>w ){
          w = strlenChar(zVal);
          zSep = " ";
        }
        if( i==iIndent && p->aiIndent && p->pStmt ){
          if( p->iIndent<p->nIndent ){
            sqlite3_fprintf(p->out, "%*.s", p->aiIndent[p->iIndent], "");
          }
          p->iIndent++;
        }
        utf8_width_print(p->out, w, zVal ? zVal : p->nullValue);
        sqlite3_fputs(i==nArg-1 ? "\n" : zSep, p->out);
      }
      break;
    }
    case MODE_Semi: {   /* .schema and .fullschema output */
      printSchemaLine(p->out, azArg[0], ";\n");
      break;
    }
    case MODE_Pretty: {  /* .schema and .fullschema with --indent */
      char *z;
      int j;
      int nParen = 0;
      char cEnd = 0;
      char c;
      int nLine = 0;
      assert( nArg==1 );
      if( azArg[0]==0 ) break;
      if( sqlite3_strlike("CREATE VIEW%", azArg[0], 0)==0
       || sqlite3_strlike("CREATE TRIG%", azArg[0], 0)==0
      ){
        sqlite3_fprintf(p->out, "%s;\n", azArg[0]);
        break;
      }
      z = sqlite3_mprintf("%s", azArg[0]);
      shell_check_oom(z);
      j = 0;
      for(i=0; IsSpace(z[i]); i++){}
      for(; (c = z[i])!=0; i++){
        if( IsSpace(c) ){
          if( z[j-1]=='\r' ) z[j-1] = '\n';
          if( IsSpace(z[j-1]) || z[j-1]=='(' ) continue;
        }else if( (c=='(' || c==')') && j>0 && IsSpace(z[j-1]) ){
          j--;
        }
        z[j++] = c;
      }
      while( j>0 && IsSpace(z[j-1]) ){ j--; }
      z[j] = 0;
      if( strlen30(z)>=79 ){
        for(i=j=0; (c = z[i])!=0; i++){ /* Copy from z[i] back to z[j] */
          if( c==cEnd ){
            cEnd = 0;
          }else if( c=='"' || c=='\'' || c=='`' ){
            cEnd = c;
          }else if( c=='[' ){
            cEnd = ']';
          }else if( c=='-' && z[i+1]=='-' ){
            cEnd = '\n';
          }else if( c=='(' ){
            nParen++;
          }else if( c==')' ){
            nParen--;
            if( nLine>0 && nParen==0 && j>0 ){
              printSchemaLineN(p->out, z, j, "\n");
              j = 0;
            }
          }
          z[j++] = c;
          if( nParen==1 && cEnd==0
           && (c=='(' || c=='\n' || (c==',' && !wsToEol(z+i+1)))
          ){
            if( c=='\n' ) j--;
            printSchemaLineN(p->out, z, j, "\n  ");
            j = 0;
            nLine++;
            while( IsSpace(z[i+1]) ){ i++; }
          }
        }
        z[j] = 0;
      }
      printSchemaLine(p->out, z, ";\n");
      sqlite3_free(z);
      break;
    }
    case MODE_List: {
      if( p->cnt++==0 && p->showHeader ){
        for(i=0; i<nArg; i++){
          sqlite3_fprintf(p->out, "%s%s", azCol[i],
                          i==nArg-1 ? p->rowSeparator : p->colSeparator);
        }
      }
      if( azArg==0 ) break;
      for(i=0; i<nArg; i++){
        char *z = azArg[i];
        if( z==0 ) z = p->nullValue;
        sqlite3_fputs(z, p->out);
        sqlite3_fputs((i<nArg-1)? p->colSeparator : p->rowSeparator, p->out);
      }
      break;
    }
    case MODE_Www:
    case MODE_Html: {
      if( p->cnt==0 && p->cMode==MODE_Www ){
        sqlite3_fputs(
          "</PRE>\n"
          "<TABLE border='1' cellspacing='0' cellpadding='2'>\n"
          ,p->out
        );
      }
      if( p->cnt==0 && (p->showHeader || p->cMode==MODE_Www) ){
        sqlite3_fputs("<TR>", p->out);
        for(i=0; i<nArg; i++){
          sqlite3_fputs("<TH>", p->out);
          output_html_string(p->out, azCol[i]);
          sqlite3_fputs("</TH>\n", p->out);
        }
        sqlite3_fputs("</TR>\n", p->out);
      }
      p->cnt++;
      if( azArg==0 ) break;
      sqlite3_fputs("<TR>", p->out);
      for(i=0; i<nArg; i++){
        sqlite3_fputs("<TD>", p->out);
        output_html_string(p->out, azArg[i] ? azArg[i] : p->nullValue);
        sqlite3_fputs("</TD>\n", p->out);
      }
      sqlite3_fputs("</TR>\n", p->out);
      break;
    }
    case MODE_Tcl: {
      if( p->cnt++==0 && p->showHeader ){
        for(i=0; i<nArg; i++){
          output_c_string(p->out, azCol[i] ? azCol[i] : "");
          if(i<nArg-1) sqlite3_fputs(p->colSeparator, p->out);
        }
        sqlite3_fputs(p->rowSeparator, p->out);
      }
      if( azArg==0 ) break;
      for(i=0; i<nArg; i++){
        output_c_string(p->out, azArg[i] ? azArg[i] : p->nullValue);
        if(i<nArg-1) sqlite3_fputs(p->colSeparator, p->out);
      }
      sqlite3_fputs(p->rowSeparator, p->out);
      break;
    }
    case MODE_Csv: {
      sqlite3_fsetmode(p->out, _O_BINARY);
      if( p->cnt++==0 && p->showHeader ){
        for(i=0; i<nArg; i++){
          output_csv(p, azCol[i] ? azCol[i] : "", i<nArg-1);
        }
        sqlite3_fputs(p->rowSeparator, p->out);
      }
      if( nArg>0 ){
        for(i=0; i<nArg; i++){
          output_csv(p, azArg[i], i<nArg-1);
        }
        sqlite3_fputs(p->rowSeparator, p->out);
      }
      setCrlfMode(p);
      break;
    }
    case MODE_Insert: {
      if( azArg==0 ) break;
      sqlite3_fprintf(p->out, "INSERT INTO %s",p->zDestTable);
      if( p->showHeader ){
        sqlite3_fputs("(", p->out);
        for(i=0; i<nArg; i++){
          if( i>0 ) sqlite3_fputs(",", p->out);
          if( quoteChar(azCol[i]) ){
            char *z = sqlite3_mprintf("\"%w\"", azCol[i]);
            shell_check_oom(z);
            sqlite3_fputs(z, p->out);
            sqlite3_free(z);
          }else{
            sqlite3_fprintf(p->out, "%s", azCol[i]);
          }
        }
        sqlite3_fputs(")", p->out);
      }
      p->cnt++;
      for(i=0; i<nArg; i++){
        sqlite3_fputs(i>0 ? "," : " VALUES(", p->out);
        if( (azArg[i]==0) || (aiType && aiType[i]==SQLITE_NULL) ){
          sqlite3_fputs("NULL", p->out);
        }else if( aiType && aiType[i]==SQLITE_TEXT ){
          if( ShellHasFlag(p, SHFLG_Newlines) ){
            output_quoted_string(p, azArg[i]);
          }else{
            output_quoted_escaped_string(p, azArg[i]);
          }
        }else if( aiType && aiType[i]==SQLITE_INTEGER ){
          sqlite3_fputs(azArg[i], p->out);
        }else if( aiType && aiType[i]==SQLITE_FLOAT ){
          char z[50];
          double r = sqlite3_column_double(p->pStmt, i);
          sqlite3_uint64 ur;
          memcpy(&ur,&r,sizeof(r));
          if( ur==0x7ff0000000000000LL ){
            sqlite3_fputs("9.0e+999", p->out);
          }else if( ur==0xfff0000000000000LL ){
            sqlite3_fputs("-9.0e+999", p->out);
          }else{
            sqlite3_int64 ir = (sqlite3_int64)r;
            if( r==(double)ir ){
              sqlite3_snprintf(50,z,"%lld.0", ir);
            }else{
              sqlite3_snprintf(50,z,"%!.20g", r);
            }
            sqlite3_fputs(z, p->out);
          }
        }else if( aiType && aiType[i]==SQLITE_BLOB && p->pStmt ){
          const void *pBlob = sqlite3_column_blob(p->pStmt, i);
          int nBlob = sqlite3_column_bytes(p->pStmt, i);
          output_hex_blob(p->out, pBlob, nBlob);
        }else if( isNumber(azArg[i], 0) ){
          sqlite3_fputs(azArg[i], p->out);
        }else if( ShellHasFlag(p, SHFLG_Newlines) ){
          output_quoted_string(p, azArg[i]);
        }else{
          output_quoted_escaped_string(p, azArg[i]);
        }
      }
      sqlite3_fputs(");\n", p->out);
      break;
    }
    case MODE_Json: {
      if( azArg==0 ) break;
      if( p->cnt==0 ){
        sqlite3_fputs("[{", p->out);
      }else{
        sqlite3_fputs(",\n{", p->out);
      }
      p->cnt++;
      for(i=0; i<nArg; i++){
        output_json_string(p->out, azCol[i], -1);
        sqlite3_fputs(":", p->out);
        if( (azArg[i]==0) || (aiType && aiType[i]==SQLITE_NULL) ){
          sqlite3_fputs("null", p->out);
        }else if( aiType && aiType[i]==SQLITE_FLOAT ){
          char z[50];
          double r = sqlite3_column_double(p->pStmt, i);
          sqlite3_uint64 ur;
          memcpy(&ur,&r,sizeof(r));
          if( ur==0x7ff0000000000000LL ){
            sqlite3_fputs("9.0e+999", p->out);
          }else if( ur==0xfff0000000000000LL ){
            sqlite3_fputs("-9.0e+999", p->out);
          }else{
            sqlite3_snprintf(50,z,"%!.20g", r);
            sqlite3_fputs(z, p->out);
          }
        }else if( aiType && aiType[i]==SQLITE_BLOB && p->pStmt ){
          const void *pBlob = sqlite3_column_blob(p->pStmt, i);
          int nBlob = sqlite3_column_bytes(p->pStmt, i);
          output_json_string(p->out, pBlob, nBlob);
        }else if( aiType && aiType[i]==SQLITE_TEXT ){
          output_json_string(p->out, azArg[i], -1);
        }else{
          sqlite3_fputs(azArg[i], p->out);
        }
        if( i<nArg-1 ){
          sqlite3_fputs(",", p->out);
        }
      }
      sqlite3_fputs("}", p->out);
      break;
    }
    case MODE_Quote: {
      if( azArg==0 ) break;
      if( p->cnt==0 && p->showHeader ){
        for(i=0; i<nArg; i++){
          if( i>0 ) sqlite3_fputs(p->colSeparator, p->out);
          output_quoted_string(p, azCol[i]);
        }
        sqlite3_fputs(p->rowSeparator, p->out);
      }
      p->cnt++;
      for(i=0; i<nArg; i++){
        if( i>0 ) sqlite3_fputs(p->colSeparator, p->out);
        if( (azArg[i]==0) || (aiType && aiType[i]==SQLITE_NULL) ){
          sqlite3_fputs("NULL", p->out);
        }else if( aiType && aiType[i]==SQLITE_TEXT ){
          output_quoted_string(p, azArg[i]);
        }else if( aiType && aiType[i]==SQLITE_INTEGER ){
          sqlite3_fputs(azArg[i], p->out);
        }else if( aiType && aiType[i]==SQLITE_FLOAT ){
          char z[50];
          double r = sqlite3_column_double(p->pStmt, i);
          sqlite3_snprintf(50,z,"%!.20g", r);
          sqlite3_fputs(z, p->out);
        }else if( aiType && aiType[i]==SQLITE_BLOB && p->pStmt ){
          const void *pBlob = sqlite3_column_blob(p->pStmt, i);
          int nBlob = sqlite3_column_bytes(p->pStmt, i);
          output_hex_blob(p->out, pBlob, nBlob);
        }else if( isNumber(azArg[i], 0) ){
          sqlite3_fputs(azArg[i], p->out);
        }else{
          output_quoted_string(p, azArg[i]);
        }
      }
      sqlite3_fputs(p->rowSeparator, p->out);
      break;
    }
    case MODE_Ascii: {
      if( p->cnt++==0 && p->showHeader ){
        for(i=0; i<nArg; i++){
          if( i>0 ) sqlite3_fputs(p->colSeparator, p->out);
          sqlite3_fputs(azCol[i] ? azCol[i] : "", p->out);
        }
        sqlite3_fputs(p->rowSeparator, p->out);
      }
      if( azArg==0 ) break;
      for(i=0; i<nArg; i++){
        if( i>0 ) sqlite3_fputs(p->colSeparator, p->out);
        sqlite3_fputs(azArg[i] ? azArg[i] : p->nullValue, p->out);
      }
      sqlite3_fputs(p->rowSeparator, p->out);
      break;
    }
    case MODE_EQP: {
      eqp_append(p, atoi(azArg[0]), atoi(azArg[1]), azArg[3]);
      break;
    }
  }
  return 0;
}

/*
** This is the callback routine that the SQLite library
** invokes for each row of a query result.
*/
static int callback(void *pArg, int nArg, char **azArg, char **azCol){
  /* since we don't have type info, call the shell_callback with a NULL value */
  return shell_callback(pArg, nArg, azArg, azCol, NULL);
}

/*
** This is the callback routine from sqlite3_exec() that appends all
** output onto the end of a ShellText object.
*/
static int captureOutputCallback(void *pArg, int nArg, char **azArg, char **az){
  ShellText *p = (ShellText*)pArg;
  int i;
  UNUSED_PARAMETER(az);
  if( azArg==0 ) return 0;
  if( p->n ) appendText(p, "|", 0);
  for(i=0; i<nArg; i++){
    if( i ) appendText(p, ",", 0);
    if( azArg[i] ) appendText(p, azArg[i], 0);
  }
  return 0;
}

/*
** Generate an appropriate SELFTEST table in the main database.
*/
static void createSelftestTable(ShellState *p){
  char *zErrMsg = 0;
  sqlite3_exec(p->db,
    "SAVEPOINT selftest_init;\n"
    "CREATE TABLE IF NOT EXISTS selftest(\n"
    "  tno INTEGER PRIMARY KEY,\n"   /* Test number */
    "  op TEXT,\n"                   /* Operator:  memo run */
    "  cmd TEXT,\n"                  /* Command text */
    "  ans TEXT\n"                   /* Desired answer */
    ");"
    "CREATE TEMP TABLE [_shell$self](op,cmd,ans);\n"
    "INSERT INTO [_shell$self](rowid,op,cmd)\n"
    "  VALUES(coalesce((SELECT (max(tno)+100)/10 FROM selftest),10),\n"
    "         'memo','Tests generated by --init');\n"
    "INSERT INTO [_shell$self]\n"
    "  SELECT 'run',\n"
    "    'SELECT hex(sha3_query(''SELECT type,name,tbl_name,sql "
                                 "FROM sqlite_schema ORDER BY 2'',224))',\n"
    "    hex(sha3_query('SELECT type,name,tbl_name,sql "
                          "FROM sqlite_schema ORDER BY 2',224));\n"
    "INSERT INTO [_shell$self]\n"
    "  SELECT 'run',"
    "    'SELECT hex(sha3_query(''SELECT * FROM \"' ||"
    "        printf('%w',name) || '\" NOT INDEXED'',224))',\n"
    "    hex(sha3_query(printf('SELECT * FROM \"%w\" NOT INDEXED',name),224))\n"
    "  FROM (\n"
    "    SELECT name FROM sqlite_schema\n"
    "     WHERE type='table'\n"
    "       AND name<>'selftest'\n"
    "       AND coalesce(rootpage,0)>0\n"
    "  )\n"
    " ORDER BY name;\n"
    "INSERT INTO [_shell$self]\n"
    "  VALUES('run','PRAGMA integrity_check','ok');\n"
    "INSERT INTO selftest(tno,op,cmd,ans)"
    "  SELECT rowid*10,op,cmd,ans FROM [_shell$self];\n"
    "DROP TABLE [_shell$self];"
    ,0,0,&zErrMsg);
  if( zErrMsg ){
    sqlite3_fprintf(stderr, "SELFTEST initialization failure: %s\n", zErrMsg);
    sqlite3_free(zErrMsg);
  }
  sqlite3_exec(p->db, "RELEASE selftest_init",0,0,0);
}


/*
** Set the destination table field of the ShellState structure to
** the name of the table given.  Escape any quote characters in the
** table name.
*/
static void set_table_name(ShellState *p, const char *zName){
  int i, n;
  char cQuote;
  char *z;

  if( p->zDestTable ){
    free(p->zDestTable);
    p->zDestTable = 0;
  }
  if( zName==0 ) return;
  cQuote = quoteChar(zName);
  n = strlen30(zName);
  if( cQuote ) n += n+2;
  z = p->zDestTable = malloc( n+1 );
  shell_check_oom(z);
  n = 0;
  if( cQuote ) z[n++] = cQuote;
  for(i=0; zName[i]; i++){
    z[n++] = zName[i];
    if( zName[i]==cQuote ) z[n++] = cQuote;
  }
  if( cQuote ) z[n++] = cQuote;
  z[n] = 0;
}

/*
** Maybe construct two lines of text that point out the position of a
** syntax error.  Return a pointer to the text, in memory obtained from
** sqlite3_malloc().  Or, if the most recent error does not involve a
** specific token that we can point to, return an empty string.
**
** In all cases, the memory returned is obtained from sqlite3_malloc64()
** and should be released by the caller invoking sqlite3_free().
*/
static char *shell_error_context(const char *zSql, sqlite3 *db){
  int iOffset;
  size_t len;
  char *zCode;
  char *zMsg;
  int i;
  if( db==0
   || zSql==0
   || (iOffset = sqlite3_error_offset(db))<0
   || iOffset>=(int)strlen(zSql)
  ){
    return sqlite3_mprintf("");
  }
  while( iOffset>50 ){
    iOffset--;
    zSql++;
    while( (zSql[0]&0xc0)==0x80 ){ zSql++; iOffset--; }
  }
  len = strlen(zSql);
  if( len>78 ){
    len = 78;
    while( len>0 && (zSql[len]&0xc0)==0x80 ) len--;
  }
  zCode = sqlite3_mprintf("%.*s", len, zSql);
  shell_check_oom(zCode);
  for(i=0; zCode[i]; i++){ if( IsSpace(zSql[i]) ) zCode[i] = ' '; }
  if( iOffset<25 ){
    zMsg = sqlite3_mprintf("\n  %z\n  %*s^--- error here", zCode,iOffset,"");
  }else{
    zMsg = sqlite3_mprintf("\n  %z\n  %*serror here ---^", zCode,iOffset-14,"");
  }
  return zMsg;
}


/*
** Execute a query statement that will generate SQL output.  Print
** the result columns, comma-separated, on a line and then add a
** semicolon terminator to the end of that line.
**
** If the number of columns is 1 and that column contains text "--"
** then write the semicolon on a separate line.  That way, if a
** "--" comment occurs at the end of the statement, the comment
** won't consume the semicolon terminator.
*/
static int run_table_dump_query(
  ShellState *p,           /* Query context */
  const char *zSelect      /* SELECT statement to extract content */
){
  sqlite3_stmt *pSelect;
  int rc;
  int nResult;
  int i;
  const char *z;
  rc = sqlite3_prepare_v2(p->db, zSelect, -1, &pSelect, 0);
  if( rc!=SQLITE_OK || !pSelect ){
    char *zContext = shell_error_context(zSelect, p->db);
    sqlite3_fprintf(p->out, "/**** ERROR: (%d) %s *****/\n%s",
          rc, sqlite3_errmsg(p->db), zContext);
    sqlite3_free(zContext);
    if( (rc&0xff)!=SQLITE_CORRUPT ) p->nErr++;
    return rc;
  }
  rc = sqlite3_step(pSelect);
  nResult = sqlite3_column_count(pSelect);
  while( rc==SQLITE_ROW ){
    z = (const char*)sqlite3_column_text(pSelect, 0);
    sqlite3_fprintf(p->out, "%s", z);
    for(i=1; i<nResult; i++){
      sqlite3_fprintf(p->out, ",%s", sqlite3_column_text(pSelect, i));
    }
    if( z==0 ) z = "";
    while( z[0] && (z[0]!='-' || z[1]!='-') ) z++;
    if( z[0] ){
      sqlite3_fputs("\n;\n", p->out);
    }else{
      sqlite3_fputs(";\n", p->out);
    }
    rc = sqlite3_step(pSelect);
  }
  rc = sqlite3_finalize(pSelect);
  if( rc!=SQLITE_OK ){
    sqlite3_fprintf(p->out, "/**** ERROR: (%d) %s *****/\n",
                    rc, sqlite3_errmsg(p->db));
    if( (rc&0xff)!=SQLITE_CORRUPT ) p->nErr++;
  }
  return rc;
}

/*
** Allocate space and save off string indicating current error.
*/
static char *save_err_msg(
  sqlite3 *db,           /* Database to query */
  const char *zPhase,    /* When the error occurs */
  int rc,                /* Error code returned from API */
  const char *zSql       /* SQL string, or NULL */
){
  char *zErr;
  char *zContext;
  sqlite3_str *pStr = sqlite3_str_new(0);
  sqlite3_str_appendf(pStr, "%s, %s", zPhase, sqlite3_errmsg(db));
  if( rc>1 ){
    sqlite3_str_appendf(pStr, " (%d)", rc);
  }
  zContext = shell_error_context(zSql, db);
  if( zContext ){
    sqlite3_str_appendall(pStr, zContext);
    sqlite3_free(zContext);
  }
  zErr = sqlite3_str_finish(pStr);
  shell_check_oom(zErr);
  return zErr;
}

#ifdef __linux__
/*
** Attempt to display I/O stats on Linux using /proc/PID/io
*/
static void displayLinuxIoStats(FILE *out){
  FILE *in;
  char z[200];
  sqlite3_snprintf(sizeof(z), z, "/proc/%d/io", getpid());
  in = sqlite3_fopen(z, "rb");
  if( in==0 ) return;
  while( sqlite3_fgets(z, sizeof(z), in)!=0 ){
    static const struct {
      const char *zPattern;
      const char *zDesc;
    } aTrans[] = {
      { "rchar: ",                  "Bytes received by read():" },
      { "wchar: ",                  "Bytes sent to write():"    },
      { "syscr: ",                  "Read() system calls:"      },
      { "syscw: ",                  "Write() system calls:"     },
      { "read_bytes: ",             "Bytes read from storage:"  },
      { "write_bytes: ",            "Bytes written to storage:" },
      { "cancelled_write_bytes: ",  "Cancelled write bytes:"    },
    };
    int i;
    for(i=0; i<ArraySize(aTrans); i++){
      int n = strlen30(aTrans[i].zPattern);
      if( cli_strncmp(aTrans[i].zPattern, z, n)==0 ){
        sqlite3_fprintf(out, "%-36s %s", aTrans[i].zDesc, &z[n]);
        break;
      }
    }
  }
  fclose(in);
}
#endif

/*
** Display a single line of status using 64-bit values.
*/
static void displayStatLine(
  FILE *out,                /* Write to this channel */
  char *zLabel,             /* Label for this one line */
  char *zFormat,            /* Format for the result */
  int iStatusCtrl,          /* Which status to display */
  int bReset                /* True to reset the stats */
){
  sqlite3_int64 iCur = -1;
  sqlite3_int64 iHiwtr = -1;
  int i, nPercent;
  char zLine[200];
  sqlite3_status64(iStatusCtrl, &iCur, &iHiwtr, bReset);
  for(i=0, nPercent=0; zFormat[i]; i++){
    if( zFormat[i]=='%' ) nPercent++;
  }
  if( nPercent>1 ){
    sqlite3_snprintf(sizeof(zLine), zLine, zFormat, iCur, iHiwtr);
  }else{
    sqlite3_snprintf(sizeof(zLine), zLine, zFormat, iHiwtr);
  }
  sqlite3_fprintf(out, "%-36s %s\n", zLabel, zLine);
}

/*
** Display memory stats.
*/
static int display_stats(
  sqlite3 *db,                /* Database to query */
  ShellState *pArg,           /* Pointer to ShellState */
  int bReset                  /* True to reset the stats */
){
  int iCur;
  int iHiwtr;
  FILE *out;
  if( pArg==0 || pArg->out==0 ) return 0;
  out = pArg->out;

  if( pArg->pStmt && pArg->statsOn==2 ){
    int nCol, i, x;
    sqlite3_stmt *pStmt = pArg->pStmt;
    char z[100];
    nCol = sqlite3_column_count(pStmt);
    sqlite3_fprintf(out, "%-36s %d\n", "Number of output columns:", nCol);
    for(i=0; i<nCol; i++){
      sqlite3_snprintf(sizeof(z),z,"Column %d %nname:", i, &x);
      sqlite3_fprintf(out, "%-36s %s\n", z, sqlite3_column_name(pStmt,i));
#ifndef SQLITE_OMIT_DECLTYPE
      sqlite3_snprintf(30, z+x, "declared type:");
      sqlite3_fprintf(out, "%-36s %s\n", z, sqlite3_column_decltype(pStmt, i));
#endif
#ifdef SQLITE_ENABLE_COLUMN_METADATA
      sqlite3_snprintf(30, z+x, "database name:");
      sqlite3_fprintf(out, "%-36s %s\n", z,
                           sqlite3_column_database_name(pStmt,i));
      sqlite3_snprintf(30, z+x, "table name:");
      sqlite3_fprintf(out, "%-36s %s\n", z, sqlite3_column_table_name(pStmt,i));
      sqlite3_snprintf(30, z+x, "origin name:");
      sqlite3_fprintf(out, "%-36s %s\n", z,sqlite3_column_origin_name(pStmt,i));
#endif
    }
  }

  if( pArg->statsOn==3 ){
    if( pArg->pStmt ){
      iCur = sqlite3_stmt_status(pArg->pStmt, SQLITE_STMTSTATUS_VM_STEP,bReset);
      sqlite3_fprintf(out, "VM-steps: %d\n", iCur);
    }
    return 0;
  }

  displayStatLine(out, "Memory Used:",
     "%lld (max %lld) bytes", SQLITE_STATUS_MEMORY_USED, bReset);
  displayStatLine(out, "Number of Outstanding Allocations:",
     "%lld (max %lld)", SQLITE_STATUS_MALLOC_COUNT, bReset);
  if( pArg->shellFlgs & SHFLG_Pagecache ){
    displayStatLine(out, "Number of Pcache Pages Used:",
       "%lld (max %lld) pages", SQLITE_STATUS_PAGECACHE_USED, bReset);
  }
  displayStatLine(out, "Number of Pcache Overflow Bytes:",
     "%lld (max %lld) bytes", SQLITE_STATUS_PAGECACHE_OVERFLOW, bReset);
  displayStatLine(out, "Largest Allocation:",
     "%lld bytes", SQLITE_STATUS_MALLOC_SIZE, bReset);
  displayStatLine(out, "Largest Pcache Allocation:",
     "%lld bytes", SQLITE_STATUS_PAGECACHE_SIZE, bReset);
#ifdef YYTRACKMAXSTACKDEPTH
  displayStatLine(out, "Deepest Parser Stack:",
     "%lld (max %lld)", SQLITE_STATUS_PARSER_STACK, bReset);
#endif

  if( db ){
    if( pArg->shellFlgs & SHFLG_Lookaside ){
      iHiwtr = iCur = -1;
      sqlite3_db_status(db, SQLITE_DBSTATUS_LOOKASIDE_USED,
                        &iCur, &iHiwtr, bReset);
      sqlite3_fprintf(out, 
           "Lookaside Slots Used:                %d (max %d)\n", iCur, iHiwtr);
      sqlite3_db_status(db, SQLITE_DBSTATUS_LOOKASIDE_HIT,
                        &iCur, &iHiwtr, bReset);
      sqlite3_fprintf(out,
           "Successful lookaside attempts:       %d\n", iHiwtr);
      sqlite3_db_status(db, SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE,
                        &iCur, &iHiwtr, bReset);
      sqlite3_fprintf(out,
           "Lookaside failures due to size:      %d\n", iHiwtr);
      sqlite3_db_status(db, SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL,
                        &iCur, &iHiwtr, bReset);
      sqlite3_fprintf(out,
           "Lookaside failures due to OOM:       %d\n", iHiwtr);
    }
    iHiwtr = iCur = -1;
    sqlite3_db_status(db, SQLITE_DBSTATUS_CACHE_USED, &iCur, &iHiwtr, bReset);
    sqlite3_fprintf(out,
           "Pager Heap Usage:                    %d bytes\n", iCur);
    iHiwtr = iCur = -1;
    sqlite3_db_status(db, SQLITE_DBSTATUS_CACHE_HIT, &iCur, &iHiwtr, 1);
    sqlite3_fprintf(out,
           "Page cache hits:                     %d\n", iCur);
    iHiwtr = iCur = -1;
    sqlite3_db_status(db, SQLITE_DBSTATUS_CACHE_MISS, &iCur, &iHiwtr, 1);
    sqlite3_fprintf(out,
           "Page cache misses:                   %d\n", iCur);
    iHiwtr = iCur = -1;
    sqlite3_db_status(db, SQLITE_DBSTATUS_CACHE_WRITE, &iCur, &iHiwtr, 1);
    sqlite3_fprintf(out,
           "Page cache writes:                   %d\n", iCur);
    iHiwtr = iCur = -1;
    sqlite3_db_status(db, SQLITE_DBSTATUS_CACHE_SPILL, &iCur, &iHiwtr, 1);
    sqlite3_fprintf(out,
           "Page cache spills:                   %d\n", iCur);
    iHiwtr = iCur = -1;
    sqlite3_db_status(db, SQLITE_DBSTATUS_SCHEMA_USED, &iCur, &iHiwtr, bReset);
    sqlite3_fprintf(out,
           "Schema Heap Usage:                   %d bytes\n", iCur);
    iHiwtr = iCur = -1;
    sqlite3_db_status(db, SQLITE_DBSTATUS_STMT_USED, &iCur, &iHiwtr, bReset);
    sqlite3_fprintf(out,
           "Statement Heap/Lookaside Usage:      %d bytes\n", iCur);
  }

  if( pArg->pStmt ){
    int iHit, iMiss;
    iCur = sqlite3_stmt_status(pArg->pStmt, SQLITE_STMTSTATUS_FULLSCAN_STEP,
                               bReset);
    sqlite3_fprintf(out,
           "Fullscan Steps:                      %d\n", iCur);
    iCur = sqlite3_stmt_status(pArg->pStmt, SQLITE_STMTSTATUS_SORT, bReset);
    sqlite3_fprintf(out,
           "Sort Operations:                     %d\n", iCur);
    iCur = sqlite3_stmt_status(pArg->pStmt, SQLITE_STMTSTATUS_AUTOINDEX,bReset);
    sqlite3_fprintf(out,
           "Autoindex Inserts:                   %d\n", iCur);
    iHit = sqlite3_stmt_status(pArg->pStmt, SQLITE_STMTSTATUS_FILTER_HIT,
                               bReset);
    iMiss = sqlite3_stmt_status(pArg->pStmt, SQLITE_STMTSTATUS_FILTER_MISS,
                                bReset);
    if( iHit || iMiss ){
      sqlite3_fprintf(out,
           "Bloom filter bypass taken:           %d/%d\n", iHit, iHit+iMiss);
    }
    iCur = sqlite3_stmt_status(pArg->pStmt, SQLITE_STMTSTATUS_VM_STEP, bReset);
    sqlite3_fprintf(out,
           "Virtual Machine Steps:               %d\n", iCur);
    iCur = sqlite3_stmt_status(pArg->pStmt, SQLITE_STMTSTATUS_REPREPARE,bReset);
    sqlite3_fprintf(out,
           "Reprepare operations:                %d\n", iCur);
    iCur = sqlite3_stmt_status(pArg->pStmt, SQLITE_STMTSTATUS_RUN, bReset);
    sqlite3_fprintf(out,
           "Number of times run:                 %d\n", iCur);
    iCur = sqlite3_stmt_status(pArg->pStmt, SQLITE_STMTSTATUS_MEMUSED, bReset);
    sqlite3_fprintf(out,
           "Memory used by prepared stmt:        %d\n", iCur);
  }

#ifdef __linux__
  displayLinuxIoStats(pArg->out);
#endif

  /* Do not remove this machine readable comment: extra-stats-output-here */

  return 0;
}


#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
static int scanStatsHeight(sqlite3_stmt *p, int iEntry){
  int iPid = 0;
  int ret = 1;
  sqlite3_stmt_scanstatus_v2(p, iEntry,
      SQLITE_SCANSTAT_SELECTID, SQLITE_SCANSTAT_COMPLEX, (void*)&iPid
  );
  while( iPid!=0 ){
    int ii;
    for(ii=0; 1; ii++){
      int iId;
      int res;
      res = sqlite3_stmt_scanstatus_v2(p, ii,
          SQLITE_SCANSTAT_SELECTID, SQLITE_SCANSTAT_COMPLEX, (void*)&iId
      );
      if( res ) break;
      if( iId==iPid ){
        sqlite3_stmt_scanstatus_v2(p, ii,
            SQLITE_SCANSTAT_PARENTID, SQLITE_SCANSTAT_COMPLEX, (void*)&iPid
        );
      }
    }
    ret++;
  }
  return ret;
}
#endif

#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
static void display_explain_scanstats(
  sqlite3 *db,                    /* Database to query */
  ShellState *pArg                /* Pointer to ShellState */
){
  static const int f = SQLITE_SCANSTAT_COMPLEX;
  sqlite3_stmt *p = pArg->pStmt;
  int ii = 0;
  i64 nTotal = 0;
  int nWidth = 0;
  eqp_reset(pArg);

  for(ii=0; 1; ii++){
    const char *z = 0;
    int n = 0;
    if( sqlite3_stmt_scanstatus_v2(p,ii,SQLITE_SCANSTAT_EXPLAIN,f,(void*)&z) ){
      break;
    }
    n = (int)strlen(z) + scanStatsHeight(p, ii)*3;
    if( n>nWidth ) nWidth = n;
  }
  nWidth += 4;

  sqlite3_stmt_scanstatus_v2(p, -1, SQLITE_SCANSTAT_NCYCLE, f, (void*)&nTotal);
  for(ii=0; 1; ii++){
    i64 nLoop = 0;
    i64 nRow = 0;
    i64 nCycle = 0;
    int iId = 0;
    int iPid = 0;
    const char *zo = 0;
    const char *zName = 0;
    char *zText = 0;
    double rEst = 0.0;

    if( sqlite3_stmt_scanstatus_v2(p,ii,SQLITE_SCANSTAT_EXPLAIN,f,(void*)&zo) ){
      break;
    }
    sqlite3_stmt_scanstatus_v2(p, ii, SQLITE_SCANSTAT_EST,f,(void*)&rEst);
    sqlite3_stmt_scanstatus_v2(p, ii, SQLITE_SCANSTAT_NLOOP,f,(void*)&nLoop);
    sqlite3_stmt_scanstatus_v2(p, ii, SQLITE_SCANSTAT_NVISIT,f,(void*)&nRow);
    sqlite3_stmt_scanstatus_v2(p, ii, SQLITE_SCANSTAT_NCYCLE,f,(void*)&nCycle);
    sqlite3_stmt_scanstatus_v2(p, ii, SQLITE_SCANSTAT_SELECTID,f,(void*)&iId);
    sqlite3_stmt_scanstatus_v2(p, ii, SQLITE_SCANSTAT_PARENTID,f,(void*)&iPid);
    sqlite3_stmt_scanstatus_v2(p, ii, SQLITE_SCANSTAT_NAME,f,(void*)&zName);

    zText = sqlite3_mprintf("%s", zo);
    if( nCycle>=0 || nLoop>=0 || nRow>=0 ){
      char *z = 0;
      if( nCycle>=0 && nTotal>0 ){
        z = sqlite3_mprintf("%zcycles=%lld [%d%%]", z,
            nCycle, ((nCycle*100)+nTotal/2) / nTotal
        );
      }
      if( nLoop>=0 ){
        z = sqlite3_mprintf("%z%sloops=%lld", z, z ? " " : "", nLoop);
      }
      if( nRow>=0 ){
        z = sqlite3_mprintf("%z%srows=%lld", z, z ? " " : "", nRow);
      }

      if( zName && pArg->scanstatsOn>1 ){
        double rpl = (double)nRow / (double)nLoop;
        z = sqlite3_mprintf("%z rpl=%.1f est=%.1f", z, rpl, rEst);
      }

      zText = sqlite3_mprintf(
          "% *z (%z)", -1*(nWidth-scanStatsHeight(p, ii)*3), zText, z
      );
    }

    eqp_append(pArg, iId, iPid, zText);
    sqlite3_free(zText);
  }

  eqp_render(pArg, nTotal);
}
#endif


/*
** Parameter azArray points to a zero-terminated array of strings. zStr
** points to a single nul-terminated string. Return non-zero if zStr
** is equal, according to strcmp(), to any of the strings in the array.
** Otherwise, return zero.
*/
static int str_in_array(const char *zStr, const char **azArray){
  int i;
  for(i=0; azArray[i]; i++){
    if( 0==cli_strcmp(zStr, azArray[i]) ) return 1;
  }
  return 0;
}

/*
** If compiled statement pSql appears to be an EXPLAIN statement, allocate
** and populate the ShellState.aiIndent[] array with the number of
** spaces each opcode should be indented before it is output.
**
** The indenting rules are:
**
**     * For each "Next", "Prev", "VNext" or "VPrev" instruction, indent
**       all opcodes that occur between the p2 jump destination and the opcode
**       itself by 2 spaces.
**
**     * Do the previous for "Return" instructions for when P2 is positive.
**       See tag-20220407a in wherecode.c and vdbe.c.
**
**     * For each "Goto", if the jump destination is earlier in the program
**       and ends on one of:
**          Yield  SeekGt  SeekLt  RowSetRead  Rewind
**       or if the P1 parameter is one instead of zero,
**       then indent all opcodes between the earlier instruction
**       and "Goto" by 2 spaces.
*/
static void explain_data_prepare(ShellState *p, sqlite3_stmt *pSql){
  int *abYield = 0;               /* True if op is an OP_Yield */
  int nAlloc = 0;                 /* Allocated size of p->aiIndent[], abYield */
  int iOp;                        /* Index of operation in p->aiIndent[] */

  const char *azNext[] = { "Next", "Prev", "VPrev", "VNext", "SorterNext",
                           "Return", 0 };
  const char *azYield[] = { "Yield", "SeekLT", "SeekGT", "RowSetRead",
                            "Rewind", 0 };
  const char *azGoto[] = { "Goto", 0 };

  /* The caller guarantees that the leftmost 4 columns of the statement
  ** passed to this function are equivalent to the leftmost 4 columns
  ** of EXPLAIN statement output. In practice the statement may be
  ** an EXPLAIN, or it may be a query on the bytecode() virtual table.  */
  assert( sqlite3_column_count(pSql)>=4 );
  assert( 0==sqlite3_stricmp( sqlite3_column_name(pSql, 0), "addr" ) );
  assert( 0==sqlite3_stricmp( sqlite3_column_name(pSql, 1), "opcode" ) );
  assert( 0==sqlite3_stricmp( sqlite3_column_name(pSql, 2), "p1" ) );
  assert( 0==sqlite3_stricmp( sqlite3_column_name(pSql, 3), "p2" ) );

  for(iOp=0; SQLITE_ROW==sqlite3_step(pSql); iOp++){
    int i;
    int iAddr = sqlite3_column_int(pSql, 0);
    const char *zOp = (const char*)sqlite3_column_text(pSql, 1);
    int p1 = sqlite3_column_int(pSql, 2);
    int p2 = sqlite3_column_int(pSql, 3);

    /* Assuming that p2 is an instruction address, set variable p2op to the
    ** index of that instruction in the aiIndent[] array. p2 and p2op may be
    ** different if the current instruction is part of a sub-program generated
    ** by an SQL trigger or foreign key.  */
    int p2op = (p2 + (iOp-iAddr));

    /* Grow the p->aiIndent array as required */
    if( iOp>=nAlloc ){
      nAlloc += 100;
      p->aiIndent = (int*)sqlite3_realloc64(p->aiIndent, nAlloc*sizeof(int));
      shell_check_oom(p->aiIndent);
      abYield = (int*)sqlite3_realloc64(abYield, nAlloc*sizeof(int));
      shell_check_oom(abYield);
    }

    abYield[iOp] = str_in_array(zOp, azYield);
    p->aiIndent[iOp] = 0;
    p->nIndent = iOp+1;
    if( str_in_array(zOp, azNext) && p2op>0 ){
      for(i=p2op; i<iOp; i++) p->aiIndent[i] += 2;
    }
    if( str_in_array(zOp, azGoto) && p2op<iOp && (abYield[p2op] || p1) ){
      for(i=p2op; i<iOp; i++) p->aiIndent[i] += 2;
    }
  }

  p->iIndent = 0;
  sqlite3_free(abYield);
  sqlite3_reset(pSql);
}

/*
** Free the array allocated by explain_data_prepare().
*/
static void explain_data_delete(ShellState *p){
  sqlite3_free(p->aiIndent);
  p->aiIndent = 0;
  p->nIndent = 0;
  p->iIndent = 0;
}

static void exec_prepared_stmt(ShellState*, sqlite3_stmt*);

/*
** Display scan stats.
*/
static void display_scanstats(
  sqlite3 *db,                    /* Database to query */
  ShellState *pArg                /* Pointer to ShellState */
){
#ifndef SQLITE_ENABLE_STMT_SCANSTATUS
  UNUSED_PARAMETER(db);
  UNUSED_PARAMETER(pArg);
#else
  if( pArg->scanstatsOn==3 ){
    const char *zSql =
      "  SELECT addr, opcode, p1, p2, p3, p4, p5, comment, nexec,"
      "   format('% 6s (%.2f%%)',"
      "      CASE WHEN ncycle<100_000 THEN ncycle || ' '"
      "         WHEN ncycle<100_000_000 THEN (ncycle/1_000) || 'K'"
      "         WHEN ncycle<100_000_000_000 THEN (ncycle/1_000_000) || 'M'"
      "         ELSE (ncycle/1000_000_000) || 'G' END,"
      "       ncycle*100.0/(sum(ncycle) OVER ())"
      "   )  AS cycles"
      "   FROM bytecode(?)";

    int rc = SQLITE_OK;
    sqlite3_stmt *pStmt = 0;
    rc = sqlite3_prepare_v2(db, zSql, -1, &pStmt, 0);
    if( rc==SQLITE_OK ){
      sqlite3_stmt *pSave = pArg->pStmt;
      pArg->pStmt = pStmt;
      sqlite3_bind_pointer(pStmt, 1, pSave, "stmt-pointer", 0);

      pArg->cnt = 0;
      pArg->cMode = MODE_ScanExp;
      explain_data_prepare(pArg, pStmt);
      exec_prepared_stmt(pArg, pStmt);
      explain_data_delete(pArg);

      sqlite3_finalize(pStmt);
      pArg->pStmt = pSave;
    }
  }else{
    display_explain_scanstats(db, pArg);
  }
#endif
}

/*
** Disable and restore .wheretrace and .treetrace/.selecttrace settings.
*/
static unsigned int savedSelectTrace;
static unsigned int savedWhereTrace;
static void disable_debug_trace_modes(void){
  unsigned int zero = 0;
  sqlite3_test_control(SQLITE_TESTCTRL_TRACEFLAGS, 0, &savedSelectTrace);
  sqlite3_test_control(SQLITE_TESTCTRL_TRACEFLAGS, 1, &zero);
  sqlite3_test_control(SQLITE_TESTCTRL_TRACEFLAGS, 2, &savedWhereTrace);
  sqlite3_test_control(SQLITE_TESTCTRL_TRACEFLAGS, 3, &zero);
}
static void restore_debug_trace_modes(void){
  sqlite3_test_control(SQLITE_TESTCTRL_TRACEFLAGS, 1, &savedSelectTrace);
  sqlite3_test_control(SQLITE_TESTCTRL_TRACEFLAGS, 3, &savedWhereTrace);
}

/* Create the TEMP table used to store parameter bindings */
static void bind_table_init(ShellState *p){
  int wrSchema = 0;
  int defensiveMode = 0;
  sqlite3_db_config(p->db, SQLITE_DBCONFIG_DEFENSIVE, -1, &defensiveMode);
  sqlite3_db_config(p->db, SQLITE_DBCONFIG_DEFENSIVE, 0, 0);
  sqlite3_db_config(p->db, SQLITE_DBCONFIG_WRITABLE_SCHEMA, -1, &wrSchema);
  sqlite3_db_config(p->db, SQLITE_DBCONFIG_WRITABLE_SCHEMA, 1, 0);
  sqlite3_exec(p->db,
    "CREATE TABLE IF NOT EXISTS temp.sqlite_parameters(\n"
    "  key TEXT PRIMARY KEY,\n"
    "  value\n"
    ") WITHOUT ROWID;",
    0, 0, 0);
  sqlite3_db_config(p->db, SQLITE_DBCONFIG_WRITABLE_SCHEMA, wrSchema, 0);
  sqlite3_db_config(p->db, SQLITE_DBCONFIG_DEFENSIVE, defensiveMode, 0);
}

/*
** Bind parameters on a prepared statement.
**
** Parameter bindings are taken from a TEMP table of the form:
**
**    CREATE TEMP TABLE sqlite_parameters(key TEXT PRIMARY KEY, value)
**    WITHOUT ROWID;
**
** No bindings occur if this table does not exist.  The name of the table
** begins with "sqlite_" so that it will not collide with ordinary application
** tables.  The table must be in the TEMP schema.
*/
static void bind_prepared_stmt(ShellState *pArg, sqlite3_stmt *pStmt){
  int nVar;
  int i;
  int rc;
  sqlite3_stmt *pQ = 0;

  nVar = sqlite3_bind_parameter_count(pStmt);
  if( nVar==0 ) return;  /* Nothing to do */
  if( sqlite3_table_column_metadata(pArg->db, "TEMP", "sqlite_parameters",
                                    "key", 0, 0, 0, 0, 0)!=SQLITE_OK ){
    rc = SQLITE_NOTFOUND;
    pQ = 0;
  }else{
    rc = sqlite3_prepare_v2(pArg->db,
            "SELECT value FROM temp.sqlite_parameters"
            " WHERE key=?1", -1, &pQ, 0);
  }
  for(i=1; i<=nVar; i++){
    char zNum[30];
    const char *zVar = sqlite3_bind_parameter_name(pStmt, i);
    if( zVar==0 ){
      sqlite3_snprintf(sizeof(zNum),zNum,"?%d",i);
      zVar = zNum;
    }
    sqlite3_bind_text(pQ, 1, zVar, -1, SQLITE_STATIC);
    if( rc==SQLITE_OK && pQ && sqlite3_step(pQ)==SQLITE_ROW ){
      sqlite3_bind_value(pStmt, i, sqlite3_column_value(pQ, 0));
#ifdef NAN
    }else if( sqlite3_strlike("_NAN", zVar, 0)==0 ){
      sqlite3_bind_double(pStmt, i, NAN);
#endif
#ifdef INFINITY
    }else if( sqlite3_strlike("_INF", zVar, 0)==0 ){
      sqlite3_bind_double(pStmt, i, INFINITY);
#endif
    }else if( strncmp(zVar, "$int_", 5)==0 ){
      sqlite3_bind_int(pStmt, i, atoi(&zVar[5]));
    }else if( strncmp(zVar, "$text_", 6)==0 ){
      size_t szVar = strlen(zVar);
      char *zBuf = sqlite3_malloc64( szVar-5 );
      if( zBuf ){
        memcpy(zBuf, &zVar[6], szVar-5);
        sqlite3_bind_text64(pStmt, i, zBuf, szVar-6, sqlite3_free, SQLITE_UTF8);
      }
    }else{
      sqlite3_bind_null(pStmt, i);
    }
    sqlite3_reset(pQ);
  }
  sqlite3_finalize(pQ);
}

/*
** UTF8 box-drawing characters.  Imagine box lines like this:
**
**           1
**           |
**       4 --+-- 2
**           |
**           3
**
** Each box characters has between 2 and 4 of the lines leading from
** the center.  The characters are here identified by the numbers of
** their corresponding lines.
*/
#define BOX_24   "\342\224\200"  /* U+2500 --- */
#define BOX_13   "\342\224\202"  /* U+2502  |  */
#define BOX_23   "\342\224\214"  /* U+250c  ,- */
#define BOX_34   "\342\224\220"  /* U+2510 -,  */
#define BOX_12   "\342\224\224"  /* U+2514  '- */
#define BOX_14   "\342\224\230"  /* U+2518 -'  */
#define BOX_123  "\342\224\234"  /* U+251c  |- */
#define BOX_134  "\342\224\244"  /* U+2524 -|  */
#define BOX_234  "\342\224\254"  /* U+252c -,- */
#define BOX_124  "\342\224\264"  /* U+2534 -'- */
#define BOX_1234 "\342\224\274"  /* U+253c -|- */

/* Draw horizontal line N characters long using unicode box
** characters
*/
static void print_box_line(FILE *out, int N){
  const char zDash[] =
      BOX_24 BOX_24 BOX_24 BOX_24 BOX_24 BOX_24 BOX_24 BOX_24 BOX_24 BOX_24
      BOX_24 BOX_24 BOX_24 BOX_24 BOX_24 BOX_24 BOX_24 BOX_24 BOX_24 BOX_24;
  const int nDash = sizeof(zDash) - 1;
  N *= 3;
  while( N>nDash ){
    sqlite3_fputs(zDash, out);
    N -= nDash;
  }
  sqlite3_fprintf(out, "%.*s", N, zDash);
}

/*
** Draw a horizontal separator for a MODE_Box table.
*/
static void print_box_row_separator(
  ShellState *p,
  int nArg,
  const char *zSep1,
  const char *zSep2,
  const char *zSep3
){
  int i;
  if( nArg>0 ){
    sqlite3_fputs(zSep1, p->out);
    print_box_line(p->out, p->actualWidth[0]+2);
    for(i=1; i<nArg; i++){
      sqlite3_fputs(zSep2, p->out);
      print_box_line(p->out, p->actualWidth[i]+2);
    }
    sqlite3_fputs(zSep3, p->out);
  }
  sqlite3_fputs("\n", p->out);
}

/*
** z[] is a line of text that is to be displayed the .mode box or table or
** similar tabular formats.  z[] might contain control characters such
** as \n, \t, \f, or \r.
**
** Compute characters to display on the first line of z[].  Stop at the
** first \r, \n, or \f.  Expand \t into spaces.  Return a copy (obtained
** from malloc()) of that first line, which caller should free sometime.
** Write anything to display on the next line into *pzTail.  If this is
** the last line, write a NULL into *pzTail. (*pzTail is not allocated.)
*/
static char *translateForDisplayAndDup(
  const unsigned char *z,            /* Input text to be transformed */
  const unsigned char **pzTail,      /* OUT: Tail of the input for next line */
  int mxWidth,                       /* Max width.  0 means no limit */
  u8 bWordWrap                       /* If true, avoid breaking mid-word */
){
  int i;                 /* Input bytes consumed */
  int j;                 /* Output bytes generated */
  int k;                 /* Input bytes to be displayed */
  int n;                 /* Output column number */
  unsigned char *zOut;   /* Output text */

  if( z==0 ){
    *pzTail = 0;
    return 0;
  }
  if( mxWidth<0 ) mxWidth = -mxWidth;
  if( mxWidth==0 ) mxWidth = 1000000;
  i = j = n = 0;
  while( n<mxWidth ){
    unsigned char c = z[i];
    if( c>=0xc0 ){
      int u;
      int len = decodeUtf8(&z[i], &u);
      i += len;
      j += len;
      n += cli_wcwidth(u);
      continue;
    }
    if( c>=' ' ){
      n++;
      i++;
      j++;
      continue;
    }
    if( c=='\t' ){
      do{
        n++;
        j++;
      }while( (n&7)!=0 && n<mxWidth );
      i++;
      continue;
    }
    break;
  }
  if( n>=mxWidth && bWordWrap  ){
    /* Perhaps try to back up to a better place to break the line */
    for(k=i; k>i/2; k--){
      if( isspace(z[k-1]) ) break;
    }
    if( k<=i/2 ){
      for(k=i; k>i/2; k--){
        if( isalnum(z[k-1])!=isalnum(z[k]) && (z[k]&0xc0)!=0x80 ) break;
      }
    }
    if( k<=i/2 ){
      k = i;
    }else{
      i = k;
      while( z[i]==' ' ) i++;
    }
  }else{
    k = i;
  }
  if( n>=mxWidth && z[i]>=' ' ){
   *pzTail = &z[i];
  }else if( z[i]=='\r' && z[i+1]=='\n' ){
    *pzTail = z[i+2] ? &z[i+2] : 0;
  }else if( z[i]==0 || z[i+1]==0 ){
    *pzTail = 0;
  }else{
    *pzTail = &z[i+1];
  }
  zOut = malloc( j+1 );
  shell_check_oom(zOut);
  i = j = n = 0;
  while( i<k ){
    unsigned char c = z[i];
    if( c>=0xc0 ){
      int u;
      int len = decodeUtf8(&z[i], &u);
      do{ zOut[j++] = z[i++]; }while( (--len)>0 );
      n += cli_wcwidth(u);
      continue;
    }
    if( c>=' ' ){
      n++;
      zOut[j++] = z[i++];
      continue;
    }
    if( z[i]=='\t' ){
      do{
        n++;
        zOut[j++] = ' ';
      }while( (n&7)!=0 && n<mxWidth );
      i++;
      continue;
    }
    break;
  }
  zOut[j] = 0;
  return (char*)zOut;
}

/* Extract the value of the i-th current column for pStmt as an SQL literal
** value.  Memory is obtained from sqlite3_malloc64() and must be freed by
** the caller.
*/
static char *quoted_column(sqlite3_stmt *pStmt, int i){
  switch( sqlite3_column_type(pStmt, i) ){
    case SQLITE_NULL: {
      return sqlite3_mprintf("NULL");
    }
    case SQLITE_INTEGER:
    case SQLITE_FLOAT: {
      return sqlite3_mprintf("%s",sqlite3_column_text(pStmt,i));
    }
    case SQLITE_TEXT: {
      return sqlite3_mprintf("%Q",sqlite3_column_text(pStmt,i));
    }
    case SQLITE_BLOB: {
      int j;
      sqlite3_str *pStr = sqlite3_str_new(0);
      const unsigned char *a = sqlite3_column_blob(pStmt,i);
      int n = sqlite3_column_bytes(pStmt,i);
      sqlite3_str_append(pStr, "x'", 2);
      for(j=0; j<n; j++){
        sqlite3_str_appendf(pStr, "%02x", a[j]);
      }
      sqlite3_str_append(pStr, "'", 1);
      return sqlite3_str_finish(pStr);
    }
  }
  return 0; /* Not reached */
}

/*
** Run a prepared statement and output the result in one of the
** table-oriented formats: MODE_Column, MODE_Markdown, MODE_Table,
** or MODE_Box.
**
** This is different from ordinary exec_prepared_stmt() in that
** it has to run the entire query and gather the results into memory
** first, in order to determine column widths, before providing
** any output.
*/
static void exec_prepared_stmt_columnar(
  ShellState *p,                        /* Pointer to ShellState */
  sqlite3_stmt *pStmt                   /* Statement to run */
){
  sqlite3_int64 nRow = 0;
  int nColumn = 0;
  char **azData = 0;
  sqlite3_int64 nAlloc = 0;
  char *abRowDiv = 0;
  const unsigned char *uz;
  const char *z;
  char **azQuoted = 0;
  int rc;
  sqlite3_int64 i, nData;
  int j, nTotal, w, n;
  const char *colSep = 0;
  const char *rowSep = 0;
  const unsigned char **azNextLine = 0;
  int bNextLine = 0;
  int bMultiLineRowExists = 0;
  int bw = p->cmOpts.bWordWrap;
  const char *zEmpty = "";
  const char *zShowNull = p->nullValue;

  rc = sqlite3_step(pStmt);
  if( rc!=SQLITE_ROW ) return;
  nColumn = sqlite3_column_count(pStmt);
  if( nColumn==0 ) goto columnar_end;
  nAlloc = nColumn*4;
  if( nAlloc<=0 ) nAlloc = 1;
  azData = sqlite3_malloc64( nAlloc*sizeof(char*) );
  shell_check_oom(azData);
  azNextLine = sqlite3_malloc64( nColumn*sizeof(char*) );
  shell_check_oom(azNextLine);
  memset((void*)azNextLine, 0, nColumn*sizeof(char*) );
  if( p->cmOpts.bQuote ){
    azQuoted = sqlite3_malloc64( nColumn*sizeof(char*) );
    shell_check_oom(azQuoted);
    memset(azQuoted, 0, nColumn*sizeof(char*) );
  }
  abRowDiv = sqlite3_malloc64( nAlloc/nColumn );
  shell_check_oom(abRowDiv);
  if( nColumn>p->nWidth ){
    p->colWidth = realloc(p->colWidth, (nColumn+1)*2*sizeof(int));
    shell_check_oom(p->colWidth);
    for(i=p->nWidth; i<nColumn; i++) p->colWidth[i] = 0;
    p->nWidth = nColumn;
    p->actualWidth = &p->colWidth[nColumn];
  }
  memset(p->actualWidth, 0, nColumn*sizeof(int));
  for(i=0; i<nColumn; i++){
    w = p->colWidth[i];
    if( w<0 ) w = -w;
    p->actualWidth[i] = w;
  }
  for(i=0; i<nColumn; i++){
    const unsigned char *zNotUsed;
    int wx = p->colWidth[i];
    if( wx==0 ){
      wx = p->cmOpts.iWrap;
    }
    if( wx<0 ) wx = -wx;
    uz = (const unsigned char*)sqlite3_column_name(pStmt,i);
    if( uz==0 ) uz = (u8*)"";
    azData[i] = translateForDisplayAndDup(uz, &zNotUsed, wx, bw);
  }
  do{
    int useNextLine = bNextLine;
    bNextLine = 0;
    if( (nRow+2)*nColumn >= nAlloc ){
      nAlloc *= 2;
      azData = sqlite3_realloc64(azData, nAlloc*sizeof(char*));
      shell_check_oom(azData);
      abRowDiv = sqlite3_realloc64(abRowDiv, nAlloc/nColumn);
      shell_check_oom(abRowDiv);
    }
    abRowDiv[nRow] = 1;
    nRow++;
    for(i=0; i<nColumn; i++){
      int wx = p->colWidth[i];
      if( wx==0 ){
        wx = p->cmOpts.iWrap;
      }
      if( wx<0 ) wx = -wx;
      if( useNextLine ){
        uz = azNextLine[i];
        if( uz==0 ) uz = (u8*)zEmpty;
      }else if( p->cmOpts.bQuote ){
        sqlite3_free(azQuoted[i]);
        azQuoted[i] = quoted_column(pStmt,i);
        uz = (const unsigned char*)azQuoted[i];
      }else{
        uz = (const unsigned char*)sqlite3_column_text(pStmt,i);
        if( uz==0 ) uz = (u8*)zShowNull;
      }
      azData[nRow*nColumn + i]
        = translateForDisplayAndDup(uz, &azNextLine[i], wx, bw);
      if( azNextLine[i] ){
        bNextLine = 1;
        abRowDiv[nRow-1] = 0;
        bMultiLineRowExists = 1;
      }
    }
  }while( bNextLine || sqlite3_step(pStmt)==SQLITE_ROW );
  nTotal = nColumn*(nRow+1);
  for(i=0; i<nTotal; i++){
    z = azData[i];
    if( z==0 ) z = (char*)zEmpty;
    n = strlenChar(z);
    j = i%nColumn;
    if( n>p->actualWidth[j] ) p->actualWidth[j] = n;
  }
  if( seenInterrupt ) goto columnar_end;
  switch( p->cMode ){
    case MODE_Column: {
      colSep = "  ";
      rowSep = "\n";
      if( p->showHeader ){
        for(i=0; i<nColumn; i++){
          w = p->actualWidth[i];
          if( p->colWidth[i]<0 ) w = -w;
          utf8_width_print(p->out, w, azData[i]);
          sqlite3_fputs(i==nColumn-1?"\n":"  ", p->out);
        }
        for(i=0; i<nColumn; i++){
          print_dashes(p->out, p->actualWidth[i]);
          sqlite3_fputs(i==nColumn-1?"\n":"  ", p->out);
        }
      }
      break;
    }
    case MODE_Table: {
      colSep = " | ";
      rowSep = " |\n";
      print_row_separator(p, nColumn, "+");
      sqlite3_fputs("| ", p->out);
      for(i=0; i<nColumn; i++){
        w = p->actualWidth[i];
        n = strlenChar(azData[i]);
        sqlite3_fprintf(p->out, "%*s%s%*s", (w-n)/2, "",
                        azData[i], (w-n+1)/2, "");
        sqlite3_fputs(i==nColumn-1?" |\n":" | ", p->out);
      }
      print_row_separator(p, nColumn, "+");
      break;
    }
    case MODE_Markdown: {
      colSep = " | ";
      rowSep = " |\n";
      sqlite3_fputs("| ", p->out);
      for(i=0; i<nColumn; i++){
        w = p->actualWidth[i];
        n = strlenChar(azData[i]);
        sqlite3_fprintf(p->out, "%*s%s%*s", (w-n)/2, "",
                        azData[i], (w-n+1)/2, "");
        sqlite3_fputs(i==nColumn-1?" |\n":" | ", p->out);
      }
      print_row_separator(p, nColumn, "|");
      break;
    }
    case MODE_Box: {
      colSep = " " BOX_13 " ";
      rowSep = " " BOX_13 "\n";
      print_box_row_separator(p, nColumn, BOX_23, BOX_234, BOX_34);
      sqlite3_fputs(BOX_13 " ", p->out);
      for(i=0; i<nColumn; i++){
        w = p->actualWidth[i];
        n = strlenChar(azData[i]);
        sqlite3_fprintf(p->out, "%*s%s%*s%s",
              (w-n)/2, "", azData[i], (w-n+1)/2, "",
              i==nColumn-1?" "BOX_13"\n":" "BOX_13" ");
      }
      print_box_row_separator(p, nColumn, BOX_123, BOX_1234, BOX_134);
      break;
    }
  }
  for(i=nColumn, j=0; i<nTotal; i++, j++){
    if( j==0 && p->cMode!=MODE_Column ){
      sqlite3_fputs(p->cMode==MODE_Box?BOX_13" ":"| ", p->out);
    }
    z = azData[i];
    if( z==0 ) z = p->nullValue;
    w = p->actualWidth[j];
    if( p->colWidth[j]<0 ) w = -w;
    utf8_width_print(p->out, w, z);
    if( j==nColumn-1 ){
      sqlite3_fputs(rowSep, p->out);
      if( bMultiLineRowExists && abRowDiv[i/nColumn-1] && i+1<nTotal ){
        if( p->cMode==MODE_Table ){
          print_row_separator(p, nColumn, "+");
        }else if( p->cMode==MODE_Box ){
          print_box_row_separator(p, nColumn, BOX_123, BOX_1234, BOX_134);
        }else if( p->cMode==MODE_Column ){
          sqlite3_fputs("\n", p->out);
        }
      }
      j = -1;
      if( seenInterrupt ) goto columnar_end;
    }else{
      sqlite3_fputs(colSep, p->out);
    }
  }
  if( p->cMode==MODE_Table ){
    print_row_separator(p, nColumn, "+");
  }else if( p->cMode==MODE_Box ){
    print_box_row_separator(p, nColumn, BOX_12, BOX_124, BOX_14);
  }
columnar_end:
  if( seenInterrupt ){
    sqlite3_fputs("Interrupt\n", p->out);
  }
  nData = (nRow+1)*nColumn;
  for(i=0; i<nData; i++){
    z = azData[i];
    if( z!=zEmpty && z!=zShowNull ) free(azData[i]);
  }
  sqlite3_free(azData);
  sqlite3_free((void*)azNextLine);
  sqlite3_free(abRowDiv);
  if( azQuoted ){
    for(i=0; i<nColumn; i++) sqlite3_free(azQuoted[i]);
    sqlite3_free(azQuoted);
  }
}

/*
** Run a prepared statement
*/
static void exec_prepared_stmt(
  ShellState *pArg,                                /* Pointer to ShellState */
  sqlite3_stmt *pStmt                              /* Statement to run */
){
  int rc;
  sqlite3_uint64 nRow = 0;

  if( pArg->cMode==MODE_Column
   || pArg->cMode==MODE_Table
   || pArg->cMode==MODE_Box
   || pArg->cMode==MODE_Markdown
  ){
    exec_prepared_stmt_columnar(pArg, pStmt);
    return;
  }

  /* perform the first step.  this will tell us if we
  ** have a result set or not and how wide it is.
  */
  rc = sqlite3_step(pStmt);
  /* if we have a result set... */
  if( SQLITE_ROW == rc ){
    /* allocate space for col name ptr, value ptr, and type */
    int nCol = sqlite3_column_count(pStmt);
    void *pData = sqlite3_malloc64(3*nCol*sizeof(const char*) + 1);
    if( !pData ){
      shell_out_of_memory();
    }else{
      char **azCols = (char **)pData;      /* Names of result columns */
      char **azVals = &azCols[nCol];       /* Results */
      int *aiTypes = (int *)&azVals[nCol]; /* Result types */
      int i, x;
      assert(sizeof(int) <= sizeof(char *));
      /* save off ptrs to column names */
      for(i=0; i<nCol; i++){
        azCols[i] = (char *)sqlite3_column_name(pStmt, i);
      }
      do{
        nRow++;
        /* extract the data and data types */
        for(i=0; i<nCol; i++){
          aiTypes[i] = x = sqlite3_column_type(pStmt, i);
          if( x==SQLITE_BLOB
           && pArg
           && (pArg->cMode==MODE_Insert || pArg->cMode==MODE_Quote)
          ){
            azVals[i] = "";
          }else{
            azVals[i] = (char*)sqlite3_column_text(pStmt, i);
          }
          if( !azVals[i] && (aiTypes[i]!=SQLITE_NULL) ){
            rc = SQLITE_NOMEM;
            break; /* from for */
          }
        } /* end for */

        /* if data and types extracted successfully... */
        if( SQLITE_ROW == rc ){
          /* call the supplied callback with the result row data */
          if( shell_callback(pArg, nCol, azVals, azCols, aiTypes) ){
            rc = SQLITE_ABORT;
          }else{
            rc = sqlite3_step(pStmt);
          }
        }
      } while( SQLITE_ROW == rc );
      sqlite3_free(pData);
      if( pArg->cMode==MODE_Json ){
        sqlite3_fputs("]\n", pArg->out);
      }else if( pArg->cMode==MODE_Www ){
        sqlite3_fputs("</TABLE>\n<PRE>\n", pArg->out);
      }else if( pArg->cMode==MODE_Count ){
        char zBuf[200];
        sqlite3_snprintf(sizeof(zBuf), zBuf, "%llu row%s\n",
                         nRow, nRow!=1 ? "s" : "");
        printf("%s", zBuf);
      }
    }
  }
}

#ifndef SQLITE_OMIT_VIRTUALTABLE
/*
** This function is called to process SQL if the previous shell command
** was ".expert". It passes the SQL in the second argument directly to
** the sqlite3expert object.
**
** If successful, SQLITE_OK is returned. Otherwise, an SQLite error
** code. In this case, (*pzErr) may be set to point to a buffer containing
** an English language error message. It is the responsibility of the
** caller to eventually free this buffer using sqlite3_free().
*/
static int expertHandleSQL(
  ShellState *pState,
  const char *zSql,
  char **pzErr
){
  assert( pState->expert.pExpert );
  assert( pzErr==0 || *pzErr==0 );
  return sqlite3_expert_sql(pState->expert.pExpert, zSql, pzErr);
}

/*
** This function is called either to silently clean up the object
** created by the ".expert" command (if bCancel==1), or to generate a
** report from it and then clean it up (if bCancel==0).
**
** If successful, SQLITE_OK is returned. Otherwise, an SQLite error
** code. In this case, (*pzErr) may be set to point to a buffer containing
** an English language error message. It is the responsibility of the
** caller to eventually free this buffer using sqlite3_free().
*/
static int expertFinish(
  ShellState *pState,
  int bCancel,
  char **pzErr
){
  int rc = SQLITE_OK;
  sqlite3expert *p = pState->expert.pExpert;
  FILE *out = pState->out;
  assert( p );
  assert( bCancel || pzErr==0 || *pzErr==0 );
  if( bCancel==0 ){
    int bVerbose = pState->expert.bVerbose;

    rc = sqlite3_expert_analyze(p, pzErr);
    if( rc==SQLITE_OK ){
      int nQuery = sqlite3_expert_count(p);
      int i;

      if( bVerbose ){
        const char *zCand = sqlite3_expert_report(p,0,EXPERT_REPORT_CANDIDATES);
        sqlite3_fputs("-- Candidates -----------------------------\n", out);
        sqlite3_fprintf(out, "%s\n", zCand);
      }
      for(i=0; i<nQuery; i++){
        const char *zSql = sqlite3_expert_report(p, i, EXPERT_REPORT_SQL);
        const char *zIdx = sqlite3_expert_report(p, i, EXPERT_REPORT_INDEXES);
        const char *zEQP = sqlite3_expert_report(p, i, EXPERT_REPORT_PLAN);
        if( zIdx==0 ) zIdx = "(no new indexes)\n";
        if( bVerbose ){
          sqlite3_fprintf(out,
              "-- Query %d --------------------------------\n"
              "%s\n\n"
              ,i+1, zSql);
        }
        sqlite3_fprintf(out, "%s\n%s\n", zIdx, zEQP);
      }
    }
  }
  sqlite3_expert_destroy(p);
  pState->expert.pExpert = 0;
  return rc;
}

/*
** Implementation of ".expert" dot command.
*/
static int expertDotCommand(
  ShellState *pState,             /* Current shell tool state */
  char **azArg,                   /* Array of arguments passed to dot command */
  int nArg                        /* Number of entries in azArg[] */
){
  int rc = SQLITE_OK;
  char *zErr = 0;
  int i;
  int iSample = 0;

  assert( pState->expert.pExpert==0 );
  memset(&pState->expert, 0, sizeof(ExpertInfo));

  for(i=1; rc==SQLITE_OK && i<nArg; i++){
    char *z = azArg[i];
    int n;
    if( z[0]=='-' && z[1]=='-' ) z++;
    n = strlen30(z);
    if( n>=2 && 0==cli_strncmp(z, "-verbose", n) ){
      pState->expert.bVerbose = 1;
    }
    else if( n>=2 && 0==cli_strncmp(z, "-sample", n) ){
      if( i==(nArg-1) ){
        sqlite3_fprintf(stderr, "option requires an argument: %s\n", z);
        rc = SQLITE_ERROR;
      }else{
        iSample = (int)integerValue(azArg[++i]);
        if( iSample<0 || iSample>100 ){
          sqlite3_fprintf(stderr,"value out of range: %s\n", azArg[i]);
          rc = SQLITE_ERROR;
        }
      }
    }
    else{
      sqlite3_fprintf(stderr,"unknown option: %s\n", z);
      rc = SQLITE_ERROR;
    }
  }

  if( rc==SQLITE_OK ){
    pState->expert.pExpert = sqlite3_expert_new(pState->db, &zErr);
    if( pState->expert.pExpert==0 ){
      sqlite3_fprintf(stderr,
          "sqlite3_expert_new: %s\n", zErr ? zErr : "out of memory");
      rc = SQLITE_ERROR;
    }else{
      sqlite3_expert_config(
          pState->expert.pExpert, EXPERT_CONFIG_SAMPLE, iSample
      );
    }
  }
  sqlite3_free(zErr);

  return rc;
}
#endif /* ifndef SQLITE_OMIT_VIRTUALTABLE */

/*
** Execute a statement or set of statements.  Print
** any result rows/columns depending on the current mode
** set via the supplied callback.
**
** This is very similar to SQLite's built-in sqlite3_exec()
** function except it takes a slightly different callback
** and callback data argument.
*/
static int shell_exec(
  ShellState *pArg,                         /* Pointer to ShellState */
  const char *zSql,                         /* SQL to be evaluated */
  char **pzErrMsg                           /* Error msg written here */
){
  sqlite3_stmt *pStmt = NULL;     /* Statement to execute. */
  int rc = SQLITE_OK;             /* Return Code */
  int rc2;
  const char *zLeftover;          /* Tail of unprocessed SQL */
  sqlite3 *db = pArg->db;

  if( pzErrMsg ){
    *pzErrMsg = NULL;
  }

#ifndef SQLITE_OMIT_VIRTUALTABLE
  if( pArg->expert.pExpert ){
    rc = expertHandleSQL(pArg, zSql, pzErrMsg);
    return expertFinish(pArg, (rc!=SQLITE_OK), pzErrMsg);
  }
#endif

  while( zSql[0] && (SQLITE_OK == rc) ){
    static const char *zStmtSql;
    rc = sqlite3_prepare_v2(db, zSql, -1, &pStmt, &zLeftover);
    if( SQLITE_OK != rc ){
      if( pzErrMsg ){
        *pzErrMsg = save_err_msg(db, "in prepare", rc, zSql);
      }
    }else{
      if( !pStmt ){
        /* this happens for a comment or white-space */
        zSql = zLeftover;
        while( IsSpace(zSql[0]) ) zSql++;
        continue;
      }
      zStmtSql = sqlite3_sql(pStmt);
      if( zStmtSql==0 ) zStmtSql = "";
      while( IsSpace(zStmtSql[0]) ) zStmtSql++;

      /* save off the prepared statement handle and reset row count */
      if( pArg ){
        pArg->pStmt = pStmt;
        pArg->cnt = 0;
      }

      /* Show the EXPLAIN QUERY PLAN if .eqp is on */
      if( pArg && pArg->autoEQP && sqlite3_stmt_isexplain(pStmt)==0 ){
        sqlite3_stmt *pExplain;
        int triggerEQP = 0;
        disable_debug_trace_modes();
        sqlite3_db_config(db, SQLITE_DBCONFIG_TRIGGER_EQP, -1, &triggerEQP);
        if( pArg->autoEQP>=AUTOEQP_trigger ){
          sqlite3_db_config(db, SQLITE_DBCONFIG_TRIGGER_EQP, 1, 0);
        }
        pExplain = pStmt;
        sqlite3_reset(pExplain);
        rc = sqlite3_stmt_explain(pExplain, 2);
        if( rc==SQLITE_OK ){
          bind_prepared_stmt(pArg, pExplain);
          while( sqlite3_step(pExplain)==SQLITE_ROW ){
            const char *zEQPLine = (const char*)sqlite3_column_text(pExplain,3);
            int iEqpId = sqlite3_column_int(pExplain, 0);
            int iParentId = sqlite3_column_int(pExplain, 1);
            if( zEQPLine==0 ) zEQPLine = "";
            if( zEQPLine[0]=='-' ) eqp_render(pArg, 0);
            eqp_append(pArg, iEqpId, iParentId, zEQPLine);
          }
          eqp_render(pArg, 0);
        }
        if( pArg->autoEQP>=AUTOEQP_full ){
          /* Also do an EXPLAIN for ".eqp full" mode */
          sqlite3_reset(pExplain);
          rc = sqlite3_stmt_explain(pExplain, 1);
          if( rc==SQLITE_OK ){
            pArg->cMode = MODE_Explain;
            assert( sqlite3_stmt_isexplain(pExplain)==1 );
            bind_prepared_stmt(pArg, pExplain);
            explain_data_prepare(pArg, pExplain);
            exec_prepared_stmt(pArg, pExplain);
            explain_data_delete(pArg);
          }
        }
        if( pArg->autoEQP>=AUTOEQP_trigger && triggerEQP==0 ){
          sqlite3_db_config(db, SQLITE_DBCONFIG_TRIGGER_EQP, 0, 0);
        }
        sqlite3_reset(pStmt);
        sqlite3_stmt_explain(pStmt, 0);
        restore_debug_trace_modes();
      }

      if( pArg ){
        int bIsExplain = (sqlite3_stmt_isexplain(pStmt)==1);
        pArg->cMode = pArg->mode;
        if( pArg->autoExplain ){
          if( bIsExplain ){
            pArg->cMode = MODE_Explain;
          }
          if( sqlite3_stmt_isexplain(pStmt)==2 ){
            pArg->cMode = MODE_EQP;
          }
        }

        /* If the shell is currently in ".explain" mode, gather the extra
        ** data required to add indents to the output.*/
        if( pArg->cMode==MODE_Explain && bIsExplain ){
          explain_data_prepare(pArg, pStmt);
        }
      }

      bind_prepared_stmt(pArg, pStmt);
      exec_prepared_stmt(pArg, pStmt);
      explain_data_delete(pArg);
      eqp_render(pArg, 0);

      /* print usage stats if stats on */
      if( pArg && pArg->statsOn ){
        display_stats(db, pArg, 0);
      }

      /* print loop-counters if required */
      if( pArg && pArg->scanstatsOn ){
        display_scanstats(db, pArg);
      }

      /* Finalize the statement just executed. If this fails, save a
      ** copy of the error message. Otherwise, set zSql to point to the
      ** next statement to execute. */
      rc2 = sqlite3_finalize(pStmt);
      if( rc!=SQLITE_NOMEM ) rc = rc2;
      if( rc==SQLITE_OK ){
        zSql = zLeftover;
        while( IsSpace(zSql[0]) ) zSql++;
      }else if( pzErrMsg ){
        *pzErrMsg = save_err_msg(db, "stepping", rc, 0);
      }

      /* clear saved stmt handle */
      if( pArg ){
        pArg->pStmt = NULL;
      }
    }
  } /* end while */

  return rc;
}

/*
** Release memory previously allocated by tableColumnList().
*/
static void freeColumnList(char **azCol){
  int i;
  for(i=1; azCol[i]; i++){
    sqlite3_free(azCol[i]);
  }
  /* azCol[0] is a static string */
  sqlite3_free(azCol);
}

/*
** Return a list of pointers to strings which are the names of all
** columns in table zTab.   The memory to hold the names is dynamically
** allocated and must be released by the caller using a subsequent call
** to freeColumnList().
**
** The azCol[0] entry is usually NULL.  However, if zTab contains a rowid
** value that needs to be preserved, then azCol[0] is filled in with the
** name of the rowid column.
**
** The first regular column in the table is azCol[1].  The list is terminated
** by an entry with azCol[i]==0.
*/
static char **tableColumnList(ShellState *p, const char *zTab){
  char **azCol = 0;
  sqlite3_stmt *pStmt;
  char *zSql;
  int nCol = 0;
  int nAlloc = 0;
  int nPK = 0;       /* Number of PRIMARY KEY columns seen */
  int isIPK = 0;     /* True if one PRIMARY KEY column of type INTEGER */
  int preserveRowid = ShellHasFlag(p, SHFLG_PreserveRowid);
  int rc;

  zSql = sqlite3_mprintf("PRAGMA table_info=%Q", zTab);
  shell_check_oom(zSql);
  rc = sqlite3_prepare_v2(p->db, zSql, -1, &pStmt, 0);
  sqlite3_free(zSql);
  if( rc ) return 0;
  while( sqlite3_step(pStmt)==SQLITE_ROW ){
    if( nCol>=nAlloc-2 ){
      nAlloc = nAlloc*2 + nCol + 10;
      azCol = sqlite3_realloc(azCol, nAlloc*sizeof(azCol[0]));
      shell_check_oom(azCol);
    }
    azCol[++nCol] = sqlite3_mprintf("%s", sqlite3_column_text(pStmt, 1));
    shell_check_oom(azCol[nCol]);
    if( sqlite3_column_int(pStmt, 5) ){
      nPK++;
      if( nPK==1
       && sqlite3_stricmp((const char*)sqlite3_column_text(pStmt,2),
                          "INTEGER")==0
      ){
        isIPK = 1;
      }else{
        isIPK = 0;
      }
    }
  }
  sqlite3_finalize(pStmt);
  if( azCol==0 ) return 0;
  azCol[0] = 0;
  azCol[nCol+1] = 0;

  /* The decision of whether or not a rowid really needs to be preserved
  ** is tricky.  We never need to preserve a rowid for a WITHOUT ROWID table
  ** or a table with an INTEGER PRIMARY KEY.  We are unable to preserve
  ** rowids on tables where the rowid is inaccessible because there are other
  ** columns in the table named "rowid", "_rowid_", and "oid".
  */
  if( preserveRowid && isIPK ){
    /* If a single PRIMARY KEY column with type INTEGER was seen, then it
    ** might be an alias for the ROWID.  But it might also be a WITHOUT ROWID
    ** table or a INTEGER PRIMARY KEY DESC column, neither of which are
    ** ROWID aliases.  To distinguish these cases, check to see if
    ** there is a "pk" entry in "PRAGMA index_list".  There will be
    ** no "pk" index if the PRIMARY KEY really is an alias for the ROWID.
    */
    zSql = sqlite3_mprintf("SELECT 1 FROM pragma_index_list(%Q)"
                           " WHERE origin='pk'", zTab);
    shell_check_oom(zSql);
    rc = sqlite3_prepare_v2(p->db, zSql, -1, &pStmt, 0);
    sqlite3_free(zSql);
    if( rc ){
      freeColumnList(azCol);
      return 0;
    }
    rc = sqlite3_step(pStmt);
    sqlite3_finalize(pStmt);
    preserveRowid = rc==SQLITE_ROW;
  }
  if( preserveRowid ){
    /* Only preserve the rowid if we can find a name to use for the
    ** rowid */
    static char *azRowid[] = { "rowid", "_rowid_", "oid" };
    int i, j;
    for(j=0; j<3; j++){
      for(i=1; i<=nCol; i++){
        if( sqlite3_stricmp(azRowid[j],azCol[i])==0 ) break;
      }
      if( i>nCol ){
        /* At this point, we know that azRowid[j] is not the name of any
        ** ordinary column in the table.  Verify that azRowid[j] is a valid
        ** name for the rowid before adding it to azCol[0].  WITHOUT ROWID
        ** tables will fail this last check */
        rc = sqlite3_table_column_metadata(p->db,0,zTab,azRowid[j],0,0,0,0,0);
        if( rc==SQLITE_OK ) azCol[0] = azRowid[j];
        break;
      }
    }
  }
  return azCol;
}

/*
** Toggle the reverse_unordered_selects setting.
*/
static void toggleSelectOrder(sqlite3 *db){
  sqlite3_stmt *pStmt = 0;
  int iSetting = 0;
  char zStmt[100];
  sqlite3_prepare_v2(db, "PRAGMA reverse_unordered_selects", -1, &pStmt, 0);
  if( sqlite3_step(pStmt)==SQLITE_ROW ){
    iSetting = sqlite3_column_int(pStmt, 0);
  }
  sqlite3_finalize(pStmt);
  sqlite3_snprintf(sizeof(zStmt), zStmt,
       "PRAGMA reverse_unordered_selects(%d)", !iSetting);
  sqlite3_exec(db, zStmt, 0, 0, 0);
}

/*
** This is a different callback routine used for dumping the database.
** Each row received by this callback consists of a table name,
** the table type ("index" or "table") and SQL to create the table.
** This routine should print text sufficient to recreate the table.
*/
static int dump_callback(void *pArg, int nArg, char **azArg, char **azNotUsed){
  int rc;
  const char *zTable;
  const char *zType;
  const char *zSql;
  ShellState *p = (ShellState *)pArg;
  int dataOnly;
  int noSys;

  UNUSED_PARAMETER(azNotUsed);
  if( nArg!=3 || azArg==0 ) return 0;
  zTable = azArg[0];
  zType = azArg[1];
  zSql = azArg[2];
  if( zTable==0 ) return 0;
  if( zType==0 ) return 0;
  dataOnly = (p->shellFlgs & SHFLG_DumpDataOnly)!=0;
  noSys    = (p->shellFlgs & SHFLG_DumpNoSys)!=0;

  if( cli_strcmp(zTable, "sqlite_sequence")==0 && !noSys ){
    /* no-op */
  }else if( sqlite3_strglob("sqlite_stat?", zTable)==0 && !noSys ){
    if( !dataOnly ) sqlite3_fputs("ANALYZE sqlite_schema;\n", p->out);
  }else if( cli_strncmp(zTable, "sqlite_", 7)==0 ){
    return 0;
  }else if( dataOnly ){
    /* no-op */
  }else if( cli_strncmp(zSql, "CREATE VIRTUAL TABLE", 20)==0 ){
    char *zIns;
    if( !p->writableSchema ){
      sqlite3_fputs("PRAGMA writable_schema=ON;\n", p->out);
      p->writableSchema = 1;
    }
    zIns = sqlite3_mprintf(
       "INSERT INTO sqlite_schema(type,name,tbl_name,rootpage,sql)"
       "VALUES('table','%q','%q',0,'%q');",
       zTable, zTable, zSql);
    shell_check_oom(zIns);
    sqlite3_fprintf(p->out, "%s\n", zIns);
    sqlite3_free(zIns);
    return 0;
  }else{
    printSchemaLine(p->out, zSql, ";\n");
  }

  if( cli_strcmp(zType, "table")==0 ){
    ShellText sSelect;
    ShellText sTable;
    char **azCol;
    int i;
    char *savedDestTable;
    int savedMode;

    azCol = tableColumnList(p, zTable);
    if( azCol==0 ){
      p->nErr++;
      return 0;
    }

    /* Always quote the table name, even if it appears to be pure ascii,
    ** in case it is a keyword. Ex:  INSERT INTO "table" ... */
    initText(&sTable);
    appendText(&sTable, zTable, quoteChar(zTable));
    /* If preserving the rowid, add a column list after the table name.
    ** In other words:  "INSERT INTO tab(rowid,a,b,c,...) VALUES(...)"
    ** instead of the usual "INSERT INTO tab VALUES(...)".
    */
    if( azCol[0] ){
      appendText(&sTable, "(", 0);
      appendText(&sTable, azCol[0], 0);
      for(i=1; azCol[i]; i++){
        appendText(&sTable, ",", 0);
        appendText(&sTable, azCol[i], quoteChar(azCol[i]));
      }
      appendText(&sTable, ")", 0);
    }

    /* Build an appropriate SELECT statement */
    initText(&sSelect);
    appendText(&sSelect, "SELECT ", 0);
    if( azCol[0] ){
      appendText(&sSelect, azCol[0], 0);
      appendText(&sSelect, ",", 0);
    }
    for(i=1; azCol[i]; i++){
      appendText(&sSelect, azCol[i], quoteChar(azCol[i]));
      if( azCol[i+1] ){
        appendText(&sSelect, ",", 0);
      }
    }
    freeColumnList(azCol);
    appendText(&sSelect, " FROM ", 0);
    appendText(&sSelect, zTable, quoteChar(zTable));

    savedDestTable = p->zDestTable;
    savedMode = p->mode;
    p->zDestTable = sTable.z;
    p->mode = p->cMode = MODE_Insert;
    rc = shell_exec(p, sSelect.z, 0);
    if( (rc&0xff)==SQLITE_CORRUPT ){
      sqlite3_fputs("/****** CORRUPTION ERROR *******/\n", p->out);
      toggleSelectOrder(p->db);
      shell_exec(p, sSelect.z, 0);
      toggleSelectOrder(p->db);
    }
    p->zDestTable = savedDestTable;
    p->mode = savedMode;
    freeText(&sTable);
    freeText(&sSelect);
    if( rc ) p->nErr++;
  }
  return 0;
}

/*
** Run zQuery.  Use dump_callback() as the callback routine so that
** the contents of the query are output as SQL statements.
**
** If we get a SQLITE_CORRUPT error, rerun the query after appending
** "ORDER BY rowid DESC" to the end.
*/
static int run_schema_dump_query(
  ShellState *p,
  const char *zQuery
){
  int rc;
  char *zErr = 0;
  rc = sqlite3_exec(p->db, zQuery, dump_callback, p, &zErr);
  if( rc==SQLITE_CORRUPT ){
    char *zQ2;
    int len = strlen30(zQuery);
    sqlite3_fputs("/****** CORRUPTION ERROR *******/\n", p->out);
    if( zErr ){
      sqlite3_fprintf(p->out, "/****** %s ******/\n", zErr);
      sqlite3_free(zErr);
      zErr = 0;
    }
    zQ2 = malloc( len+100 );
    if( zQ2==0 ) return rc;
    sqlite3_snprintf(len+100, zQ2, "%s ORDER BY rowid DESC", zQuery);
    rc = sqlite3_exec(p->db, zQ2, dump_callback, p, &zErr);
    if( rc ){
      sqlite3_fprintf(p->out, "/****** ERROR: %s ******/\n", zErr);
    }else{
      rc = SQLITE_CORRUPT;
    }
    sqlite3_free(zErr);
    free(zQ2);
  }
  return rc;
}

/*
** Text of help messages.
**
** The help text for each individual command begins with a line that starts
** with ".".  Subsequent lines are supplemental information.
**
** There must be two or more spaces between the end of the command and the
** start of the description of what that command does.
*/
static const char *(azHelp[]) = {
#if defined(SQLITE_HAVE_ZLIB) && !defined(SQLITE_OMIT_VIRTUALTABLE) \
  && !defined(SQLITE_SHELL_FIDDLE)
  ".archive ...             Manage SQL archives",
  "   Each command must have exactly one of the following options:",
  "     -c, --create               Create a new archive",
  "     -u, --update               Add or update files with changed mtime",
  "     -i, --insert               Like -u but always add even if unchanged",
  "     -r, --remove               Remove files from archive",
  "     -t, --list                 List contents of archive",
  "     -x, --extract              Extract files from archive",
  "   Optional arguments:",
  "     -v, --verbose              Print each filename as it is processed",
  "     -f FILE, --file FILE       Use archive FILE (default is current db)",
  "     -a FILE, --append FILE     Open FILE using the apndvfs VFS",
  "     -C DIR, --directory DIR    Read/extract files from directory DIR",
  "     -g, --glob                 Use glob matching for names in archive",
  "     -n, --dryrun               Show the SQL that would have occurred",
  "   Examples:",
  "     .ar -cf ARCHIVE foo bar  # Create ARCHIVE from files foo and bar",
  "     .ar -tf ARCHIVE          # List members of ARCHIVE",
  "     .ar -xvf ARCHIVE         # Verbosely extract files from ARCHIVE",
  "   See also:",
  "      http://sqlite.org/cli.html#sqlite_archive_support",
#endif
#ifndef SQLITE_OMIT_AUTHORIZATION
  ".auth ON|OFF             Show authorizer callbacks",
#endif
#ifndef SQLITE_SHELL_FIDDLE
  ".backup ?DB? FILE        Backup DB (default \"main\") to FILE",
  "   Options:",
  "       --append            Use the appendvfs",
  "       --async             Write to FILE without journal and fsync()",
#endif
  ".bail on|off             Stop after hitting an error.  Default OFF",
#ifndef SQLITE_SHELL_FIDDLE
  ".cd DIRECTORY            Change the working directory to DIRECTORY",
#endif
  ".changes on|off          Show number of rows changed by SQL",
#ifndef SQLITE_SHELL_FIDDLE
  ".check GLOB              Fail if output since .testcase does not match",
  ".clone NEWDB             Clone data into NEWDB from the existing database",
#endif
  ".connection [close] [#]  Open or close an auxiliary database connection",
  ".crlf ?on|off?           Whether or not to use \\r\\n line endings",
  ".databases               List names and files of attached databases",
  ".dbconfig ?op? ?val?     List or change sqlite3_db_config() options",
#if SQLITE_SHELL_HAVE_RECOVER
  ".dbinfo ?DB?             Show status information about the database",
#endif
  ".dump ?OBJECTS?          Render database content as SQL",
  "   Options:",
  "     --data-only            Output only INSERT statements",
  "     --newlines             Allow unescaped newline characters in output",
  "     --nosys                Omit system tables (ex: \"sqlite_stat1\")",
  "     --preserve-rowids      Include ROWID values in the output",
  "   OBJECTS is a LIKE pattern for tables, indexes, triggers or views to dump",
  "   Additional LIKE patterns can be given in subsequent arguments",
  ".echo on|off             Turn command echo on or off",
  ".eqp on|off|full|...     Enable or disable automatic EXPLAIN QUERY PLAN",
  "   Other Modes:",
#ifdef SQLITE_DEBUG
  "      test                  Show raw EXPLAIN QUERY PLAN output",
  "      trace                 Like \"full\" but enable \"PRAGMA vdbe_trace\"",
#endif
  "      trigger               Like \"full\" but also show trigger bytecode",
#ifndef SQLITE_SHELL_FIDDLE
  ".excel                   Display the output of next command in spreadsheet",
  "   --bom                   Put a UTF8 byte-order mark on intermediate file",
#endif
#ifndef SQLITE_SHELL_FIDDLE
  ".exit ?CODE?             Exit this program with return-code CODE",
#endif
  ".expert                  EXPERIMENTAL. Suggest indexes for queries",
  ".explain ?on|off|auto?   Change the EXPLAIN formatting mode.  Default: auto",
  ".filectrl CMD ...        Run various sqlite3_file_control() operations",
  "   --schema SCHEMA         Use SCHEMA instead of \"main\"",
  "   --help                  Show CMD details",
  ".fullschema ?--indent?   Show schema and the content of sqlite_stat tables",
  ".headers on|off          Turn display of headers on or off",
  ".help ?-all? ?PATTERN?   Show help text for PATTERN",
#ifndef SQLITE_SHELL_FIDDLE
  ".import FILE TABLE       Import data from FILE into TABLE",
  "   Options:",
  "     --ascii               Use \\037 and \\036 as column and row separators",
  "     --csv                 Use , and \\n as column and row separators",
  "     --skip N              Skip the first N rows of input",
  "     --schema S            Target table to be S.TABLE",
  "     -v                    \"Verbose\" - increase auxiliary output",
  "   Notes:",
  "     *  If TABLE does not exist, it is created.  The first row of input",
  "        determines the column names.",
  "     *  If neither --csv or --ascii are used, the input mode is derived",
  "        from the \".mode\" output mode",
  "     *  If FILE begins with \"|\" then it is a command that generates the",
  "        input text.",
#endif
#ifndef SQLITE_OMIT_TEST_CONTROL
  ",imposter INDEX TABLE    Create imposter table TABLE on index INDEX",
#endif
  ".indexes ?TABLE?         Show names of indexes",
  "                           If TABLE is specified, only show indexes for",
  "                           tables matching TABLE using the LIKE operator.",
  ".intck ?STEPS_PER_UNLOCK?  Run an incremental integrity check on the db",
#ifdef SQLITE_ENABLE_IOTRACE
  ",iotrace FILE            Enable I/O diagnostic logging to FILE",
#endif
  ".limit ?LIMIT? ?VAL?     Display or change the value of an SQLITE_LIMIT",
  ".lint OPTIONS            Report potential schema issues.",
  "     Options:",
  "        fkey-indexes     Find missing foreign key indexes",
#if !defined(SQLITE_OMIT_LOAD_EXTENSION) && !defined(SQLITE_SHELL_FIDDLE)
  ".load FILE ?ENTRY?       Load an extension library",
#endif
#if !defined(SQLITE_SHELL_FIDDLE)
  ".log FILE|on|off         Turn logging on or off.  FILE can be stderr/stdout",
#else
  ".log on|off              Turn logging on or off.",
#endif
  ".mode MODE ?OPTIONS?     Set output mode",
  "   MODE is one of:",
  "     ascii       Columns/rows delimited by 0x1F and 0x1E",
  "     box         Tables using unicode box-drawing characters",
  "     csv         Comma-separated values",
  "     column      Output in columns.  (See .width)",
  "     html        HTML <table> code",
  "     insert      SQL insert statements for TABLE",
  "     json        Results in a JSON array",
  "     line        One value per line",
  "     list        Values delimited by \"|\"",
  "     markdown    Markdown table format",
  "     qbox        Shorthand for \"box --wrap 60 --quote\"",
  "     quote       Escape answers as for SQL",
  "     table       ASCII-art table",
  "     tabs        Tab-separated values",
  "     tcl         TCL list elements",
  "   OPTIONS: (for columnar modes or insert mode):",
  "     --wrap N       Wrap output lines to no longer than N characters",
  "     --wordwrap B   Wrap or not at word boundaries per B (on/off)",
  "     --ww           Shorthand for \"--wordwrap 1\"",
  "     --quote        Quote output text as SQL literals",
  "     --noquote      Do not quote output text",
  "     TABLE          The name of SQL table used for \"insert\" mode",
#ifndef SQLITE_SHELL_FIDDLE
  ".nonce STRING            Suspend safe mode for one command if nonce matches",
#endif
  ".nullvalue STRING        Use STRING in place of NULL values",
#ifndef SQLITE_SHELL_FIDDLE
  ".once ?OPTIONS? ?FILE?   Output for the next SQL command only to FILE",
  "     If FILE begins with '|' then open as a pipe",
  "       --bom    Put a UTF8 byte-order mark at the beginning",
  "       -e       Send output to the system text editor",
  "       --plain  Use text/plain output instead of HTML for -w option",
  "       -w       Send output as HTML to a web browser (same as \".www\")",
  "       -x       Send output as CSV to a spreadsheet (same as \".excel\")",
  /* Note that .open is (partially) available in WASM builds but is
  ** currently only intended to be used by the fiddle tool, not
  ** end users, so is "undocumented." */
  ".open ?OPTIONS? ?FILE?   Close existing database and reopen FILE",
  "     Options:",
  "        --append        Use appendvfs to append database to the end of FILE",
#endif
#ifndef SQLITE_OMIT_DESERIALIZE
  "        --deserialize   Load into memory using sqlite3_deserialize()",
  "        --hexdb         Load the output of \"dbtotxt\" as an in-memory db",
  "        --maxsize N     Maximum size for --hexdb or --deserialized database",
#endif
  "        --new           Initialize FILE to an empty database",
  "        --nofollow      Do not follow symbolic links",
  "        --readonly      Open FILE readonly",
  "        --zip           FILE is a ZIP archive",
#ifndef SQLITE_SHELL_FIDDLE
  ".output ?FILE?           Send output to FILE or stdout if FILE is omitted",
  "   If FILE begins with '|' then open it as a pipe.",
  "   Options:",
  "     --bom                 Prefix output with a UTF8 byte-order mark",
  "     -e                    Send output to the system text editor",
  "     --plain               Use text/plain for -w option",
  "     -w                    Send output to a web browser",
  "     -x                    Send output as CSV to a spreadsheet",
#endif
  ".parameter CMD ...       Manage SQL parameter bindings",
  "   clear                   Erase all bindings",
  "   init                    Initialize the TEMP table that holds bindings",
  "   list                    List the current parameter bindings",
  "   set PARAMETER VALUE     Given SQL parameter PARAMETER a value of VALUE",
  "                           PARAMETER should start with one of: $ : @ ?",
  "   unset PARAMETER         Remove PARAMETER from the binding table",
  ".print STRING...         Print literal STRING",
#ifndef SQLITE_OMIT_PROGRESS_CALLBACK
  ".progress N              Invoke progress handler after every N opcodes",
  "   --limit N                 Interrupt after N progress callbacks",
  "   --once                    Do no more than one progress interrupt",
  "   --quiet|-q                No output except at interrupts",
  "   --reset                   Reset the count for each input and interrupt",
#endif
  ".prompt MAIN CONTINUE    Replace the standard prompts",
#ifndef SQLITE_SHELL_FIDDLE
  ".quit                    Stop interpreting input stream, exit if primary.",
  ".read FILE               Read input from FILE or command output",
  "    If FILE begins with \"|\", it is a command that generates the input.",
#endif
#if SQLITE_SHELL_HAVE_RECOVER
  ".recover                 Recover as much data as possible from corrupt db.",
  "   --ignore-freelist        Ignore pages that appear to be on db freelist",
  "   --lost-and-found TABLE   Alternative name for the lost-and-found table",
  "   --no-rowids              Do not attempt to recover rowid values",
  "                            that are not also INTEGER PRIMARY KEYs",
#endif
#ifndef SQLITE_SHELL_FIDDLE
  ".restore ?DB? FILE       Restore content of DB (default \"main\") from FILE",
  ".save ?OPTIONS? FILE     Write database to FILE (an alias for .backup ...)",
#endif
  ".scanstats on|off|est    Turn sqlite3_stmt_scanstatus() metrics on or off",
  ".schema ?PATTERN?        Show the CREATE statements matching PATTERN",
  "   Options:",
  "      --indent             Try to pretty-print the schema",
  "      --nosys              Omit objects whose names start with \"sqlite_\"",
  ",selftest ?OPTIONS?      Run tests defined in the SELFTEST table",
  "    Options:",
  "       --init               Create a new SELFTEST table",
  "       -v                   Verbose output",
  ".separator COL ?ROW?     Change the column and row separators",
#if defined(SQLITE_ENABLE_SESSION)
  ".session ?NAME? CMD ...  Create or control sessions",
  "   Subcommands:",
  "     attach TABLE             Attach TABLE",
  "     changeset FILE           Write a changeset into FILE",
  "     close                    Close one session",
  "     enable ?BOOLEAN?         Set or query the enable bit",
  "     filter GLOB...           Reject tables matching GLOBs",
  "     indirect ?BOOLEAN?       Mark or query the indirect status",
  "     isempty                  Query whether the session is empty",
  "     list                     List currently open session names",
  "     open DB NAME             Open a new session on DB",
  "     patchset FILE            Write a patchset into FILE",
  "   If ?NAME? is omitted, the first defined session is used.",
#endif
  ".sha3sum ...             Compute a SHA3 hash of database content",
  "    Options:",
  "      --schema              Also hash the sqlite_schema table",
  "      --sha3-224            Use the sha3-224 algorithm",
  "      --sha3-256            Use the sha3-256 algorithm (default)",
  "      --sha3-384            Use the sha3-384 algorithm",
  "      --sha3-512            Use the sha3-512 algorithm",
  "    Any other argument is a LIKE pattern for tables to hash",
#if !defined(SQLITE_NOHAVE_SYSTEM) && !defined(SQLITE_SHELL_FIDDLE)
  ".shell CMD ARGS...       Run CMD ARGS... in a system shell",
#endif
  ".show                    Show the current values for various settings",
  ".stats ?ARG?             Show stats or turn stats on or off",
  "   off                      Turn off automatic stat display",
  "   on                       Turn on automatic stat display",
  "   stmt                     Show statement stats",
  "   vmstep                   Show the virtual machine step count only",
#if !defined(SQLITE_NOHAVE_SYSTEM) && !defined(SQLITE_SHELL_FIDDLE)
  ".system CMD ARGS...      Run CMD ARGS... in a system shell",
#endif
  ".tables ?TABLE?          List names of tables matching LIKE pattern TABLE",
#ifndef SQLITE_SHELL_FIDDLE
  ",testcase NAME           Begin redirecting output to 'testcase-out.txt'",
#endif
  ",testctrl CMD ...        Run various sqlite3_test_control() operations",
  "                           Run \".testctrl\" with no arguments for details",
  ".timeout MS              Try opening locked tables for MS milliseconds",
  ".timer on|off            Turn SQL timer on or off",
#ifndef SQLITE_OMIT_TRACE
  ".trace ?OPTIONS?         Output each SQL statement as it is run",
  "    FILE                    Send output to FILE",
  "    stdout                  Send output to stdout",
  "    stderr                  Send output to stderr",
  "    off                     Disable tracing",
  "    --expanded              Expand query parameters",
#ifdef SQLITE_ENABLE_NORMALIZE
  "    --normalized            Normal the SQL statements",
#endif
  "    --plain                 Show SQL as it is input",
  "    --stmt                  Trace statement execution (SQLITE_TRACE_STMT)",
  "    --profile               Profile statements (SQLITE_TRACE_PROFILE)",
  "    --row                   Trace each row (SQLITE_TRACE_ROW)",
  "    --close                 Trace connection close (SQLITE_TRACE_CLOSE)",
#endif /* SQLITE_OMIT_TRACE */
#ifdef SQLITE_DEBUG
  ".unmodule NAME ...       Unregister virtual table modules",
  "    --allexcept             Unregister everything except those named",
#endif
  ".version                 Show source, library and compiler versions",
  ".vfsinfo ?AUX?           Information about the top-level VFS",
  ".vfslist                 List all available VFSes",
  ".vfsname ?AUX?           Print the name of the VFS stack",
  ".width NUM1 NUM2 ...     Set minimum column widths for columnar output",
  "     Negative values right-justify",
#ifndef SQLITE_SHELL_FIDDLE
  ".www                     Display output of the next command in web browser",
  "    --plain                 Show results as text/plain, not as HTML",
#endif
};

/*
** Output help text.
**
** zPattern describes the set of commands for which help text is provided.
** If zPattern is NULL, then show all commands, but only give a one-line
** description of each.
**
** Return the number of matches.
*/
static int showHelp(FILE *out, const char *zPattern){
  int i = 0;
  int j = 0;
  int n = 0;
  char *zPat;
  if( zPattern==0
   || zPattern[0]=='0'
   || cli_strcmp(zPattern,"-a")==0
   || cli_strcmp(zPattern,"-all")==0
   || cli_strcmp(zPattern,"--all")==0
  ){
    enum HelpWanted { HW_NoCull = 0, HW_SummaryOnly = 1, HW_Undoc = 2 };
    enum HelpHave { HH_Undoc = 2, HH_Summary = 1, HH_More = 0 };
    /* Show all or most commands
    ** *zPattern==0   => summary of documented commands only
    ** *zPattern=='0' => whole help for undocumented commands
    ** Otherwise      => whole help for documented commands
    */
    enum HelpWanted hw = HW_SummaryOnly;
    enum HelpHave hh = HH_More;
    if( zPattern!=0 ){
      hw = (*zPattern=='0')? HW_NoCull|HW_Undoc : HW_NoCull;
    }
    for(i=0; i<ArraySize(azHelp); i++){
      switch( azHelp[i][0] ){
      case ',':
        hh = HH_Summary|HH_Undoc;
        break;
      case '.':
        hh = HH_Summary;
        break;
      default:
        hh &= ~HH_Summary;
        break;
      }
      if( ((hw^hh)&HH_Undoc)==0 ){
        if( (hh&HH_Summary)!=0 ){
          sqlite3_fprintf(out, ".%s\n", azHelp[i]+1);
          ++n;
        }else if( (hw&HW_SummaryOnly)==0 ){
          sqlite3_fprintf(out, "%s\n", azHelp[i]);
        }
      }
    }
  }else{
    /* Seek documented commands for which zPattern is an exact prefix */
    zPat = sqlite3_mprintf(".%s*", zPattern);
    shell_check_oom(zPat);
    for(i=0; i<ArraySize(azHelp); i++){
      if( sqlite3_strglob(zPat, azHelp[i])==0 ){
        sqlite3_fprintf(out, "%s\n", azHelp[i]);
        j = i+1;
        n++;
      }
    }
    sqlite3_free(zPat);
    if( n ){
      if( n==1 ){
        /* when zPattern is a prefix of exactly one command, then include
        ** the details of that command, which should begin at offset j */
        while( j<ArraySize(azHelp)-1 && azHelp[j][0]==' ' ){
          sqlite3_fprintf(out, "%s\n", azHelp[j]);
          j++;
        }
      }
      return n;
    }
    /* Look for documented commands that contain zPattern anywhere.
    ** Show complete text of all documented commands that match. */
    zPat = sqlite3_mprintf("%%%s%%", zPattern);
    shell_check_oom(zPat);
    for(i=0; i<ArraySize(azHelp); i++){
      if( azHelp[i][0]==',' ){
        while( i<ArraySize(azHelp)-1 && azHelp[i+1][0]==' ' ) ++i;
        continue;
      }
      if( azHelp[i][0]=='.' ) j = i;
      if( sqlite3_strlike(zPat, azHelp[i], 0)==0 ){
        sqlite3_fprintf(out, "%s\n", azHelp[j]);
        while( j<ArraySize(azHelp)-1 && azHelp[j+1][0]==' ' ){
          j++;
          sqlite3_fprintf(out, "%s\n", azHelp[j]);
        }
        i = j;
        n++;
      }
    }
    sqlite3_free(zPat);
  }
  return n;
}

/* Forward reference */
static int process_input(ShellState *p);

/*
** Read the content of file zName into memory obtained from sqlite3_malloc64()
** and return a pointer to the buffer. The caller is responsible for freeing
** the memory.
**
** If parameter pnByte is not NULL, (*pnByte) is set to the number of bytes
** read.
**
** For convenience, a nul-terminator byte is always appended to the data read
** from the file before the buffer is returned. This byte is not included in
** the final value of (*pnByte), if applicable.
**
** NULL is returned if any error is encountered. The final value of *pnByte
** is undefined in this case.
*/
static char *readFile(const char *zName, int *pnByte){
  FILE *in = sqlite3_fopen(zName, "rb");
  long nIn;
  size_t nRead;
  char *pBuf;
  int rc;
  if( in==0 ) return 0;
  rc = fseek(in, 0, SEEK_END);
  if( rc!=0 ){
    sqlite3_fprintf(stderr,"Error: '%s' not seekable\n", zName);
    fclose(in);
    return 0;
  }
  nIn = ftell(in);
  rewind(in);
  pBuf = sqlite3_malloc64( nIn+1 );
  if( pBuf==0 ){
    sqlite3_fputs("Error: out of memory\n", stderr);
    fclose(in);
    return 0;
  }
  nRead = fread(pBuf, nIn, 1, in);
  fclose(in);
  if( nRead!=1 ){
    sqlite3_free(pBuf);
    sqlite3_fprintf(stderr,"Error: cannot read '%s'\n", zName);
    return 0;
  }
  pBuf[nIn] = 0;
  if( pnByte ) *pnByte = nIn;
  return pBuf;
}

#if defined(SQLITE_ENABLE_SESSION)
/*
** Close a single OpenSession object and release all of its associated
** resources.
*/
static void session_close(OpenSession *pSession){
  int i;
  sqlite3session_delete(pSession->p);
  sqlite3_free(pSession->zName);
  for(i=0; i<pSession->nFilter; i++){
    sqlite3_free(pSession->azFilter[i]);
  }
  sqlite3_free(pSession->azFilter);
  memset(pSession, 0, sizeof(OpenSession));
}
#endif

/*
** Close all OpenSession objects and release all associated resources.
*/
#if defined(SQLITE_ENABLE_SESSION)
static void session_close_all(ShellState *p, int i){
  int j;
  struct AuxDb *pAuxDb = i<0 ? p->pAuxDb : &p->aAuxDb[i];
  for(j=0; j<pAuxDb->nSession; j++){
    session_close(&pAuxDb->aSession[j]);
  }
  pAuxDb->nSession = 0;
}
#else
# define session_close_all(X,Y)
#endif

/*
** Implementation of the xFilter function for an open session.  Omit
** any tables named by ".session filter" but let all other table through.
*/
#if defined(SQLITE_ENABLE_SESSION)
static int session_filter(void *pCtx, const char *zTab){
  OpenSession *pSession = (OpenSession*)pCtx;
  int i;
  for(i=0; i<pSession->nFilter; i++){
    if( sqlite3_strglob(pSession->azFilter[i], zTab)==0 ) return 0;
  }
  return 1;
}
#endif

/*
** Try to deduce the type of file for zName based on its content.  Return
** one of the SHELL_OPEN_* constants.
**
** If the file does not exist or is empty but its name looks like a ZIP
** archive and the dfltZip flag is true, then assume it is a ZIP archive.
** Otherwise, assume an ordinary database regardless of the filename if
** the type cannot be determined from content.
*/
int deduceDatabaseType(const char *zName, int dfltZip){
  FILE *f = sqlite3_fopen(zName, "rb");
  size_t n;
  int rc = SHELL_OPEN_UNSPEC;
  char zBuf[100];
  if( f==0 ){
    if( dfltZip && sqlite3_strlike("%.zip",zName,0)==0 ){
       return SHELL_OPEN_ZIPFILE;
    }else{
       return SHELL_OPEN_NORMAL;
    }
  }
  n = fread(zBuf, 16, 1, f);
  if( n==1 && memcmp(zBuf, "SQLite format 3", 16)==0 ){
    fclose(f);
    return SHELL_OPEN_NORMAL;
  }
  fseek(f, -25, SEEK_END);
  n = fread(zBuf, 25, 1, f);
  if( n==1 && memcmp(zBuf, "Start-Of-SQLite3-", 17)==0 ){
    rc = SHELL_OPEN_APPENDVFS;
  }else{
    fseek(f, -22, SEEK_END);
    n = fread(zBuf, 22, 1, f);
    if( n==1 && zBuf[0]==0x50 && zBuf[1]==0x4b && zBuf[2]==0x05
       && zBuf[3]==0x06 ){
      rc = SHELL_OPEN_ZIPFILE;
    }else if( n==0 && dfltZip && sqlite3_strlike("%.zip",zName,0)==0 ){
      rc = SHELL_OPEN_ZIPFILE;
    }
  }
  fclose(f);
  return rc;
}

#ifndef SQLITE_OMIT_DESERIALIZE
/*
** Reconstruct an in-memory database using the output from the "dbtotxt"
** program.  Read content from the file in p->aAuxDb[].zDbFilename.
** If p->aAuxDb[].zDbFilename is 0, then read from standard input.
*/
static unsigned char *readHexDb(ShellState *p, int *pnData){
  unsigned char *a = 0;
  int nLine;
  int n = 0;
  int pgsz = 0;
  int iOffset = 0;
  int j, k;
  int rc;
  FILE *in;
  const char *zDbFilename = p->pAuxDb->zDbFilename;
  unsigned int x[16];
  char zLine[1000];
  if( zDbFilename ){
    in = sqlite3_fopen(zDbFilename, "r");
    if( in==0 ){
      sqlite3_fprintf(stderr,"cannot open \"%s\" for reading\n", zDbFilename);
      return 0;
    }
    nLine = 0;
  }else{
    in = p->in;
    nLine = p->lineno;
    if( in==0 ) in = stdin;
  }
  *pnData = 0;
  nLine++;
  if( sqlite3_fgets(zLine, sizeof(zLine), in)==0 ) goto readHexDb_error;
  rc = sscanf(zLine, "| size %d pagesize %d", &n, &pgsz);
  if( rc!=2 ) goto readHexDb_error;
  if( n<0 ) goto readHexDb_error;
  if( pgsz<512 || pgsz>65536 || (pgsz&(pgsz-1))!=0 ) goto readHexDb_error;
  n = (n+pgsz-1)&~(pgsz-1);  /* Round n up to the next multiple of pgsz */
  a = sqlite3_malloc( n ? n : 1 );
  shell_check_oom(a);
  memset(a, 0, n);
  if( pgsz<512 || pgsz>65536 || (pgsz & (pgsz-1))!=0 ){
    sqlite3_fputs("invalid pagesize\n", stderr);
    goto readHexDb_error;
  }
  for(nLine++; sqlite3_fgets(zLine, sizeof(zLine), in)!=0; nLine++){
    rc = sscanf(zLine, "| page %d offset %d", &j, &k);
    if( rc==2 ){
      iOffset = k;
      continue;
    }
    if( cli_strncmp(zLine, "| end ", 6)==0 ){
      break;
    }
    rc = sscanf(zLine,"| %d: %x %x %x %x %x %x %x %x %x %x %x %x %x %x %x %x",
                &j, &x[0], &x[1], &x[2], &x[3], &x[4], &x[5], &x[6], &x[7],
                &x[8], &x[9], &x[10], &x[11], &x[12], &x[13], &x[14], &x[15]);
    if( rc==17 ){
      k = iOffset+j;
      if( k+16<=n && k>=0 ){
        int ii;
        for(ii=0; ii<16; ii++) a[k+ii] = x[ii]&0xff;
      }
    }
  }
  *pnData = n;
  if( in!=p->in ){
    fclose(in);
  }else{
    p->lineno = nLine;
  }
  return a;

readHexDb_error:
  if( in!=p->in ){
    fclose(in);
  }else{
    while( sqlite3_fgets(zLine, sizeof(zLine), p->in)!=0 ){
      nLine++;
      if(cli_strncmp(zLine, "| end ", 6)==0 ) break;
    }
    p->lineno = nLine;
  }
  sqlite3_free(a);
  sqlite3_fprintf(stderr,"Error on line %d of --hexdb input\n", nLine);
  return 0;
}
#endif /* SQLITE_OMIT_DESERIALIZE */

/*
** Scalar function "usleep(X)" invokes sqlite3_sleep(X) and returns X.
*/
static void shellUSleepFunc(
  sqlite3_context *context,
  int argcUnused,
  sqlite3_value **argv
){
  int sleep = sqlite3_value_int(argv[0]);
  (void)argcUnused;
  sqlite3_sleep(sleep/1000);
  sqlite3_result_int(context, sleep);
}

/* Flags for open_db().
**
** The default behavior of open_db() is to exit(1) if the database fails to
** open.  The OPEN_DB_KEEPALIVE flag changes that so that it prints an error
** but still returns without calling exit.
**
** The OPEN_DB_ZIPFILE flag causes open_db() to prefer to open files as a
** ZIP archive if the file does not exist or is empty and its name matches
** the *.zip pattern.
*/
#define OPEN_DB_KEEPALIVE   0x001   /* Return after error if true */
#define OPEN_DB_ZIPFILE     0x002   /* Open as ZIP if name matches *.zip */

/*
** Make sure the database is open.  If it is not, then open it.  If
** the database fails to open, print an error message and exit.
*/
static void open_db(ShellState *p, int openFlags){
  if( p->db==0 ){
    const char *zDbFilename = p->pAuxDb->zDbFilename;
    if( p->openMode==SHELL_OPEN_UNSPEC ){
      if( zDbFilename==0 || zDbFilename[0]==0 ){
        p->openMode = SHELL_OPEN_NORMAL;
      }else{
        p->openMode = (u8)deduceDatabaseType(zDbFilename,
                             (openFlags & OPEN_DB_ZIPFILE)!=0);
      }
    }
    switch( p->openMode ){
      case SHELL_OPEN_APPENDVFS: {
        sqlite3_open_v2(zDbFilename, &p->db,
           SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE|p->openFlags, "apndvfs");
        break;
      }
      case SHELL_OPEN_HEXDB:
      case SHELL_OPEN_DESERIALIZE: {
        sqlite3_open(0, &p->db);
        break;
      }
      case SHELL_OPEN_ZIPFILE: {
        sqlite3_open(":memory:", &p->db);
        break;
      }
      case SHELL_OPEN_READONLY: {
        sqlite3_open_v2(zDbFilename, &p->db,
            SQLITE_OPEN_READONLY|p->openFlags, 0);
        break;
      }
      case SHELL_OPEN_UNSPEC:
      case SHELL_OPEN_NORMAL: {
        sqlite3_open_v2(zDbFilename, &p->db,
           SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE|p->openFlags, 0);
        break;
      }
    }
    if( p->db==0 || SQLITE_OK!=sqlite3_errcode(p->db) ){
      sqlite3_fprintf(stderr,"Error: unable to open database \"%s\": %s\n",
            zDbFilename, sqlite3_errmsg(p->db));
      if( (openFlags & OPEN_DB_KEEPALIVE)==0 ){
        exit(1);
      }
      sqlite3_close(p->db);
      sqlite3_open(":memory:", &p->db);
      if( p->db==0 || SQLITE_OK!=sqlite3_errcode(p->db) ){
        sqlite3_fputs("Also: unable to open substitute in-memory database.\n",
                      stderr);
        exit(1);
      }else{
        sqlite3_fprintf(stderr,
              "Notice: using substitute in-memory database instead of \"%s\"\n",
              zDbFilename);
      }
    }
    globalDb = p->db;
    sqlite3_db_config(p->db, SQLITE_DBCONFIG_STMT_SCANSTATUS, (int)0, (int*)0);

    /* Reflect the use or absence of --unsafe-testing invocation. */
    {
      int testmode_on = ShellHasFlag(p,SHFLG_TestingMode);
      sqlite3_db_config(p->db, SQLITE_DBCONFIG_TRUSTED_SCHEMA, testmode_on,0);
      sqlite3_db_config(p->db, SQLITE_DBCONFIG_DEFENSIVE, !testmode_on,0);
    }

#ifndef SQLITE_OMIT_LOAD_EXTENSION
    sqlite3_enable_load_extension(p->db, 1);
#endif
    sqlite3_sha_init(p->db, 0, 0);
    sqlite3_shathree_init(p->db, 0, 0);
    sqlite3_uint_init(p->db, 0, 0);
    sqlite3_stmtrand_init(p->db, 0, 0);
    sqlite3_decimal_init(p->db, 0, 0);
    sqlite3_percentile_init(p->db, 0, 0);
    sqlite3_base64_init(p->db, 0, 0);
    sqlite3_base85_init(p->db, 0, 0);
    sqlite3_regexp_init(p->db, 0, 0);
    sqlite3_ieee_init(p->db, 0, 0);
    sqlite3_series_init(p->db, 0, 0);
#ifndef SQLITE_SHELL_FIDDLE
    sqlite3_fileio_init(p->db, 0, 0);
    sqlite3_completion_init(p->db, 0, 0);
#endif
#ifdef SQLITE_HAVE_ZLIB
    if( !p->bSafeModePersist ){
      sqlite3_zipfile_init(p->db, 0, 0);
      sqlite3_sqlar_init(p->db, 0, 0);
    }
#endif
#ifdef SQLITE_SHELL_EXTFUNCS
    /* Create a preprocessing mechanism for extensions to make
     * their own provisions for being built into the shell.
     * This is a short-span macro. See further below for usage.
     */
#define SHELL_SUB_MACRO(base, variant) base ## _ ## variant
#define SHELL_SUBMACRO(base, variant) SHELL_SUB_MACRO(base, variant)
    /* Let custom-included extensions get their ..._init() called.
     * The WHATEVER_INIT( db, pzErrorMsg, pApi ) macro should cause
     * the extension's sqlite3_*_init( db, pzErrorMsg, pApi )
     * initialization routine to be called.
     */
    {
      int irc = SHELL_SUBMACRO(SQLITE_SHELL_EXTFUNCS, INIT)(p->db);
    /* Let custom-included extensions expose their functionality.
     * The WHATEVER_EXPOSE( db, pzErrorMsg ) macro should cause
     * the SQL functions, virtual tables, collating sequences or
     * VFS's implemented by the extension to be registered.
     */
      if( irc==SQLITE_OK
          || irc==SQLITE_OK_LOAD_PERMANENTLY ){
        SHELL_SUBMACRO(SQLITE_SHELL_EXTFUNCS, EXPOSE)(p->db, 0);
      }
#undef SHELL_SUB_MACRO
#undef SHELL_SUBMACRO
    }
#endif

    sqlite3_create_function(p->db, "strtod", 1, SQLITE_UTF8, 0,
                            shellStrtod, 0, 0);
    sqlite3_create_function(p->db, "dtostr", 1, SQLITE_UTF8, 0,
                            shellDtostr, 0, 0);
    sqlite3_create_function(p->db, "dtostr", 2, SQLITE_UTF8, 0,
                            shellDtostr, 0, 0);
    sqlite3_create_function(p->db, "shell_add_schema", 3, SQLITE_UTF8, 0,
                            shellAddSchemaName, 0, 0);
    sqlite3_create_function(p->db, "shell_module_schema", 1, SQLITE_UTF8, 0,
                            shellModuleSchema, 0, 0);
    sqlite3_create_function(p->db, "shell_putsnl", 1, SQLITE_UTF8, p,
                            shellPutsFunc, 0, 0);
    sqlite3_create_function(p->db, "usleep",1,SQLITE_UTF8,0,
                            shellUSleepFunc, 0, 0);
#ifndef SQLITE_NOHAVE_SYSTEM
    sqlite3_create_function(p->db, "edit", 1, SQLITE_UTF8, 0,
                            editFunc, 0, 0);
    sqlite3_create_function(p->db, "edit", 2, SQLITE_UTF8, 0,
                            editFunc, 0, 0);
#endif

    if( p->openMode==SHELL_OPEN_ZIPFILE ){
      char *zSql = sqlite3_mprintf(
         "CREATE VIRTUAL TABLE zip USING zipfile(%Q);", zDbFilename);
      shell_check_oom(zSql);
      sqlite3_exec(p->db, zSql, 0, 0, 0);
      sqlite3_free(zSql);
    }
#ifndef SQLITE_OMIT_DESERIALIZE
    else
    if( p->openMode==SHELL_OPEN_DESERIALIZE || p->openMode==SHELL_OPEN_HEXDB ){
      int rc;
      int nData = 0;
      unsigned char *aData;
      if( p->openMode==SHELL_OPEN_DESERIALIZE ){
        aData = (unsigned char*)readFile(zDbFilename, &nData);
      }else{
        aData = readHexDb(p, &nData);
      }
      if( aData==0 ){
        return;
      }
      rc = sqlite3_deserialize(p->db, "main", aData, nData, nData,
                   SQLITE_DESERIALIZE_RESIZEABLE |
                   SQLITE_DESERIALIZE_FREEONCLOSE);
      if( rc ){
        sqlite3_fprintf(stderr,"Error: sqlite3_deserialize() returns %d\n", rc);
      }
      if( p->szMax>0 ){
        sqlite3_file_control(p->db, "main", SQLITE_FCNTL_SIZE_LIMIT, &p->szMax);
      }
    }
#endif
  }
  if( p->db!=0 ){
    if( p->bSafeModePersist ){
      sqlite3_set_authorizer(p->db, safeModeAuth, p);
    }
    sqlite3_db_config(
        p->db, SQLITE_DBCONFIG_STMT_SCANSTATUS, p->scanstatsOn, (int*)0
    );
  }
}

/*
** Attempt to close the database connection.  Report errors.
*/
void close_db(sqlite3 *db){
  int rc = sqlite3_close(db);
  if( rc ){
    sqlite3_fprintf(stderr,
        "Error: sqlite3_close() returns %d: %s\n", rc, sqlite3_errmsg(db));
  }
}

#if HAVE_READLINE || HAVE_EDITLINE
/*
** Readline completion callbacks
*/
static char *readline_completion_generator(const char *text, int state){
  static sqlite3_stmt *pStmt = 0;
  char *zRet;
  if( state==0 ){
    char *zSql;
    sqlite3_finalize(pStmt);
    zSql = sqlite3_mprintf("SELECT DISTINCT candidate COLLATE nocase"
                           "  FROM completion(%Q) ORDER BY 1", text);
    shell_check_oom(zSql);
    sqlite3_prepare_v2(globalDb, zSql, -1, &pStmt, 0);
    sqlite3_free(zSql);
  }
  if( sqlite3_step(pStmt)==SQLITE_ROW ){
    const char *z = (const char*)sqlite3_column_text(pStmt,0);
    zRet = z ? strdup(z) : 0;
  }else{
    sqlite3_finalize(pStmt);
    pStmt = 0;
    zRet = 0;
  }
  return zRet;
}
static char **readline_completion(const char *zText, int iStart, int iEnd){
  (void)iStart;
  (void)iEnd;
  rl_attempted_completion_over = 1;
  return rl_completion_matches(zText, readline_completion_generator);
}

#elif HAVE_LINENOISE
/*
** Linenoise completion callback. Note that the 3rd argument is from
** the "msteveb" version of linenoise, not the "antirez" version.
*/
static void linenoise_completion(const char *zLine, linenoiseCompletions *lc,
                                 void *pUserData){
  i64 nLine = strlen(zLine);
  i64 i, iStart;
  sqlite3_stmt *pStmt = 0;
  char *zSql;
  char zBuf[1000];

  UNUSED_PARAMETER(pUserData);
  if( nLine>(i64)sizeof(zBuf)-30 ) return;
  if( zLine[0]=='.' || zLine[0]=='#') return;
  for(i=nLine-1; i>=0 && (isalnum(zLine[i]) || zLine[i]=='_'); i--){}
  if( i==nLine-1 ) return;
  iStart = i+1;
  memcpy(zBuf, zLine, iStart);
  zSql = sqlite3_mprintf("SELECT DISTINCT candidate COLLATE nocase"
                         "  FROM completion(%Q,%Q) ORDER BY 1",
                         &zLine[iStart], zLine);
  shell_check_oom(zSql);
  sqlite3_prepare_v2(globalDb, zSql, -1, &pStmt, 0);
  sqlite3_free(zSql);
  sqlite3_exec(globalDb, "PRAGMA page_count", 0, 0, 0); /* Load the schema */
  while( sqlite3_step(pStmt)==SQLITE_ROW ){
    const char *zCompletion = (const char*)sqlite3_column_text(pStmt, 0);
    int nCompletion = sqlite3_column_bytes(pStmt, 0);
    if( iStart+nCompletion < (i64)sizeof(zBuf)-1 && zCompletion ){
      memcpy(zBuf+iStart, zCompletion, nCompletion+1);
      linenoiseAddCompletion(lc, zBuf);
    }
  }
  sqlite3_finalize(pStmt);
}
#endif

/*
** Do C-language style dequoting.
**
**    \a    -> alarm
**    \b    -> backspace
**    \t    -> tab
**    \n    -> newline
**    \v    -> vertical tab
**    \f    -> form feed
**    \r    -> carriage return
**    \s    -> space
**    \"    -> "
**    \'    -> '
**    \\    -> backslash
**    \NNN  -> ascii character NNN in octal
**    \xHH  -> ascii character HH in hexadecimal
*/
static void resolve_backslashes(char *z){
  int i, j;
  char c;
  while( *z && *z!='\\' ) z++;
  for(i=j=0; (c = z[i])!=0; i++, j++){
    if( c=='\\' && z[i+1]!=0 ){
      c = z[++i];
      if( c=='a' ){
        c = '\a';
      }else if( c=='b' ){
        c = '\b';
      }else if( c=='t' ){
        c = '\t';
      }else if( c=='n' ){
        c = '\n';
      }else if( c=='v' ){
        c = '\v';
      }else if( c=='f' ){
        c = '\f';
      }else if( c=='r' ){
        c = '\r';
      }else if( c=='"' ){
        c = '"';
      }else if( c=='\'' ){
        c = '\'';
      }else if( c=='\\' ){
        c = '\\';
      }else if( c=='x' ){
        int nhd = 0, hdv;
        u8 hv = 0;
        while( nhd<2 && (c=z[i+1+nhd])!=0 && (hdv=hexDigitValue(c))>=0 ){
          hv = (u8)((hv<<4)|hdv);
          ++nhd;
        }
        i += nhd;
        c = (u8)hv;
      }else if( c>='0' && c<='7' ){
        c -= '0';
        if( z[i+1]>='0' && z[i+1]<='7' ){
          i++;
          c = (c<<3) + z[i] - '0';
          if( z[i+1]>='0' && z[i+1]<='7' ){
            i++;
            c = (c<<3) + z[i] - '0';
          }
        }
      }
    }
    z[j] = c;
  }
  if( j<i ) z[j] = 0;
}

/*
** Interpret zArg as either an integer or a boolean value.  Return 1 or 0
** for TRUE and FALSE.  Return the integer value if appropriate.
*/
static int booleanValue(const char *zArg){
  int i;
  if( zArg[0]=='0' && zArg[1]=='x' ){
    for(i=2; hexDigitValue(zArg[i])>=0; i++){}
  }else{
    for(i=0; zArg[i]>='0' && zArg[i]<='9'; i++){}
  }
  if( i>0 && zArg[i]==0 ) return (int)(integerValue(zArg) & 0xffffffff);
  if( sqlite3_stricmp(zArg, "on")==0 || sqlite3_stricmp(zArg,"yes")==0 ){
    return 1;
  }
  if( sqlite3_stricmp(zArg, "off")==0 || sqlite3_stricmp(zArg,"no")==0 ){
    return 0;
  }
  sqlite3_fprintf(stderr,
       "ERROR: Not a boolean value: \"%s\". Assuming \"no\".\n", zArg);
  return 0;
}

/*
** Set or clear a shell flag according to a boolean value.
*/
static void setOrClearFlag(ShellState *p, unsigned mFlag, const char *zArg){
  if( booleanValue(zArg) ){
    ShellSetFlag(p, mFlag);
  }else{
    ShellClearFlag(p, mFlag);
  }
}

/*
** Close an output file, assuming it is not stderr or stdout
*/
static void output_file_close(FILE *f){
  if( f && f!=stdout && f!=stderr ) fclose(f);
}

/*
** Try to open an output file.   The names "stdout" and "stderr" are
** recognized and do the right thing.  NULL is returned if the output
** filename is "off".
*/
static FILE *output_file_open(const char *zFile){
  FILE *f;
  if( cli_strcmp(zFile,"stdout")==0 ){
    f = stdout;
  }else if( cli_strcmp(zFile, "stderr")==0 ){
    f = stderr;
  }else if( cli_strcmp(zFile, "off")==0 ){
    f = 0;
  }else{
    f = sqlite3_fopen(zFile, "w");
    if( f==0 ){
      sqlite3_fprintf(stderr,"Error: cannot open \"%s\"\n", zFile);
    }
  }
  return f;
}

#ifndef SQLITE_OMIT_TRACE
/*
** A routine for handling output from sqlite3_trace().
*/
static int sql_trace_callback(
  unsigned mType,         /* The trace type */
  void *pArg,             /* The ShellState pointer */
  void *pP,               /* Usually a pointer to sqlite_stmt */
  void *pX                /* Auxiliary output */
){
  ShellState *p = (ShellState*)pArg;
  sqlite3_stmt *pStmt;
  const char *zSql;
  i64 nSql;
  if( p->traceOut==0 ) return 0;
  if( mType==SQLITE_TRACE_CLOSE ){
    sputz(p->traceOut, "-- closing database connection\n");
    return 0;
  }
  if( mType!=SQLITE_TRACE_ROW && pX!=0 && ((const char*)pX)[0]=='-' ){
    zSql = (const char*)pX;
  }else{
    pStmt = (sqlite3_stmt*)pP;
    switch( p->eTraceType ){
      case SHELL_TRACE_EXPANDED: {
        zSql = sqlite3_expanded_sql(pStmt);
        break;
      }
#ifdef SQLITE_ENABLE_NORMALIZE
      case SHELL_TRACE_NORMALIZED: {
        zSql = sqlite3_normalized_sql(pStmt);
        break;
      }
#endif
      default: {
        zSql = sqlite3_sql(pStmt);
        break;
      }
    }
  }
  if( zSql==0 ) return 0;
  nSql = strlen(zSql);
  if( nSql>1000000000 ) nSql = 1000000000;
  while( nSql>0 && zSql[nSql-1]==';' ){ nSql--; }
  switch( mType ){
    case SQLITE_TRACE_ROW:
    case SQLITE_TRACE_STMT: {
      sqlite3_fprintf(p->traceOut, "%.*s;\n", (int)nSql, zSql);
      break;
    }
    case SQLITE_TRACE_PROFILE: {
      sqlite3_int64 nNanosec = pX ? *(sqlite3_int64*)pX : 0;
      sqlite3_fprintf(p->traceOut,
                      "%.*s; -- %lld ns\n", (int)nSql, zSql, nNanosec);
      break;
    }
  }
  return 0;
}
#endif

/*
** A no-op routine that runs with the ".breakpoint" doc-command.  This is
** a useful spot to set a debugger breakpoint.
**
** This routine does not do anything practical.  The code are there simply
** to prevent the compiler from optimizing this routine out.
*/
static void test_breakpoint(void){
  static unsigned int nCall = 0;
  if( (nCall++)==0xffffffff ) printf("Many .breakpoints have run\n");
}

/*
** An object used to read a CSV and other files for import.
*/
typedef struct ImportCtx ImportCtx;
struct ImportCtx {
  const char *zFile;  /* Name of the input file */
  FILE *in;           /* Read the CSV text from this input stream */
  int (SQLITE_CDECL *xCloser)(FILE*);      /* Func to close in */
  char *z;            /* Accumulated text for a field */
  int n;              /* Number of bytes in z */
  int nAlloc;         /* Space allocated for z[] */
  int nLine;          /* Current line number */
  int nRow;           /* Number of rows imported */
  int nErr;           /* Number of errors encountered */
  int bNotFirst;      /* True if one or more bytes already read */
  int cTerm;          /* Character that terminated the most recent field */
  int cColSep;        /* The column separator character.  (Usually ",") */
  int cRowSep;        /* The row separator character.  (Usually "\n") */
};

/* Clean up resourced used by an ImportCtx */
static void import_cleanup(ImportCtx *p){
  if( p->in!=0 && p->xCloser!=0 ){
    p->xCloser(p->in);
    p->in = 0;
  }
  sqlite3_free(p->z);
  p->z = 0;
}

/* Append a single byte to z[] */
static void import_append_char(ImportCtx *p, int c){
  if( p->n+1>=p->nAlloc ){
    p->nAlloc += p->nAlloc + 100;
    p->z = sqlite3_realloc64(p->z, p->nAlloc);
    shell_check_oom(p->z);
  }
  p->z[p->n++] = (char)c;
}

/* Read a single field of CSV text.  Compatible with rfc4180 and extended
** with the option of having a separator other than ",".
**
**   +  Input comes from p->in.
**   +  Store results in p->z of length p->n.  Space to hold p->z comes
**      from sqlite3_malloc64().
**   +  Use p->cSep as the column separator.  The default is ",".
**   +  Use p->rSep as the row separator.  The default is "\n".
**   +  Keep track of the line number in p->nLine.
**   +  Store the character that terminates the field in p->cTerm.  Store
**      EOF on end-of-file.
**   +  Report syntax errors on stderr
*/
static char *SQLITE_CDECL csv_read_one_field(ImportCtx *p){
  int c;
  int cSep = (u8)p->cColSep;
  int rSep = (u8)p->cRowSep;
  p->n = 0;
  c = fgetc(p->in);
  if( c==EOF || seenInterrupt ){
    p->cTerm = EOF;
    return 0;
  }
  if( c=='"' ){
    int pc, ppc;
    int startLine = p->nLine;
    int cQuote = c;
    pc = ppc = 0;
    while( 1 ){
      c = fgetc(p->in);
      if( c==rSep ) p->nLine++;
      if( c==cQuote ){
        if( pc==cQuote ){
          pc = 0;
          continue;
        }
      }
      if( (c==cSep && pc==cQuote)
       || (c==rSep && pc==cQuote)
       || (c==rSep && pc=='\r' && ppc==cQuote)
       || (c==EOF && pc==cQuote)
      ){
        do{ p->n--; }while( p->z[p->n]!=cQuote );
        p->cTerm = c;
        break;
      }
      if( pc==cQuote && c!='\r' ){
        sqlite3_fprintf(stderr,"%s:%d: unescaped %c character\n", 
                        p->zFile, p->nLine, cQuote);
      }
      if( c==EOF ){
        sqlite3_fprintf(stderr,"%s:%d: unterminated %c-quoted field\n",
              p->zFile, startLine, cQuote);
        p->cTerm = c;
        break;
      }
      import_append_char(p, c);
      ppc = pc;
      pc = c;
    }
  }else{
    /* If this is the first field being parsed and it begins with the
    ** UTF-8 BOM  (0xEF BB BF) then skip the BOM */
    if( (c&0xff)==0xef && p->bNotFirst==0 ){
      import_append_char(p, c);
      c = fgetc(p->in);
      if( (c&0xff)==0xbb ){
        import_append_char(p, c);
        c = fgetc(p->in);
        if( (c&0xff)==0xbf ){
          p->bNotFirst = 1;
          p->n = 0;
          return csv_read_one_field(p);
        }
      }
    }
    while( c!=EOF && c!=cSep && c!=rSep ){
      import_append_char(p, c);
      c = fgetc(p->in);
    }
    if( c==rSep ){
      p->nLine++;
      if( p->n>0 && p->z[p->n-1]=='\r' ) p->n--;
    }
    p->cTerm = c;
  }
  if( p->z ) p->z[p->n] = 0;
  p->bNotFirst = 1;
  return p->z;
}

/* Read a single field of ASCII delimited text.
**
**   +  Input comes from p->in.
**   +  Store results in p->z of length p->n.  Space to hold p->z comes
**      from sqlite3_malloc64().
**   +  Use p->cSep as the column separator.  The default is "\x1F".
**   +  Use p->rSep as the row separator.  The default is "\x1E".
**   +  Keep track of the row number in p->nLine.
**   +  Store the character that terminates the field in p->cTerm.  Store
**      EOF on end-of-file.
**   +  Report syntax errors on stderr
*/
static char *SQLITE_CDECL ascii_read_one_field(ImportCtx *p){
  int c;
  int cSep = (u8)p->cColSep;
  int rSep = (u8)p->cRowSep;
  p->n = 0;
  c = fgetc(p->in);
  if( c==EOF || seenInterrupt ){
    p->cTerm = EOF;
    return 0;
  }
  while( c!=EOF && c!=cSep && c!=rSep ){
    import_append_char(p, c);
    c = fgetc(p->in);
  }
  if( c==rSep ){
    p->nLine++;
  }
  p->cTerm = c;
  if( p->z ) p->z[p->n] = 0;
  return p->z;
}

/*
** Try to transfer data for table zTable.  If an error is seen while
** moving forward, try to go backwards.  The backwards movement won't
** work for WITHOUT ROWID tables.
*/
static void tryToCloneData(
  ShellState *p,
  sqlite3 *newDb,
  const char *zTable
){
  sqlite3_stmt *pQuery = 0;
  sqlite3_stmt *pInsert = 0;
  char *zQuery = 0;
  char *zInsert = 0;
  int rc;
  int i, j, n;
  int nTable = strlen30(zTable);
  int k = 0;
  int cnt = 0;
  const int spinRate = 10000;

  zQuery = sqlite3_mprintf("SELECT * FROM \"%w\"", zTable);
  shell_check_oom(zQuery);
  rc = sqlite3_prepare_v2(p->db, zQuery, -1, &pQuery, 0);
  if( rc ){
    sqlite3_fprintf(stderr,"Error %d: %s on [%s]\n",
          sqlite3_extended_errcode(p->db), sqlite3_errmsg(p->db), zQuery);
    goto end_data_xfer;
  }
  n = sqlite3_column_count(pQuery);
  zInsert = sqlite3_malloc64(200 + nTable + n*3);
  shell_check_oom(zInsert);
  sqlite3_snprintf(200+nTable,zInsert,
                   "INSERT OR IGNORE INTO \"%s\" VALUES(?", zTable);
  i = strlen30(zInsert);
  for(j=1; j<n; j++){
    memcpy(zInsert+i, ",?", 2);
    i += 2;
  }
  memcpy(zInsert+i, ");", 3);
  rc = sqlite3_prepare_v2(newDb, zInsert, -1, &pInsert, 0);
  if( rc ){
    sqlite3_fprintf(stderr,"Error %d: %s on [%s]\n",
          sqlite3_extended_errcode(newDb), sqlite3_errmsg(newDb), zInsert);
    goto end_data_xfer;
  }
  for(k=0; k<2; k++){
    while( (rc = sqlite3_step(pQuery))==SQLITE_ROW ){
      for(i=0; i<n; i++){
        switch( sqlite3_column_type(pQuery, i) ){
          case SQLITE_NULL: {
            sqlite3_bind_null(pInsert, i+1);
            break;
          }
          case SQLITE_INTEGER: {
            sqlite3_bind_int64(pInsert, i+1, sqlite3_column_int64(pQuery,i));
            break;
          }
          case SQLITE_FLOAT: {
            sqlite3_bind_double(pInsert, i+1, sqlite3_column_double(pQuery,i));
            break;
          }
          case SQLITE_TEXT: {
            sqlite3_bind_text(pInsert, i+1,
                             (const char*)sqlite3_column_text(pQuery,i),
                             -1, SQLITE_STATIC);
            break;
          }
          case SQLITE_BLOB: {
            sqlite3_bind_blob(pInsert, i+1, sqlite3_column_blob(pQuery,i),
                                            sqlite3_column_bytes(pQuery,i),
                                            SQLITE_STATIC);
            break;
          }
        }
      } /* End for */
      rc = sqlite3_step(pInsert);
      if( rc!=SQLITE_OK && rc!=SQLITE_ROW && rc!=SQLITE_DONE ){
        sqlite3_fprintf(stderr,"Error %d: %s\n",
              sqlite3_extended_errcode(newDb), sqlite3_errmsg(newDb));
      }
      sqlite3_reset(pInsert);
      cnt++;
      if( (cnt%spinRate)==0 ){
        printf("%c\b", "|/-\\"[(cnt/spinRate)%4]);
        fflush(stdout);
      }
    } /* End while */
    if( rc==SQLITE_DONE ) break;
    sqlite3_finalize(pQuery);
    sqlite3_free(zQuery);
    zQuery = sqlite3_mprintf("SELECT * FROM \"%w\" ORDER BY rowid DESC;",
                             zTable);
    shell_check_oom(zQuery);
    rc = sqlite3_prepare_v2(p->db, zQuery, -1, &pQuery, 0);
    if( rc ){
      sqlite3_fprintf(stderr,"Warning: cannot step \"%s\" backwards", zTable);
      break;
    }
  } /* End for(k=0...) */

end_data_xfer:
  sqlite3_finalize(pQuery);
  sqlite3_finalize(pInsert);
  sqlite3_free(zQuery);
  sqlite3_free(zInsert);
}


/*
** Try to transfer all rows of the schema that match zWhere.  For
** each row, invoke xForEach() on the object defined by that row.
** If an error is encountered while moving forward through the
** sqlite_schema table, try again moving backwards.
*/
static void tryToCloneSchema(
  ShellState *p,
  sqlite3 *newDb,
  const char *zWhere,
  void (*xForEach)(ShellState*,sqlite3*,const char*)
){
  sqlite3_stmt *pQuery = 0;
  char *zQuery = 0;
  int rc;
  const unsigned char *zName;
  const unsigned char *zSql;
  char *zErrMsg = 0;

  zQuery = sqlite3_mprintf("SELECT name, sql FROM sqlite_schema"
                           " WHERE %s ORDER BY rowid ASC", zWhere);
  shell_check_oom(zQuery);
  rc = sqlite3_prepare_v2(p->db, zQuery, -1, &pQuery, 0);
  if( rc ){
    sqlite3_fprintf(stderr,
          "Error: (%d) %s on [%s]\n", sqlite3_extended_errcode(p->db),
          sqlite3_errmsg(p->db), zQuery);
    goto end_schema_xfer;
  }
  while( (rc = sqlite3_step(pQuery))==SQLITE_ROW ){
    zName = sqlite3_column_text(pQuery, 0);
    zSql = sqlite3_column_text(pQuery, 1);
    if( zName==0 || zSql==0 ) continue;
    if( sqlite3_stricmp((char*)zName, "sqlite_sequence")!=0 ){
      sqlite3_fprintf(stdout, "%s... ", zName); fflush(stdout);
      sqlite3_exec(newDb, (const char*)zSql, 0, 0, &zErrMsg);
      if( zErrMsg ){
        sqlite3_fprintf(stderr,"Error: %s\nSQL: [%s]\n", zErrMsg, zSql);
        sqlite3_free(zErrMsg);
        zErrMsg = 0;
      }
    }
    if( xForEach ){
      xForEach(p, newDb, (const char*)zName);
    }
    sputz(stdout, "done\n");
  }
  if( rc!=SQLITE_DONE ){
    sqlite3_finalize(pQuery);
    sqlite3_free(zQuery);
    zQuery = sqlite3_mprintf("SELECT name, sql FROM sqlite_schema"
                             " WHERE %s ORDER BY rowid DESC", zWhere);
    shell_check_oom(zQuery);
    rc = sqlite3_prepare_v2(p->db, zQuery, -1, &pQuery, 0);
    if( rc ){
      sqlite3_fprintf(stderr,"Error: (%d) %s on [%s]\n",
            sqlite3_extended_errcode(p->db), sqlite3_errmsg(p->db), zQuery);
      goto end_schema_xfer;
    }
    while( sqlite3_step(pQuery)==SQLITE_ROW ){
      zName = sqlite3_column_text(pQuery, 0);
      zSql = sqlite3_column_text(pQuery, 1);
      if( zName==0 || zSql==0 ) continue;
      if( sqlite3_stricmp((char*)zName, "sqlite_sequence")==0 ) continue;
      sqlite3_fprintf(stdout, "%s... ", zName); fflush(stdout);
      sqlite3_exec(newDb, (const char*)zSql, 0, 0, &zErrMsg);
      if( zErrMsg ){
        sqlite3_fprintf(stderr,"Error: %s\nSQL: [%s]\n", zErrMsg, zSql);
        sqlite3_free(zErrMsg);
        zErrMsg = 0;
      }
      if( xForEach ){
        xForEach(p, newDb, (const char*)zName);
      }
      sputz(stdout, "done\n");
    }
  }
end_schema_xfer:
  sqlite3_finalize(pQuery);
  sqlite3_free(zQuery);
}

/*
** Open a new database file named "zNewDb".  Try to recover as much information
** as possible out of the main database (which might be corrupt) and write it
** into zNewDb.
*/
static void tryToClone(ShellState *p, const char *zNewDb){
  int rc;
  sqlite3 *newDb = 0;
  if( access(zNewDb,0)==0 ){
    sqlite3_fprintf(stderr,"File \"%s\" already exists.\n", zNewDb);
    return;
  }
  rc = sqlite3_open(zNewDb, &newDb);
  if( rc ){
    sqlite3_fprintf(stderr,
        "Cannot create output database: %s\n", sqlite3_errmsg(newDb));
  }else{
    sqlite3_exec(p->db, "PRAGMA writable_schema=ON;", 0, 0, 0);
    sqlite3_exec(newDb, "BEGIN EXCLUSIVE;", 0, 0, 0);
    tryToCloneSchema(p, newDb, "type='table'", tryToCloneData);
    tryToCloneSchema(p, newDb, "type!='table'", 0);
    sqlite3_exec(newDb, "COMMIT;", 0, 0, 0);
    sqlite3_exec(p->db, "PRAGMA writable_schema=OFF;", 0, 0, 0);
  }
  close_db(newDb);
}

#ifndef SQLITE_SHELL_FIDDLE
/*
** Change the output stream (file or pipe or console) to something else.
*/
static void output_redir(ShellState *p, FILE *pfNew){
  if( p->out != stdout ){
    sqlite3_fputs("Output already redirected.\n", stderr);
  }else{
    p->out = pfNew;
    setCrlfMode(p);
    if( p->mode==MODE_Www ){
      sqlite3_fputs(
        "<!DOCTYPE html>\n"
        "<HTML><BODY><PRE>\n",
        p->out
      );
    }
  }
}

/*
** Change the output file back to stdout.
**
** If the p->doXdgOpen flag is set, that means the output was being
** redirected to a temporary file named by p->zTempFile.  In that case,
** launch start/open/xdg-open on that temporary file.
*/
static void output_reset(ShellState *p){
  if( p->outfile[0]=='|' ){
#ifndef SQLITE_OMIT_POPEN
    pclose(p->out);
#endif
  }else{
    if( p->mode==MODE_Www ){
      sqlite3_fputs("</PRE></BODY></HTML>\n", p->out);
    }
    output_file_close(p->out);
#ifndef SQLITE_NOHAVE_SYSTEM
    if( p->doXdgOpen ){
      const char *zXdgOpenCmd =
#if defined(_WIN32)
      "start";
#elif defined(__APPLE__)
      "open";
#else
      "xdg-open";
#endif
      char *zCmd;
      zCmd = sqlite3_mprintf("%s %s", zXdgOpenCmd, p->zTempFile);
      if( system(zCmd) ){
        sqlite3_fprintf(stderr,"Failed: [%s]\n", zCmd);
      }else{
        /* Give the start/open/xdg-open command some time to get
        ** going before we continue, and potential delete the
        ** p->zTempFile data file out from under it */
        sqlite3_sleep(2000);
      }
      sqlite3_free(zCmd);
      outputModePop(p);
      p->doXdgOpen = 0;
    }
#endif /* !defined(SQLITE_NOHAVE_SYSTEM) */
  }
  p->outfile[0] = 0;
  p->out = stdout;
  setCrlfMode(p);
}
#else
# define output_redir(SS,pfO)
# define output_reset(SS)
#endif

/*
** Run an SQL command and return the single integer result.
*/
static int db_int(sqlite3 *db, const char *zSql){
  sqlite3_stmt *pStmt;
  int res = 0;
  sqlite3_prepare_v2(db, zSql, -1, &pStmt, 0);
  if( pStmt && sqlite3_step(pStmt)==SQLITE_ROW ){
    res = sqlite3_column_int(pStmt,0);
  }
  sqlite3_finalize(pStmt);
  return res;
}

#if SQLITE_SHELL_HAVE_RECOVER
/*
** Convert a 2-byte or 4-byte big-endian integer into a native integer
*/
static unsigned int get2byteInt(unsigned char *a){
  return (a[0]<<8) + a[1];
}
static unsigned int get4byteInt(unsigned char *a){
  return (a[0]<<24) + (a[1]<<16) + (a[2]<<8) + a[3];
}

/*
** Implementation of the ".dbinfo" command.
**
** Return 1 on error, 2 to exit, and 0 otherwise.
*/
static int shell_dbinfo_command(ShellState *p, int nArg, char **azArg){
  static const struct { const char *zName; int ofst; } aField[] = {
     { "file change counter:",  24  },
     { "database page count:",  28  },
     { "freelist page count:",  36  },
     { "schema cookie:",        40  },
     { "schema format:",        44  },
     { "default cache size:",   48  },
     { "autovacuum top root:",  52  },
     { "incremental vacuum:",   64  },
     { "text encoding:",        56  },
     { "user version:",         60  },
     { "application id:",       68  },
     { "software version:",     96  },
  };
  static const struct { const char *zName; const char *zSql; } aQuery[] = {
     { "number of tables:",
       "SELECT count(*) FROM %s WHERE type='table'" },
     { "number of indexes:",
       "SELECT count(*) FROM %s WHERE type='index'" },
     { "number of triggers:",
       "SELECT count(*) FROM %s WHERE type='trigger'" },
     { "number of views:",
       "SELECT count(*) FROM %s WHERE type='view'" },
     { "schema size:",
       "SELECT total(length(sql)) FROM %s" },
  };
  int i, rc;
  unsigned iDataVersion;
  char *zSchemaTab;
  char *zDb = nArg>=2 ? azArg[1] : "main";
  sqlite3_stmt *pStmt = 0;
  unsigned char aHdr[100];
  open_db(p, 0);
  if( p->db==0 ) return 1;
  rc = sqlite3_prepare_v2(p->db,
             "SELECT data FROM sqlite_dbpage(?1) WHERE pgno=1",
             -1, &pStmt, 0);
  if( rc ){
    sqlite3_fprintf(stderr,"error: %s\n", sqlite3_errmsg(p->db));
    sqlite3_finalize(pStmt);
    return 1;
  }
  sqlite3_bind_text(pStmt, 1, zDb, -1, SQLITE_STATIC);
  if( sqlite3_step(pStmt)==SQLITE_ROW
   && sqlite3_column_bytes(pStmt,0)>100
  ){
    const u8 *pb = sqlite3_column_blob(pStmt,0);
    shell_check_oom(pb);
    memcpy(aHdr, pb, 100);
    sqlite3_finalize(pStmt);
  }else{
    sqlite3_fputs("unable to read database header\n", stderr);
    sqlite3_finalize(pStmt);
    return 1;
  }
  i = get2byteInt(aHdr+16);
  if( i==1 ) i = 65536;
  sqlite3_fprintf(p->out, "%-20s %d\n", "database page size:", i);
  sqlite3_fprintf(p->out, "%-20s %d\n", "write format:", aHdr[18]);
  sqlite3_fprintf(p->out, "%-20s %d\n", "read format:", aHdr[19]);
  sqlite3_fprintf(p->out, "%-20s %d\n", "reserved bytes:", aHdr[20]);
  for(i=0; i<ArraySize(aField); i++){
    int ofst = aField[i].ofst;
    unsigned int val = get4byteInt(aHdr + ofst);
    sqlite3_fprintf(p->out, "%-20s %u", aField[i].zName, val);
    switch( ofst ){
      case 56: {
        if( val==1 ) sqlite3_fputs(" (utf8)", p->out);
        if( val==2 ) sqlite3_fputs(" (utf16le)", p->out);
        if( val==3 ) sqlite3_fputs(" (utf16be)", p->out);
      }
    }
    sqlite3_fputs("\n", p->out);
  }
  if( zDb==0 ){
    zSchemaTab = sqlite3_mprintf("main.sqlite_schema");
  }else if( cli_strcmp(zDb,"temp")==0 ){
    zSchemaTab = sqlite3_mprintf("%s", "sqlite_temp_schema");
  }else{
    zSchemaTab = sqlite3_mprintf("\"%w\".sqlite_schema", zDb);
  }
  for(i=0; i<ArraySize(aQuery); i++){
    char *zSql = sqlite3_mprintf(aQuery[i].zSql, zSchemaTab);
    int val = db_int(p->db, zSql);
    sqlite3_free(zSql);
    sqlite3_fprintf(p->out, "%-20s %d\n", aQuery[i].zName, val);
  }
  sqlite3_free(zSchemaTab);
  sqlite3_file_control(p->db, zDb, SQLITE_FCNTL_DATA_VERSION, &iDataVersion);
  sqlite3_fprintf(p->out, "%-20s %u\n", "data version", iDataVersion);
  return 0;
}
#endif /* SQLITE_SHELL_HAVE_RECOVER */

/*
** Print the given string as an error message.
*/
static void shellEmitError(const char *zErr){
  sqlite3_fprintf(stderr,"Error: %s\n", zErr);
}
/*
** Print the current sqlite3_errmsg() value to stderr and return 1.
*/
static int shellDatabaseError(sqlite3 *db){
  shellEmitError(sqlite3_errmsg(db));
  return 1;
}

/*
** Compare the pattern in zGlob[] against the text in z[].  Return TRUE
** if they match and FALSE (0) if they do not match.
**
** Globbing rules:
**
**      '*'       Matches any sequence of zero or more characters.
**
**      '?'       Matches exactly one character.
**
**     [...]      Matches one character from the enclosed list of
**                characters.
**
**     [^...]     Matches one character not in the enclosed list.
**
**      '#'       Matches any sequence of one or more digits with an
**                optional + or - sign in front
**
**      ' '       Any span of whitespace matches any other span of
**                whitespace.
**
** Extra whitespace at the end of z[] is ignored.
*/
static int testcase_glob(const char *zGlob, const char *z){
  int c, c2;
  int invert;
  int seen;

  while( (c = (*(zGlob++)))!=0 ){
    if( IsSpace(c) ){
      if( !IsSpace(*z) ) return 0;
      while( IsSpace(*zGlob) ) zGlob++;
      while( IsSpace(*z) ) z++;
    }else if( c=='*' ){
      while( (c=(*(zGlob++))) == '*' || c=='?' ){
        if( c=='?' && (*(z++))==0 ) return 0;
      }
      if( c==0 ){
        return 1;
      }else if( c=='[' ){
        while( *z && testcase_glob(zGlob-1,z)==0 ){
          z++;
        }
        return (*z)!=0;
      }
      while( (c2 = (*(z++)))!=0 ){
        while( c2!=c ){
          c2 = *(z++);
          if( c2==0 ) return 0;
        }
        if( testcase_glob(zGlob,z) ) return 1;
      }
      return 0;
    }else if( c=='?' ){
      if( (*(z++))==0 ) return 0;
    }else if( c=='[' ){
      int prior_c = 0;
      seen = 0;
      invert = 0;
      c = *(z++);
      if( c==0 ) return 0;
      c2 = *(zGlob++);
      if( c2=='^' ){
        invert = 1;
        c2 = *(zGlob++);
      }
      if( c2==']' ){
        if( c==']' ) seen = 1;
        c2 = *(zGlob++);
      }
      while( c2 && c2!=']' ){
        if( c2=='-' && zGlob[0]!=']' && zGlob[0]!=0 && prior_c>0 ){
          c2 = *(zGlob++);
          if( c>=prior_c && c<=c2 ) seen = 1;
          prior_c = 0;
        }else{
          if( c==c2 ){
            seen = 1;
          }
          prior_c = c2;
        }
        c2 = *(zGlob++);
      }
      if( c2==0 || (seen ^ invert)==0 ) return 0;
    }else if( c=='#' ){
      if( (z[0]=='-' || z[0]=='+') && IsDigit(z[1]) ) z++;
      if( !IsDigit(z[0]) ) return 0;
      z++;
      while( IsDigit(z[0]) ){ z++; }
    }else{
      if( c!=(*(z++)) ) return 0;
    }
  }
  while( IsSpace(*z) ){ z++; }
  return *z==0;
}


/*
** Compare the string as a command-line option with either one or two
** initial "-" characters.
*/
static int optionMatch(const char *zStr, const char *zOpt){
  if( zStr[0]!='-' ) return 0;
  zStr++;
  if( zStr[0]=='-' ) zStr++;
  return cli_strcmp(zStr, zOpt)==0;
}

/*
** Delete a file.
*/
int shellDeleteFile(const char *zFilename){
  int rc;
#ifdef _WIN32
  wchar_t *z = sqlite3_win32_utf8_to_unicode(zFilename);
  rc = _wunlink(z);
  sqlite3_free(z);
#else
  rc = unlink(zFilename);
#endif
  return rc;
}

/*
** Try to delete the temporary file (if there is one) and free the
** memory used to hold the name of the temp file.
*/
static void clearTempFile(ShellState *p){
  if( p->zTempFile==0 ) return;
  if( p->doXdgOpen ) return;
  if( shellDeleteFile(p->zTempFile) ) return;
  sqlite3_free(p->zTempFile);
  p->zTempFile = 0;
}

/*
** Create a new temp file name with the given suffix.
*/
static void newTempFile(ShellState *p, const char *zSuffix){
  clearTempFile(p);
  sqlite3_free(p->zTempFile);
  p->zTempFile = 0;
  if( p->db ){
    sqlite3_file_control(p->db, 0, SQLITE_FCNTL_TEMPFILENAME, &p->zTempFile);
  }
  if( p->zTempFile==0 ){
    /* If p->db is an in-memory database then the TEMPFILENAME file-control
    ** will not work and we will need to fallback to guessing */
    char *zTemp;
    sqlite3_uint64 r;
    sqlite3_randomness(sizeof(r), &r);
    zTemp = getenv("TEMP");
    if( zTemp==0 ) zTemp = getenv("TMP");
    if( zTemp==0 ){
#ifdef _WIN32
      zTemp = "\\tmp";
#else
      zTemp = "/tmp";
#endif
    }
    p->zTempFile = sqlite3_mprintf("%s/temp%llx.%s", zTemp, r, zSuffix);
  }else{
    p->zTempFile = sqlite3_mprintf("%z.%s", p->zTempFile, zSuffix);
  }
  shell_check_oom(p->zTempFile);
}


/*
** The implementation of SQL scalar function fkey_collate_clause(), used
** by the ".lint fkey-indexes" command. This scalar function is always
** called with four arguments - the parent table name, the parent column name,
** the child table name and the child column name.
**
**   fkey_collate_clause('parent-tab', 'parent-col', 'child-tab', 'child-col')
**
** If either of the named tables or columns do not exist, this function
** returns an empty string. An empty string is also returned if both tables
** and columns exist but have the same default collation sequence. Or,
** if both exist but the default collation sequences are different, this
** function returns the string " COLLATE <parent-collation>", where
** <parent-collation> is the default collation sequence of the parent column.
*/
static void shellFkeyCollateClause(
  sqlite3_context *pCtx,
  int nVal,
  sqlite3_value **apVal
){
  sqlite3 *db = sqlite3_context_db_handle(pCtx);
  const char *zParent;
  const char *zParentCol;
  const char *zParentSeq;
  const char *zChild;
  const char *zChildCol;
  const char *zChildSeq = 0;  /* Initialize to avoid false-positive warning */
  int rc;

  assert( nVal==4 );
  zParent = (const char*)sqlite3_value_text(apVal[0]);
  zParentCol = (const char*)sqlite3_value_text(apVal[1]);
  zChild = (const char*)sqlite3_value_text(apVal[2]);
  zChildCol = (const char*)sqlite3_value_text(apVal[3]);

  sqlite3_result_text(pCtx, "", -1, SQLITE_STATIC);
  rc = sqlite3_table_column_metadata(
      db, "main", zParent, zParentCol, 0, &zParentSeq, 0, 0, 0
  );
  if( rc==SQLITE_OK ){
    rc = sqlite3_table_column_metadata(
        db, "main", zChild, zChildCol, 0, &zChildSeq, 0, 0, 0
    );
  }

  if( rc==SQLITE_OK && sqlite3_stricmp(zParentSeq, zChildSeq) ){
    char *z = sqlite3_mprintf(" COLLATE %s", zParentSeq);
    sqlite3_result_text(pCtx, z, -1, SQLITE_TRANSIENT);
    sqlite3_free(z);
  }
}


/*
** The implementation of dot-command ".lint fkey-indexes".
*/
static int lintFkeyIndexes(
  ShellState *pState,             /* Current shell tool state */
  char **azArg,                   /* Array of arguments passed to dot command */
  int nArg                        /* Number of entries in azArg[] */
){
  sqlite3 *db = pState->db;       /* Database handle to query "main" db of */
  int bVerbose = 0;               /* If -verbose is present */
  int bGroupByParent = 0;         /* If -groupbyparent is present */
  int i;                          /* To iterate through azArg[] */
  const char *zIndent = "";       /* How much to indent CREATE INDEX by */
  int rc;                         /* Return code */
  sqlite3_stmt *pSql = 0;         /* Compiled version of SQL statement below */
  FILE *out = pState->out;        /* Send output here */

  /*
  ** This SELECT statement returns one row for each foreign key constraint
  ** in the schema of the main database. The column values are:
  **
  ** 0. The text of an SQL statement similar to:
  **
  **      "EXPLAIN QUERY PLAN SELECT 1 FROM child_table WHERE child_key=?"
  **
  **    This SELECT is similar to the one that the foreign keys implementation
  **    needs to run internally on child tables. If there is an index that can
  **    be used to optimize this query, then it can also be used by the FK
  **    implementation to optimize DELETE or UPDATE statements on the parent
  **    table.
  **
  ** 1. A GLOB pattern suitable for sqlite3_strglob(). If the plan output by
  **    the EXPLAIN QUERY PLAN command matches this pattern, then the schema
  **    contains an index that can be used to optimize the query.
  **
  ** 2. Human readable text that describes the child table and columns. e.g.
  **
  **       "child_table(child_key1, child_key2)"
  **
  ** 3. Human readable text that describes the parent table and columns. e.g.
  **
  **       "parent_table(parent_key1, parent_key2)"
  **
  ** 4. A full CREATE INDEX statement for an index that could be used to
  **    optimize DELETE or UPDATE statements on the parent table. e.g.
  **
  **       "CREATE INDEX child_table_child_key ON child_table(child_key)"
  **
  ** 5. The name of the parent table.
  **
  ** These six values are used by the C logic below to generate the report.
  */
  const char *zSql =
  "SELECT "
    "     'EXPLAIN QUERY PLAN SELECT 1 FROM ' || quote(s.name) || ' WHERE '"
    "  || group_concat(quote(s.name) || '.' || quote(f.[from]) || '=?' "
    "  || fkey_collate_clause("
    "       f.[table], COALESCE(f.[to], p.[name]), s.name, f.[from]),' AND ')"
    ", "
    "     'SEARCH ' || s.name || ' USING COVERING INDEX*('"
    "  || group_concat('*=?', ' AND ') || ')'"
    ", "
    "     s.name  || '(' || group_concat(f.[from],  ', ') || ')'"
    ", "
    "     f.[table] || '(' || group_concat(COALESCE(f.[to], p.[name])) || ')'"
    ", "
    "     'CREATE INDEX ' || quote(s.name ||'_'|| group_concat(f.[from], '_'))"
    "  || ' ON ' || quote(s.name) || '('"
    "  || group_concat(quote(f.[from]) ||"
    "        fkey_collate_clause("
    "          f.[table], COALESCE(f.[to], p.[name]), s.name, f.[from]), ', ')"
    "  || ');'"
    ", "
    "     f.[table] "
    "FROM sqlite_schema AS s, pragma_foreign_key_list(s.name) AS f "
    "LEFT JOIN pragma_table_info AS p ON (pk-1=seq AND p.arg=f.[table]) "
    "GROUP BY s.name, f.id "
    "ORDER BY (CASE WHEN ? THEN f.[table] ELSE s.name END)"
  ;
  const char *zGlobIPK = "SEARCH * USING INTEGER PRIMARY KEY (rowid=?)";

  for(i=2; i<nArg; i++){
    int n = strlen30(azArg[i]);
    if( n>1 && sqlite3_strnicmp("-verbose", azArg[i], n)==0 ){
      bVerbose = 1;
    }
    else if( n>1 && sqlite3_strnicmp("-groupbyparent", azArg[i], n)==0 ){
      bGroupByParent = 1;
      zIndent = "    ";
    }
    else{
      sqlite3_fprintf(stderr,
           "Usage: %s %s ?-verbose? ?-groupbyparent?\n", azArg[0], azArg[1]);
      return SQLITE_ERROR;
    }
  }

  /* Register the fkey_collate_clause() SQL function */
  rc = sqlite3_create_function(db, "fkey_collate_clause", 4, SQLITE_UTF8,
      0, shellFkeyCollateClause, 0, 0
  );


  if( rc==SQLITE_OK ){
    rc = sqlite3_prepare_v2(db, zSql, -1, &pSql, 0);
  }
  if( rc==SQLITE_OK ){
    sqlite3_bind_int(pSql, 1, bGroupByParent);
  }

  if( rc==SQLITE_OK ){
    int rc2;
    char *zPrev = 0;
    while( SQLITE_ROW==sqlite3_step(pSql) ){
      int res = -1;
      sqlite3_stmt *pExplain = 0;
      const char *zEQP = (const char*)sqlite3_column_text(pSql, 0);
      const char *zGlob = (const char*)sqlite3_column_text(pSql, 1);
      const char *zFrom = (const char*)sqlite3_column_text(pSql, 2);
      const char *zTarget = (const char*)sqlite3_column_text(pSql, 3);
      const char *zCI = (const char*)sqlite3_column_text(pSql, 4);
      const char *zParent = (const char*)sqlite3_column_text(pSql, 5);

      if( zEQP==0 ) continue;
      if( zGlob==0 ) continue;
      rc = sqlite3_prepare_v2(db, zEQP, -1, &pExplain, 0);
      if( rc!=SQLITE_OK ) break;
      if( SQLITE_ROW==sqlite3_step(pExplain) ){
        const char *zPlan = (const char*)sqlite3_column_text(pExplain, 3);
        res = zPlan!=0 && (  0==sqlite3_strglob(zGlob, zPlan)
                          || 0==sqlite3_strglob(zGlobIPK, zPlan));
      }
      rc = sqlite3_finalize(pExplain);
      if( rc!=SQLITE_OK ) break;

      if( res<0 ){
        sqlite3_fputs("Error: internal error", stderr);
        break;
      }else{
        if( bGroupByParent
        && (bVerbose || res==0)
        && (zPrev==0 || sqlite3_stricmp(zParent, zPrev))
        ){
          sqlite3_fprintf(out, "-- Parent table %s\n", zParent);
          sqlite3_free(zPrev);
          zPrev = sqlite3_mprintf("%s", zParent);
        }

        if( res==0 ){
          sqlite3_fprintf(out, "%s%s --> %s\n", zIndent, zCI, zTarget);
        }else if( bVerbose ){
          sqlite3_fprintf(out,
                "%s/* no extra indexes required for %s -> %s */\n",
                zIndent, zFrom, zTarget
          );
        }
      }
    }
    sqlite3_free(zPrev);

    if( rc!=SQLITE_OK ){
      sqlite3_fprintf(stderr,"%s\n", sqlite3_errmsg(db));
    }

    rc2 = sqlite3_finalize(pSql);
    if( rc==SQLITE_OK && rc2!=SQLITE_OK ){
      rc = rc2;
      sqlite3_fprintf(stderr,"%s\n", sqlite3_errmsg(db));
    }
  }else{
    sqlite3_fprintf(stderr,"%s\n", sqlite3_errmsg(db));
  }

  return rc;
}

/*
** Implementation of ".lint" dot command.
*/
static int lintDotCommand(
  ShellState *pState,             /* Current shell tool state */
  char **azArg,                   /* Array of arguments passed to dot command */
  int nArg                        /* Number of entries in azArg[] */
){
  int n;
  n = (nArg>=2 ? strlen30(azArg[1]) : 0);
  if( n<1 || sqlite3_strnicmp(azArg[1], "fkey-indexes", n) ) goto usage;
  return lintFkeyIndexes(pState, azArg, nArg);

 usage:
  sqlite3_fprintf(stderr,"Usage %s sub-command ?switches...?\n", azArg[0]);
  sqlite3_fprintf(stderr, "Where sub-commands are:\n");
  sqlite3_fprintf(stderr, "    fkey-indexes\n");
  return SQLITE_ERROR;
}

static void shellPrepare(
  sqlite3 *db,
  int *pRc,
  const char *zSql,
  sqlite3_stmt **ppStmt
){
  *ppStmt = 0;
  if( *pRc==SQLITE_OK ){
    int rc = sqlite3_prepare_v2(db, zSql, -1, ppStmt, 0);
    if( rc!=SQLITE_OK ){
      sqlite3_fprintf(stderr,
         "sql error: %s (%d)\n", sqlite3_errmsg(db), sqlite3_errcode(db));
      *pRc = rc;
    }
  }
}

/*
** Create a prepared statement using printf-style arguments for the SQL.
*/
static void shellPreparePrintf(
  sqlite3 *db,
  int *pRc,
  sqlite3_stmt **ppStmt,
  const char *zFmt,
  ...
){
  *ppStmt = 0;
  if( *pRc==SQLITE_OK ){
    va_list ap;
    char *z;
    va_start(ap, zFmt);
    z = sqlite3_vmprintf(zFmt, ap);
    va_end(ap);
    if( z==0 ){
      *pRc = SQLITE_NOMEM;
    }else{
      shellPrepare(db, pRc, z, ppStmt);
      sqlite3_free(z);
    }
  }
}

/* 
** Finalize the prepared statement created using shellPreparePrintf().
*/
static void shellFinalize(
  int *pRc,
  sqlite3_stmt *pStmt
){
  if( pStmt ){
    sqlite3 *db = sqlite3_db_handle(pStmt);
    int rc = sqlite3_finalize(pStmt);
    if( *pRc==SQLITE_OK ){
      if( rc!=SQLITE_OK ){
        sqlite3_fprintf(stderr,"SQL error: %s\n", sqlite3_errmsg(db));
      }
      *pRc = rc;
    }
  }
}

#if !defined SQLITE_OMIT_VIRTUALTABLE
/* Reset the prepared statement created using shellPreparePrintf().
**
** This routine is could be marked "static".  But it is not always used,
** depending on compile-time options.  By omitting the "static", we avoid
** nuisance compiler warnings about "defined but not used".
*/
void shellReset(
  int *pRc,
  sqlite3_stmt *pStmt
){
  int rc = sqlite3_reset(pStmt);
  if( *pRc==SQLITE_OK ){
    if( rc!=SQLITE_OK ){
      sqlite3 *db = sqlite3_db_handle(pStmt);
      sqlite3_fprintf(stderr,"SQL error: %s\n", sqlite3_errmsg(db));
    }
    *pRc = rc;
  }
}
#endif /* !defined SQLITE_OMIT_VIRTUALTABLE */

#if !defined(SQLITE_OMIT_VIRTUALTABLE) && defined(SQLITE_HAVE_ZLIB)
/******************************************************************************
** The ".archive" or ".ar" command.
*/
/*
** Structure representing a single ".ar" command.
*/
typedef struct ArCommand ArCommand;
struct ArCommand {
  u8 eCmd;                        /* An AR_CMD_* value */
  u8 bVerbose;                    /* True if --verbose */
  u8 bZip;                        /* True if the archive is a ZIP */
  u8 bDryRun;                     /* True if --dry-run */
  u8 bAppend;                     /* True if --append */
  u8 bGlob;                       /* True if --glob */
  u8 fromCmdLine;                 /* Run from -A instead of .archive */
  int nArg;                       /* Number of command arguments */
  char *zSrcTable;                /* "sqlar", "zipfile($file)" or "zip" */
  const char *zFile;              /* --file argument, or NULL */
  const char *zDir;               /* --directory argument, or NULL */
  char **azArg;                   /* Array of command arguments */
  ShellState *p;                  /* Shell state */
  FILE *out;                      /* Output to this stream */
  sqlite3 *db;                    /* Database containing the archive */
};

/*
** Print a usage message for the .ar command to stderr and return SQLITE_ERROR.
*/
static int arUsage(FILE *f){
  showHelp(f,"archive");
  return SQLITE_ERROR;
}

/*
** Print an error message for the .ar command to stderr and return
** SQLITE_ERROR.
*/
static int arErrorMsg(ArCommand *pAr, const char *zFmt, ...){
  va_list ap;
  char *z;
  va_start(ap, zFmt);
  z = sqlite3_vmprintf(zFmt, ap);
  va_end(ap);
  shellEmitError(z);
  if( pAr->fromCmdLine ){
    sqlite3_fputs("Use \"-A\" for more help\n", stderr);
  }else{
    sqlite3_fputs("Use \".archive --help\" for more help\n", stderr);
  }
  sqlite3_free(z);
  return SQLITE_ERROR;
}

/*
** Values for ArCommand.eCmd.
*/
#define AR_CMD_CREATE       1
#define AR_CMD_UPDATE       2
#define AR_CMD_INSERT       3
#define AR_CMD_EXTRACT      4
#define AR_CMD_LIST         5
#define AR_CMD_HELP         6
#define AR_CMD_REMOVE       7

/*
** Other (non-command) switches.
*/
#define AR_SWITCH_VERBOSE     8
#define AR_SWITCH_FILE        9
#define AR_SWITCH_DIRECTORY  10
#define AR_SWITCH_APPEND     11
#define AR_SWITCH_DRYRUN     12
#define AR_SWITCH_GLOB       13

static int arProcessSwitch(ArCommand *pAr, int eSwitch, const char *zArg){
  switch( eSwitch ){
    case AR_CMD_CREATE:
    case AR_CMD_EXTRACT:
    case AR_CMD_LIST:
    case AR_CMD_REMOVE:
    case AR_CMD_UPDATE:
    case AR_CMD_INSERT:
    case AR_CMD_HELP:
      if( pAr->eCmd ){
        return arErrorMsg(pAr, "multiple command options");
      }
      pAr->eCmd = eSwitch;
      break;

    case AR_SWITCH_DRYRUN:
      pAr->bDryRun = 1;
      break;
    case AR_SWITCH_GLOB:
      pAr->bGlob = 1;
      break;
    case AR_SWITCH_VERBOSE:
      pAr->bVerbose = 1;
      break;
    case AR_SWITCH_APPEND:
      pAr->bAppend = 1;
      deliberate_fall_through;
    case AR_SWITCH_FILE:
      pAr->zFile = zArg;
      break;
    case AR_SWITCH_DIRECTORY:
      pAr->zDir = zArg;
      break;
  }

  return SQLITE_OK;
}

/*
** Parse the command line for an ".ar" command. The results are written into
** structure (*pAr). SQLITE_OK is returned if the command line is parsed
** successfully, otherwise an error message is written to stderr and
** SQLITE_ERROR returned.
*/
static int arParseCommand(
  char **azArg,                   /* Array of arguments passed to dot command */
  int nArg,                       /* Number of entries in azArg[] */
  ArCommand *pAr                  /* Populate this object */
){
  struct ArSwitch {
    const char *zLong;
    char cShort;
    u8 eSwitch;
    u8 bArg;
  } aSwitch[] = {
    { "create",    'c', AR_CMD_CREATE,       0 },
    { "extract",   'x', AR_CMD_EXTRACT,      0 },
    { "insert",    'i', AR_CMD_INSERT,       0 },
    { "list",      't', AR_CMD_LIST,         0 },
    { "remove",    'r', AR_CMD_REMOVE,       0 },
    { "update",    'u', AR_CMD_UPDATE,       0 },
    { "help",      'h', AR_CMD_HELP,         0 },
    { "verbose",   'v', AR_SWITCH_VERBOSE,   0 },
    { "file",      'f', AR_SWITCH_FILE,      1 },
    { "append",    'a', AR_SWITCH_APPEND,    1 },
    { "directory", 'C', AR_SWITCH_DIRECTORY, 1 },
    { "dryrun",    'n', AR_SWITCH_DRYRUN,    0 },
    { "glob",      'g', AR_SWITCH_GLOB,      0 },
  };
  int nSwitch = sizeof(aSwitch) / sizeof(struct ArSwitch);
  struct ArSwitch *pEnd = &aSwitch[nSwitch];

  if( nArg<=1 ){
    sqlite3_fprintf(stderr, "Wrong number of arguments.  Usage:\n");
    return arUsage(stderr);
  }else{
    char *z = azArg[1];
    if( z[0]!='-' ){
      /* Traditional style [tar] invocation */
      int i;
      int iArg = 2;
      for(i=0; z[i]; i++){
        const char *zArg = 0;
        struct ArSwitch *pOpt;
        for(pOpt=&aSwitch[0]; pOpt<pEnd; pOpt++){
          if( z[i]==pOpt->cShort ) break;
        }
        if( pOpt==pEnd ){
          return arErrorMsg(pAr, "unrecognized option: %c", z[i]);
        }
        if( pOpt->bArg ){
          if( iArg>=nArg ){
            return arErrorMsg(pAr, "option requires an argument: %c",z[i]);
          }
          zArg = azArg[iArg++];
        }
        if( arProcessSwitch(pAr, pOpt->eSwitch, zArg) ) return SQLITE_ERROR;
      }
      pAr->nArg = nArg-iArg;
      if( pAr->nArg>0 ){
        pAr->azArg = &azArg[iArg];
      }
    }else{
      /* Non-traditional invocation */
      int iArg;
      for(iArg=1; iArg<nArg; iArg++){
        int n;
        z = azArg[iArg];
        if( z[0]!='-' ){
          /* All remaining command line words are command arguments. */
          pAr->azArg = &azArg[iArg];
          pAr->nArg = nArg-iArg;
          break;
        }
        n = strlen30(z);

        if( z[1]!='-' ){
          int i;
          /* One or more short options */
          for(i=1; i<n; i++){
            const char *zArg = 0;
            struct ArSwitch *pOpt;
            for(pOpt=&aSwitch[0]; pOpt<pEnd; pOpt++){
              if( z[i]==pOpt->cShort ) break;
            }
            if( pOpt==pEnd ){
              return arErrorMsg(pAr, "unrecognized option: %c", z[i]);
            }
            if( pOpt->bArg ){
              if( i<(n-1) ){
                zArg = &z[i+1];
                i = n;
              }else{
                if( iArg>=(nArg-1) ){
                  return arErrorMsg(pAr, "option requires an argument: %c",
                                    z[i]);
                }
                zArg = azArg[++iArg];
              }
            }
            if( arProcessSwitch(pAr, pOpt->eSwitch, zArg) ) return SQLITE_ERROR;
          }
        }else if( z[2]=='\0' ){
          /* A -- option, indicating that all remaining command line words
          ** are command arguments.  */
          pAr->azArg = &azArg[iArg+1];
          pAr->nArg = nArg-iArg-1;
          break;
        }else{
          /* A long option */
          const char *zArg = 0;             /* Argument for option, if any */
          struct ArSwitch *pMatch = 0;      /* Matching option */
          struct ArSwitch *pOpt;            /* Iterator */
          for(pOpt=&aSwitch[0]; pOpt<pEnd; pOpt++){
            const char *zLong = pOpt->zLong;
            if( (n-2)<=strlen30(zLong) && 0==memcmp(&z[2], zLong, n-2) ){
              if( pMatch ){
                return arErrorMsg(pAr, "ambiguous option: %s",z);
              }else{
                pMatch = pOpt;
              }
            }
          }

          if( pMatch==0 ){
            return arErrorMsg(pAr, "unrecognized option: %s", z);
          }
          if( pMatch->bArg ){
            if( iArg>=(nArg-1) ){
              return arErrorMsg(pAr, "option requires an argument: %s", z);
            }
            zArg = azArg[++iArg];
          }
          if( arProcessSwitch(pAr, pMatch->eSwitch, zArg) ) return SQLITE_ERROR;
        }
      }
    }
  }
  if( pAr->eCmd==0 ){
    sqlite3_fprintf(stderr, "Required argument missing.  Usage:\n");
    return arUsage(stderr);
  }
  return SQLITE_OK;
}

/*
** This function assumes that all arguments within the ArCommand.azArg[]
** array refer to archive members, as for the --extract, --list or --remove
** commands. It checks that each of them are "present". If any specified
** file is not present in the archive, an error is printed to stderr and an
** error code returned. Otherwise, if all specified arguments are present
** in the archive, SQLITE_OK is returned. Here, "present" means either an
** exact equality when pAr->bGlob is false or a "name GLOB pattern" match
** when pAr->bGlob is true.
**
** This function strips any trailing '/' characters from each argument.
** This is consistent with the way the [tar] command seems to work on
** Linux.
*/
static int arCheckEntries(ArCommand *pAr){
  int rc = SQLITE_OK;
  if( pAr->nArg ){
    int i, j;
    sqlite3_stmt *pTest = 0;
    const char *zSel = (pAr->bGlob)
      ? "SELECT name FROM %s WHERE glob($name,name)"
      : "SELECT name FROM %s WHERE name=$name";

    shellPreparePrintf(pAr->db, &rc, &pTest, zSel, pAr->zSrcTable);
    j = sqlite3_bind_parameter_index(pTest, "$name");
    for(i=0; i<pAr->nArg && rc==SQLITE_OK; i++){
      char *z = pAr->azArg[i];
      int n = strlen30(z);
      int bOk = 0;
      while( n>0 && z[n-1]=='/' ) n--;
      z[n] = '\0';
      sqlite3_bind_text(pTest, j, z, -1, SQLITE_STATIC);
      if( SQLITE_ROW==sqlite3_step(pTest) ){
        bOk = 1;
      }
      shellReset(&rc, pTest);
      if( rc==SQLITE_OK && bOk==0 ){
        sqlite3_fprintf(stderr,"not found in archive: %s\n", z);
        rc = SQLITE_ERROR;
      }
    }
    shellFinalize(&rc, pTest);
  }
  return rc;
}

/*
** Format a WHERE clause that can be used against the "sqlar" table to
** identify all archive members that match the command arguments held
** in (*pAr). Leave this WHERE clause in (*pzWhere) before returning.
** The caller is responsible for eventually calling sqlite3_free() on
** any non-NULL (*pzWhere) value. Here, "match" means strict equality
** when pAr->bGlob is false and GLOB match when pAr->bGlob is true.
*/
static void arWhereClause(
  int *pRc,
  ArCommand *pAr,
  char **pzWhere                  /* OUT: New WHERE clause */
){
  char *zWhere = 0;
  const char *zSameOp = (pAr->bGlob)? "GLOB" : "=";
  if( *pRc==SQLITE_OK ){
    if( pAr->nArg==0 ){
      zWhere = sqlite3_mprintf("1");
    }else{
      int i;
      const char *zSep = "";
      for(i=0; i<pAr->nArg; i++){
        const char *z = pAr->azArg[i];
        zWhere = sqlite3_mprintf(
          "%z%s name %s '%q' OR substr(name,1,%d) %s '%q/'",
          zWhere, zSep, zSameOp, z, strlen30(z)+1, zSameOp, z
        );
        if( zWhere==0 ){
          *pRc = SQLITE_NOMEM;
          break;
        }
        zSep = " OR ";
      }
    }
  }
  *pzWhere = zWhere;
}

/*
** Implementation of .ar "lisT" command.
*/
static int arListCommand(ArCommand *pAr){
  const char *zSql = "SELECT %s FROM %s WHERE %s";
  const char *azCols[] = {
    "name",
    "lsmode(mode), sz, datetime(mtime, 'unixepoch'), name"
  };

  char *zWhere = 0;
  sqlite3_stmt *pSql = 0;
  int rc;

  rc = arCheckEntries(pAr);
  arWhereClause(&rc, pAr, &zWhere);

  shellPreparePrintf(pAr->db, &rc, &pSql, zSql, azCols[pAr->bVerbose],
                     pAr->zSrcTable, zWhere);
  if( pAr->bDryRun ){
    sqlite3_fprintf(pAr->out, "%s\n", sqlite3_sql(pSql));
  }else{
    while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pSql) ){
      if( pAr->bVerbose ){
        sqlite3_fprintf(pAr->out, "%s % 10d  %s  %s\n",
              sqlite3_column_text(pSql, 0), sqlite3_column_int(pSql, 1),
              sqlite3_column_text(pSql, 2),sqlite3_column_text(pSql, 3));
      }else{
        sqlite3_fprintf(pAr->out, "%s\n", sqlite3_column_text(pSql, 0));
      }
    }
  }
  shellFinalize(&rc, pSql);
  sqlite3_free(zWhere);
  return rc;
}

/*
** Implementation of .ar "Remove" command.
*/
static int arRemoveCommand(ArCommand *pAr){
  int rc = 0;
  char *zSql = 0;
  char *zWhere = 0;

  if( pAr->nArg ){
    /* Verify that args actually exist within the archive before proceeding.
    ** And formulate a WHERE clause to match them.  */
    rc = arCheckEntries(pAr);
    arWhereClause(&rc, pAr, &zWhere);
  }
  if( rc==SQLITE_OK ){
    zSql = sqlite3_mprintf("DELETE FROM %s WHERE %s;",
                           pAr->zSrcTable, zWhere);
    if( pAr->bDryRun ){
      sqlite3_fprintf(pAr->out, "%s\n", zSql);
    }else{
      char *zErr = 0;
      rc = sqlite3_exec(pAr->db, "SAVEPOINT ar;", 0, 0, 0);
      if( rc==SQLITE_OK ){
        rc = sqlite3_exec(pAr->db, zSql, 0, 0, &zErr);
        if( rc!=SQLITE_OK ){
          sqlite3_exec(pAr->db, "ROLLBACK TO ar; RELEASE ar;", 0, 0, 0);
        }else{
          rc = sqlite3_exec(pAr->db, "RELEASE ar;", 0, 0, 0);
        }
      }
      if( zErr ){
        sqlite3_fprintf(stdout, "ERROR: %s\n", zErr); /* stdout? */
        sqlite3_free(zErr);
      }
    }
  }
  sqlite3_free(zWhere);
  sqlite3_free(zSql);
  return rc;
}

/*
** Implementation of .ar "eXtract" command.
*/
static int arExtractCommand(ArCommand *pAr){
  const char *zSql1 =
    "SELECT "
    " ($dir || name),"
    " writefile(($dir || name), %s, mode, mtime) "
    "FROM %s WHERE (%s) AND (data IS NULL OR $dirOnly = 0)"
    " AND name NOT GLOB '*..[/\\]*'";

  const char *azExtraArg[] = {
    "sqlar_uncompress(data, sz)",
    "data"
  };

  sqlite3_stmt *pSql = 0;
  int rc = SQLITE_OK;
  char *zDir = 0;
  char *zWhere = 0;
  int i, j;

  /* If arguments are specified, check that they actually exist within
  ** the archive before proceeding. And formulate a WHERE clause to
  ** match them.  */
  rc = arCheckEntries(pAr);
  arWhereClause(&rc, pAr, &zWhere);

  if( rc==SQLITE_OK ){
    if( pAr->zDir ){
      zDir = sqlite3_mprintf("%s/", pAr->zDir);
    }else{
      zDir = sqlite3_mprintf("");
    }
    if( zDir==0 ) rc = SQLITE_NOMEM;
  }

  shellPreparePrintf(pAr->db, &rc, &pSql, zSql1,
      azExtraArg[pAr->bZip], pAr->zSrcTable, zWhere
  );

  if( rc==SQLITE_OK ){
    j = sqlite3_bind_parameter_index(pSql, "$dir");
    sqlite3_bind_text(pSql, j, zDir, -1, SQLITE_STATIC);

    /* Run the SELECT statement twice. The first time, writefile() is called
    ** for all archive members that should be extracted. The second time,
    ** only for the directories. This is because the timestamps for
    ** extracted directories must be reset after they are populated (as
    ** populating them changes the timestamp).  */
    for(i=0; i<2; i++){
      j = sqlite3_bind_parameter_index(pSql, "$dirOnly");
      sqlite3_bind_int(pSql, j, i);
      if( pAr->bDryRun ){
        sqlite3_fprintf(pAr->out, "%s\n", sqlite3_sql(pSql));
      }else{
        while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pSql) ){
          if( i==0 && pAr->bVerbose ){
            sqlite3_fprintf(pAr->out, "%s\n", sqlite3_column_text(pSql, 0));
          }
        }
      }
      shellReset(&rc, pSql);
    }
    shellFinalize(&rc, pSql);
  }

  sqlite3_free(zDir);
  sqlite3_free(zWhere);
  return rc;
}

/*
** Run the SQL statement in zSql.  Or if doing a --dryrun, merely print it out.
*/
static int arExecSql(ArCommand *pAr, const char *zSql){
  int rc;
  if( pAr->bDryRun ){
    sqlite3_fprintf(pAr->out, "%s\n", zSql);
    rc = SQLITE_OK;
  }else{
    char *zErr = 0;
    rc = sqlite3_exec(pAr->db, zSql, 0, 0, &zErr);
    if( zErr ){
      sqlite3_fprintf(stdout, "ERROR: %s\n", zErr);
      sqlite3_free(zErr);
    }
  }
  return rc;
}


/*
** Implementation of .ar "create", "insert", and "update" commands.
**
**     create    ->     Create a new SQL archive
**     insert    ->     Insert or reinsert all files listed
**     update    ->     Insert files that have changed or that were not
**                      previously in the archive
**
** Create the "sqlar" table in the database if it does not already exist.
** Then add each file in the azFile[] array to the archive. Directories
** are added recursively. If argument bVerbose is non-zero, a message is
** printed on stdout for each file archived.
**
** The create command is the same as update, except that it drops
** any existing "sqlar" table before beginning.  The "insert" command
** always overwrites every file named on the command-line, where as
** "update" only overwrites if the size or mtime or mode has changed.
*/
static int arCreateOrUpdateCommand(
  ArCommand *pAr,                 /* Command arguments and options */
  int bUpdate,                    /* true for a --create. */
  int bOnlyIfChanged              /* Only update if file has changed */
){
  const char *zCreate =
      "CREATE TABLE IF NOT EXISTS sqlar(\n"
      "  name TEXT PRIMARY KEY,  -- name of the file\n"
      "  mode INT,               -- access permissions\n"
      "  mtime INT,              -- last modification time\n"
      "  sz INT,                 -- original file size\n"
      "  data BLOB               -- compressed content\n"
      ")";
  const char *zDrop = "DROP TABLE IF EXISTS sqlar";
  const char *zInsertFmt[2] = {
     "REPLACE INTO %s(name,mode,mtime,sz,data)\n"
     "  SELECT\n"
     "    %s,\n"
     "    mode,\n"
     "    mtime,\n"
     "    CASE substr(lsmode(mode),1,1)\n"
     "      WHEN '-' THEN length(data)\n"
     "      WHEN 'd' THEN 0\n"
     "      ELSE -1 END,\n"
     "    sqlar_compress(data)\n"
     "  FROM fsdir(%Q,%Q) AS disk\n"
     "  WHERE lsmode(mode) NOT LIKE '?%%'%s;"
     ,
     "REPLACE INTO %s(name,mode,mtime,data)\n"
     "  SELECT\n"
     "    %s,\n"
     "    mode,\n"
     "    mtime,\n"
     "    data\n"
     "  FROM fsdir(%Q,%Q) AS disk\n"
     "  WHERE lsmode(mode) NOT LIKE '?%%'%s;"
  };
  int i;                          /* For iterating through azFile[] */
  int rc;                         /* Return code */
  const char *zTab = 0;           /* SQL table into which to insert */
  char *zSql;
  char zTemp[50];
  char *zExists = 0;

  arExecSql(pAr, "PRAGMA page_size=512");
  rc = arExecSql(pAr, "SAVEPOINT ar;");
  if( rc!=SQLITE_OK ) return rc;
  zTemp[0] = 0;
  if( pAr->bZip ){
    /* Initialize the zipfile virtual table, if necessary */
    if( pAr->zFile ){
      sqlite3_uint64 r;
      sqlite3_randomness(sizeof(r),&r);
      sqlite3_snprintf(sizeof(zTemp),zTemp,"zip%016llx",r);
      zTab = zTemp;
      zSql = sqlite3_mprintf(
         "CREATE VIRTUAL TABLE temp.%s USING zipfile(%Q)",
         zTab, pAr->zFile
      );
      rc = arExecSql(pAr, zSql);
      sqlite3_free(zSql);
    }else{
      zTab = "zip";
    }
  }else{
    /* Initialize the table for an SQLAR */
    zTab = "sqlar";
    if( bUpdate==0 ){
      rc = arExecSql(pAr, zDrop);
      if( rc!=SQLITE_OK ) goto end_ar_transaction;
    }
    rc = arExecSql(pAr, zCreate);
  }
  if( bOnlyIfChanged ){
    zExists = sqlite3_mprintf(
      " AND NOT EXISTS("
          "SELECT 1 FROM %s AS mem"
          " WHERE mem.name=disk.name"
          " AND mem.mtime=disk.mtime"
          " AND mem.mode=disk.mode)", zTab);
  }else{
    zExists = sqlite3_mprintf("");
  }
  if( zExists==0 ) rc = SQLITE_NOMEM;
  for(i=0; i<pAr->nArg && rc==SQLITE_OK; i++){
    char *zSql2 = sqlite3_mprintf(zInsertFmt[pAr->bZip], zTab,
        pAr->bVerbose ? "shell_putsnl(name)" : "name",
        pAr->azArg[i], pAr->zDir, zExists);
    rc = arExecSql(pAr, zSql2);
    sqlite3_free(zSql2);
  }
end_ar_transaction:
  if( rc!=SQLITE_OK ){
    sqlite3_exec(pAr->db, "ROLLBACK TO ar; RELEASE ar;", 0, 0, 0);
  }else{
    rc = arExecSql(pAr, "RELEASE ar;");
    if( pAr->bZip && pAr->zFile ){
      zSql = sqlite3_mprintf("DROP TABLE %s", zTemp);
      arExecSql(pAr, zSql);
      sqlite3_free(zSql);
    }
  }
  sqlite3_free(zExists);
  return rc;
}

/*
** Implementation of ".ar" dot command.
*/
static int arDotCommand(
  ShellState *pState,          /* Current shell tool state */
  int fromCmdLine,             /* True if -A command-line option, not .ar cmd */
  char **azArg,                /* Array of arguments passed to dot command */
  int nArg                     /* Number of entries in azArg[] */
){
  ArCommand cmd;
  int rc;
  memset(&cmd, 0, sizeof(cmd));
  cmd.fromCmdLine = fromCmdLine;
  rc = arParseCommand(azArg, nArg, &cmd);
  if( rc==SQLITE_OK ){
    int eDbType = SHELL_OPEN_UNSPEC;
    cmd.p = pState;
    cmd.out = pState->out;
    cmd.db = pState->db;
    if( cmd.zFile ){
      eDbType = deduceDatabaseType(cmd.zFile, 1);
    }else{
      eDbType = pState->openMode;
    }
    if( eDbType==SHELL_OPEN_ZIPFILE ){
      if( cmd.eCmd==AR_CMD_EXTRACT || cmd.eCmd==AR_CMD_LIST ){
        if( cmd.zFile==0 ){
          cmd.zSrcTable = sqlite3_mprintf("zip");
        }else{
          cmd.zSrcTable = sqlite3_mprintf("zipfile(%Q)", cmd.zFile);
        }
      }
      cmd.bZip = 1;
    }else if( cmd.zFile ){
      int flags;
      if( cmd.bAppend ) eDbType = SHELL_OPEN_APPENDVFS;
      if( cmd.eCmd==AR_CMD_CREATE || cmd.eCmd==AR_CMD_INSERT
           || cmd.eCmd==AR_CMD_REMOVE || cmd.eCmd==AR_CMD_UPDATE ){
        flags = SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE;
      }else{
        flags = SQLITE_OPEN_READONLY;
      }
      cmd.db = 0;
      if( cmd.bDryRun ){
        sqlite3_fprintf(cmd.out, "-- open database '%s'%s\n", cmd.zFile,
              eDbType==SHELL_OPEN_APPENDVFS ? " using 'apndvfs'" : "");
      }
      rc = sqlite3_open_v2(cmd.zFile, &cmd.db, flags,
             eDbType==SHELL_OPEN_APPENDVFS ? "apndvfs" : 0);
      if( rc!=SQLITE_OK ){
        sqlite3_fprintf(stderr, "cannot open file: %s (%s)\n",
                        cmd.zFile, sqlite3_errmsg(cmd.db));
        goto end_ar_command;
      }
      sqlite3_fileio_init(cmd.db, 0, 0);
      sqlite3_sqlar_init(cmd.db, 0, 0);
      sqlite3_create_function(cmd.db, "shell_putsnl", 1, SQLITE_UTF8, cmd.p,
                              shellPutsFunc, 0, 0);

    }
    if( cmd.zSrcTable==0 && cmd.bZip==0 && cmd.eCmd!=AR_CMD_HELP ){
      if( cmd.eCmd!=AR_CMD_CREATE
       && sqlite3_table_column_metadata(cmd.db,0,"sqlar","name",0,0,0,0,0)
      ){
        sqlite3_fprintf(stderr, "database does not contain an 'sqlar' table\n");
        rc = SQLITE_ERROR;
        goto end_ar_command;
      }
      cmd.zSrcTable = sqlite3_mprintf("sqlar");
    }

    switch( cmd.eCmd ){
      case AR_CMD_CREATE:
        rc = arCreateOrUpdateCommand(&cmd, 0, 0);
        break;

      case AR_CMD_EXTRACT:
        rc = arExtractCommand(&cmd);
        break;

      case AR_CMD_LIST:
        rc = arListCommand(&cmd);
        break;

      case AR_CMD_HELP:
        arUsage(pState->out);
        break;

      case AR_CMD_INSERT:
        rc = arCreateOrUpdateCommand(&cmd, 1, 0);
        break;

      case AR_CMD_REMOVE:
        rc = arRemoveCommand(&cmd);
        break;

      default:
        assert( cmd.eCmd==AR_CMD_UPDATE );
        rc = arCreateOrUpdateCommand(&cmd, 1, 1);
        break;
    }
  }
end_ar_command:
  if( cmd.db!=pState->db ){
    close_db(cmd.db);
  }
  sqlite3_free(cmd.zSrcTable);

  return rc;
}
/* End of the ".archive" or ".ar" command logic
*******************************************************************************/
#endif /* !defined(SQLITE_OMIT_VIRTUALTABLE) && defined(SQLITE_HAVE_ZLIB) */

#if SQLITE_SHELL_HAVE_RECOVER

/*
** This function is used as a callback by the recover extension. Simply
** print the supplied SQL statement to stdout.
*/
static int recoverSqlCb(void *pCtx, const char *zSql){
  ShellState *pState = (ShellState*)pCtx;
  sqlite3_fprintf(pState->out, "%s;\n", zSql);
  return SQLITE_OK;
}

/*
** This function is called to recover data from the database. A script
** to construct a new database containing all recovered data is output
** on stream pState->out.
*/
static int recoverDatabaseCmd(ShellState *pState, int nArg, char **azArg){
  int rc = SQLITE_OK;
  const char *zRecoveryDb = "";   /* Name of "recovery" database.  Debug only */
  const char *zLAF = "lost_and_found";
  int bFreelist = 1;              /* 0 if --ignore-freelist is specified */
  int bRowids = 1;                /* 0 if --no-rowids */
  sqlite3_recover *p = 0;
  int i = 0;

  for(i=1; i<nArg; i++){
    char *z = azArg[i];
    int n;
    if( z[0]=='-' && z[1]=='-' ) z++;
    n = strlen30(z);
    if( n<=17 && memcmp("-ignore-freelist", z, n)==0 ){
      bFreelist = 0;
    }else
    if( n<=12 && memcmp("-recovery-db", z, n)==0 && i<(nArg-1) ){
      /* This option determines the name of the ATTACH-ed database used
      ** internally by the recovery extension.  The default is "" which
      ** means to use a temporary database that is automatically deleted
      ** when closed.  This option is undocumented and might disappear at
      ** any moment. */
      i++;
      zRecoveryDb = azArg[i];
    }else
    if( n<=15 && memcmp("-lost-and-found", z, n)==0 && i<(nArg-1) ){
      i++;
      zLAF = azArg[i];
    }else
    if( n<=10 && memcmp("-no-rowids", z, n)==0 ){
      bRowids = 0;
    }
    else{
      sqlite3_fprintf(stderr,"unexpected option: %s\n", azArg[i]);
      showHelp(pState->out, azArg[0]);
      return 1;
    }
  }

  p = sqlite3_recover_init_sql(
      pState->db, "main", recoverSqlCb, (void*)pState
  );

  sqlite3_recover_config(p, 789, (void*)zRecoveryDb);  /* Debug use only */
  sqlite3_recover_config(p, SQLITE_RECOVER_LOST_AND_FOUND, (void*)zLAF);
  sqlite3_recover_config(p, SQLITE_RECOVER_ROWIDS, (void*)&bRowids);
  sqlite3_recover_config(p, SQLITE_RECOVER_FREELIST_CORRUPT,(void*)&bFreelist);

  sqlite3_recover_run(p);
  if( sqlite3_recover_errcode(p)!=SQLITE_OK ){
    const char *zErr = sqlite3_recover_errmsg(p);
    int errCode = sqlite3_recover_errcode(p);
    sqlite3_fprintf(stderr,"sql error: %s (%d)\n", zErr, errCode);
  }
  rc = sqlite3_recover_finish(p);
  return rc;
}
#endif /* SQLITE_SHELL_HAVE_RECOVER */

/*
** Implementation of ".intck STEPS_PER_UNLOCK" command.
*/
static int intckDatabaseCmd(ShellState *pState, i64 nStepPerUnlock){
  sqlite3_intck *p = 0;
  int rc = SQLITE_OK;

  rc = sqlite3_intck_open(pState->db, "main", &p);
  if( rc==SQLITE_OK ){
    i64 nStep = 0;
    i64 nError = 0;
    const char *zErr = 0;
    while( SQLITE_OK==sqlite3_intck_step(p) ){
      const char *zMsg = sqlite3_intck_message(p);
      if( zMsg ){
        sqlite3_fprintf(pState->out, "%s\n", zMsg);
        nError++;
      }
      nStep++;
      if( nStepPerUnlock && (nStep % nStepPerUnlock)==0 ){
        sqlite3_intck_unlock(p);
      }
    }
    rc = sqlite3_intck_error(p, &zErr);
    if( zErr ){
      sqlite3_fprintf(stderr,"%s\n", zErr);
    }
    sqlite3_intck_close(p);

    sqlite3_fprintf(pState->out, "%lld steps, %lld errors\n", nStep, nError);
  }

  return rc;
}

/*
 * zAutoColumn(zCol, &db, ?) => Maybe init db, add column zCol to it.
 * zAutoColumn(0, &db, ?) => (db!=0) Form columns spec for CREATE TABLE,
 *   close db and set it to 0, and return the columns spec, to later
 *   be sqlite3_free()'ed by the caller.
 * The return is 0 when either:
 *   (a) The db was not initialized and zCol==0 (There are no columns.)
 *   (b) zCol!=0  (Column was added, db initialized as needed.)
 * The 3rd argument, pRenamed, references an out parameter. If the
 * pointer is non-zero, its referent will be set to a summary of renames
 * done if renaming was necessary, or set to 0 if none was done. The out
 * string (if any) must be sqlite3_free()'ed by the caller.
 */
#ifdef SHELL_DEBUG
#define rc_err_oom_die(rc) \
  if( rc==SQLITE_NOMEM ) shell_check_oom(0); \
  else if(!(rc==SQLITE_OK||rc==SQLITE_DONE)) \
    sqlite3_fprintf(stderr,"E:%d\n",rc), assert(0)
#else
static void rc_err_oom_die(int rc){
  if( rc==SQLITE_NOMEM ) shell_check_oom(0);
  assert(rc==SQLITE_OK||rc==SQLITE_DONE);
}
#endif

#ifdef SHELL_COLFIX_DB /* If this is set, the DB can be in a file. */
static char zCOL_DB[] = SHELL_STRINGIFY(SHELL_COLFIX_DB);
#else  /* Otherwise, memory is faster/better for the transient DB. */
static const char *zCOL_DB = ":memory:";
#endif

/* Define character (as C string) to separate generated column ordinal
 * from protected part of incoming column names. This defaults to "_"
 * so that incoming column identifiers that did not need not be quoted
 * remain usable without being quoted. It must be one character.
 */
#ifndef SHELL_AUTOCOLUMN_SEP
# define AUTOCOLUMN_SEP "_"
#else
# define AUTOCOLUMN_SEP SHELL_STRINGIFY(SHELL_AUTOCOLUMN_SEP)
#endif

static char *zAutoColumn(const char *zColNew, sqlite3 **pDb, char **pzRenamed){
  /* Queries and D{D,M}L used here */
  static const char * const zTabMake = "\
CREATE TABLE ColNames(\
 cpos INTEGER PRIMARY KEY,\
 name TEXT, nlen INT, chop INT, reps INT, suff TEXT);\
CREATE VIEW RepeatedNames AS \
SELECT DISTINCT t.name FROM ColNames t \
WHERE t.name COLLATE NOCASE IN (\
 SELECT o.name FROM ColNames o WHERE o.cpos<>t.cpos\
);\
";
  static const char * const zTabFill = "\
INSERT INTO ColNames(name,nlen,chop,reps,suff)\
 VALUES(iif(length(?1)>0,?1,'?'),max(length(?1),1),0,0,'')\
";
  static const char * const zHasDupes = "\
SELECT count(DISTINCT (substring(name,1,nlen-chop)||suff) COLLATE NOCASE)\
 <count(name) FROM ColNames\
";
#ifdef SHELL_COLUMN_RENAME_CLEAN
  static const char * const zDedoctor = "\
UPDATE ColNames SET chop=iif(\
  (substring(name,nlen,1) BETWEEN '0' AND '9')\
  AND (rtrim(name,'0123456790') glob '*"AUTOCOLUMN_SEP"'),\
 nlen-length(rtrim(name, '"AUTOCOLUMN_SEP"0123456789')),\
 0\
)\
";
#endif
  static const char * const zSetReps = "\
UPDATE ColNames AS t SET reps=\
(SELECT count(*) FROM ColNames d \
 WHERE substring(t.name,1,t.nlen-t.chop)=substring(d.name,1,d.nlen-d.chop)\
 COLLATE NOCASE\
)\
";
#ifdef SQLITE_ENABLE_MATH_FUNCTIONS
  static const char * const zColDigits = "\
SELECT CAST(ceil(log(count(*)+0.5)) AS INT) FROM ColNames \
";
#else
  /* Counting on SQLITE_MAX_COLUMN < 100,000 here. (32767 is the hard limit.) */
  static const char * const zColDigits = "\
SELECT CASE WHEN (nc < 10) THEN 1 WHEN (nc < 100) THEN 2 \
 WHEN (nc < 1000) THEN 3 WHEN (nc < 10000) THEN 4 \
 ELSE 5 FROM (SELECT count(*) AS nc FROM ColNames) \
";
#endif
  static const char * const zRenameRank =
#ifdef SHELL_COLUMN_RENAME_CLEAN
    "UPDATE ColNames AS t SET suff="
    "iif(reps>1, printf('%c%0*d', '"AUTOCOLUMN_SEP"', $1, cpos), '')"
#else /* ...RENAME_MINIMAL_ONE_PASS */
"WITH Lzn(nlz) AS (" /* Find minimum extraneous leading 0's for uniqueness */
"  SELECT 0 AS nlz"
"  UNION"
"  SELECT nlz+1 AS nlz FROM Lzn"
"  WHERE EXISTS("
"   SELECT 1"
"   FROM ColNames t, ColNames o"
"   WHERE"
"    iif(t.name IN (SELECT * FROM RepeatedNames),"
"     printf('%s"AUTOCOLUMN_SEP"%s',"
"      t.name, substring(printf('%.*c%0.*d',nlz+1,'0',$1,t.cpos),2)),"
"     t.name"
"    )"
"    ="
"    iif(o.name IN (SELECT * FROM RepeatedNames),"
"     printf('%s"AUTOCOLUMN_SEP"%s',"
"      o.name, substring(printf('%.*c%0.*d',nlz+1,'0',$1,o.cpos),2)),"
"     o.name"
"    )"
"    COLLATE NOCASE"
"    AND o.cpos<>t.cpos"
"   GROUP BY t.cpos"
"  )"
") UPDATE Colnames AS t SET"
" chop = 0," /* No chopping, never touch incoming names. */
" suff = iif(name IN (SELECT * FROM RepeatedNames),"
"  printf('"AUTOCOLUMN_SEP"%s', substring("
"   printf('%.*c%0.*d',(SELECT max(nlz) FROM Lzn)+1,'0',1,t.cpos),2)),"
"  ''"
" )"
#endif
    ;
  static const char * const zCollectVar = "\
SELECT\
 '('||x'0a'\
 || group_concat(\
  cname||' TEXT',\
  ','||iif((cpos-1)%4>0, ' ', x'0a'||' '))\
 ||')' AS ColsSpec \
FROM (\
 SELECT cpos, printf('\"%w\"',printf('%!.*s%s', nlen-chop,name,suff)) AS cname \
 FROM ColNames ORDER BY cpos\
)";
  static const char * const zRenamesDone =
    "SELECT group_concat("
    " printf('\"%w\" to \"%w\"',name,printf('%!.*s%s', nlen-chop, name, suff)),"
    " ','||x'0a')"
    "FROM ColNames WHERE suff<>'' OR chop!=0"
    ;
  int rc;
  sqlite3_stmt *pStmt = 0;
  assert(pDb!=0);
  if( zColNew ){
    /* Add initial or additional column. Init db if necessary. */
    if( *pDb==0 ){
      if( SQLITE_OK!=sqlite3_open(zCOL_DB, pDb) ) return 0;
#ifdef SHELL_COLFIX_DB
      if(*zCOL_DB!=':')
        sqlite3_exec(*pDb,"drop table if exists ColNames;"
                     "drop view if exists RepeatedNames;",0,0,0);
#endif
#undef SHELL_COLFIX_DB
      rc = sqlite3_exec(*pDb, zTabMake, 0, 0, 0);
      rc_err_oom_die(rc);
    }
    assert(*pDb!=0);
    rc = sqlite3_prepare_v2(*pDb, zTabFill, -1, &pStmt, 0);
    rc_err_oom_die(rc);
    rc = sqlite3_bind_text(pStmt, 1, zColNew, -1, 0);
    rc_err_oom_die(rc);
    rc = sqlite3_step(pStmt);
    rc_err_oom_die(rc);
    sqlite3_finalize(pStmt);
    return 0;
  }else if( *pDb==0 ){
    return 0;
  }else{
    /* Formulate the columns spec, close the DB, zero *pDb. */
    char *zColsSpec = 0;
    int hasDupes = db_int(*pDb, zHasDupes);
    int nDigits = (hasDupes)? db_int(*pDb, zColDigits) : 0;
    if( hasDupes ){
#ifdef SHELL_COLUMN_RENAME_CLEAN
      rc = sqlite3_exec(*pDb, zDedoctor, 0, 0, 0);
      rc_err_oom_die(rc);
#endif
      rc = sqlite3_exec(*pDb, zSetReps, 0, 0, 0);
      rc_err_oom_die(rc);
      rc = sqlite3_prepare_v2(*pDb, zRenameRank, -1, &pStmt, 0);
      rc_err_oom_die(rc);
      sqlite3_bind_int(pStmt, 1, nDigits);
      rc = sqlite3_step(pStmt);
      sqlite3_finalize(pStmt);
      if( rc!=SQLITE_DONE ) rc_err_oom_die(SQLITE_NOMEM);
    }
    assert(db_int(*pDb, zHasDupes)==0); /* Consider: remove this */
    rc = sqlite3_prepare_v2(*pDb, zCollectVar, -1, &pStmt, 0);
    rc_err_oom_die(rc);
    rc = sqlite3_step(pStmt);
    if( rc==SQLITE_ROW ){
      zColsSpec = sqlite3_mprintf("%s", sqlite3_column_text(pStmt, 0));
    }else{
      zColsSpec = 0;
    }
    if( pzRenamed!=0 ){
      if( !hasDupes ) *pzRenamed = 0;
      else{
        sqlite3_finalize(pStmt);
        if( SQLITE_OK==sqlite3_prepare_v2(*pDb, zRenamesDone, -1, &pStmt, 0)
            && SQLITE_ROW==sqlite3_step(pStmt) ){
          *pzRenamed = sqlite3_mprintf("%s", sqlite3_column_text(pStmt, 0));
        }else
          *pzRenamed = 0;
      }
    }
    sqlite3_finalize(pStmt);
    sqlite3_close(*pDb);
    *pDb = 0;
    return zColsSpec;
  }
}

/*
** Check if the sqlite_schema table contains one or more virtual tables. If
** parameter zLike is not NULL, then it is an SQL expression that the
** sqlite_schema row must also match. If one or more such rows are found,
** print the following warning to the output:
**
** WARNING: Script requires that SQLITE_DBCONFIG_DEFENSIVE be disabled
*/
static int outputDumpWarning(ShellState *p, const char *zLike){
  int rc = SQLITE_OK;
  sqlite3_stmt *pStmt = 0;
  shellPreparePrintf(p->db, &rc, &pStmt,
    "SELECT 1 FROM sqlite_schema o WHERE "
    "sql LIKE 'CREATE VIRTUAL TABLE%%' AND %s", zLike ? zLike : "true"
  );
  if( rc==SQLITE_OK && sqlite3_step(pStmt)==SQLITE_ROW ){
    sqlite3_fputs("/* WARNING: "
          "Script requires that SQLITE_DBCONFIG_DEFENSIVE be disabled */\n",
          p->out
    );
  }
  shellFinalize(&rc, pStmt);
  return rc;
}

/*
** Fault-Simulator state and logic.
*/
static struct {
  int iId;           /* ID that triggers a simulated fault.  -1 means "any" */
  int iErr;          /* The error code to return on a fault */
  int iCnt;          /* Trigger the fault only if iCnt is already zero */
  int iInterval;     /* Reset iCnt to this value after each fault */
  int eVerbose;      /* When to print output */
  int nHit;          /* Number of hits seen so far */
  int nRepeat;       /* Turn off after this many hits.  0 for never */
  int nSkip;         /* Skip this many before first fault */
} faultsim_state = {-1, 0, 0, 0, 0, 0, 0, 0};

/*
** This is the fault-sim callback
*/
static int faultsim_callback(int iArg){
  if( faultsim_state.iId>0 && faultsim_state.iId!=iArg ){
    return SQLITE_OK;
  }
  if( faultsim_state.iCnt ){
    if( faultsim_state.iCnt>0 ) faultsim_state.iCnt--;
    if( faultsim_state.eVerbose>=2 ){
      sqlite3_fprintf(stdout, 
         "FAULT-SIM id=%d no-fault (cnt=%d)\n", iArg, faultsim_state.iCnt);
    }
    return SQLITE_OK;
  }
  if( faultsim_state.eVerbose>=1 ){
    sqlite3_fprintf(stdout, 
         "FAULT-SIM id=%d returns %d\n", iArg, faultsim_state.iErr);
  }
  faultsim_state.iCnt = faultsim_state.iInterval;
  faultsim_state.nHit++;
  if( faultsim_state.nRepeat>0 && faultsim_state.nRepeat<=faultsim_state.nHit ){
    faultsim_state.iCnt = -1;
  }
  return faultsim_state.iErr;
}

/*
** If an input line begins with "." then invoke this routine to
** process that line.
**
** Return 1 on error, 2 to exit, and 0 otherwise.
*/
static int do_meta_command(char *zLine, ShellState *p){
  int h = 1;
  int nArg = 0;
  int n, c;
  int rc = 0;
  char *azArg[52];

#ifndef SQLITE_OMIT_VIRTUALTABLE
  if( p->expert.pExpert ){
    expertFinish(p, 1, 0);
  }
#endif

  /* Parse the input line into tokens.
  */
  while( zLine[h] && nArg<ArraySize(azArg)-1 ){
    while( IsSpace(zLine[h]) ){ h++; }
    if( zLine[h]==0 ) break;
    if( zLine[h]=='\'' || zLine[h]=='"' ){
      int delim = zLine[h++];
      azArg[nArg++] = &zLine[h];
      while( zLine[h] && zLine[h]!=delim ){
        if( zLine[h]=='\\' && delim=='"' && zLine[h+1]!=0 ) h++;
        h++;
      }
      if( zLine[h]==delim ){
        zLine[h++] = 0;
      }
      if( delim=='"' ) resolve_backslashes(azArg[nArg-1]);
    }else{
      azArg[nArg++] = &zLine[h];
      while( zLine[h] && !IsSpace(zLine[h]) ){ h++; }
      if( zLine[h] ) zLine[h++] = 0;
    }
  }
  azArg[nArg] = 0;

  /* Process the input line.
  */
  if( nArg==0 ) return 0; /* no tokens, no error */
  n = strlen30(azArg[0]);
  c = azArg[0][0];
  clearTempFile(p);

#ifndef SQLITE_OMIT_AUTHORIZATION
  if( c=='a' && cli_strncmp(azArg[0], "auth", n)==0 ){
    if( nArg!=2 ){
      sqlite3_fprintf(stderr, "Usage: .auth ON|OFF\n");
      rc = 1;
      goto meta_command_exit;
    }
    open_db(p, 0);
    if( booleanValue(azArg[1]) ){
      sqlite3_set_authorizer(p->db, shellAuth, p);
    }else if( p->bSafeModePersist ){
      sqlite3_set_authorizer(p->db, safeModeAuth, p);
    }else{
      sqlite3_set_authorizer(p->db, 0, 0);
    }
  }else
#endif

#if !defined(SQLITE_OMIT_VIRTUALTABLE) && defined(SQLITE_HAVE_ZLIB) \
  && !defined(SQLITE_SHELL_FIDDLE)
  if( c=='a' && cli_strncmp(azArg[0], "archive", n)==0 ){
    open_db(p, 0);
    failIfSafeMode(p, "cannot run .archive in safe mode");
    rc = arDotCommand(p, 0, azArg, nArg);
  }else
#endif

#ifndef SQLITE_SHELL_FIDDLE
  if( (c=='b' && n>=3 && cli_strncmp(azArg[0], "backup", n)==0)
   || (c=='s' && n>=3 && cli_strncmp(azArg[0], "save", n)==0)
  ){
    const char *zDestFile = 0;
    const char *zDb = 0;
    sqlite3 *pDest;
    sqlite3_backup *pBackup;
    int j;
    int bAsync = 0;
    const char *zVfs = 0;
    failIfSafeMode(p, "cannot run .%s in safe mode", azArg[0]);
    for(j=1; j<nArg; j++){
      const char *z = azArg[j];
      if( z[0]=='-' ){
        if( z[1]=='-' ) z++;
        if( cli_strcmp(z, "-append")==0 ){
          zVfs = "apndvfs";
        }else
        if( cli_strcmp(z, "-async")==0 ){
          bAsync = 1;
        }else
        {
          sqlite3_fprintf(stderr,"unknown option: %s\n", azArg[j]);
          return 1;
        }
      }else if( zDestFile==0 ){
        zDestFile = azArg[j];
      }else if( zDb==0 ){
        zDb = zDestFile;
        zDestFile = azArg[j];
      }else{
        sqlite3_fprintf(stderr, "Usage: .backup ?DB? ?OPTIONS? FILENAME\n");
        return 1;
      }
    }
    if( zDestFile==0 ){
      sqlite3_fprintf(stderr, "missing FILENAME argument on .backup\n");
      return 1;
    }
    if( zDb==0 ) zDb = "main";
    rc = sqlite3_open_v2(zDestFile, &pDest,
                  SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE, zVfs);
    if( rc!=SQLITE_OK ){
      sqlite3_fprintf(stderr,"Error: cannot open \"%s\"\n", zDestFile);
      close_db(pDest);
      return 1;
    }
    if( bAsync ){
      sqlite3_exec(pDest, "PRAGMA synchronous=OFF; PRAGMA journal_mode=OFF;",
                   0, 0, 0);
    }
    open_db(p, 0);
    pBackup = sqlite3_backup_init(pDest, "main", p->db, zDb);
    if( pBackup==0 ){
      shellDatabaseError(pDest);
      close_db(pDest);
      return 1;
    }
    while(  (rc = sqlite3_backup_step(pBackup,100))==SQLITE_OK ){}
    sqlite3_backup_finish(pBackup);
    if( rc==SQLITE_DONE ){
      rc = 0;
    }else{
      shellDatabaseError(pDest);
      rc = 1;
    }
    close_db(pDest);
  }else
#endif /* !defined(SQLITE_SHELL_FIDDLE) */

  if( c=='b' && n>=3 && cli_strncmp(azArg[0], "bail", n)==0 ){
    if( nArg==2 ){
      bail_on_error = booleanValue(azArg[1]);
    }else{
      eputz("Usage: .bail on|off\n");
      rc = 1;
    }
  }else

  /* Undocumented.  Legacy only.  See "crlf" below */
  if( c=='b' && n>=3 && cli_strncmp(azArg[0], "binary", n)==0 ){
    eputz("The \".binary\" command is deprecated.\n");
    rc = 1;
  }else

  /* The undocumented ".breakpoint" command causes a call to the no-op
  ** routine named test_breakpoint().
  */
  if( c=='b' && n>=3 && cli_strncmp(azArg[0], "breakpoint", n)==0 ){
    test_breakpoint();
  }else

#ifndef SQLITE_SHELL_FIDDLE
  if( c=='c' && cli_strcmp(azArg[0],"cd")==0 ){
    failIfSafeMode(p, "cannot run .cd in safe mode");
    if( nArg==2 ){
#if defined(_WIN32) || defined(WIN32)
      wchar_t *z = sqlite3_win32_utf8_to_unicode(azArg[1]);
      rc = !SetCurrentDirectoryW(z);
      sqlite3_free(z);
#else
      rc = chdir(azArg[1]);
#endif
      if( rc ){
        sqlite3_fprintf(stderr,"Cannot change to directory \"%s\"\n", azArg[1]);
        rc = 1;
      }
    }else{
      eputz("Usage: .cd DIRECTORY\n");
      rc = 1;
    }
  }else
#endif /* !defined(SQLITE_SHELL_FIDDLE) */

  if( c=='c' && n>=3 && cli_strncmp(azArg[0], "changes", n)==0 ){
    if( nArg==2 ){
      setOrClearFlag(p, SHFLG_CountChanges, azArg[1]);
    }else{
      eputz("Usage: .changes on|off\n");
      rc = 1;
    }
  }else

#ifndef SQLITE_SHELL_FIDDLE
  /* Cancel output redirection, if it is currently set (by .testcase)
  ** Then read the content of the testcase-out.txt file and compare against
  ** azArg[1].  If there are differences, report an error and exit.
  */
  if( c=='c' && n>=3 && cli_strncmp(azArg[0], "check", n)==0 ){
    char *zRes = 0;
    output_reset(p);
    if( nArg!=2 ){
      eputz("Usage: .check GLOB-PATTERN\n");
      rc = 2;
    }else if( (zRes = readFile("testcase-out.txt", 0))==0 ){
      rc = 2;
    }else if( testcase_glob(azArg[1],zRes)==0 ){
      sqlite3_fprintf(stderr,
            "testcase-%s FAILED\n Expected: [%s]\n      Got: [%s]\n",
            p->zTestcase, azArg[1], zRes);
      rc = 1;
    }else{
      sqlite3_fprintf(p->out, "testcase-%s ok\n", p->zTestcase);
      p->nCheck++;
    }
    sqlite3_free(zRes);
  }else
#endif /* !defined(SQLITE_SHELL_FIDDLE) */

#ifndef SQLITE_SHELL_FIDDLE
  if( c=='c' && cli_strncmp(azArg[0], "clone", n)==0 ){
    failIfSafeMode(p, "cannot run .clone in safe mode");
    if( nArg==2 ){
      tryToClone(p, azArg[1]);
    }else{
      eputz("Usage: .clone FILENAME\n");
      rc = 1;
    }
  }else
#endif /* !defined(SQLITE_SHELL_FIDDLE) */

  if( c=='c' && cli_strncmp(azArg[0], "connection", n)==0 ){
    if( nArg==1 ){
      /* List available connections */
      int i;
      for(i=0; i<ArraySize(p->aAuxDb); i++){
        const char *zFile = p->aAuxDb[i].zDbFilename;
        if( p->aAuxDb[i].db==0 && p->pAuxDb!=&p->aAuxDb[i] ){
          zFile = "(not open)";
        }else if( zFile==0 ){
          zFile = "(memory)";
        }else if( zFile[0]==0 ){
          zFile = "(temporary-file)";
        }
        if( p->pAuxDb == &p->aAuxDb[i] ){
          sqlite3_fprintf(stdout, "ACTIVE %d: %s\n", i, zFile);
        }else if( p->aAuxDb[i].db!=0 ){
          sqlite3_fprintf(stdout, "       %d: %s\n", i, zFile);
        }
      }
    }else if( nArg==2 && IsDigit(azArg[1][0]) && azArg[1][1]==0 ){
      int i = azArg[1][0] - '0';
      if( p->pAuxDb != &p->aAuxDb[i] && i>=0 && i<ArraySize(p->aAuxDb) ){
        p->pAuxDb->db = p->db;
        p->pAuxDb = &p->aAuxDb[i];
        globalDb = p->db = p->pAuxDb->db;
        p->pAuxDb->db = 0;
      }
    }else if( nArg==3 && cli_strcmp(azArg[1], "close")==0
           && IsDigit(azArg[2][0]) && azArg[2][1]==0 ){
      int i = azArg[2][0] - '0';
      if( i<0 || i>=ArraySize(p->aAuxDb) ){
        /* No-op */
      }else if( p->pAuxDb == &p->aAuxDb[i] ){
        eputz("cannot close the active database connection\n");
        rc = 1;
      }else if( p->aAuxDb[i].db ){
        session_close_all(p, i);
        close_db(p->aAuxDb[i].db);
        p->aAuxDb[i].db = 0;
      }
    }else{
      eputz("Usage: .connection [close] [CONNECTION-NUMBER]\n");
      rc = 1;
    }
  }else

  if( c=='c' && n==4
   && (cli_strncmp(azArg[0], "crlf", n)==0
       || cli_strncmp(azArg[0], "crnl",n)==0)
  ){
    if( nArg==2 ){
#ifdef _WIN32
      p->crlfMode = booleanValue(azArg[1]);
#else
      p->crlfMode = 0;
#endif
    }
    sqlite3_fprintf(stderr, "crlf is %s\n", p->crlfMode ? "ON" : "OFF");
  }else

  if( c=='d' && n>1 && cli_strncmp(azArg[0], "databases", n)==0 ){
    char **azName = 0;
    int nName = 0;
    sqlite3_stmt *pStmt;
    int i;
    open_db(p, 0);
    rc = sqlite3_prepare_v2(p->db, "PRAGMA database_list", -1, &pStmt, 0);
    if( rc ){
      shellDatabaseError(p->db);
      rc = 1;
    }else{
      while( sqlite3_step(pStmt)==SQLITE_ROW ){
        const char *zSchema = (const char *)sqlite3_column_text(pStmt,1);
        const char *zFile = (const char*)sqlite3_column_text(pStmt,2);
        if( zSchema==0 || zFile==0 ) continue;
        azName = sqlite3_realloc(azName, (nName+1)*2*sizeof(char*));
        shell_check_oom(azName);
        azName[nName*2] = strdup(zSchema);
        azName[nName*2+1] = strdup(zFile);
        nName++;
      }
    }
    sqlite3_finalize(pStmt);
    for(i=0; i<nName; i++){
      int eTxn = sqlite3_txn_state(p->db, azName[i*2]);
      int bRdonly = sqlite3_db_readonly(p->db, azName[i*2]);
      const char *z = azName[i*2+1];
      sqlite3_fprintf(p->out, "%s: %s %s%s\n",
            azName[i*2], z && z[0] ? z : "\"\"", bRdonly ? "r/o" : "r/w",
            eTxn==SQLITE_TXN_NONE ? "" :
            eTxn==SQLITE_TXN_READ ? " read-txn" : " write-txn");
      free(azName[i*2]);
      free(azName[i*2+1]);
    }
    sqlite3_free(azName);
  }else

  if( c=='d' && n>=3 && cli_strncmp(azArg[0], "dbconfig", n)==0 ){
    static const struct DbConfigChoices {
      const char *zName;
      int op;
    } aDbConfig[] = {
        { "defensive",          SQLITE_DBCONFIG_DEFENSIVE             },
        { "dqs_ddl",            SQLITE_DBCONFIG_DQS_DDL               },
        { "dqs_dml",            SQLITE_DBCONFIG_DQS_DML               },
        { "enable_fkey",        SQLITE_DBCONFIG_ENABLE_FKEY           },
        { "enable_qpsg",        SQLITE_DBCONFIG_ENABLE_QPSG           },
        { "enable_trigger",     SQLITE_DBCONFIG_ENABLE_TRIGGER        },
        { "enable_view",        SQLITE_DBCONFIG_ENABLE_VIEW           },
        { "fts3_tokenizer",     SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER },
        { "legacy_alter_table", SQLITE_DBCONFIG_LEGACY_ALTER_TABLE    },
        { "legacy_file_format", SQLITE_DBCONFIG_LEGACY_FILE_FORMAT    },
        { "load_extension",     SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION },
        { "no_ckpt_on_close",   SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE      },
        { "reset_database",     SQLITE_DBCONFIG_RESET_DATABASE        },
        { "reverse_scanorder",  SQLITE_DBCONFIG_REVERSE_SCANORDER     },
        { "stmt_scanstatus",    SQLITE_DBCONFIG_STMT_SCANSTATUS       },
        { "trigger_eqp",        SQLITE_DBCONFIG_TRIGGER_EQP           },
        { "trusted_schema",     SQLITE_DBCONFIG_TRUSTED_SCHEMA        },
        { "writable_schema",    SQLITE_DBCONFIG_WRITABLE_SCHEMA       },
    };
    int ii, v;
    open_db(p, 0);
    for(ii=0; ii<ArraySize(aDbConfig); ii++){
      if( nArg>1 && cli_strcmp(azArg[1], aDbConfig[ii].zName)!=0 ) continue;
      if( nArg>=3 ){
        sqlite3_db_config(p->db, aDbConfig[ii].op, booleanValue(azArg[2]), 0);
      }
      sqlite3_db_config(p->db, aDbConfig[ii].op, -1, &v);
      sqlite3_fprintf(p->out, "%19s %s\n",
                      aDbConfig[ii].zName, v ? "on" : "off");
      if( nArg>1 ) break;
    }
    if( nArg>1 && ii==ArraySize(aDbConfig) ){
      sqlite3_fprintf(stderr,"Error: unknown dbconfig \"%s\"\n", azArg[1]);
      eputz("Enter \".dbconfig\" with no arguments for a list\n");
    }
  }else

#if SQLITE_SHELL_HAVE_RECOVER
  if( c=='d' && n>=3 && cli_strncmp(azArg[0], "dbinfo", n)==0 ){
    rc = shell_dbinfo_command(p, nArg, azArg);
  }else

  if( c=='r' && cli_strncmp(azArg[0], "recover", n)==0 ){
    open_db(p, 0);
    rc = recoverDatabaseCmd(p, nArg, azArg);
  }else
#endif /* SQLITE_SHELL_HAVE_RECOVER */

  if( c=='d' && cli_strncmp(azArg[0], "dump", n)==0 ){
    char *zLike = 0;
    char *zSql;
    int i;
    int savedShowHeader = p->showHeader;
    int savedShellFlags = p->shellFlgs;
    ShellClearFlag(p,
       SHFLG_PreserveRowid|SHFLG_Newlines|SHFLG_Echo
       |SHFLG_DumpDataOnly|SHFLG_DumpNoSys);
    for(i=1; i<nArg; i++){
      if( azArg[i][0]=='-' ){
        const char *z = azArg[i]+1;
        if( z[0]=='-' ) z++;
        if( cli_strcmp(z,"preserve-rowids")==0 ){
#ifdef SQLITE_OMIT_VIRTUALTABLE
          eputz("The --preserve-rowids option is not compatible"
                " with SQLITE_OMIT_VIRTUALTABLE\n");
          rc = 1;
          sqlite3_free(zLike);
          goto meta_command_exit;
#else
          ShellSetFlag(p, SHFLG_PreserveRowid);
#endif
        }else
        if( cli_strcmp(z,"newlines")==0 ){
          ShellSetFlag(p, SHFLG_Newlines);
        }else
        if( cli_strcmp(z,"data-only")==0 ){
          ShellSetFlag(p, SHFLG_DumpDataOnly);
        }else
        if( cli_strcmp(z,"nosys")==0 ){
          ShellSetFlag(p, SHFLG_DumpNoSys);
        }else
        {
          sqlite3_fprintf(stderr,
               "Unknown option \"%s\" on \".dump\"\n", azArg[i]);
          rc = 1;
          sqlite3_free(zLike);
          goto meta_command_exit;
        }
      }else{
        /* azArg[i] contains a LIKE pattern. This ".dump" request should
        ** only dump data for tables for which either the table name matches
        ** the LIKE pattern, or the table appears to be a shadow table of
        ** a virtual table for which the name matches the LIKE pattern.
        */
        char *zExpr = sqlite3_mprintf(
            "name LIKE %Q ESCAPE '\\' OR EXISTS ("
            "  SELECT 1 FROM sqlite_schema WHERE "
            "    name LIKE %Q ESCAPE '\\' AND"
            "    sql LIKE 'CREATE VIRTUAL TABLE%%' AND"
            "    substr(o.name, 1, length(name)+1) == (name||'_')"
            ")", azArg[i], azArg[i]
        );

        if( zLike ){
          zLike = sqlite3_mprintf("%z OR %z", zLike, zExpr);
        }else{
          zLike = zExpr;
        }
      }
    }

    open_db(p, 0);

    outputDumpWarning(p, zLike);
    if( (p->shellFlgs & SHFLG_DumpDataOnly)==0 ){
      /* When playing back a "dump", the content might appear in an order
      ** which causes immediate foreign key constraints to be violated.
      ** So disable foreign-key constraint enforcement to prevent problems. */
      sqlite3_fputs("PRAGMA foreign_keys=OFF;\n", p->out);
      sqlite3_fputs("BEGIN TRANSACTION;\n", p->out);
    }
    p->writableSchema = 0;
    p->showHeader = 0;
    /* Set writable_schema=ON since doing so forces SQLite to initialize
    ** as much of the schema as it can even if the sqlite_schema table is
    ** corrupt. */
    sqlite3_exec(p->db, "SAVEPOINT dump; PRAGMA writable_schema=ON", 0, 0, 0);
    p->nErr = 0;
    if( zLike==0 ) zLike = sqlite3_mprintf("true");
    zSql = sqlite3_mprintf(
      "SELECT name, type, sql FROM sqlite_schema AS o "
      "WHERE (%s) AND type=='table'"
      "  AND sql NOT NULL"
      " ORDER BY tbl_name='sqlite_sequence', rowid",
      zLike
    );
    run_schema_dump_query(p,zSql);
    sqlite3_free(zSql);
    if( (p->shellFlgs & SHFLG_DumpDataOnly)==0 ){
      zSql = sqlite3_mprintf(
        "SELECT sql FROM sqlite_schema AS o "
        "WHERE (%s) AND sql NOT NULL"
        "  AND type IN ('index','trigger','view') "
        "ORDER BY type COLLATE NOCASE DESC",
        zLike
      );
      run_table_dump_query(p, zSql);
      sqlite3_free(zSql);
    }
    sqlite3_free(zLike);
    if( p->writableSchema ){
      sqlite3_fputs("PRAGMA writable_schema=OFF;\n", p->out);
      p->writableSchema = 0;
    }
    sqlite3_exec(p->db, "PRAGMA writable_schema=OFF;", 0, 0, 0);
    sqlite3_exec(p->db, "RELEASE dump;", 0, 0, 0);
    if( (p->shellFlgs & SHFLG_DumpDataOnly)==0 ){
      sqlite3_fputs(p->nErr?"ROLLBACK; -- due to errors\n":"COMMIT;\n", p->out);
    }
    p->showHeader = savedShowHeader;
    p->shellFlgs = savedShellFlags;
  }else

  if( c=='e' && cli_strncmp(azArg[0], "echo", n)==0 ){
    if( nArg==2 ){
      setOrClearFlag(p, SHFLG_Echo, azArg[1]);
    }else{
      eputz("Usage: .echo on|off\n");
      rc = 1;
    }
  }else

  if( c=='e' && cli_strncmp(azArg[0], "eqp", n)==0 ){
    if( nArg==2 ){
      p->autoEQPtest = 0;
      if( p->autoEQPtrace ){
        if( p->db ) sqlite3_exec(p->db, "PRAGMA vdbe_trace=OFF;", 0, 0, 0);
        p->autoEQPtrace = 0;
      }
      if( cli_strcmp(azArg[1],"full")==0 ){
        p->autoEQP = AUTOEQP_full;
      }else if( cli_strcmp(azArg[1],"trigger")==0 ){
        p->autoEQP = AUTOEQP_trigger;
#ifdef SQLITE_DEBUG
      }else if( cli_strcmp(azArg[1],"test")==0 ){
        p->autoEQP = AUTOEQP_on;
        p->autoEQPtest = 1;
      }else if( cli_strcmp(azArg[1],"trace")==0 ){
        p->autoEQP = AUTOEQP_full;
        p->autoEQPtrace = 1;
        open_db(p, 0);
        sqlite3_exec(p->db, "SELECT name FROM sqlite_schema LIMIT 1", 0, 0, 0);
        sqlite3_exec(p->db, "PRAGMA vdbe_trace=ON;", 0, 0, 0);
#endif
      }else{
        p->autoEQP = (u8)booleanValue(azArg[1]);
      }
    }else{
      eputz("Usage: .eqp off|on|trace|trigger|full\n");
      rc = 1;
    }
  }else

#ifndef SQLITE_SHELL_FIDDLE
  if( c=='e' && cli_strncmp(azArg[0], "exit", n)==0 ){
    if( nArg>1 && (rc = (int)integerValue(azArg[1]))!=0 ) exit(rc);
    rc = 2;
  }else
#endif

  /* The ".explain" command is automatic now.  It is largely pointless.  It
  ** retained purely for backwards compatibility */
  if( c=='e' && cli_strncmp(azArg[0], "explain", n)==0 ){
    int val = 1;
    if( nArg>=2 ){
      if( cli_strcmp(azArg[1],"auto")==0 ){
        val = 99;
      }else{
        val =  booleanValue(azArg[1]);
      }
    }
    if( val==1 && p->mode!=MODE_Explain ){
      p->normalMode = p->mode;
      p->mode = MODE_Explain;
      p->autoExplain = 0;
    }else if( val==0 ){
      if( p->mode==MODE_Explain ) p->mode = p->normalMode;
      p->autoExplain = 0;
    }else if( val==99 ){
      if( p->mode==MODE_Explain ) p->mode = p->normalMode;
      p->autoExplain = 1;
    }
  }else

#ifndef SQLITE_OMIT_VIRTUALTABLE
  if( c=='e' && cli_strncmp(azArg[0], "expert", n)==0 ){
    if( p->bSafeMode ){
      sqlite3_fprintf(stderr,
            "Cannot run experimental commands such as \"%s\" in safe mode\n",
            azArg[0]);
      rc = 1;
    }else{
      open_db(p, 0);
      expertDotCommand(p, azArg, nArg);
    }
  }else
#endif

  if( c=='f' && cli_strncmp(azArg[0], "filectrl", n)==0 ){
    static const struct {
       const char *zCtrlName;   /* Name of a test-control option */
       int ctrlCode;            /* Integer code for that option */
       const char *zUsage;      /* Usage notes */
    } aCtrl[] = {
      { "chunk_size",     SQLITE_FCNTL_CHUNK_SIZE,      "SIZE"           },
      { "data_version",   SQLITE_FCNTL_DATA_VERSION,    ""               },
      { "has_moved",      SQLITE_FCNTL_HAS_MOVED,       ""               },
      { "lock_timeout",   SQLITE_FCNTL_LOCK_TIMEOUT,    "MILLISEC"       },
      { "persist_wal",    SQLITE_FCNTL_PERSIST_WAL,     "[BOOLEAN]"      },
   /* { "pragma",         SQLITE_FCNTL_PRAGMA,          "NAME ARG"       },*/
      { "psow",       SQLITE_FCNTL_POWERSAFE_OVERWRITE, "[BOOLEAN]"      },
      { "reserve_bytes",  SQLITE_FCNTL_RESERVE_BYTES,   "[N]"            },
      { "size_limit",     SQLITE_FCNTL_SIZE_LIMIT,      "[LIMIT]"        },
      { "tempfilename",   SQLITE_FCNTL_TEMPFILENAME,    ""               },
   /* { "win32_av_retry", SQLITE_FCNTL_WIN32_AV_RETRY,  "COUNT DELAY"    },*/
    };
    int filectrl = -1;
    int iCtrl = -1;
    sqlite3_int64 iRes = 0;  /* Integer result to display if rc2==1 */
    int isOk = 0;            /* 0: usage  1: %lld  2: no-result */
    int n2, i;
    const char *zCmd = 0;
    const char *zSchema = 0;

    open_db(p, 0);
    zCmd = nArg>=2 ? azArg[1] : "help";

    if( zCmd[0]=='-'
     && (cli_strcmp(zCmd,"--schema")==0 || cli_strcmp(zCmd,"-schema")==0)
     && nArg>=4
    ){
      zSchema = azArg[2];
      for(i=3; i<nArg; i++) azArg[i-2] = azArg[i];
      nArg -= 2;
      zCmd = azArg[1];
    }

    /* The argument can optionally begin with "-" or "--" */
    if( zCmd[0]=='-' && zCmd[1] ){
      zCmd++;
      if( zCmd[0]=='-' && zCmd[1] ) zCmd++;
    }

    /* --help lists all file-controls */
    if( cli_strcmp(zCmd,"help")==0 ){
      sqlite3_fputs("Available file-controls:\n", p->out);
      for(i=0; i<ArraySize(aCtrl); i++){
        sqlite3_fprintf(p->out,
               "  .filectrl %s %s\n", aCtrl[i].zCtrlName, aCtrl[i].zUsage);
      }
      rc = 1;
      goto meta_command_exit;
    }

    /* convert filectrl text option to value. allow any unique prefix
    ** of the option name, or a numerical value. */
    n2 = strlen30(zCmd);
    for(i=0; i<ArraySize(aCtrl); i++){
      if( cli_strncmp(zCmd, aCtrl[i].zCtrlName, n2)==0 ){
        if( filectrl<0 ){
          filectrl = aCtrl[i].ctrlCode;
          iCtrl = i;
        }else{
          sqlite3_fprintf(stderr,"Error: ambiguous file-control: \"%s\"\n"
                "Use \".filectrl --help\" for help\n", zCmd);
          rc = 1;
          goto meta_command_exit;
        }
      }
    }
    if( filectrl<0 ){
      sqlite3_fprintf(stderr,"Error: unknown file-control: %s\n"
            "Use \".filectrl --help\" for help\n", zCmd);
    }else{
      switch(filectrl){
        case SQLITE_FCNTL_SIZE_LIMIT: {
          if( nArg!=2 && nArg!=3 ) break;
          iRes = nArg==3 ? integerValue(azArg[2]) : -1;
          sqlite3_file_control(p->db, zSchema, SQLITE_FCNTL_SIZE_LIMIT, &iRes);
          isOk = 1;
          break;
        }
        case SQLITE_FCNTL_LOCK_TIMEOUT:
        case SQLITE_FCNTL_CHUNK_SIZE: {
          int x;
          if( nArg!=3 ) break;
          x = (int)integerValue(azArg[2]);
          sqlite3_file_control(p->db, zSchema, filectrl, &x);
          isOk = 2;
          break;
        }
        case SQLITE_FCNTL_PERSIST_WAL:
        case SQLITE_FCNTL_POWERSAFE_OVERWRITE: {
          int x;
          if( nArg!=2 && nArg!=3 ) break;
          x = nArg==3 ? booleanValue(azArg[2]) : -1;
          sqlite3_file_control(p->db, zSchema, filectrl, &x);
          iRes = x;
          isOk = 1;
          break;
        }
        case SQLITE_FCNTL_DATA_VERSION:
        case SQLITE_FCNTL_HAS_MOVED: {
          int x;
          if( nArg!=2 ) break;
          sqlite3_file_control(p->db, zSchema, filectrl, &x);
          iRes = x;
          isOk = 1;
          break;
        }
        case SQLITE_FCNTL_TEMPFILENAME: {
          char *z = 0;
          if( nArg!=2 ) break;
          sqlite3_file_control(p->db, zSchema, filectrl, &z);
          if( z ){
            sqlite3_fprintf(p->out, "%s\n", z);
            sqlite3_free(z);
          }
          isOk = 2;
          break;
        }
        case SQLITE_FCNTL_RESERVE_BYTES: {
          int x;
          if( nArg>=3 ){
            x = atoi(azArg[2]);
            sqlite3_file_control(p->db, zSchema, filectrl, &x);
          }
          x = -1;
          sqlite3_file_control(p->db, zSchema, filectrl, &x);
          sqlite3_fprintf(p->out, "%d\n", x);
          isOk = 2;
          break;
        }
      }
    }
    if( isOk==0 && iCtrl>=0 ){
      sqlite3_fprintf(p->out, "Usage: .filectrl %s %s\n",
                      zCmd, aCtrl[iCtrl].zUsage);
      rc = 1;
    }else if( isOk==1 ){
      char zBuf[100];
      sqlite3_snprintf(sizeof(zBuf), zBuf, "%lld", iRes);
      sqlite3_fprintf(p->out, "%s\n", zBuf);
    }
  }else

  if( c=='f' && cli_strncmp(azArg[0], "fullschema", n)==0 ){
    ShellState data;
    int doStats = 0;
    memcpy(&data, p, sizeof(data));
    data.showHeader = 0;
    data.cMode = data.mode = MODE_Semi;
    if( nArg==2 && optionMatch(azArg[1], "indent") ){
      data.cMode = data.mode = MODE_Pretty;
      nArg = 1;
    }
    if( nArg!=1 ){
      eputz("Usage: .fullschema ?--indent?\n");
      rc = 1;
      goto meta_command_exit;
    }
    open_db(p, 0);
    rc = sqlite3_exec(p->db,
       "SELECT sql FROM"
       "  (SELECT sql sql, type type, tbl_name tbl_name, name name, rowid x"
       "     FROM sqlite_schema UNION ALL"
       "   SELECT sql, type, tbl_name, name, rowid FROM sqlite_temp_schema) "
       "WHERE type!='meta' AND sql NOTNULL AND name NOT LIKE 'sqlite_%' "
       "ORDER BY x",
       callback, &data, 0
    );
    if( rc==SQLITE_OK ){
      sqlite3_stmt *pStmt;
      rc = sqlite3_prepare_v2(p->db,
               "SELECT rowid FROM sqlite_schema"
               " WHERE name GLOB 'sqlite_stat[134]'",
               -1, &pStmt, 0);
      if( rc==SQLITE_OK ){
        doStats = sqlite3_step(pStmt)==SQLITE_ROW;
        sqlite3_finalize(pStmt);
      }
    }
    if( doStats==0 ){
      sqlite3_fputs("/* No STAT tables available */\n", p->out);
    }else{
      sqlite3_fputs("ANALYZE sqlite_schema;\n", p->out);
      data.cMode = data.mode = MODE_Insert;
      data.zDestTable = "sqlite_stat1";
      shell_exec(&data, "SELECT * FROM sqlite_stat1", 0);
      data.zDestTable = "sqlite_stat4";
      shell_exec(&data, "SELECT * FROM sqlite_stat4", 0);
      sqlite3_fputs("ANALYZE sqlite_schema;\n", p->out);
    }
  }else

  if( c=='h' && cli_strncmp(azArg[0], "headers", n)==0 ){
    if( nArg==2 ){
      p->showHeader = booleanValue(azArg[1]);
      p->shellFlgs |= SHFLG_HeaderSet;
    }else{
      eputz("Usage: .headers on|off\n");
      rc = 1;
    }
  }else

  if( c=='h' && cli_strncmp(azArg[0], "help", n)==0 ){
    if( nArg>=2 ){
      n = showHelp(p->out, azArg[1]);
      if( n==0 ){
        sqlite3_fprintf(p->out, "Nothing matches '%s'\n", azArg[1]);
      }
    }else{
      showHelp(p->out, 0);
    }
  }else

#ifndef SQLITE_SHELL_FIDDLE
  if( c=='i' && cli_strncmp(azArg[0], "import", n)==0 ){
    char *zTable = 0;           /* Insert data into this table */
    char *zSchema = 0;          /* Schema of zTable */
    char *zFile = 0;            /* Name of file to extra content from */
    sqlite3_stmt *pStmt = NULL; /* A statement */
    int nCol;                   /* Number of columns in the table */
    i64 nByte;                  /* Number of bytes in an SQL string */
    int i, j;                   /* Loop counters */
    int needCommit;             /* True to COMMIT or ROLLBACK at end */
    int nSep;                   /* Number of bytes in p->colSeparator[] */
    char *zSql = 0;             /* An SQL statement */
    ImportCtx sCtx;             /* Reader context */
    char *(SQLITE_CDECL *xRead)(ImportCtx*); /* Func to read one value */
    int eVerbose = 0;           /* Larger for more console output */
    int nSkip = 0;              /* Initial lines to skip */
    int useOutputMode = 1;      /* Use output mode to determine separators */
    char *zCreate = 0;          /* CREATE TABLE statement text */

    failIfSafeMode(p, "cannot run .import in safe mode");
    memset(&sCtx, 0, sizeof(sCtx));
    if( p->mode==MODE_Ascii ){
      xRead = ascii_read_one_field;
    }else{
      xRead = csv_read_one_field;
    }
    rc = 1;
    for(i=1; i<nArg; i++){
      char *z = azArg[i];
      if( z[0]=='-' && z[1]=='-' ) z++;
      if( z[0]!='-' ){
        if( zFile==0 ){
          zFile = z;
        }else if( zTable==0 ){
          zTable = z;
        }else{
          sqlite3_fprintf(p->out, "ERROR: extra argument: \"%s\". Usage:\n",z);
          showHelp(p->out, "import");
          goto meta_command_exit;
        }
      }else if( cli_strcmp(z,"-v")==0 ){
        eVerbose++;
      }else if( cli_strcmp(z,"-schema")==0 && i<nArg-1 ){
        zSchema = azArg[++i];
      }else if( cli_strcmp(z,"-skip")==0 && i<nArg-1 ){
        nSkip = integerValue(azArg[++i]);
      }else if( cli_strcmp(z,"-ascii")==0 ){
        sCtx.cColSep = SEP_Unit[0];
        sCtx.cRowSep = SEP_Record[0];
        xRead = ascii_read_one_field;
        useOutputMode = 0;
      }else if( cli_strcmp(z,"-csv")==0 ){
        sCtx.cColSep = ',';
        sCtx.cRowSep = '\n';
        xRead = csv_read_one_field;
        useOutputMode = 0;
      }else{
        sqlite3_fprintf(p->out, "ERROR: unknown option: \"%s\".  Usage:\n", z);
        showHelp(p->out, "import");
        goto meta_command_exit;
      }
    }
    if( zTable==0 ){
      sqlite3_fprintf(p->out, "ERROR: missing %s argument. Usage:\n",
            zFile==0 ? "FILE" : "TABLE");
      showHelp(p->out, "import");
      goto meta_command_exit;
    }
    seenInterrupt = 0;
    open_db(p, 0);
    if( useOutputMode ){
      /* If neither the --csv or --ascii options are specified, then set
      ** the column and row separator characters from the output mode. */
      nSep = strlen30(p->colSeparator);
      if( nSep==0 ){
        eputz("Error: non-null column separator required for import\n");
        goto meta_command_exit;
      }
      if( nSep>1 ){
        eputz("Error: multi-character column separators not allowed"
              " for import\n");
        goto meta_command_exit;
      }
      nSep = strlen30(p->rowSeparator);
      if( nSep==0 ){
        eputz("Error: non-null row separator required for import\n");
        goto meta_command_exit;
      }
      if( nSep==2 && p->mode==MODE_Csv
       && cli_strcmp(p->rowSeparator,SEP_CrLf)==0
      ){
        /* When importing CSV (only), if the row separator is set to the
        ** default output row separator, change it to the default input
        ** row separator.  This avoids having to maintain different input
        ** and output row separators. */
        sqlite3_snprintf(sizeof(p->rowSeparator), p->rowSeparator, SEP_Row);
        nSep = strlen30(p->rowSeparator);
      }
      if( nSep>1 ){
        eputz("Error: multi-character row separators not allowed"
              " for import\n");
        goto meta_command_exit;
      }
      sCtx.cColSep = (u8)p->colSeparator[0];
      sCtx.cRowSep = (u8)p->rowSeparator[0];
    }
    sCtx.zFile = zFile;
    sCtx.nLine = 1;
    if( sCtx.zFile[0]=='|' ){
#ifdef SQLITE_OMIT_POPEN
      eputz("Error: pipes are not supported in this OS\n");
      goto meta_command_exit;
#else
      sCtx.in = sqlite3_popen(sCtx.zFile+1, "r");
      sCtx.zFile = "<pipe>";
      sCtx.xCloser = pclose;
#endif
    }else{
      sCtx.in = sqlite3_fopen(sCtx.zFile, "rb");
      sCtx.xCloser = fclose;
    }
    if( sCtx.in==0 ){
      sqlite3_fprintf(stderr,"Error: cannot open \"%s\"\n", zFile);
      goto meta_command_exit;
    }
    if( eVerbose>=2 || (eVerbose>=1 && useOutputMode) ){
      char zSep[2];
      zSep[1] = 0;
      zSep[0] = sCtx.cColSep;
      sqlite3_fputs("Column separator ", p->out);
      output_c_string(p->out, zSep);
      sqlite3_fputs(", row separator ", p->out);
      zSep[0] = sCtx.cRowSep;
      output_c_string(p->out, zSep);
      sqlite3_fputs("\n", p->out);
    }
    sCtx.z = sqlite3_malloc64(120);
    if( sCtx.z==0 ){
      import_cleanup(&sCtx);
      shell_out_of_memory();
    }
    /* Below, resources must be freed before exit. */
    while( (nSkip--)>0 ){
      while( xRead(&sCtx) && sCtx.cTerm==sCtx.cColSep ){}
    }
    import_append_char(&sCtx, 0);    /* To ensure sCtx.z is allocated */
    if( sqlite3_table_column_metadata(p->db, zSchema, zTable,0,0,0,0,0,0) ){
      /* Table does not exist.  Create it. */
      sqlite3 *dbCols = 0;
      char *zRenames = 0;
      char *zColDefs;
      zCreate = sqlite3_mprintf("CREATE TABLE \"%w\".\"%w\"", 
                    zSchema ? zSchema : "main", zTable);
      while( xRead(&sCtx) ){
        zAutoColumn(sCtx.z, &dbCols, 0);
        if( sCtx.cTerm!=sCtx.cColSep ) break;
      }
      zColDefs = zAutoColumn(0, &dbCols, &zRenames);
      if( zRenames!=0 ){
        sqlite3_fprintf((stdin_is_interactive && p->in==stdin)? p->out : stderr,
              "Columns renamed during .import %s due to duplicates:\n"
              "%s\n", sCtx.zFile, zRenames);
        sqlite3_free(zRenames);
      }
      assert(dbCols==0);
      if( zColDefs==0 ){
        sqlite3_fprintf(stderr,"%s: empty file\n", sCtx.zFile);
        import_cleanup(&sCtx);
        rc = 1;
        sqlite3_free(zCreate);
        goto meta_command_exit;
      }
      zCreate = sqlite3_mprintf("%z%z\n", zCreate, zColDefs);
      if( zCreate==0 ){
        import_cleanup(&sCtx);
        shell_out_of_memory();
      }
      if( eVerbose>=1 ){
        sqlite3_fprintf(p->out, "%s\n", zCreate);
      }
      rc = sqlite3_exec(p->db, zCreate, 0, 0, 0);
      if( rc ){
        sqlite3_fprintf(stderr,
             "%s failed:\n%s\n", zCreate, sqlite3_errmsg(p->db));
      }
      sqlite3_free(zCreate);
      zCreate = 0;
      if( rc ){
        import_cleanup(&sCtx);
        rc = 1;
        goto meta_command_exit;
      }
    }
    zSql = sqlite3_mprintf("SELECT count(*) FROM pragma_table_info(%Q,%Q);",
                           zTable, zSchema);
    if( zSql==0 ){
      import_cleanup(&sCtx);
      shell_out_of_memory();
    }
    rc =  sqlite3_prepare_v2(p->db, zSql, -1, &pStmt, 0);
    sqlite3_free(zSql);
    zSql = 0;
    if( rc ){
      if (pStmt) sqlite3_finalize(pStmt);
      shellDatabaseError(p->db);
      import_cleanup(&sCtx);
      rc = 1;
      goto meta_command_exit;
    }
    if( sqlite3_step(pStmt)==SQLITE_ROW ){
      nCol = sqlite3_column_int(pStmt, 0);
    }else{
      nCol = 0;
    }
    sqlite3_finalize(pStmt);
    pStmt = 0;
    if( nCol==0 ) return 0; /* no columns, no error */

    nByte = 64                 /* space for "INSERT INTO", "VALUES(", ")\0" */
          + (zSchema ? strlen(zSchema)*2 + 2: 0)  /* Quoted schema name */
          + strlen(zTable)*2 + 2                  /* Quoted table name */
          + nCol*2;            /* Space for ",?" for each column */
    zSql = sqlite3_malloc64( nByte );
    if( zSql==0 ){
      import_cleanup(&sCtx);
      shell_out_of_memory();
    }
    if( zSchema ){
      sqlite3_snprintf(nByte, zSql, "INSERT INTO \"%w\".\"%w\" VALUES(?", 
                       zSchema, zTable);
    }else{
      sqlite3_snprintf(nByte, zSql, "INSERT INTO \"%w\" VALUES(?", zTable);
    }
    j = strlen30(zSql);
    for(i=1; i<nCol; i++){
      zSql[j++] = ',';
      zSql[j++] = '?';
    }
    zSql[j++] = ')';
    zSql[j] = 0;
    assert( j<nByte );
    if( eVerbose>=2 ){
      sqlite3_fprintf(p->out, "Insert using: %s\n", zSql);
    }
    rc = sqlite3_prepare_v2(p->db, zSql, -1, &pStmt, 0);
    sqlite3_free(zSql);
    zSql = 0;
    if( rc ){
      shellDatabaseError(p->db);
      if (pStmt) sqlite3_finalize(pStmt);
      import_cleanup(&sCtx);
      rc = 1;
      goto meta_command_exit;
    }
    needCommit = sqlite3_get_autocommit(p->db);
    if( needCommit ) sqlite3_exec(p->db, "BEGIN", 0, 0, 0);
    do{
      int startLine = sCtx.nLine;
      for(i=0; i<nCol; i++){
        char *z = xRead(&sCtx);
        /*
        ** Did we reach end-of-file before finding any columns?
        ** If so, stop instead of NULL filling the remaining columns.
        */
        if( z==0 && i==0 ) break;
        /*
        ** Did we reach end-of-file OR end-of-line before finding any
        ** columns in ASCII mode?  If so, stop instead of NULL filling
        ** the remaining columns.
        */
        if( p->mode==MODE_Ascii && (z==0 || z[0]==0) && i==0 ) break;
        /*
        ** For CSV mode, per RFC 4180, accept EOF in lieu of final
        ** record terminator but only for last field of multi-field row.
        ** (If there are too few fields, it's not valid CSV anyway.)
        */
        if( z==0 && (xRead==csv_read_one_field) && i==nCol-1 && i>0 ){
          z = "";
        }
        sqlite3_bind_text(pStmt, i+1, z, -1, SQLITE_TRANSIENT);
        if( i<nCol-1 && sCtx.cTerm!=sCtx.cColSep ){
          sqlite3_fprintf(stderr,"%s:%d: expected %d columns but found %d"
                " - filling the rest with NULL\n",
                sCtx.zFile, startLine, nCol, i+1);
          i += 2;
          while( i<=nCol ){ sqlite3_bind_null(pStmt, i); i++; }
        }
      }
      if( sCtx.cTerm==sCtx.cColSep ){
        do{
          xRead(&sCtx);
          i++;
        }while( sCtx.cTerm==sCtx.cColSep );
        sqlite3_fprintf(stderr,
              "%s:%d: expected %d columns but found %d - extras ignored\n",
              sCtx.zFile, startLine, nCol, i);
      }
      if( i>=nCol ){
        sqlite3_step(pStmt);
        rc = sqlite3_reset(pStmt);
        if( rc!=SQLITE_OK ){
          sqlite3_fprintf(stderr,"%s:%d: INSERT failed: %s\n",
                sCtx.zFile, startLine, sqlite3_errmsg(p->db));
          sCtx.nErr++;
        }else{
          sCtx.nRow++;
        }
      }
    }while( sCtx.cTerm!=EOF );

    import_cleanup(&sCtx);
    sqlite3_finalize(pStmt);
    if( needCommit ) sqlite3_exec(p->db, "COMMIT", 0, 0, 0);
    if( eVerbose>0 ){
      sqlite3_fprintf(p->out,
            "Added %d rows with %d errors using %d lines of input\n",
            sCtx.nRow, sCtx.nErr, sCtx.nLine-1);
    }
  }else
#endif /* !defined(SQLITE_SHELL_FIDDLE) */

#ifndef SQLITE_UNTESTABLE
  if( c=='i' && cli_strncmp(azArg[0], "imposter", n)==0 ){
    char *zSql;
    char *zCollist = 0;
    sqlite3_stmt *pStmt;
    int tnum = 0;
    int isWO = 0;  /* True if making an imposter of a WITHOUT ROWID table */
    int lenPK = 0; /* Length of the PRIMARY KEY string for isWO tables */
    int i;
    if( !ShellHasFlag(p,SHFLG_TestingMode) ){
      sqlite3_fprintf(stderr,".%s unavailable without --unsafe-testing\n",
            "imposter");
      rc = 1;
      goto meta_command_exit;
    }
    if( !(nArg==3 || (nArg==2 && sqlite3_stricmp(azArg[1],"off")==0)) ){
      eputz("Usage: .imposter INDEX IMPOSTER\n"
            "       .imposter off\n");
      /* Also allowed, but not documented:
      **
      **    .imposter TABLE IMPOSTER
      **
      ** where TABLE is a WITHOUT ROWID table.  In that case, the
      ** imposter is another WITHOUT ROWID table with the columns in
      ** storage order. */
      rc = 1;
      goto meta_command_exit;
    }
    open_db(p, 0);
    if( nArg==2 ){
      sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, p->db, "main", 0, 1);
      goto meta_command_exit;
    }
    zSql = sqlite3_mprintf(
      "SELECT rootpage, 0 FROM sqlite_schema"
      " WHERE name='%q' AND type='index'"
      "UNION ALL "
      "SELECT rootpage, 1 FROM sqlite_schema"
      " WHERE name='%q' AND type='table'"
      "   AND sql LIKE '%%without%%rowid%%'",
      azArg[1], azArg[1]
    );
    sqlite3_prepare_v2(p->db, zSql, -1, &pStmt, 0);
    sqlite3_free(zSql);
    if( sqlite3_step(pStmt)==SQLITE_ROW ){
      tnum = sqlite3_column_int(pStmt, 0);
      isWO = sqlite3_column_int(pStmt, 1);
    }
    sqlite3_finalize(pStmt);
    zSql = sqlite3_mprintf("PRAGMA index_xinfo='%q'", azArg[1]);
    rc = sqlite3_prepare_v2(p->db, zSql, -1, &pStmt, 0);
    sqlite3_free(zSql);
    i = 0;
    while( rc==SQLITE_OK && sqlite3_step(pStmt)==SQLITE_ROW ){
      char zLabel[20];
      const char *zCol = (const char*)sqlite3_column_text(pStmt,2);
      i++;
      if( zCol==0 ){
        if( sqlite3_column_int(pStmt,1)==-1 ){
          zCol = "_ROWID_";
        }else{
          sqlite3_snprintf(sizeof(zLabel),zLabel,"expr%d",i);
          zCol = zLabel;
        }
      }
      if( isWO && lenPK==0 && sqlite3_column_int(pStmt,5)==0 && zCollist ){
        lenPK = (int)strlen(zCollist);
      }
      if( zCollist==0 ){
        zCollist = sqlite3_mprintf("\"%w\"", zCol);
      }else{
        zCollist = sqlite3_mprintf("%z,\"%w\"", zCollist, zCol);
      }
    }
    sqlite3_finalize(pStmt);
    if( i==0 || tnum==0 ){
      sqlite3_fprintf(stderr,"no such index: \"%s\"\n", azArg[1]);
      rc = 1;
      sqlite3_free(zCollist);
      goto meta_command_exit;
    }
    if( lenPK==0 ) lenPK = 100000;
    zSql = sqlite3_mprintf(
          "CREATE TABLE \"%w\"(%s,PRIMARY KEY(%.*s))WITHOUT ROWID",
          azArg[2], zCollist, lenPK, zCollist);
    sqlite3_free(zCollist);
    rc = sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, p->db, "main", 1, tnum);
    if( rc==SQLITE_OK ){
      rc = sqlite3_exec(p->db, zSql, 0, 0, 0);
      sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, p->db, "main", 0, 0);
      if( rc ){
        sqlite3_fprintf(stderr,
              "Error in [%s]: %s\n", zSql, sqlite3_errmsg(p->db));
      }else{
        sqlite3_fprintf(stdout, "%s;\n", zSql);
        sqlite3_fprintf(stdout,
              "WARNING: writing to an imposter table will corrupt"
              " the \"%s\" %s!\n", azArg[1], isWO ? "table" : "index");
      }
    }else{
      sqlite3_fprintf(stderr,"SQLITE_TESTCTRL_IMPOSTER returns %d\n", rc);
      rc = 1;
    }
    sqlite3_free(zSql);
  }else
#endif /* !defined(SQLITE_OMIT_TEST_CONTROL) */

  if( c=='i' && cli_strncmp(azArg[0], "intck", n)==0 ){
    i64 iArg = 0;
    if( nArg==2 ){
      iArg = integerValue(azArg[1]);
      if( iArg==0 ) iArg = -1;
    }
    if( (nArg!=1 && nArg!=2) || iArg<0 ){
      sqlite3_fprintf(stderr,"%s","Usage: .intck STEPS_PER_UNLOCK\n");
      rc = 1;
      goto meta_command_exit;
    }
    open_db(p, 0);
    rc = intckDatabaseCmd(p, iArg);
  }else

#ifdef SQLITE_ENABLE_IOTRACE
  if( c=='i' && cli_strncmp(azArg[0], "iotrace", n)==0 ){
    SQLITE_API extern void (SQLITE_CDECL *sqlite3IoTrace)(const char*, ...);
    if( iotrace && iotrace!=stdout ) fclose(iotrace);
    iotrace = 0;
    if( nArg<2 ){
      sqlite3IoTrace = 0;
    }else if( cli_strcmp(azArg[1], "-")==0 ){
      sqlite3IoTrace = iotracePrintf;
      iotrace = stdout;
    }else{
      iotrace = sqlite3_fopen(azArg[1], "w");
      if( iotrace==0 ){
        sqlite3_fprintf(stderr,"Error: cannot open \"%s\"\n", azArg[1]);
        sqlite3IoTrace = 0;
        rc = 1;
      }else{
        sqlite3IoTrace = iotracePrintf;
      }
    }
  }else
#endif

  if( c=='l' && n>=5 && cli_strncmp(azArg[0], "limits", n)==0 ){
    static const struct {
       const char *zLimitName;   /* Name of a limit */
       int limitCode;            /* Integer code for that limit */
    } aLimit[] = {
      { "length",                SQLITE_LIMIT_LENGTH                    },
      { "sql_length",            SQLITE_LIMIT_SQL_LENGTH                },
      { "column",                SQLITE_LIMIT_COLUMN                    },
      { "expr_depth",            SQLITE_LIMIT_EXPR_DEPTH                },
      { "compound_select",       SQLITE_LIMIT_COMPOUND_SELECT           },
      { "vdbe_op",               SQLITE_LIMIT_VDBE_OP                   },
      { "function_arg",          SQLITE_LIMIT_FUNCTION_ARG              },
      { "attached",              SQLITE_LIMIT_ATTACHED                  },
      { "like_pattern_length",   SQLITE_LIMIT_LIKE_PATTERN_LENGTH       },
      { "variable_number",       SQLITE_LIMIT_VARIABLE_NUMBER           },
      { "trigger_depth",         SQLITE_LIMIT_TRIGGER_DEPTH             },
      { "worker_threads",        SQLITE_LIMIT_WORKER_THREADS            },
    };
    int i, n2;
    open_db(p, 0);
    if( nArg==1 ){
      for(i=0; i<ArraySize(aLimit); i++){
        sqlite3_fprintf(stdout, "%20s %d\n", aLimit[i].zLimitName,
              sqlite3_limit(p->db, aLimit[i].limitCode, -1));
      }
    }else if( nArg>3 ){
      eputz("Usage: .limit NAME ?NEW-VALUE?\n");
      rc = 1;
      goto meta_command_exit;
    }else{
      int iLimit = -1;
      n2 = strlen30(azArg[1]);
      for(i=0; i<ArraySize(aLimit); i++){
        if( sqlite3_strnicmp(aLimit[i].zLimitName, azArg[1], n2)==0 ){
          if( iLimit<0 ){
            iLimit = i;
          }else{
            sqlite3_fprintf(stderr,"ambiguous limit: \"%s\"\n", azArg[1]);
            rc = 1;
            goto meta_command_exit;
          }
        }
      }
      if( iLimit<0 ){
        sqlite3_fprintf(stderr,"unknown limit: \"%s\"\n"
              "enter \".limits\" with no arguments for a list.\n",
              azArg[1]);
        rc = 1;
        goto meta_command_exit;
      }
      if( nArg==3 ){
        sqlite3_limit(p->db, aLimit[iLimit].limitCode,
                      (int)integerValue(azArg[2]));
      }
      sqlite3_fprintf(stdout, "%20s %d\n", aLimit[iLimit].zLimitName,
            sqlite3_limit(p->db, aLimit[iLimit].limitCode, -1));
    }
  }else

  if( c=='l' && n>2 && cli_strncmp(azArg[0], "lint", n)==0 ){
    open_db(p, 0);
    lintDotCommand(p, azArg, nArg);
  }else

#if !defined(SQLITE_OMIT_LOAD_EXTENSION) && !defined(SQLITE_SHELL_FIDDLE)
  if( c=='l' && cli_strncmp(azArg[0], "load", n)==0 ){
    const char *zFile, *zProc;
    char *zErrMsg = 0;
    failIfSafeMode(p, "cannot run .load in safe mode");
    if( nArg<2 || azArg[1][0]==0 ){
      /* Must have a non-empty FILE. (Will not load self.) */
      eputz("Usage: .load FILE ?ENTRYPOINT?\n");
      rc = 1;
      goto meta_command_exit;
    }
    zFile = azArg[1];
    zProc = nArg>=3 ? azArg[2] : 0;
    open_db(p, 0);
    rc = sqlite3_load_extension(p->db, zFile, zProc, &zErrMsg);
    if( rc!=SQLITE_OK ){
      shellEmitError(zErrMsg);
      sqlite3_free(zErrMsg);
      rc = 1;
    }
  }else
#endif

  if( c=='l' && cli_strncmp(azArg[0], "log", n)==0 ){
    if( nArg!=2 ){
      eputz("Usage: .log FILENAME\n");
      rc = 1;
    }else{
      const char *zFile = azArg[1];
      if( p->bSafeMode
       && cli_strcmp(zFile,"on")!=0
       && cli_strcmp(zFile,"off")!=0
      ){
        sputz(stdout, "cannot set .log to anything other"
              " than \"on\" or \"off\"\n");
        zFile = "off";
      }
      output_file_close(p->pLog);
      if( cli_strcmp(zFile,"on")==0 ) zFile = "stdout";
      p->pLog = output_file_open(zFile);
    }
  }else

  if( c=='m' && cli_strncmp(azArg[0], "mode", n)==0 ){
    const char *zMode = 0;
    const char *zTabname = 0;
    int i, n2;
    ColModeOpts cmOpts = ColModeOpts_default;
    for(i=1; i<nArg; i++){
      const char *z = azArg[i];
      if( optionMatch(z,"wrap") && i+1<nArg ){
        cmOpts.iWrap = integerValue(azArg[++i]);
      }else if( optionMatch(z,"ww") ){
        cmOpts.bWordWrap = 1;
      }else if( optionMatch(z,"wordwrap") && i+1<nArg ){
        cmOpts.bWordWrap = (u8)booleanValue(azArg[++i]);
      }else if( optionMatch(z,"quote") ){
        cmOpts.bQuote = 1;
      }else if( optionMatch(z,"noquote") ){
        cmOpts.bQuote = 0;
      }else if( zMode==0 ){
        zMode = z;
        /* Apply defaults for qbox pseudo-mode.  If that
         * overwrites already-set values, user was informed of this.
         */
        if( cli_strcmp(z, "qbox")==0 ){
          ColModeOpts cmo = ColModeOpts_default_qbox;
          zMode = "box";
          cmOpts = cmo;
        }
      }else if( zTabname==0 ){
        zTabname = z;
      }else if( z[0]=='-' ){
        sqlite3_fprintf(stderr,"unknown option: %s\n", z);
        eputz("options:\n"
              "  --noquote\n"
              "  --quote\n"
              "  --wordwrap on/off\n"
              "  --wrap N\n"
              "  --ww\n");
        rc = 1;
        goto meta_command_exit;
      }else{
        sqlite3_fprintf(stderr,"extra argument: \"%s\"\n", z);
        rc = 1;
        goto meta_command_exit;
      }
    }
    if( zMode==0 ){
      if( p->mode==MODE_Column
       || (p->mode>=MODE_Markdown && p->mode<=MODE_Box)
      ){
        sqlite3_fprintf(p->out,
              "current output mode: %s --wrap %d --wordwrap %s --%squote\n",
              modeDescr[p->mode], p->cmOpts.iWrap,
              p->cmOpts.bWordWrap ? "on" : "off",
              p->cmOpts.bQuote ? "" : "no");
      }else{
        sqlite3_fprintf(p->out,
              "current output mode: %s\n", modeDescr[p->mode]);
      }
      zMode = modeDescr[p->mode];
    }
    n2 = strlen30(zMode);
    if( cli_strncmp(zMode,"lines",n2)==0 ){
      p->mode = MODE_Line;
      sqlite3_snprintf(sizeof(p->rowSeparator), p->rowSeparator, SEP_Row);
    }else if( cli_strncmp(zMode,"columns",n2)==0 ){
      p->mode = MODE_Column;
      if( (p->shellFlgs & SHFLG_HeaderSet)==0 ){
        p->showHeader = 1;
      }
      sqlite3_snprintf(sizeof(p->rowSeparator), p->rowSeparator, SEP_Row);
      p->cmOpts = cmOpts;
    }else if( cli_strncmp(zMode,"list",n2)==0 ){
      p->mode = MODE_List;
      sqlite3_snprintf(sizeof(p->colSeparator), p->colSeparator, SEP_Column);
      sqlite3_snprintf(sizeof(p->rowSeparator), p->rowSeparator, SEP_Row);
    }else if( cli_strncmp(zMode,"html",n2)==0 ){
      p->mode = MODE_Html;
    }else if( cli_strncmp(zMode,"tcl",n2)==0 ){
      p->mode = MODE_Tcl;
      sqlite3_snprintf(sizeof(p->colSeparator), p->colSeparator, SEP_Space);
      sqlite3_snprintf(sizeof(p->rowSeparator), p->rowSeparator, SEP_Row);
    }else if( cli_strncmp(zMode,"csv",n2)==0 ){
      p->mode = MODE_Csv;
      sqlite3_snprintf(sizeof(p->colSeparator), p->colSeparator, SEP_Comma);
      sqlite3_snprintf(sizeof(p->rowSeparator), p->rowSeparator, SEP_CrLf);
    }else if( cli_strncmp(zMode,"tabs",n2)==0 ){
      p->mode = MODE_List;
      sqlite3_snprintf(sizeof(p->colSeparator), p->colSeparator, SEP_Tab);
    }else if( cli_strncmp(zMode,"insert",n2)==0 ){
      p->mode = MODE_Insert;
      set_table_name(p, zTabname ? zTabname : "table");
    }else if( cli_strncmp(zMode,"quote",n2)==0 ){
      p->mode = MODE_Quote;
      sqlite3_snprintf(sizeof(p->colSeparator), p->colSeparator, SEP_Comma);
      sqlite3_snprintf(sizeof(p->rowSeparator), p->rowSeparator, SEP_Row);
    }else if( cli_strncmp(zMode,"ascii",n2)==0 ){
      p->mode = MODE_Ascii;
      sqlite3_snprintf(sizeof(p->colSeparator), p->colSeparator, SEP_Unit);
      sqlite3_snprintf(sizeof(p->rowSeparator), p->rowSeparator, SEP_Record);
    }else if( cli_strncmp(zMode,"markdown",n2)==0 ){
      p->mode = MODE_Markdown;
      p->cmOpts = cmOpts;
    }else if( cli_strncmp(zMode,"table",n2)==0 ){
      p->mode = MODE_Table;
      p->cmOpts = cmOpts;
    }else if( cli_strncmp(zMode,"box",n2)==0 ){
      p->mode = MODE_Box;
      p->cmOpts = cmOpts;
    }else if( cli_strncmp(zMode,"count",n2)==0 ){
      p->mode = MODE_Count;
    }else if( cli_strncmp(zMode,"off",n2)==0 ){
      p->mode = MODE_Off;
    }else if( cli_strncmp(zMode,"json",n2)==0 ){
      p->mode = MODE_Json;
    }else{
      eputz("Error: mode should be one of: "
            "ascii box column csv html insert json line list markdown "
            "qbox quote table tabs tcl\n");
      rc = 1;
    }
    p->cMode = p->mode;
  }else

#ifndef SQLITE_SHELL_FIDDLE
  if( c=='n' && cli_strcmp(azArg[0], "nonce")==0 ){
    if( nArg!=2 ){
      eputz("Usage: .nonce NONCE\n");
      rc = 1;
    }else if( p->zNonce==0 || cli_strcmp(azArg[1],p->zNonce)!=0 ){
      sqlite3_fprintf(stderr,"line %d: incorrect nonce: \"%s\"\n",
            p->lineno, azArg[1]);
      exit(1);
    }else{
      p->bSafeMode = 0;
      return 0;  /* Return immediately to bypass the safe mode reset
                 ** at the end of this procedure */
    }
  }else
#endif /* !defined(SQLITE_SHELL_FIDDLE) */

  if( c=='n' && cli_strncmp(azArg[0], "nullvalue", n)==0 ){
    if( nArg==2 ){
      sqlite3_snprintf(sizeof(p->nullValue), p->nullValue,
                       "%.*s", (int)ArraySize(p->nullValue)-1, azArg[1]);
    }else{
      eputz("Usage: .nullvalue STRING\n");
      rc = 1;
    }
  }else

  if( c=='o' && cli_strncmp(azArg[0], "open", n)==0 && n>=2 ){
    const char *zFN = 0;     /* Pointer to constant filename */
    char *zNewFilename = 0;  /* Name of the database file to open */
    int iName = 1;           /* Index in azArg[] of the filename */
    int newFlag = 0;         /* True to delete file before opening */
    int openMode = SHELL_OPEN_UNSPEC;

    /* Check for command-line arguments */
    for(iName=1; iName<nArg; iName++){
      const char *z = azArg[iName];
#ifndef SQLITE_SHELL_FIDDLE
      if( optionMatch(z,"new") ){
        newFlag = 1;
#ifdef SQLITE_HAVE_ZLIB
      }else if( optionMatch(z, "zip") ){
        openMode = SHELL_OPEN_ZIPFILE;
#endif
      }else if( optionMatch(z, "append") ){
        openMode = SHELL_OPEN_APPENDVFS;
      }else if( optionMatch(z, "readonly") ){
        openMode = SHELL_OPEN_READONLY;
      }else if( optionMatch(z, "nofollow") ){
        p->openFlags |= SQLITE_OPEN_NOFOLLOW;
#ifndef SQLITE_OMIT_DESERIALIZE
      }else if( optionMatch(z, "deserialize") ){
        openMode = SHELL_OPEN_DESERIALIZE;
      }else if( optionMatch(z, "hexdb") ){
        openMode = SHELL_OPEN_HEXDB;
      }else if( optionMatch(z, "maxsize") && iName+1<nArg ){
        p->szMax = integerValue(azArg[++iName]);
#endif /* SQLITE_OMIT_DESERIALIZE */
      }else
#endif /* !SQLITE_SHELL_FIDDLE */
      if( z[0]=='-' ){
        sqlite3_fprintf(stderr,"unknown option: %s\n", z);
        rc = 1;
        goto meta_command_exit;
      }else if( zFN ){
        sqlite3_fprintf(stderr,"extra argument: \"%s\"\n", z);
        rc = 1;
        goto meta_command_exit;
      }else{
        zFN = z;
      }
    }

    /* Close the existing database */
    session_close_all(p, -1);
    close_db(p->db);
    p->db = 0;
    p->pAuxDb->zDbFilename = 0;
    sqlite3_free(p->pAuxDb->zFreeOnClose);
    p->pAuxDb->zFreeOnClose = 0;
    p->openMode = openMode;
    p->openFlags = 0;
    p->szMax = 0;

    /* If a filename is specified, try to open it first */
    if( zFN || p->openMode==SHELL_OPEN_HEXDB ){
      if( newFlag && zFN && !p->bSafeMode ) shellDeleteFile(zFN);
#ifndef SQLITE_SHELL_FIDDLE
      if( p->bSafeMode
       && p->openMode!=SHELL_OPEN_HEXDB
       && zFN
       && cli_strcmp(zFN,":memory:")!=0
      ){
        failIfSafeMode(p, "cannot open disk-based database files in safe mode");
      }
#else
      /* WASM mode has its own sandboxed pseudo-filesystem. */
#endif
      if( zFN ){
        zNewFilename = sqlite3_mprintf("%s", zFN);
        shell_check_oom(zNewFilename);
      }else{
        zNewFilename = 0;
      }
      p->pAuxDb->zDbFilename = zNewFilename;
      open_db(p, OPEN_DB_KEEPALIVE);
      if( p->db==0 ){
        sqlite3_fprintf(stderr,"Error: cannot open '%s'\n", zNewFilename);
        sqlite3_free(zNewFilename);
      }else{
        p->pAuxDb->zFreeOnClose = zNewFilename;
      }
    }
    if( p->db==0 ){
      /* As a fall-back open a TEMP database */
      p->pAuxDb->zDbFilename = 0;
      open_db(p, 0);
    }
  }else

#ifndef SQLITE_SHELL_FIDDLE
  if( (c=='o'
        && (cli_strncmp(azArg[0], "output", n)==0
            || cli_strncmp(azArg[0], "once", n)==0))
   || (c=='e' && n==5 && cli_strcmp(azArg[0],"excel")==0)
   || (c=='w' && n==3 && cli_strcmp(azArg[0],"www")==0)
  ){
    char *zFile = 0;
    int i;
    int eMode = 0;
    int bOnce = 0;            /* 0: .output, 1: .once, 2: .excel/.www */
    int bPlain = 0;           /* --plain option */
    static const char *zBomUtf8 = "\357\273\277";
    const char *zBom = 0;

    failIfSafeMode(p, "cannot run .%s in safe mode", azArg[0]);
    if( c=='e' ){
      eMode = 'x';
      bOnce = 2;
    }else if( c=='w' ){
      eMode = 'w';
      bOnce = 2;
    }else if( cli_strncmp(azArg[0],"once",n)==0 ){
      bOnce = 1;
    }
    for(i=1; i<nArg; i++){
      char *z = azArg[i];
      if( z[0]=='-' ){
        if( z[1]=='-' ) z++;
        if( cli_strcmp(z,"-bom")==0 ){
          zBom = zBomUtf8;
        }else if( cli_strcmp(z,"-plain")==0 ){
          bPlain = 1;
        }else if( c=='o' && cli_strcmp(z,"-x")==0 ){
          eMode = 'x';  /* spreadsheet */
        }else if( c=='o' && cli_strcmp(z,"-e")==0 ){
          eMode = 'e';  /* text editor */
        }else if( c=='o' && cli_strcmp(z,"-w")==0 ){
          eMode = 'w';  /* Web browser */
        }else{
          sqlite3_fprintf(p->out, 
                          "ERROR: unknown option: \"%s\". Usage:\n", azArg[i]);
          showHelp(p->out, azArg[0]);
          rc = 1;
          goto meta_command_exit;
        }
      }else if( zFile==0 && eMode==0 ){
        zFile = sqlite3_mprintf("%s", z);
        if( zFile && zFile[0]=='|' ){
          while( i+1<nArg ) zFile = sqlite3_mprintf("%z %s", zFile, azArg[++i]);
          break;
        }
      }else{
        sqlite3_fprintf(p->out,
            "ERROR: extra parameter: \"%s\".  Usage:\n", azArg[i]);
        showHelp(p->out, azArg[0]);
        rc = 1;
        sqlite3_free(zFile);
        goto meta_command_exit;
      }
    }
    if( zFile==0 ){
      zFile = sqlite3_mprintf("stdout");
    }
    if( bOnce ){
      p->outCount = 2;
    }else{
      p->outCount = 0;
    }
    output_reset(p);
#ifndef SQLITE_NOHAVE_SYSTEM
    if( eMode=='e' || eMode=='x' || eMode=='w' ){
      p->doXdgOpen = 1;
      outputModePush(p);
      if( eMode=='x' ){
        /* spreadsheet mode.  Output as CSV. */
        newTempFile(p, "csv");
        ShellClearFlag(p, SHFLG_Echo);
        p->mode = MODE_Csv;
        sqlite3_snprintf(sizeof(p->colSeparator), p->colSeparator, SEP_Comma);
        sqlite3_snprintf(sizeof(p->rowSeparator), p->rowSeparator, SEP_CrLf);
#ifdef _WIN32
        zBom = zBomUtf8;  /* Always include the BOM on Windows, as Excel does
                          ** not work without it. */
#endif
      }else if( eMode=='w' ){
        /* web-browser mode. */
        newTempFile(p, "html");
        if( !bPlain ) p->mode = MODE_Www;
      }else{
        /* text editor mode */
        newTempFile(p, "txt");
      }
      sqlite3_free(zFile);
      zFile = sqlite3_mprintf("%s", p->zTempFile);
    }
#endif /* SQLITE_NOHAVE_SYSTEM */
    shell_check_oom(zFile);
    if( zFile[0]=='|' ){
#ifdef SQLITE_OMIT_POPEN
      eputz("Error: pipes are not supported in this OS\n");
      rc = 1;
      output_redir(p, stdout);
#else
      FILE *pfPipe = sqlite3_popen(zFile + 1, "w");
      if( pfPipe==0 ){
        sqlite3_fprintf(stderr,"Error: cannot open pipe \"%s\"\n", zFile + 1);
        rc = 1;
      }else{
        output_redir(p, pfPipe);
        if( zBom ) sqlite3_fputs(zBom, pfPipe);
        sqlite3_snprintf(sizeof(p->outfile), p->outfile, "%s", zFile);
      }
#endif
    }else{
      FILE *pfFile = output_file_open(zFile);
      if( pfFile==0 ){
        if( cli_strcmp(zFile,"off")!=0 ){
          sqlite3_fprintf(stderr,"Error: cannot write to \"%s\"\n", zFile);
        }
        rc = 1;
      } else {
        output_redir(p, pfFile);
        if( zBom ) sqlite3_fputs(zBom, pfFile);
        if( bPlain && eMode=='w' ){
          sqlite3_fputs(
            "<!DOCTYPE html>\n<BODY>\n<PLAINTEXT>\n",
            pfFile
          );
        }
        sqlite3_snprintf(sizeof(p->outfile), p->outfile, "%s", zFile);
      }
    }
    sqlite3_free(zFile);
  }else
#endif /* !defined(SQLITE_SHELL_FIDDLE) */

  if( c=='p' && n>=3 && cli_strncmp(azArg[0], "parameter", n)==0 ){
    open_db(p,0);
    if( nArg<=1 ) goto parameter_syntax_error;

    /* .parameter clear
    ** Clear all bind parameters by dropping the TEMP table that holds them.
    */
    if( nArg==2 && cli_strcmp(azArg[1],"clear")==0 ){
      sqlite3_exec(p->db, "DROP TABLE IF EXISTS temp.sqlite_parameters;",
                   0, 0, 0);
    }else

    /* .parameter list
    ** List all bind parameters.
    */
    if( nArg==2 && cli_strcmp(azArg[1],"list")==0 ){
      sqlite3_stmt *pStmt = 0;
      int rx;
      int len = 0;
      rx = sqlite3_prepare_v2(p->db,
             "SELECT max(length(key)) "
             "FROM temp.sqlite_parameters;", -1, &pStmt, 0);
      if( rx==SQLITE_OK && sqlite3_step(pStmt)==SQLITE_ROW ){
        len = sqlite3_column_int(pStmt, 0);
        if( len>40 ) len = 40;
      }
      sqlite3_finalize(pStmt);
      pStmt = 0;
      if( len ){
        rx = sqlite3_prepare_v2(p->db,
             "SELECT key, quote(value) "
             "FROM temp.sqlite_parameters;", -1, &pStmt, 0);
        while( rx==SQLITE_OK && sqlite3_step(pStmt)==SQLITE_ROW ){
          sqlite3_fprintf(p->out,
                "%-*s %s\n", len, sqlite3_column_text(pStmt,0),
                sqlite3_column_text(pStmt,1));
        }
        sqlite3_finalize(pStmt);
      }
    }else

    /* .parameter init
    ** Make sure the TEMP table used to hold bind parameters exists.
    ** Create it if necessary.
    */
    if( nArg==2 && cli_strcmp(azArg[1],"init")==0 ){
      bind_table_init(p);
    }else

    /* .parameter set NAME VALUE
    ** Set or reset a bind parameter.  NAME should be the full parameter
    ** name exactly as it appears in the query.  (ex: $abc, @def).  The
    ** VALUE can be in either SQL literal notation, or if not it will be
    ** understood to be a text string.
    */
    if( nArg==4 && cli_strcmp(azArg[1],"set")==0 ){
      int rx;
      char *zSql;
      sqlite3_stmt *pStmt;
      const char *zKey = azArg[2];
      const char *zValue = azArg[3];
      bind_table_init(p);
      zSql = sqlite3_mprintf(
                  "REPLACE INTO temp.sqlite_parameters(key,value)"
                  "VALUES(%Q,%s);", zKey, zValue);
      shell_check_oom(zSql);
      pStmt = 0;
      rx = sqlite3_prepare_v2(p->db, zSql, -1, &pStmt, 0);
      sqlite3_free(zSql);
      if( rx!=SQLITE_OK ){
        sqlite3_finalize(pStmt);
        pStmt = 0;
        zSql = sqlite3_mprintf(
                   "REPLACE INTO temp.sqlite_parameters(key,value)"
                   "VALUES(%Q,%Q);", zKey, zValue);
        shell_check_oom(zSql);
        rx = sqlite3_prepare_v2(p->db, zSql, -1, &pStmt, 0);
        sqlite3_free(zSql);
        if( rx!=SQLITE_OK ){
          sqlite3_fprintf(p->out, "Error: %s\n", sqlite3_errmsg(p->db));
          sqlite3_finalize(pStmt);
          pStmt = 0;
          rc = 1;
        }
      }
      sqlite3_step(pStmt);
      sqlite3_finalize(pStmt);
    }else

    /* .parameter unset NAME
    ** Remove the NAME binding from the parameter binding table, if it
    ** exists.
    */
    if( nArg==3 && cli_strcmp(azArg[1],"unset")==0 ){
      char *zSql = sqlite3_mprintf(
          "DELETE FROM temp.sqlite_parameters WHERE key=%Q", azArg[2]);
      shell_check_oom(zSql);
      sqlite3_exec(p->db, zSql, 0, 0, 0);
      sqlite3_free(zSql);
    }else
    /* If no command name matches, show a syntax error */
    parameter_syntax_error:
    showHelp(p->out, "parameter");
  }else

  if( c=='p' && n>=3 && cli_strncmp(azArg[0], "print", n)==0 ){
    int i;
    for(i=1; i<nArg; i++){
      if( i>1 ) sqlite3_fputs(" ", p->out);
      sqlite3_fputs(azArg[i], p->out);
    }
    sqlite3_fputs("\n", p->out);
  }else

#ifndef SQLITE_OMIT_PROGRESS_CALLBACK
  if( c=='p' && n>=3 && cli_strncmp(azArg[0], "progress", n)==0 ){
    int i;
    int nn = 0;
    p->flgProgress = 0;
    p->mxProgress = 0;
    p->nProgress = 0;
    for(i=1; i<nArg; i++){
      const char *z = azArg[i];
      if( z[0]=='-' ){
        z++;
        if( z[0]=='-' ) z++;
        if( cli_strcmp(z,"quiet")==0 || cli_strcmp(z,"q")==0 ){
          p->flgProgress |= SHELL_PROGRESS_QUIET;
          continue;
        }
        if( cli_strcmp(z,"reset")==0 ){
          p->flgProgress |= SHELL_PROGRESS_RESET;
          continue;
        }
        if( cli_strcmp(z,"once")==0 ){
          p->flgProgress |= SHELL_PROGRESS_ONCE;
          continue;
        }
        if( cli_strcmp(z,"limit")==0 ){
          if( i+1>=nArg ){
            eputz("Error: missing argument on --limit\n");
            rc = 1;
            goto meta_command_exit;
          }else{
            p->mxProgress = (int)integerValue(azArg[++i]);
          }
          continue;
        }
        sqlite3_fprintf(stderr,"Error: unknown option: \"%s\"\n", azArg[i]);
        rc = 1;
        goto meta_command_exit;
      }else{
        nn = (int)integerValue(z);
      }
    }
    open_db(p, 0);
    sqlite3_progress_handler(p->db, nn, progress_handler, p);
  }else
#endif /* SQLITE_OMIT_PROGRESS_CALLBACK */

  if( c=='p' && cli_strncmp(azArg[0], "prompt", n)==0 ){
    if( nArg >= 2) {
      shell_strncpy(mainPrompt,azArg[1],(int)ArraySize(mainPrompt)-1);
    }
    if( nArg >= 3) {
      shell_strncpy(continuePrompt,azArg[2],(int)ArraySize(continuePrompt)-1);
    }
  }else

#ifndef SQLITE_SHELL_FIDDLE
  if( c=='q' && cli_strncmp(azArg[0], "quit", n)==0 ){
    rc = 2;
  }else
#endif

#ifndef SQLITE_SHELL_FIDDLE
  if( c=='r' && n>=3 && cli_strncmp(azArg[0], "read", n)==0 ){
    FILE *inSaved = p->in;
    int savedLineno = p->lineno;
    failIfSafeMode(p, "cannot run .read in safe mode");
    if( nArg!=2 ){
      eputz("Usage: .read FILE\n");
      rc = 1;
      goto meta_command_exit;
    }
    if( azArg[1][0]=='|' ){
#ifdef SQLITE_OMIT_POPEN
      eputz("Error: pipes are not supported in this OS\n");
      rc = 1;
#else
      p->in = sqlite3_popen(azArg[1]+1, "r");
      if( p->in==0 ){
        sqlite3_fprintf(stderr,"Error: cannot open \"%s\"\n", azArg[1]);
        rc = 1;
      }else{
        rc = process_input(p);
        pclose(p->in);
      }
#endif
    }else if( (p->in = openChrSource(azArg[1]))==0 ){
      sqlite3_fprintf(stderr,"Error: cannot open \"%s\"\n", azArg[1]);
      rc = 1;
    }else{
      rc = process_input(p);
      fclose(p->in);
    }
    p->in = inSaved;
    p->lineno = savedLineno;
  }else
#endif /* !defined(SQLITE_SHELL_FIDDLE) */

#ifndef SQLITE_SHELL_FIDDLE
  if( c=='r' && n>=3 && cli_strncmp(azArg[0], "restore", n)==0 ){
    const char *zSrcFile;
    const char *zDb;
    sqlite3 *pSrc;
    sqlite3_backup *pBackup;
    int nTimeout = 0;

    failIfSafeMode(p, "cannot run .restore in safe mode");
    if( nArg==2 ){
      zSrcFile = azArg[1];
      zDb = "main";
    }else if( nArg==3 ){
      zSrcFile = azArg[2];
      zDb = azArg[1];
    }else{
      eputz("Usage: .restore ?DB? FILE\n");
      rc = 1;
      goto meta_command_exit;
    }
    rc = sqlite3_open(zSrcFile, &pSrc);
    if( rc!=SQLITE_OK ){
      sqlite3_fprintf(stderr,"Error: cannot open \"%s\"\n", zSrcFile);
      close_db(pSrc);
      return 1;
    }
    open_db(p, 0);
    pBackup = sqlite3_backup_init(p->db, zDb, pSrc, "main");
    if( pBackup==0 ){
      shellDatabaseError(p->db);
      close_db(pSrc);
      return 1;
    }
    while( (rc = sqlite3_backup_step(pBackup,100))==SQLITE_OK
          || rc==SQLITE_BUSY  ){
      if( rc==SQLITE_BUSY ){
        if( nTimeout++ >= 3 ) break;
        sqlite3_sleep(100);
      }
    }
    sqlite3_backup_finish(pBackup);
    if( rc==SQLITE_DONE ){
      rc = 0;
    }else if( rc==SQLITE_BUSY || rc==SQLITE_LOCKED ){
      eputz("Error: source database is busy\n");
      rc = 1;
    }else{
      shellDatabaseError(p->db);
      rc = 1;
    }
    close_db(pSrc);
  }else
#endif /* !defined(SQLITE_SHELL_FIDDLE) */

  if( c=='s' && cli_strncmp(azArg[0], "scanstats", n)==0 ){
    if( nArg==2 ){
      if( cli_strcmp(azArg[1], "vm")==0 ){
        p->scanstatsOn = 3;
      }else
      if( cli_strcmp(azArg[1], "est")==0 ){
        p->scanstatsOn = 2;
      }else{
        p->scanstatsOn = (u8)booleanValue(azArg[1]);
      }
      open_db(p, 0);
      sqlite3_db_config(
          p->db, SQLITE_DBCONFIG_STMT_SCANSTATUS, p->scanstatsOn, (int*)0
      );
#if !defined(SQLITE_ENABLE_STMT_SCANSTATUS)
      eputz("Warning: .scanstats not available in this build.\n");
#elif !defined(SQLITE_ENABLE_BYTECODE_VTAB)
      if( p->scanstatsOn==3 ){
        eputz("Warning: \".scanstats vm\" not available in this build.\n");
      }
#endif
    }else{
      eputz("Usage: .scanstats on|off|est\n");
      rc = 1;
    }
  }else

  if( c=='s' && cli_strncmp(azArg[0], "schema", n)==0 ){
    ShellText sSelect;
    ShellState data;
    char *zErrMsg = 0;
    const char *zDiv = "(";
    const char *zName = 0;
    int iSchema = 0;
    int bDebug = 0;
    int bNoSystemTabs = 0;
    int ii;

    open_db(p, 0);
    memcpy(&data, p, sizeof(data));
    data.showHeader = 0;
    data.cMode = data.mode = MODE_Semi;
    initText(&sSelect);
    for(ii=1; ii<nArg; ii++){
      if( optionMatch(azArg[ii],"indent") ){
        data.cMode = data.mode = MODE_Pretty;
      }else if( optionMatch(azArg[ii],"debug") ){
        bDebug = 1;
      }else if( optionMatch(azArg[ii],"nosys") ){
        bNoSystemTabs = 1;
      }else if( azArg[ii][0]=='-' ){
        sqlite3_fprintf(stderr,"Unknown option: \"%s\"\n", azArg[ii]);
        rc = 1;
        goto meta_command_exit;
      }else if( zName==0 ){
        zName = azArg[ii];
      }else{
        eputz("Usage: .schema ?--indent? ?--nosys? ?LIKE-PATTERN?\n");
        rc = 1;
        goto meta_command_exit;
      }
    }
    if( zName!=0 ){
      int isSchema = sqlite3_strlike(zName, "sqlite_master", '\\')==0
                  || sqlite3_strlike(zName, "sqlite_schema", '\\')==0
                  || sqlite3_strlike(zName,"sqlite_temp_master", '\\')==0
                  || sqlite3_strlike(zName,"sqlite_temp_schema", '\\')==0;
      if( isSchema ){
        char *new_argv[2], *new_colv[2];
        new_argv[0] = sqlite3_mprintf(
                      "CREATE TABLE %s (\n"
                      "  type text,\n"
                      "  name text,\n"
                      "  tbl_name text,\n"
                      "  rootpage integer,\n"
                      "  sql text\n"
                      ")", zName);
        shell_check_oom(new_argv[0]);
        new_argv[1] = 0;
        new_colv[0] = "sql";
        new_colv[1] = 0;
        callback(&data, 1, new_argv, new_colv);
        sqlite3_free(new_argv[0]);
      }
    }
    if( zDiv ){
      sqlite3_stmt *pStmt = 0;
      rc = sqlite3_prepare_v2(p->db, "SELECT name FROM pragma_database_list",
                              -1, &pStmt, 0);
      if( rc ){
        shellDatabaseError(p->db);
        sqlite3_finalize(pStmt);
        rc = 1;
        goto meta_command_exit;
      }
      appendText(&sSelect, "SELECT sql FROM", 0);
      iSchema = 0;
      while( sqlite3_step(pStmt)==SQLITE_ROW ){
        const char *zDb = (const char*)sqlite3_column_text(pStmt, 0);
        char zScNum[30];
        sqlite3_snprintf(sizeof(zScNum), zScNum, "%d", ++iSchema);
        appendText(&sSelect, zDiv, 0);
        zDiv = " UNION ALL ";
        appendText(&sSelect, "SELECT shell_add_schema(sql,", 0);
        if( sqlite3_stricmp(zDb, "main")!=0 ){
          appendText(&sSelect, zDb, '\'');
        }else{
          appendText(&sSelect, "NULL", 0);
        }
        appendText(&sSelect, ",name) AS sql, type, tbl_name, name, rowid,", 0);
        appendText(&sSelect, zScNum, 0);
        appendText(&sSelect, " AS snum, ", 0);
        appendText(&sSelect, zDb, '\'');
        appendText(&sSelect, " AS sname FROM ", 0);
        appendText(&sSelect, zDb, quoteChar(zDb));
        appendText(&sSelect, ".sqlite_schema", 0);
      }
      sqlite3_finalize(pStmt);
#ifndef SQLITE_OMIT_INTROSPECTION_PRAGMAS
      if( zName ){
        appendText(&sSelect,
           " UNION ALL SELECT shell_module_schema(name),"
           " 'table', name, name, name, 9e+99, 'main' FROM pragma_module_list",
        0);
      }
#endif
      appendText(&sSelect, ") WHERE ", 0);
      if( zName ){
        char *zQarg = sqlite3_mprintf("%Q", zName);
        int bGlob;
        shell_check_oom(zQarg);
        bGlob = strchr(zName, '*') != 0 || strchr(zName, '?') != 0 ||
                strchr(zName, '[') != 0;
        if( strchr(zName, '.') ){
          appendText(&sSelect, "lower(printf('%s.%s',sname,tbl_name))", 0);
        }else{
          appendText(&sSelect, "lower(tbl_name)", 0);
        }
        appendText(&sSelect, bGlob ? " GLOB " : " LIKE ", 0);
        appendText(&sSelect, zQarg, 0);
        if( !bGlob ){
          appendText(&sSelect, " ESCAPE '\\' ", 0);
        }
        appendText(&sSelect, " AND ", 0);
        sqlite3_free(zQarg);
      }
      if( bNoSystemTabs ){
        appendText(&sSelect, "name NOT LIKE 'sqlite_%%' AND ", 0);
      }
      appendText(&sSelect, "sql IS NOT NULL"
                           " ORDER BY snum, rowid", 0);
      if( bDebug ){
        sqlite3_fprintf(p->out, "SQL: %s;\n", sSelect.z);
      }else{
        rc = sqlite3_exec(p->db, sSelect.z, callback, &data, &zErrMsg);
      }
      freeText(&sSelect);
    }
    if( zErrMsg ){
      shellEmitError(zErrMsg);
      sqlite3_free(zErrMsg);
      rc = 1;
    }else if( rc != SQLITE_OK ){
      eputz("Error: querying schema information\n");
      rc = 1;
    }else{
      rc = 0;
    }
  }else

  if( (c=='s' && n==11 && cli_strncmp(azArg[0], "selecttrace", n)==0)
   || (c=='t' && n==9  && cli_strncmp(azArg[0], "treetrace", n)==0)
  ){
    unsigned int x = nArg>=2? (unsigned int)integerValue(azArg[1]) : 0xffffffff;
    sqlite3_test_control(SQLITE_TESTCTRL_TRACEFLAGS, 1, &x);
  }else

#if defined(SQLITE_ENABLE_SESSION)
  if( c=='s' && cli_strncmp(azArg[0],"session",n)==0 && n>=3 ){
    struct AuxDb *pAuxDb = p->pAuxDb;
    OpenSession *pSession = &pAuxDb->aSession[0];
    char **azCmd = &azArg[1];
    int iSes = 0;
    int nCmd = nArg - 1;
    int i;
    if( nArg<=1 ) goto session_syntax_error;
    open_db(p, 0);
    if( nArg>=3 ){
      for(iSes=0; iSes<pAuxDb->nSession; iSes++){
        if( cli_strcmp(pAuxDb->aSession[iSes].zName, azArg[1])==0 ) break;
      }
      if( iSes<pAuxDb->nSession ){
        pSession = &pAuxDb->aSession[iSes];
        azCmd++;
        nCmd--;
      }else{
        pSession = &pAuxDb->aSession[0];
        iSes = 0;
      }
    }

    /* .session attach TABLE
    ** Invoke the sqlite3session_attach() interface to attach a particular
    ** table so that it is never filtered.
    */
    if( cli_strcmp(azCmd[0],"attach")==0 ){
      if( nCmd!=2 ) goto session_syntax_error;
      if( pSession->p==0 ){
        session_not_open:
        eputz("ERROR: No sessions are open\n");
      }else{
        rc = sqlite3session_attach(pSession->p, azCmd[1]);
        if( rc ){
          sqlite3_fprintf(stderr,
               "ERROR: sqlite3session_attach() returns %d\n",rc);
          rc = 0;
        }
      }
    }else

    /* .session changeset FILE
    ** .session patchset FILE
    ** Write a changeset or patchset into a file.  The file is overwritten.
    */
    if( cli_strcmp(azCmd[0],"changeset")==0
     || cli_strcmp(azCmd[0],"patchset")==0
    ){
      FILE *out = 0;
      failIfSafeMode(p, "cannot run \".session %s\" in safe mode", azCmd[0]);
      if( nCmd!=2 ) goto session_syntax_error;
      if( pSession->p==0 ) goto session_not_open;
      out = sqlite3_fopen(azCmd[1], "wb");
      if( out==0 ){
        sqlite3_fprintf(stderr,"ERROR: cannot open \"%s\" for writing\n",
              azCmd[1]);
      }else{
        int szChng;
        void *pChng;
        if( azCmd[0][0]=='c' ){
          rc = sqlite3session_changeset(pSession->p, &szChng, &pChng);
        }else{
          rc = sqlite3session_patchset(pSession->p, &szChng, &pChng);
        }
        if( rc ){
          sqlite3_fprintf(stdout, "Error: error code %d\n", rc);
          rc = 0;
        }
        if( pChng
          && fwrite(pChng, szChng, 1, out)!=1 ){
          sqlite3_fprintf(stderr,
              "ERROR: Failed to write entire %d-byte output\n", szChng);
        }
        sqlite3_free(pChng);
        fclose(out);
      }
    }else

    /* .session close
    ** Close the identified session
    */
    if( cli_strcmp(azCmd[0], "close")==0 ){
      if( nCmd!=1 ) goto session_syntax_error;
      if( pAuxDb->nSession ){
        session_close(pSession);
        pAuxDb->aSession[iSes] = pAuxDb->aSession[--pAuxDb->nSession];
      }
    }else

    /* .session enable ?BOOLEAN?
    ** Query or set the enable flag
    */
    if( cli_strcmp(azCmd[0], "enable")==0 ){
      int ii;
      if( nCmd>2 ) goto session_syntax_error;
      ii = nCmd==1 ? -1 : booleanValue(azCmd[1]);
      if( pAuxDb->nSession ){
        ii = sqlite3session_enable(pSession->p, ii);
        sqlite3_fprintf(p->out,
            "session %s enable flag = %d\n", pSession->zName, ii);
      }
    }else

    /* .session filter GLOB ....
    ** Set a list of GLOB patterns of table names to be excluded.
    */
    if( cli_strcmp(azCmd[0], "filter")==0 ){
      int ii, nByte;
      if( nCmd<2 ) goto session_syntax_error;
      if( pAuxDb->nSession ){
        for(ii=0; ii<pSession->nFilter; ii++){
          sqlite3_free(pSession->azFilter[ii]);
        }
        sqlite3_free(pSession->azFilter);
        nByte = sizeof(pSession->azFilter[0])*(nCmd-1);
        pSession->azFilter = sqlite3_malloc( nByte );
        shell_check_oom( pSession->azFilter );
        for(ii=1; ii<nCmd; ii++){
          char *x = pSession->azFilter[ii-1] = sqlite3_mprintf("%s", azCmd[ii]);
          shell_check_oom(x);
        }
        pSession->nFilter = ii-1;
      }
    }else

    /* .session indirect ?BOOLEAN?
    ** Query or set the indirect flag
    */
    if( cli_strcmp(azCmd[0], "indirect")==0 ){
      int ii;
      if( nCmd>2 ) goto session_syntax_error;
      ii = nCmd==1 ? -1 : booleanValue(azCmd[1]);
      if( pAuxDb->nSession ){
        ii = sqlite3session_indirect(pSession->p, ii);
        sqlite3_fprintf(p->out,
            "session %s indirect flag = %d\n", pSession->zName, ii);
      }
    }else

    /* .session isempty
    ** Determine if the session is empty
    */
    if( cli_strcmp(azCmd[0], "isempty")==0 ){
      int ii;
      if( nCmd!=1 ) goto session_syntax_error;
      if( pAuxDb->nSession ){
        ii = sqlite3session_isempty(pSession->p);
        sqlite3_fprintf(p->out,
             "session %s isempty flag = %d\n", pSession->zName, ii);
      }
    }else

    /* .session list
    ** List all currently open sessions
    */
    if( cli_strcmp(azCmd[0],"list")==0 ){
      for(i=0; i<pAuxDb->nSession; i++){
        sqlite3_fprintf(p->out, "%d %s\n", i, pAuxDb->aSession[i].zName);
      }
    }else

    /* .session open DB NAME
    ** Open a new session called NAME on the attached database DB.
    ** DB is normally "main".
    */
    if( cli_strcmp(azCmd[0],"open")==0 ){
      char *zName;
      if( nCmd!=3 ) goto session_syntax_error;
      zName = azCmd[2];
      if( zName[0]==0 ) goto session_syntax_error;
      for(i=0; i<pAuxDb->nSession; i++){
        if( cli_strcmp(pAuxDb->aSession[i].zName,zName)==0 ){
          sqlite3_fprintf(stderr,"Session \"%s\" already exists\n", zName);
          goto meta_command_exit;
        }
      }
      if( pAuxDb->nSession>=ArraySize(pAuxDb->aSession) ){
        sqlite3_fprintf(stderr,
           "Maximum of %d sessions\n", ArraySize(pAuxDb->aSession));
        goto meta_command_exit;
      }
      pSession = &pAuxDb->aSession[pAuxDb->nSession];
      rc = sqlite3session_create(p->db, azCmd[1], &pSession->p);
      if( rc ){
        sqlite3_fprintf(stderr,"Cannot open session: error code=%d\n", rc);
        rc = 0;
        goto meta_command_exit;
      }
      pSession->nFilter = 0;
      sqlite3session_table_filter(pSession->p, session_filter, pSession);
      pAuxDb->nSession++;
      pSession->zName = sqlite3_mprintf("%s", zName);
      shell_check_oom(pSession->zName);
    }else
    /* If no command name matches, show a syntax error */
    session_syntax_error:
    showHelp(p->out, "session");
  }else
#endif

#ifdef SQLITE_DEBUG
  /* Undocumented commands for internal testing.  Subject to change
  ** without notice. */
  if( c=='s' && n>=10 && cli_strncmp(azArg[0], "selftest-", 9)==0 ){
    if( cli_strncmp(azArg[0]+9, "boolean", n-9)==0 ){
      int i, v;
      for(i=1; i<nArg; i++){
        v = booleanValue(azArg[i]);
        sqlite3_fprintf(p->out, "%s: %d 0x%x\n", azArg[i], v, v);
      }
    }
    if( cli_strncmp(azArg[0]+9, "integer", n-9)==0 ){
      int i; sqlite3_int64 v;
      for(i=1; i<nArg; i++){
        char zBuf[200];
        v = integerValue(azArg[i]);
        sqlite3_snprintf(sizeof(zBuf),zBuf,"%s: %lld 0x%llx\n", azArg[i],v,v);
        sqlite3_fputs(zBuf, p->out);
      }
    }
  }else
#endif

  if( c=='s' && n>=4 && cli_strncmp(azArg[0],"selftest",n)==0 ){
    int bIsInit = 0;         /* True to initialize the SELFTEST table */
    int bVerbose = 0;        /* Verbose output */
    int bSelftestExists;     /* True if SELFTEST already exists */
    int i, k;                /* Loop counters */
    int nTest = 0;           /* Number of tests runs */
    int nErr = 0;            /* Number of errors seen */
    ShellText str;           /* Answer for a query */
    sqlite3_stmt *pStmt = 0; /* Query against the SELFTEST table */

    open_db(p,0);
    for(i=1; i<nArg; i++){
      const char *z = azArg[i];
      if( z[0]=='-' && z[1]=='-' ) z++;
      if( cli_strcmp(z,"-init")==0 ){
        bIsInit = 1;
      }else
      if( cli_strcmp(z,"-v")==0 ){
        bVerbose++;
      }else
      {
        sqlite3_fprintf(stderr,
              "Unknown option \"%s\" on \"%s\"\n", azArg[i], azArg[0]);
        sqlite3_fputs("Should be one of: --init -v\n", stderr);
        rc = 1;
        goto meta_command_exit;
      }
    }
    if( sqlite3_table_column_metadata(p->db,"main","selftest",0,0,0,0,0,0)
           != SQLITE_OK ){
      bSelftestExists = 0;
    }else{
      bSelftestExists = 1;
    }
    if( bIsInit ){
      createSelftestTable(p);
      bSelftestExists = 1;
    }
    initText(&str);
    appendText(&str, "x", 0);
    for(k=bSelftestExists; k>=0; k--){
      if( k==1 ){
        rc = sqlite3_prepare_v2(p->db,
            "SELECT tno,op,cmd,ans FROM selftest ORDER BY tno",
            -1, &pStmt, 0);
      }else{
        rc = sqlite3_prepare_v2(p->db,
          "VALUES(0,'memo','Missing SELFTEST table - default checks only',''),"
          "      (1,'run','PRAGMA integrity_check','ok')",
          -1, &pStmt, 0);
      }
      if( rc ){
        eputz("Error querying the selftest table\n");
        rc = 1;
        sqlite3_finalize(pStmt);
        goto meta_command_exit;
      }
      for(i=1; sqlite3_step(pStmt)==SQLITE_ROW; i++){
        int tno = sqlite3_column_int(pStmt, 0);
        const char *zOp = (const char*)sqlite3_column_text(pStmt, 1);
        const char *zSql = (const char*)sqlite3_column_text(pStmt, 2);
        const char *zAns = (const char*)sqlite3_column_text(pStmt, 3);

        if( zOp==0 ) continue;
        if( zSql==0 ) continue;
        if( zAns==0 ) continue;
        k = 0;
        if( bVerbose>0 ){
          sqlite3_fprintf(stdout, "%d: %s %s\n", tno, zOp, zSql);
        }
        if( cli_strcmp(zOp,"memo")==0 ){
          sqlite3_fprintf(p->out, "%s\n", zSql);
        }else
        if( cli_strcmp(zOp,"run")==0 ){
          char *zErrMsg = 0;
          str.n = 0;
          str.z[0] = 0;
          rc = sqlite3_exec(p->db, zSql, captureOutputCallback, &str, &zErrMsg);
          nTest++;
          if( bVerbose ){
            sqlite3_fprintf(p->out, "Result: %s\n", str.z);
          }
          if( rc || zErrMsg ){
            nErr++;
            rc = 1;
            sqlite3_fprintf(p->out, "%d: error-code-%d: %s\n", tno, rc,zErrMsg);
            sqlite3_free(zErrMsg);
          }else if( cli_strcmp(zAns,str.z)!=0 ){
            nErr++;
            rc = 1;
            sqlite3_fprintf(p->out, "%d: Expected: [%s]\n", tno, zAns);
            sqlite3_fprintf(p->out, "%d:      Got: [%s]\n", tno, str.z);
          }
        }
        else{
          sqlite3_fprintf(stderr,
                "Unknown operation \"%s\" on selftest line %d\n", zOp, tno);
          rc = 1;
          break;
        }
      } /* End loop over rows of content from SELFTEST */
      sqlite3_finalize(pStmt);
    } /* End loop over k */
    freeText(&str);
    sqlite3_fprintf(p->out, "%d errors out of %d tests\n", nErr, nTest);
  }else

  if( c=='s' && cli_strncmp(azArg[0], "separator", n)==0 ){
    if( nArg<2 || nArg>3 ){
      eputz("Usage: .separator COL ?ROW?\n");
      rc = 1;
    }
    if( nArg>=2 ){
      sqlite3_snprintf(sizeof(p->colSeparator), p->colSeparator,
                       "%.*s", (int)ArraySize(p->colSeparator)-1, azArg[1]);
    }
    if( nArg>=3 ){
      sqlite3_snprintf(sizeof(p->rowSeparator), p->rowSeparator,
                       "%.*s", (int)ArraySize(p->rowSeparator)-1, azArg[2]);
    }
  }else

  if( c=='s' && n>=4 && cli_strncmp(azArg[0],"sha3sum",n)==0 ){
    const char *zLike = 0;   /* Which table to checksum. 0 means everything */
    int i;                   /* Loop counter */
    int bSchema = 0;         /* Also hash the schema */
    int bSeparate = 0;       /* Hash each table separately */
    int iSize = 224;         /* Hash algorithm to use */
    int bDebug = 0;          /* Only show the query that would have run */
    sqlite3_stmt *pStmt;     /* For querying tables names */
    char *zSql;              /* SQL to be run */
    char *zSep;              /* Separator */
    ShellText sSql;          /* Complete SQL for the query to run the hash */
    ShellText sQuery;        /* Set of queries used to read all content */
    open_db(p, 0);
    for(i=1; i<nArg; i++){
      const char *z = azArg[i];
      if( z[0]=='-' ){
        z++;
        if( z[0]=='-' ) z++;
        if( cli_strcmp(z,"schema")==0 ){
          bSchema = 1;
        }else
        if( cli_strcmp(z,"sha3-224")==0 || cli_strcmp(z,"sha3-256")==0
         || cli_strcmp(z,"sha3-384")==0 || cli_strcmp(z,"sha3-512")==0
        ){
          iSize = atoi(&z[5]);
        }else
        if( cli_strcmp(z,"debug")==0 ){
          bDebug = 1;
        }else
        {
          sqlite3_fprintf(stderr,
                  "Unknown option \"%s\" on \"%s\"\n", azArg[i], azArg[0]);
          showHelp(p->out, azArg[0]);
          rc = 1;
          goto meta_command_exit;
        }
      }else if( zLike ){
        eputz("Usage: .sha3sum ?OPTIONS? ?LIKE-PATTERN?\n");
        rc = 1;
        goto meta_command_exit;
      }else{
        zLike = z;
        bSeparate = 1;
        if( sqlite3_strlike("sqlite\\_%", zLike, '\\')==0 ) bSchema = 1;
      }
    }
    if( bSchema ){
      zSql = "SELECT lower(name) as tname FROM sqlite_schema"
             " WHERE type='table' AND coalesce(rootpage,0)>1"
             " UNION ALL SELECT 'sqlite_schema'"
             " ORDER BY 1 collate nocase";
    }else{
      zSql = "SELECT lower(name) as tname FROM sqlite_schema"
             " WHERE type='table' AND coalesce(rootpage,0)>1"
             " AND name NOT LIKE 'sqlite_%'"
             " ORDER BY 1 collate nocase";
    }
    sqlite3_prepare_v2(p->db, zSql, -1, &pStmt, 0);
    initText(&sQuery);
    initText(&sSql);
    appendText(&sSql, "WITH [sha3sum$query](a,b) AS(",0);
    zSep = "VALUES(";
    while( SQLITE_ROW==sqlite3_step(pStmt) ){
      const char *zTab = (const char*)sqlite3_column_text(pStmt,0);
      if( zTab==0 ) continue;
      if( zLike && sqlite3_strlike(zLike, zTab, 0)!=0 ) continue;
      if( cli_strncmp(zTab, "sqlite_",7)!=0 ){
        appendText(&sQuery,"SELECT * FROM ", 0);
        appendText(&sQuery,zTab,'"');
        appendText(&sQuery," NOT INDEXED;", 0);
      }else if( cli_strcmp(zTab, "sqlite_schema")==0 ){
        appendText(&sQuery,"SELECT type,name,tbl_name,sql FROM sqlite_schema"
                           " ORDER BY name;", 0);
      }else if( cli_strcmp(zTab, "sqlite_sequence")==0 ){
        appendText(&sQuery,"SELECT name,seq FROM sqlite_sequence"
                           " ORDER BY name;", 0);
      }else if( cli_strcmp(zTab, "sqlite_stat1")==0 ){
        appendText(&sQuery,"SELECT tbl,idx,stat FROM sqlite_stat1"
                           " ORDER BY tbl,idx;", 0);
      }else if( cli_strcmp(zTab, "sqlite_stat4")==0 ){
        appendText(&sQuery, "SELECT * FROM ", 0);
        appendText(&sQuery, zTab, 0);
        appendText(&sQuery, " ORDER BY tbl, idx, rowid;\n", 0);
      }
      appendText(&sSql, zSep, 0);
      appendText(&sSql, sQuery.z, '\'');
      sQuery.n = 0;
      appendText(&sSql, ",", 0);
      appendText(&sSql, zTab, '\'');
      zSep = "),(";
    }
    sqlite3_finalize(pStmt);
    if( bSeparate ){
      zSql = sqlite3_mprintf(
          "%s))"
          " SELECT lower(hex(sha3_query(a,%d))) AS hash, b AS label"
          "   FROM [sha3sum$query]",
          sSql.z, iSize);
    }else{
      zSql = sqlite3_mprintf(
          "%s))"
          " SELECT lower(hex(sha3_query(group_concat(a,''),%d))) AS hash"
          "   FROM [sha3sum$query]",
          sSql.z, iSize);
    }
    shell_check_oom(zSql);
    freeText(&sQuery);
    freeText(&sSql);
    if( bDebug ){
      sqlite3_fprintf(p->out, "%s\n", zSql);
    }else{
      shell_exec(p, zSql, 0);
    }
#if !defined(SQLITE_OMIT_SCHEMA_PRAGMAS) && !defined(SQLITE_OMIT_VIRTUALTABLE)
    {
      int lrc;
      char *zRevText = /* Query for reversible to-blob-to-text check */
        "SELECT lower(name) as tname FROM sqlite_schema\n"
        "WHERE type='table' AND coalesce(rootpage,0)>1\n"
        "AND name NOT LIKE 'sqlite_%%'%s\n"
        "ORDER BY 1 collate nocase";
      zRevText = sqlite3_mprintf(zRevText, zLike? " AND name LIKE $tspec" : "");
      zRevText = sqlite3_mprintf(
          /* lower-case query is first run, producing upper-case query. */
          "with tabcols as materialized(\n"
          "select tname, cname\n"
          "from ("
          " select printf('\"%%w\"',ss.tname) as tname,"
          " printf('\"%%w\"',ti.name) as cname\n"
          " from (%z) ss\n inner join pragma_table_info(tname) ti))\n"
          "select 'SELECT total(bad_text_count) AS bad_text_count\n"
          "FROM ('||group_concat(query, ' UNION ALL ')||')' as btc_query\n"
          " from (select 'SELECT COUNT(*) AS bad_text_count\n"
          "FROM '||tname||' WHERE '\n"
          "||group_concat('CAST(CAST('||cname||' AS BLOB) AS TEXT)<>'||cname\n"
          "|| ' AND typeof('||cname||')=''text'' ',\n"
          "' OR ') as query, tname from tabcols group by tname)"
          , zRevText);
      shell_check_oom(zRevText);
      if( bDebug ) sqlite3_fprintf(p->out, "%s\n", zRevText);
      lrc = sqlite3_prepare_v2(p->db, zRevText, -1, &pStmt, 0);
      if( lrc!=SQLITE_OK ){
        /* assert(lrc==SQLITE_NOMEM); // might also be SQLITE_ERROR if the
        ** user does cruel and unnatural things like ".limit expr_depth 0". */
        rc = 1;
      }else{
        if( zLike ) sqlite3_bind_text(pStmt,1,zLike,-1,SQLITE_STATIC);
        lrc = SQLITE_ROW==sqlite3_step(pStmt);
        if( lrc ){
          const char *zGenQuery = (char*)sqlite3_column_text(pStmt,0);
          sqlite3_stmt *pCheckStmt;
          lrc = sqlite3_prepare_v2(p->db, zGenQuery, -1, &pCheckStmt, 0);
          if( bDebug ) sqlite3_fprintf(p->out, "%s\n", zGenQuery);
          if( lrc!=SQLITE_OK ){
            rc = 1;
          }else{
            if( SQLITE_ROW==sqlite3_step(pCheckStmt) ){
              double countIrreversible = sqlite3_column_double(pCheckStmt, 0);
              if( countIrreversible>0 ){
                int sz = (int)(countIrreversible + 0.5);
                sqlite3_fprintf(stderr,
                      "Digest includes %d invalidly encoded text field%s.\n",
                      sz, (sz>1)? "s": "");
              }
            }
            sqlite3_finalize(pCheckStmt);
          }
          sqlite3_finalize(pStmt);
        }
      }
      if( rc ) eputz(".sha3sum failed.\n");
      sqlite3_free(zRevText);
    }
#endif /* !defined(*_OMIT_SCHEMA_PRAGMAS) && !defined(*_OMIT_VIRTUALTABLE) */
    sqlite3_free(zSql);
  }else

#if !defined(SQLITE_NOHAVE_SYSTEM) && !defined(SQLITE_SHELL_FIDDLE)
  if( c=='s'
   && (cli_strncmp(azArg[0], "shell", n)==0
       || cli_strncmp(azArg[0],"system",n)==0)
  ){
    char *zCmd;
    int i, x;
    failIfSafeMode(p, "cannot run .%s in safe mode", azArg[0]);
    if( nArg<2 ){
      eputz("Usage: .system COMMAND\n");
      rc = 1;
      goto meta_command_exit;
    }
    zCmd = sqlite3_mprintf(strchr(azArg[1],' ')==0?"%s":"\"%s\"", azArg[1]);
    for(i=2; i<nArg && zCmd!=0; i++){
      zCmd = sqlite3_mprintf(strchr(azArg[i],' ')==0?"%z %s":"%z \"%s\"",
                             zCmd, azArg[i]);
    }
    /*consoleRestore();*/
    x = zCmd!=0 ? system(zCmd) : 1;
    /*consoleRenewSetup();*/
    sqlite3_free(zCmd);
    if( x ) sqlite3_fprintf(stderr,"System command returns %d\n", x);
  }else
#endif /* !defined(SQLITE_NOHAVE_SYSTEM) && !defined(SQLITE_SHELL_FIDDLE) */

  if( c=='s' && cli_strncmp(azArg[0], "show", n)==0 ){
    static const char *azBool[] = { "off", "on", "trigger", "full"};
    const char *zOut;
    int i;
    if( nArg!=1 ){
      eputz("Usage: .show\n");
      rc = 1;
      goto meta_command_exit;
    }
    sqlite3_fprintf(p->out, "%12.12s: %s\n","echo",
          azBool[ShellHasFlag(p, SHFLG_Echo)]);
    sqlite3_fprintf(p->out, "%12.12s: %s\n","eqp", azBool[p->autoEQP&3]);
    sqlite3_fprintf(p->out, "%12.12s: %s\n","explain",
          p->mode==MODE_Explain ? "on" : p->autoExplain ? "auto" : "off");
    sqlite3_fprintf(p->out, "%12.12s: %s\n","headers",
          azBool[p->showHeader!=0]);
    if( p->mode==MODE_Column
     || (p->mode>=MODE_Markdown && p->mode<=MODE_Box)
    ){
      sqlite3_fprintf(p->out,
            "%12.12s: %s --wrap %d --wordwrap %s --%squote\n", "mode",
            modeDescr[p->mode], p->cmOpts.iWrap,
            p->cmOpts.bWordWrap ? "on" : "off",
            p->cmOpts.bQuote ? "" : "no");
    }else{
      sqlite3_fprintf(p->out, "%12.12s: %s\n","mode", modeDescr[p->mode]);
    }
    sqlite3_fprintf(p->out, "%12.12s: ", "nullvalue");
    output_c_string(p->out, p->nullValue);
    sqlite3_fputs("\n", p->out);
    sqlite3_fprintf(p->out, "%12.12s: %s\n","output",
          strlen30(p->outfile) ? p->outfile : "stdout");
    sqlite3_fprintf(p->out, "%12.12s: ", "colseparator");
    output_c_string(p->out, p->colSeparator);
    sqlite3_fputs("\n", p->out);
    sqlite3_fprintf(p->out, "%12.12s: ", "rowseparator");
    output_c_string(p->out, p->rowSeparator);
    sqlite3_fputs("\n", p->out);
    switch( p->statsOn ){
      case 0:  zOut = "off";     break;
      default: zOut = "on";      break;
      case 2:  zOut = "stmt";    break;
      case 3:  zOut = "vmstep";  break;
    }
    sqlite3_fprintf(p->out, "%12.12s: %s\n","stats", zOut);
    sqlite3_fprintf(p->out, "%12.12s: ", "width");
    for (i=0;i<p->nWidth;i++) {
      sqlite3_fprintf(p->out, "%d ", p->colWidth[i]);
    }
    sqlite3_fputs("\n", p->out);
    sqlite3_fprintf(p->out, "%12.12s: %s\n", "filename",
          p->pAuxDb->zDbFilename ? p->pAuxDb->zDbFilename : "");
  }else

  if( c=='s' && cli_strncmp(azArg[0], "stats", n)==0 ){
    if( nArg==2 ){
      if( cli_strcmp(azArg[1],"stmt")==0 ){
        p->statsOn = 2;
      }else if( cli_strcmp(azArg[1],"vmstep")==0 ){
        p->statsOn = 3;
      }else{
        p->statsOn = (u8)booleanValue(azArg[1]);
      }
    }else if( nArg==1 ){
      display_stats(p->db, p, 0);
    }else{
      eputz("Usage: .stats ?on|off|stmt|vmstep?\n");
      rc = 1;
    }
  }else

  if( (c=='t' && n>1 && cli_strncmp(azArg[0], "tables", n)==0)
   || (c=='i' && (cli_strncmp(azArg[0], "indices", n)==0
                 || cli_strncmp(azArg[0], "indexes", n)==0) )
  ){
    sqlite3_stmt *pStmt;
    char **azResult;
    int nRow, nAlloc;
    int ii;
    ShellText s;
    initText(&s);
    open_db(p, 0);
    rc = sqlite3_prepare_v2(p->db, "PRAGMA database_list", -1, &pStmt, 0);
    if( rc ){
      sqlite3_finalize(pStmt);
      return shellDatabaseError(p->db);
    }

    if( nArg>2 && c=='i' ){
      /* It is an historical accident that the .indexes command shows an error
      ** when called with the wrong number of arguments whereas the .tables
      ** command does not. */
      eputz("Usage: .indexes ?LIKE-PATTERN?\n");
      rc = 1;
      sqlite3_finalize(pStmt);
      goto meta_command_exit;
    }
    for(ii=0; sqlite3_step(pStmt)==SQLITE_ROW; ii++){
      const char *zDbName = (const char*)sqlite3_column_text(pStmt, 1);
      if( zDbName==0 ) continue;
      if( s.z && s.z[0] ) appendText(&s, " UNION ALL ", 0);
      if( sqlite3_stricmp(zDbName, "main")==0 ){
        appendText(&s, "SELECT name FROM ", 0);
      }else{
        appendText(&s, "SELECT ", 0);
        appendText(&s, zDbName, '\'');
        appendText(&s, "||'.'||name FROM ", 0);
      }
      appendText(&s, zDbName, '"');
      appendText(&s, ".sqlite_schema ", 0);
      if( c=='t' ){
        appendText(&s," WHERE type IN ('table','view')"
                      "   AND name NOT LIKE 'sqlite_%'"
                      "   AND name LIKE ?1", 0);
      }else{
        appendText(&s," WHERE type='index'"
                      "   AND tbl_name LIKE ?1", 0);
      }
    }
    rc = sqlite3_finalize(pStmt);
    if( rc==SQLITE_OK ){
      appendText(&s, " ORDER BY 1", 0);
      rc = sqlite3_prepare_v2(p->db, s.z, -1, &pStmt, 0);
    }
    freeText(&s);
    if( rc ) return shellDatabaseError(p->db);

    /* Run the SQL statement prepared by the above block. Store the results
    ** as an array of nul-terminated strings in azResult[].  */
    nRow = nAlloc = 0;
    azResult = 0;
    if( nArg>1 ){
      sqlite3_bind_text(pStmt, 1, azArg[1], -1, SQLITE_TRANSIENT);
    }else{
      sqlite3_bind_text(pStmt, 1, "%", -1, SQLITE_STATIC);
    }
    while( sqlite3_step(pStmt)==SQLITE_ROW ){
      if( nRow>=nAlloc ){
        char **azNew;
        int n2 = nAlloc*2 + 10;
        azNew = sqlite3_realloc64(azResult, sizeof(azResult[0])*n2);
        shell_check_oom(azNew);
        nAlloc = n2;
        azResult = azNew;
      }
      azResult[nRow] = sqlite3_mprintf("%s", sqlite3_column_text(pStmt, 0));
      shell_check_oom(azResult[nRow]);
      nRow++;
    }
    if( sqlite3_finalize(pStmt)!=SQLITE_OK ){
      rc = shellDatabaseError(p->db);
    }

    /* Pretty-print the contents of array azResult[] to the output */
    if( rc==0 && nRow>0 ){
      int len, maxlen = 0;
      int i, j;
      int nPrintCol, nPrintRow;
      for(i=0; i<nRow; i++){
        len = strlen30(azResult[i]);
        if( len>maxlen ) maxlen = len;
      }
      nPrintCol = 80/(maxlen+2);
      if( nPrintCol<1 ) nPrintCol = 1;
      nPrintRow = (nRow + nPrintCol - 1)/nPrintCol;
      for(i=0; i<nPrintRow; i++){
        for(j=i; j<nRow; j+=nPrintRow){
          char *zSp = j<nPrintRow ? "" : "  ";
          sqlite3_fprintf(p->out,
               "%s%-*s", zSp, maxlen, azResult[j] ? azResult[j]:"");
        }
        sqlite3_fputs("\n", p->out);
      }
    }

    for(ii=0; ii<nRow; ii++) sqlite3_free(azResult[ii]);
    sqlite3_free(azResult);
  }else

#ifndef SQLITE_SHELL_FIDDLE
  /* Begin redirecting output to the file "testcase-out.txt" */
  if( c=='t' && cli_strcmp(azArg[0],"testcase")==0 ){
    output_reset(p);
    p->out = output_file_open("testcase-out.txt");
    if( p->out==0 ){
      eputz("Error: cannot open 'testcase-out.txt'\n");
    }
    if( nArg>=2 ){
      sqlite3_snprintf(sizeof(p->zTestcase), p->zTestcase, "%s", azArg[1]);
    }else{
      sqlite3_snprintf(sizeof(p->zTestcase), p->zTestcase, "?");
    }
  }else
#endif /* !defined(SQLITE_SHELL_FIDDLE) */

#ifndef SQLITE_UNTESTABLE
  if( c=='t' && n>=8 && cli_strncmp(azArg[0], "testctrl", n)==0 ){
    static const struct {
       const char *zCtrlName;   /* Name of a test-control option */
       int ctrlCode;            /* Integer code for that option */
       int unSafe;              /* Not valid unless --unsafe-testing */
       const char *zUsage;      /* Usage notes */
    } aCtrl[] = {
    {"always",             SQLITE_TESTCTRL_ALWAYS, 1,     "BOOLEAN"         },
    {"assert",             SQLITE_TESTCTRL_ASSERT, 1,     "BOOLEAN"         },
  /*{"benign_malloc_hooks",SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS,1, ""        },*/
  /*{"bitvec_test",        SQLITE_TESTCTRL_BITVEC_TEST, 1,  ""              },*/
    {"byteorder",          SQLITE_TESTCTRL_BYTEORDER, 0,  ""                },
    {"extra_schema_checks",SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS,0,"BOOLEAN"  },
    {"fault_install",      SQLITE_TESTCTRL_FAULT_INSTALL, 1,"args..."       },
    {"fk_no_action",       SQLITE_TESTCTRL_FK_NO_ACTION, 0, "BOOLEAN"       },
    {"imposter",         SQLITE_TESTCTRL_IMPOSTER,1,"SCHEMA ON/OFF ROOTPAGE"},
    {"internal_functions", SQLITE_TESTCTRL_INTERNAL_FUNCTIONS,0,""          },
    {"json_selfcheck",     SQLITE_TESTCTRL_JSON_SELFCHECK ,0,"BOOLEAN"      },
    {"localtime_fault",    SQLITE_TESTCTRL_LOCALTIME_FAULT,0,"BOOLEAN"      },
    {"never_corrupt",      SQLITE_TESTCTRL_NEVER_CORRUPT,1, "BOOLEAN"       },
    {"optimizations",      SQLITE_TESTCTRL_OPTIMIZATIONS,0,"DISABLE-MASK ..."},
#ifdef YYCOVERAGE
    {"parser_coverage",    SQLITE_TESTCTRL_PARSER_COVERAGE,0,""             },
#endif
    {"pending_byte",       SQLITE_TESTCTRL_PENDING_BYTE,1, "OFFSET  "       },
    {"prng_restore",       SQLITE_TESTCTRL_PRNG_RESTORE,0, ""               },
    {"prng_save",          SQLITE_TESTCTRL_PRNG_SAVE,   0, ""               },
    {"prng_seed",          SQLITE_TESTCTRL_PRNG_SEED,   0, "SEED ?db?"      },
    {"seek_count",         SQLITE_TESTCTRL_SEEK_COUNT,  0, ""               },
    {"sorter_mmap",        SQLITE_TESTCTRL_SORTER_MMAP, 0, "NMAX"           },
    {"tune",               SQLITE_TESTCTRL_TUNE,        1, "ID VALUE"       },
    };
    int testctrl = -1;
    int iCtrl = -1;
    int rc2 = 0;    /* 0: usage.  1: %d  2: %x  3: no-output */
    int isOk = 0;
    int i, n2;
    const char *zCmd = 0;

    open_db(p, 0);
    zCmd = nArg>=2 ? azArg[1] : "help";

    /* The argument can optionally begin with "-" or "--" */
    if( zCmd[0]=='-' && zCmd[1] ){
      zCmd++;
      if( zCmd[0]=='-' && zCmd[1] ) zCmd++;
    }

    /* --help lists all test-controls */
    if( cli_strcmp(zCmd,"help")==0 ){
      sqlite3_fputs("Available test-controls:\n", p->out);
      for(i=0; i<ArraySize(aCtrl); i++){
        if( aCtrl[i].unSafe && !ShellHasFlag(p,SHFLG_TestingMode) ) continue;
        sqlite3_fprintf(p->out, "  .testctrl %s %s\n",
              aCtrl[i].zCtrlName, aCtrl[i].zUsage);
      }
      rc = 1;
      goto meta_command_exit;
    }

    /* convert testctrl text option to value. allow any unique prefix
    ** of the option name, or a numerical value. */
    n2 = strlen30(zCmd);
    for(i=0; i<ArraySize(aCtrl); i++){
      if( aCtrl[i].unSafe && !ShellHasFlag(p,SHFLG_TestingMode) ) continue;
      if( cli_strncmp(zCmd, aCtrl[i].zCtrlName, n2)==0 ){
        if( testctrl<0 ){
          testctrl = aCtrl[i].ctrlCode;
          iCtrl = i;
        }else{
          sqlite3_fprintf(stderr,"Error: ambiguous test-control: \"%s\"\n"
                "Use \".testctrl --help\" for help\n", zCmd);
          rc = 1;
          goto meta_command_exit;
        }
      }
    }
    if( testctrl<0 ){
      sqlite3_fprintf(stderr,"Error: unknown test-control: %s\n"
            "Use \".testctrl --help\" for help\n", zCmd);
    }else{
      switch(testctrl){

        /* Special processing for .testctrl opt MASK ...
        ** Each MASK argument can be one of:
        **
        **      +LABEL       Enable the named optimization 
        **
        **      -LABEL       Disable the named optimization
        **
        **      INTEGER      Mask of optimizations to disable
        */
        case SQLITE_TESTCTRL_OPTIMIZATIONS: {
          static const struct {
             unsigned int mask;    /* Mask for this optimization */
             unsigned int bDsply;  /* Display this on output */
             const char *zLabel;   /* Name of optimization */
          } aLabel[] = {
            { 0x00000001, 1, "QueryFlattener" },
            { 0x00000001, 0, "Flatten" },
            { 0x00000002, 1, "WindowFunc" },
            { 0x00000004, 1, "GroupByOrder" },
            { 0x00000008, 1, "FactorOutConst" },
            { 0x00000010, 1, "DistinctOpt" },
            { 0x00000020, 1, "CoverIdxScan" },
            { 0x00000040, 1, "OrderByIdxJoin" },
            { 0x00000080, 1, "Transitive" },
            { 0x00000100, 1, "OmitNoopJoin" },
            { 0x00000200, 1, "CountOfView" },
            { 0x00000400, 1, "CurosrHints" },
            { 0x00000800, 1, "Stat4" },
            { 0x00001000, 1, "PushDown" },
            { 0x00002000, 1, "SimplifyJoin" },
            { 0x00004000, 1, "SkipScan" },
            { 0x00008000, 1, "PropagateConst" },
            { 0x00010000, 1, "MinMaxOpt" },
            { 0x00020000, 1, "SeekScan" },
            { 0x00040000, 1, "OmitOrderBy" },
            { 0x00080000, 1, "BloomFilter" },
            { 0x00100000, 1, "BloomPulldown" },
            { 0x00200000, 1, "BalancedMerge" },
            { 0x00400000, 1, "ReleaseReg" },
            { 0x00800000, 1, "FlttnUnionAll" },
            { 0x01000000, 1, "IndexedEXpr" },
            { 0x02000000, 1, "Coroutines" },
            { 0x04000000, 1, "NullUnusedCols" },
            { 0x08000000, 1, "OnePass" },
            { 0x10000000, 1, "OrderBySubq" },
            { 0xffffffff, 0, "All" },
          };
          unsigned int curOpt;
          unsigned int newOpt;
          int ii;
          sqlite3_test_control(SQLITE_TESTCTRL_GETOPT, p->db, &curOpt);
          newOpt = curOpt;
          for(ii=2; ii<nArg; ii++){
            const char *z = azArg[ii];
            int useLabel = 0;
            const char *zLabel = 0;
            if( (z[0]=='+'|| z[0]=='-') && !IsDigit(z[1]) ){
              useLabel = z[0];
              zLabel = &z[1];
            }else if( !IsDigit(z[0]) && z[0]!=0 && !IsDigit(z[1]) ){
              useLabel = '+';
              zLabel = z;
            }else{
              newOpt = (unsigned int)strtol(z,0,0);
            }
            if( useLabel ){
              int jj;
              for(jj=0; jj<ArraySize(aLabel); jj++){
                if( sqlite3_stricmp(zLabel, aLabel[jj].zLabel)==0 ) break;
              }
              if( jj>=ArraySize(aLabel) ){
                sqlite3_fprintf(stderr,
                    "Error: no such optimization: \"%s\"\n", zLabel);
                sqlite3_fputs("Should be one of:", stderr);
                for(jj=0; jj<ArraySize(aLabel); jj++){
                  sqlite3_fprintf(stderr," %s", aLabel[jj].zLabel);
                }
                sqlite3_fputs("\n", stderr);
                rc = 1;
                goto meta_command_exit;
              }
              if( useLabel=='+' ){
                newOpt &= ~aLabel[jj].mask;
              }else{
                newOpt |= aLabel[jj].mask;
              }
            }
          }
          if( curOpt!=newOpt ){
            sqlite3_test_control(SQLITE_TESTCTRL_OPTIMIZATIONS,p->db,newOpt);
          }else if( nArg<3 ){
            curOpt = ~newOpt;
          }
          if( newOpt==0 ){
            sqlite3_fputs("+All\n", p->out);
          }else if( newOpt==0xffffffff ){
            sqlite3_fputs("-All\n", p->out);
          }else{
            int jj;
            for(jj=0; jj<ArraySize(aLabel); jj++){
              unsigned int m = aLabel[jj].mask;
              if( !aLabel[jj].bDsply  ) continue;
              if( (curOpt&m)!=(newOpt&m) ){
                sqlite3_fprintf(p->out, "%c%s\n", (newOpt & m)==0 ? '+' : '-',
                      aLabel[jj].zLabel);
              }
            }
          }
          rc2 = isOk = 3;
          break;
        }

        /* sqlite3_test_control(int, db, int) */
        case SQLITE_TESTCTRL_FK_NO_ACTION:
          if( nArg==3 ){
            unsigned int opt = (unsigned int)strtol(azArg[2], 0, 0);
            rc2 = sqlite3_test_control(testctrl, p->db, opt);
            isOk = 3;
          }
          break;

        /* sqlite3_test_control(int) */
        case SQLITE_TESTCTRL_PRNG_SAVE:
        case SQLITE_TESTCTRL_PRNG_RESTORE:
        case SQLITE_TESTCTRL_BYTEORDER:
          if( nArg==2 ){
            rc2 = sqlite3_test_control(testctrl);
            isOk = testctrl==SQLITE_TESTCTRL_BYTEORDER ? 1 : 3;
          }
          break;

        /* sqlite3_test_control(int, uint) */
        case SQLITE_TESTCTRL_PENDING_BYTE:
          if( nArg==3 ){
            unsigned int opt = (unsigned int)integerValue(azArg[2]);
            rc2 = sqlite3_test_control(testctrl, opt);
            isOk = 3;
          }
          break;

        /* sqlite3_test_control(int, int, sqlite3*) */
        case SQLITE_TESTCTRL_PRNG_SEED:
          if( nArg==3 || nArg==4 ){
            int ii = (int)integerValue(azArg[2]);
            sqlite3 *db;
            if( ii==0 && cli_strcmp(azArg[2],"random")==0 ){
              sqlite3_randomness(sizeof(ii),&ii);
              sqlite3_fprintf(stdout, "-- random seed: %d\n", ii);
            }
            if( nArg==3 ){
              db = 0;
            }else{
              db = p->db;
              /* Make sure the schema has been loaded */
              sqlite3_table_column_metadata(db, 0, "x", 0, 0, 0, 0, 0, 0);
            }
            rc2 = sqlite3_test_control(testctrl, ii, db);
            isOk = 3;
          }
          break;

        /* sqlite3_test_control(int, int) */
        case SQLITE_TESTCTRL_ASSERT:
        case SQLITE_TESTCTRL_ALWAYS:
          if( nArg==3 ){
            int opt = booleanValue(azArg[2]);
            rc2 = sqlite3_test_control(testctrl, opt);
            isOk = 1;
          }
          break;

        /* sqlite3_test_control(int, int) */
        case SQLITE_TESTCTRL_LOCALTIME_FAULT:
        case SQLITE_TESTCTRL_NEVER_CORRUPT:
          if( nArg==3 ){
            int opt = booleanValue(azArg[2]);
            rc2 = sqlite3_test_control(testctrl, opt);
            isOk = 3;
          }
          break;

        /* sqlite3_test_control(sqlite3*) */
        case SQLITE_TESTCTRL_INTERNAL_FUNCTIONS:
          rc2 = sqlite3_test_control(testctrl, p->db);
          isOk = 3;
          break;

        case SQLITE_TESTCTRL_IMPOSTER:
          if( nArg==5 ){
            rc2 = sqlite3_test_control(testctrl, p->db,
                          azArg[2],
                          integerValue(azArg[3]),
                          integerValue(azArg[4]));
            isOk = 3;
          }
          break;

        case SQLITE_TESTCTRL_SEEK_COUNT: {
          u64 x = 0;
          rc2 = sqlite3_test_control(testctrl, p->db, &x);
          sqlite3_fprintf(p->out, "%llu\n", x);
          isOk = 3;
          break;
        }

#ifdef YYCOVERAGE
        case SQLITE_TESTCTRL_PARSER_COVERAGE: {
          if( nArg==2 ){
            sqlite3_test_control(testctrl, p->out);
            isOk = 3;
          }
          break;
        }
#endif
#ifdef SQLITE_DEBUG
        case SQLITE_TESTCTRL_TUNE: {
          if( nArg==4 ){
            int id = (int)integerValue(azArg[2]);
            int val = (int)integerValue(azArg[3]);
            sqlite3_test_control(testctrl, id, &val);
            isOk = 3;
          }else if( nArg==3 ){
            int id = (int)integerValue(azArg[2]);
            sqlite3_test_control(testctrl, -id, &rc2);
            isOk = 1;
          }else if( nArg==2 ){
            int id = 1;
            while(1){
              int val = 0;
              rc2 = sqlite3_test_control(testctrl, -id, &val);
              if( rc2!=SQLITE_OK ) break;
              if( id>1 ) sqlite3_fputs("  ", p->out);
              sqlite3_fprintf(p->out, "%d: %d", id, val);
              id++;
            }
            if( id>1 ) sqlite3_fputs("\n", p->out);
            isOk = 3;
          }
          break;
        }
#endif
        case SQLITE_TESTCTRL_SORTER_MMAP:
          if( nArg==3 ){
            int opt = (unsigned int)integerValue(azArg[2]);
            rc2 = sqlite3_test_control(testctrl, p->db, opt);
            isOk = 3;
          }
          break;
        case SQLITE_TESTCTRL_JSON_SELFCHECK:
          if( nArg==2 ){
            rc2 = -1;
            isOk = 1;
          }else{
            rc2 = booleanValue(azArg[2]);
            isOk = 3;
          }
          sqlite3_test_control(testctrl, &rc2);
          break;
        case SQLITE_TESTCTRL_FAULT_INSTALL: {
          int kk;
          int bShowHelp = nArg<=2;
          isOk = 3;
          for(kk=2; kk<nArg; kk++){
            const char *z = azArg[kk];
            if( z[0]=='-' && z[1]=='-' ) z++;
            if( cli_strcmp(z,"off")==0 ){
              sqlite3_test_control(testctrl, 0);
            }else if( cli_strcmp(z,"on")==0 ){
              faultsim_state.iCnt = faultsim_state.nSkip;
              if( faultsim_state.iErr==0 ) faultsim_state.iErr = 1;
              faultsim_state.nHit = 0;
              sqlite3_test_control(testctrl, faultsim_callback);
            }else if( cli_strcmp(z,"reset")==0 ){
              faultsim_state.iCnt = faultsim_state.nSkip;
              faultsim_state.nHit = 0;
              sqlite3_test_control(testctrl, faultsim_callback);
            }else if( cli_strcmp(z,"status")==0 ){
              sqlite3_fprintf(p->out, "faultsim.iId:       %d\n",
                              faultsim_state.iId);
              sqlite3_fprintf(p->out, "faultsim.iErr:      %d\n",
                              faultsim_state.iErr);
              sqlite3_fprintf(p->out, "faultsim.iCnt:      %d\n",
                              faultsim_state.iCnt);
              sqlite3_fprintf(p->out, "faultsim.nHit:      %d\n",
                              faultsim_state.nHit);
              sqlite3_fprintf(p->out, "faultsim.iInterval: %d\n",
                              faultsim_state.iInterval);
              sqlite3_fprintf(p->out, "faultsim.eVerbose:  %d\n",
                              faultsim_state.eVerbose);
              sqlite3_fprintf(p->out, "faultsim.nRepeat:   %d\n",
                              faultsim_state.nRepeat);
              sqlite3_fprintf(p->out, "faultsim.nSkip:     %d\n",
                              faultsim_state.nSkip);
            }else if( cli_strcmp(z,"-v")==0 ){
              if( faultsim_state.eVerbose<2 ) faultsim_state.eVerbose++;
            }else if( cli_strcmp(z,"-q")==0 ){
              if( faultsim_state.eVerbose>0 ) faultsim_state.eVerbose--;
            }else if( cli_strcmp(z,"-id")==0 && kk+1<nArg ){
              faultsim_state.iId = atoi(azArg[++kk]);
            }else if( cli_strcmp(z,"-errcode")==0 && kk+1<nArg ){
              faultsim_state.iErr = atoi(azArg[++kk]);
            }else if( cli_strcmp(z,"-interval")==0 && kk+1<nArg ){
              faultsim_state.iInterval = atoi(azArg[++kk]);
            }else if( cli_strcmp(z,"-repeat")==0 && kk+1<nArg ){
              faultsim_state.nRepeat = atoi(azArg[++kk]);
           }else if( cli_strcmp(z,"-skip")==0 && kk+1<nArg ){
              faultsim_state.nSkip = atoi(azArg[++kk]);
            }else if( cli_strcmp(z,"-?")==0 || sqlite3_strglob("*help*",z)==0){
              bShowHelp = 1;
            }else{
              sqlite3_fprintf(stderr,
                  "Unrecognized fault_install argument: \"%s\"\n",
                  azArg[kk]);
              rc = 1;
              bShowHelp = 1;
              break;
            }
          }
          if( bShowHelp ){
            sqlite3_fputs(
               "Usage: .testctrl fault_install ARGS\n"
               "Possible arguments:\n"
               "   off               Disable faultsim\n"
               "   on                Activate faultsim\n"
               "   reset             Reset the trigger counter\n"
               "   status            Show current status\n"
               "   -v                Increase verbosity\n"
               "   -q                Decrease verbosity\n"
               "   --errcode N       When triggered, return N as error code\n"
               "   --id ID           Trigger only for the ID specified\n"
               "   --interval N      Trigger only after every N-th call\n"
               "   --repeat N        Turn off after N hits.  0 means never\n"
               "   --skip N          Skip the first N encounters\n"
               ,p->out
            );
          }
          break;
        }
      }
    }
    if( isOk==0 && iCtrl>=0 ){
      sqlite3_fprintf(p->out,
          "Usage: .testctrl %s %s\n", zCmd,aCtrl[iCtrl].zUsage);
      rc = 1;
    }else if( isOk==1 ){
      sqlite3_fprintf(p->out, "%d\n", rc2);
    }else if( isOk==2 ){
      sqlite3_fprintf(p->out, "0x%08x\n", rc2);
    }
  }else
#endif /* !defined(SQLITE_UNTESTABLE) */

  if( c=='t' && n>4 && cli_strncmp(azArg[0], "timeout", n)==0 ){
    open_db(p, 0);
    sqlite3_busy_timeout(p->db, nArg>=2 ? (int)integerValue(azArg[1]) : 0);
  }else

  if( c=='t' && n>=5 && cli_strncmp(azArg[0], "timer", n)==0 ){
    if( nArg==2 ){
      enableTimer = booleanValue(azArg[1]);
      if( enableTimer && !HAS_TIMER ){
        eputz("Error: timer not available on this system.\n");
        enableTimer = 0;
      }
    }else{
      eputz("Usage: .timer on|off\n");
      rc = 1;
    }
  }else

#ifndef SQLITE_OMIT_TRACE
  if( c=='t' && cli_strncmp(azArg[0], "trace", n)==0 ){
    int mType = 0;
    int jj;
    open_db(p, 0);
    for(jj=1; jj<nArg; jj++){
      const char *z = azArg[jj];
      if( z[0]=='-' ){
        if( optionMatch(z, "expanded") ){
          p->eTraceType = SHELL_TRACE_EXPANDED;
        }
#ifdef SQLITE_ENABLE_NORMALIZE
        else if( optionMatch(z, "normalized") ){
          p->eTraceType = SHELL_TRACE_NORMALIZED;
        }
#endif
        else if( optionMatch(z, "plain") ){
          p->eTraceType = SHELL_TRACE_PLAIN;
        }
        else if( optionMatch(z, "profile") ){
          mType |= SQLITE_TRACE_PROFILE;
        }
        else if( optionMatch(z, "row") ){
          mType |= SQLITE_TRACE_ROW;
        }
        else if( optionMatch(z, "stmt") ){
          mType |= SQLITE_TRACE_STMT;
        }
        else if( optionMatch(z, "close") ){
          mType |= SQLITE_TRACE_CLOSE;
        }
        else {
          sqlite3_fprintf(stderr,"Unknown option \"%s\" on \".trace\"\n", z);
          rc = 1;
          goto meta_command_exit;
        }
      }else{
        output_file_close(p->traceOut);
        p->traceOut = output_file_open(z);
      }
    }
    if( p->traceOut==0 ){
      sqlite3_trace_v2(p->db, 0, 0, 0);
    }else{
      if( mType==0 ) mType = SQLITE_TRACE_STMT;
      sqlite3_trace_v2(p->db, mType, sql_trace_callback, p);
    }
  }else
#endif /* !defined(SQLITE_OMIT_TRACE) */

#if defined(SQLITE_DEBUG) && !defined(SQLITE_OMIT_VIRTUALTABLE)
  if( c=='u' && cli_strncmp(azArg[0], "unmodule", n)==0 ){
    int ii;
    int lenOpt;
    char *zOpt;
    if( nArg<2 ){
      eputz("Usage: .unmodule [--allexcept] NAME ...\n");
      rc = 1;
      goto meta_command_exit;
    }
    open_db(p, 0);
    zOpt = azArg[1];
    if( zOpt[0]=='-' && zOpt[1]=='-' && zOpt[2]!=0 ) zOpt++;
    lenOpt = (int)strlen(zOpt);
    if( lenOpt>=3 && cli_strncmp(zOpt, "-allexcept",lenOpt)==0 ){
      assert( azArg[nArg]==0 );
      sqlite3_drop_modules(p->db, nArg>2 ? (const char**)(azArg+2) : 0);
    }else{
      for(ii=1; ii<nArg; ii++){
        sqlite3_create_module(p->db, azArg[ii], 0, 0);
      }
    }
  }else
#endif

#if SQLITE_USER_AUTHENTICATION
  if( c=='u' && cli_strncmp(azArg[0], "user", n)==0 ){
    if( nArg<2 ){
      eputz("Usage: .user SUBCOMMAND ...\n");
      rc = 1;
      goto meta_command_exit;
    }
    open_db(p, 0);
    if( cli_strcmp(azArg[1],"login")==0 ){
      if( nArg!=4 ){
        eputz("Usage: .user login USER PASSWORD\n");
        rc = 1;
        goto meta_command_exit;
      }
      rc = sqlite3_user_authenticate(p->db, azArg[2], azArg[3],
                                     strlen30(azArg[3]));
      if( rc ){
        sqlite3_fprintf(stderr,"Authentication failed for user %s\n", azArg[2]);
        rc = 1;
      }
    }else if( cli_strcmp(azArg[1],"add")==0 ){
      if( nArg!=5 ){
        eputz("Usage: .user add USER PASSWORD ISADMIN\n");
        rc = 1;
        goto meta_command_exit;
      }
      rc = sqlite3_user_add(p->db, azArg[2], azArg[3], strlen30(azArg[3]),
                            booleanValue(azArg[4]));
      if( rc ){
        sqlite3_fprintf(stderr,"User-Add failed: %d\n", rc);
        rc = 1;
      }
    }else if( cli_strcmp(azArg[1],"edit")==0 ){
      if( nArg!=5 ){
        eputz("Usage: .user edit USER PASSWORD ISADMIN\n");
        rc = 1;
        goto meta_command_exit;
      }
      rc = sqlite3_user_change(p->db, azArg[2], azArg[3], strlen30(azArg[3]),
                              booleanValue(azArg[4]));
      if( rc ){
        sqlite3_fprintf(stderr,"User-Edit failed: %d\n", rc);
        rc = 1;
      }
    }else if( cli_strcmp(azArg[1],"delete")==0 ){
      if( nArg!=3 ){
        eputz("Usage: .user delete USER\n");
        rc = 1;
        goto meta_command_exit;
      }
      rc = sqlite3_user_delete(p->db, azArg[2]);
      if( rc ){
        sqlite3_fprintf(stderr,"User-Delete failed: %d\n", rc);
        rc = 1;
      }
    }else{
      eputz("Usage: .user login|add|edit|delete ...\n");
      rc = 1;
      goto meta_command_exit;
    }
  }else
#endif /* SQLITE_USER_AUTHENTICATION */

  if( c=='v' && cli_strncmp(azArg[0], "version", n)==0 ){
    char *zPtrSz = sizeof(void*)==8 ? "64-bit" : "32-bit";
    sqlite3_fprintf(p->out, "SQLite %s %s\n" /*extra-version-info*/,
          sqlite3_libversion(), sqlite3_sourceid());
#if SQLITE_HAVE_ZLIB
    sqlite3_fprintf(p->out, "zlib version %s\n", zlibVersion());
#endif
#define CTIMEOPT_VAL_(opt) #opt
#define CTIMEOPT_VAL(opt) CTIMEOPT_VAL_(opt)
#if defined(__clang__) && defined(__clang_major__)
    sqlite3_fprintf(p->out, "clang-" CTIMEOPT_VAL(__clang_major__) "."
          CTIMEOPT_VAL(__clang_minor__) "."
          CTIMEOPT_VAL(__clang_patchlevel__) " (%s)\n", zPtrSz);
#elif defined(_MSC_VER)
    sqlite3_fprintf(p->out, "msvc-" CTIMEOPT_VAL(_MSC_VER) " (%s)\n", zPtrSz);
#elif defined(__GNUC__) && defined(__VERSION__)
    sqlite3_fprintf(p->out, "gcc-" __VERSION__ " (%s)\n", zPtrSz);
#endif
  }else

  if( c=='v' && cli_strncmp(azArg[0], "vfsinfo", n)==0 ){
    const char *zDbName = nArg==2 ? azArg[1] : "main";
    sqlite3_vfs *pVfs = 0;
    if( p->db ){
      sqlite3_file_control(p->db, zDbName, SQLITE_FCNTL_VFS_POINTER, &pVfs);
      if( pVfs ){
        sqlite3_fprintf(p->out, "vfs.zName      = \"%s\"\n", pVfs->zName);
        sqlite3_fprintf(p->out, "vfs.iVersion   = %d\n", pVfs->iVersion);
        sqlite3_fprintf(p->out, "vfs.szOsFile   = %d\n", pVfs->szOsFile);
        sqlite3_fprintf(p->out, "vfs.mxPathname = %d\n", pVfs->mxPathname);
      }
    }
  }else

  if( c=='v' && cli_strncmp(azArg[0], "vfslist", n)==0 ){
    sqlite3_vfs *pVfs;
    sqlite3_vfs *pCurrent = 0;
    if( p->db ){
      sqlite3_file_control(p->db, "main", SQLITE_FCNTL_VFS_POINTER, &pCurrent);
    }
    for(pVfs=sqlite3_vfs_find(0); pVfs; pVfs=pVfs->pNext){
      sqlite3_fprintf(p->out, "vfs.zName      = \"%s\"%s\n", pVfs->zName,
            pVfs==pCurrent ? "  <--- CURRENT" : "");
      sqlite3_fprintf(p->out, "vfs.iVersion   = %d\n", pVfs->iVersion);
      sqlite3_fprintf(p->out, "vfs.szOsFile   = %d\n", pVfs->szOsFile);
      sqlite3_fprintf(p->out, "vfs.mxPathname = %d\n", pVfs->mxPathname);
      if( pVfs->pNext ){
        sqlite3_fputs("-----------------------------------\n", p->out);
      }
    }
  }else

  if( c=='v' && cli_strncmp(azArg[0], "vfsname", n)==0 ){
    const char *zDbName = nArg==2 ? azArg[1] : "main";
    char *zVfsName = 0;
    if( p->db ){
      sqlite3_file_control(p->db, zDbName, SQLITE_FCNTL_VFSNAME, &zVfsName);
      if( zVfsName ){
        sqlite3_fprintf(p->out, "%s\n", zVfsName);
        sqlite3_free(zVfsName);
      }
    }
  }else

  if( c=='w' && cli_strncmp(azArg[0], "wheretrace", n)==0 ){
    unsigned int x = nArg>=2? (unsigned int)integerValue(azArg[1]) : 0xffffffff;
    sqlite3_test_control(SQLITE_TESTCTRL_TRACEFLAGS, 3, &x);
  }else

  if( c=='w' && cli_strncmp(azArg[0], "width", n)==0 ){
    int j;
    assert( nArg<=ArraySize(azArg) );
    p->nWidth = nArg-1;
    p->colWidth = realloc(p->colWidth, (p->nWidth+1)*sizeof(int)*2);
    if( p->colWidth==0 && p->nWidth>0 ) shell_out_of_memory();
    if( p->nWidth ) p->actualWidth = &p->colWidth[p->nWidth];
    for(j=1; j<nArg; j++){
      p->colWidth[j-1] = (int)integerValue(azArg[j]);
    }
  }else

  {
    sqlite3_fprintf(stderr,"Error: unknown command or invalid arguments: "
          " \"%s\". Enter \".help\" for help\n", azArg[0]);
    rc = 1;
  }

meta_command_exit:
  if( p->outCount ){
    p->outCount--;
    if( p->outCount==0 ) output_reset(p);
  }
  p->bSafeMode = p->bSafeModePersist;
  return rc;
}

/* Line scan result and intermediate states (supporting scan resumption)
*/
#ifndef CHAR_BIT
# define CHAR_BIT 8
#endif
typedef enum {
  QSS_HasDark = 1<<CHAR_BIT, QSS_EndingSemi = 2<<CHAR_BIT,
  QSS_CharMask = (1<<CHAR_BIT)-1, QSS_ScanMask = 3<<CHAR_BIT,
  QSS_Start = 0
} QuickScanState;
#define QSS_SETV(qss, newst) ((newst) | ((qss) & QSS_ScanMask))
#define QSS_INPLAIN(qss) (((qss)&QSS_CharMask)==QSS_Start)
#define QSS_PLAINWHITE(qss) (((qss)&~QSS_EndingSemi)==QSS_Start)
#define QSS_PLAINDARK(qss) (((qss)&~QSS_EndingSemi)==QSS_HasDark)
#define QSS_SEMITERM(qss) (((qss)&~QSS_HasDark)==QSS_EndingSemi)

/*
** Scan line for classification to guide shell's handling.
** The scan is resumable for subsequent lines when prior
** return values are passed as the 2nd argument.
*/
static QuickScanState quickscan(char *zLine, QuickScanState qss,
                                SCAN_TRACKER_REFTYPE pst){
  char cin;
  char cWait = (char)qss; /* intentional narrowing loss */
  if( cWait==0 ){
  PlainScan:
    while( (cin = *zLine++)!=0 ){
      if( IsSpace(cin) )
        continue;
      switch (cin){
      case '-':
        if( *zLine!='-' )
          break;
        while((cin = *++zLine)!=0 )
          if( cin=='\n')
            goto PlainScan;
        return qss;
      case ';':
        qss |= QSS_EndingSemi;
        continue;
      case '/':
        if( *zLine=='*' ){
          ++zLine;
          cWait = '*';
          CONTINUE_PROMPT_AWAITS(pst, "/*");
          qss = QSS_SETV(qss, cWait);
          goto TermScan;
        }
        break;
      case '[':
        cin = ']';
        deliberate_fall_through;
      case '`': case '\'': case '"':
        cWait = cin;
        qss = QSS_HasDark | cWait;
        CONTINUE_PROMPT_AWAITC(pst, cin);
        goto TermScan;
      case '(':
        CONTINUE_PAREN_INCR(pst, 1);
        break;
      case ')':
        CONTINUE_PAREN_INCR(pst, -1);
        break;
      default:
        break;
      }
      qss = (qss & ~QSS_EndingSemi) | QSS_HasDark;
    }
  }else{
  TermScan:
    while( (cin = *zLine++)!=0 ){
      if( cin==cWait ){
        switch( cWait ){
        case '*':
          if( *zLine != '/' )
            continue;
          ++zLine;
          CONTINUE_PROMPT_AWAITC(pst, 0);
          qss = QSS_SETV(qss, 0);
          goto PlainScan;
        case '`': case '\'': case '"':
          if(*zLine==cWait){
            /* Swallow doubled end-delimiter.*/
            ++zLine;
            continue;
          }
          deliberate_fall_through;
        case ']':
          CONTINUE_PROMPT_AWAITC(pst, 0);
          qss = QSS_SETV(qss, 0);
          goto PlainScan;
        default: assert(0);
        }
      }
    }
  }
  return qss;
}

/*
** Return TRUE if the line typed in is an SQL command terminator other
** than a semi-colon.  The SQL Server style "go" command is understood
** as is the Oracle "/".
*/
static int line_is_command_terminator(char *zLine){
  while( IsSpace(zLine[0]) ){ zLine++; };
  if( zLine[0]=='/' )
    zLine += 1; /* Oracle */
  else if ( ToLower(zLine[0])=='g' && ToLower(zLine[1])=='o' )
    zLine += 2; /* SQL Server */
  else
    return 0;
  return quickscan(zLine, QSS_Start, 0)==QSS_Start;
}

/*
** The CLI needs a working sqlite3_complete() to work properly.  So error
** out of the build if compiling with SQLITE_OMIT_COMPLETE.
*/
#ifdef SQLITE_OMIT_COMPLETE
# error the CLI application is imcompatable with SQLITE_OMIT_COMPLETE.
#endif

/*
** Return true if zSql is a complete SQL statement.  Return false if it
** ends in the middle of a string literal or C-style comment.
*/
static int line_is_complete(char *zSql, int nSql){
  int rc;
  if( zSql==0 ) return 1;
  zSql[nSql] = ';';
  zSql[nSql+1] = 0;
  rc = sqlite3_complete(zSql);
  zSql[nSql] = 0;
  return rc;
}

/*
** This function is called after processing each line of SQL in the
** runOneSqlLine() function. Its purpose is to detect scenarios where
** defensive mode should be automatically turned off. Specifically, when
**
**   1. The first line of input is "PRAGMA foreign_keys=OFF;",
**   2. The second line of input is "BEGIN TRANSACTION;",
**   3. The database is empty, and
**   4. The shell is not running in --safe mode.
** 
** The implementation uses the ShellState.eRestoreState to maintain state:
**
**    0: Have not seen any SQL.
**    1: Have seen "PRAGMA foreign_keys=OFF;".
**    2-6: Currently running .dump transaction. If the "2" bit is set,
**         disable DEFENSIVE when done. If "4" is set, disable DQS_DDL.
**    7: Nothing left to do. This function becomes a no-op.
*/
static int doAutoDetectRestore(ShellState *p, const char *zSql){
  int rc = SQLITE_OK;

  if( p->eRestoreState<7 ){
    switch( p->eRestoreState ){
      case 0: {
        const char *zExpect = "PRAGMA foreign_keys=OFF;";
        assert( strlen(zExpect)==24 );
        if( p->bSafeMode==0
         && strlen(zSql)>=24
         && memcmp(zSql, zExpect, 25)==0
        ){
          p->eRestoreState = 1;
        }else{
          p->eRestoreState = 7;
        }
        break;
      };
  
      case 1: {
        int bIsDump = 0;
        const char *zExpect = "BEGIN TRANSACTION;";
        assert( strlen(zExpect)==18 );
        if( memcmp(zSql, zExpect, 19)==0 ){
          /* Now check if the database is empty. */
          const char *zQuery = "SELECT 1 FROM sqlite_schema LIMIT 1";
          sqlite3_stmt *pStmt = 0;
  
          bIsDump = 1;
          shellPrepare(p->db, &rc, zQuery, &pStmt);
          if( rc==SQLITE_OK && sqlite3_step(pStmt)==SQLITE_ROW ){
            bIsDump = 0;
          }
          shellFinalize(&rc, pStmt);
        }
        if( bIsDump && rc==SQLITE_OK ){
          int bDefense = 0;
          int bDqsDdl = 0;
          sqlite3_db_config(p->db, SQLITE_DBCONFIG_DEFENSIVE, -1, &bDefense);
          sqlite3_db_config(p->db, SQLITE_DBCONFIG_DQS_DDL, -1, &bDqsDdl);
          sqlite3_db_config(p->db, SQLITE_DBCONFIG_DEFENSIVE, 0, 0);
          sqlite3_db_config(p->db, SQLITE_DBCONFIG_DQS_DDL, 1, 0);
          p->eRestoreState = (bDefense ? 2 : 0) + (bDqsDdl ? 4 : 0);
        }else{
          p->eRestoreState = 7;
        }
        break;
      }
  
      default: {
        if( sqlite3_get_autocommit(p->db) ){
          if( (p->eRestoreState & 2) ){
            sqlite3_db_config(p->db, SQLITE_DBCONFIG_DEFENSIVE, 1, 0);
          }
          if( (p->eRestoreState & 4) ){
            sqlite3_db_config(p->db, SQLITE_DBCONFIG_DQS_DDL, 0, 0);
          }
          p->eRestoreState = 7;
        }
        break;
      }
    }
  }

  return rc;
}

/*
** Run a single line of SQL.  Return the number of errors.
*/
static int runOneSqlLine(ShellState *p, char *zSql, FILE *in, int startline){
  int rc;
  char *zErrMsg = 0;

  open_db(p, 0);
  if( ShellHasFlag(p,SHFLG_Backslash) ) resolve_backslashes(zSql);
  if( p->flgProgress & SHELL_PROGRESS_RESET ) p->nProgress = 0;
  BEGIN_TIMER;
  rc = shell_exec(p, zSql, &zErrMsg);
  END_TIMER(p->out);
  if( rc || zErrMsg ){
    char zPrefix[100];
    const char *zErrorTail;
    const char *zErrorType;
    if( zErrMsg==0 ){
      zErrorType = "Error";
      zErrorTail = sqlite3_errmsg(p->db);
    }else if( cli_strncmp(zErrMsg, "in prepare, ",12)==0 ){
      zErrorType = "Parse error";
      zErrorTail = &zErrMsg[12];
    }else if( cli_strncmp(zErrMsg, "stepping, ", 10)==0 ){
      zErrorType = "Runtime error";
      zErrorTail = &zErrMsg[10];
    }else{
      zErrorType = "Error";
      zErrorTail = zErrMsg;
    }
    if( in!=0 || !stdin_is_interactive ){
      sqlite3_snprintf(sizeof(zPrefix), zPrefix,
                       "%s near line %d:", zErrorType, startline);
    }else{
      sqlite3_snprintf(sizeof(zPrefix), zPrefix, "%s:", zErrorType);
    }
    sqlite3_fprintf(stderr,"%s %s\n", zPrefix, zErrorTail);
    sqlite3_free(zErrMsg);
    zErrMsg = 0;
    return 1;
  }else if( ShellHasFlag(p, SHFLG_CountChanges) ){
    char zLineBuf[2000];
    sqlite3_snprintf(sizeof(zLineBuf), zLineBuf,
            "changes: %lld   total_changes: %lld",
            sqlite3_changes64(p->db), sqlite3_total_changes64(p->db));
    sqlite3_fprintf(p->out, "%s\n", zLineBuf);
  }

  if( doAutoDetectRestore(p, zSql) ) return 1;
  return 0;
}

static void echo_group_input(ShellState *p, const char *zDo){
  if( ShellHasFlag(p, SHFLG_Echo) ) sqlite3_fprintf(p->out, "%s\n", zDo);
}

#ifdef SQLITE_SHELL_FIDDLE
/*
** Alternate one_input_line() impl for wasm mode. This is not in the primary
** impl because we need the global shellState and cannot access it from that
** function without moving lots of code around (creating a larger/messier diff).
*/
static char *one_input_line(FILE *in, char *zPrior, int isContinuation){
  /* Parse the next line from shellState.wasm.zInput. */
  const char *zBegin = shellState.wasm.zPos;
  const char *z = zBegin;
  char *zLine = 0;
  i64 nZ = 0;

  UNUSED_PARAMETER(in);
  UNUSED_PARAMETER(isContinuation);
  if(!z || !*z){
    return 0;
  }
  while(*z && isspace(*z)) ++z;
  zBegin = z;
  for(; *z && '\n'!=*z; ++nZ, ++z){}
  if(nZ>0 && '\r'==zBegin[nZ-1]){
    --nZ;
  }
  shellState.wasm.zPos = z;
  zLine = realloc(zPrior, nZ+1);
  shell_check_oom(zLine);
  memcpy(zLine, zBegin, nZ);
  zLine[nZ] = 0;
  return zLine;
}
#endif /* SQLITE_SHELL_FIDDLE */

/*
** Read input from *in and process it.  If *in==0 then input
** is interactive - the user is typing it it.  Otherwise, input
** is coming from a file or device.  A prompt is issued and history
** is saved only if input is interactive.  An interrupt signal will
** cause this routine to exit immediately, unless input is interactive.
**
** Return the number of errors.
*/
static int process_input(ShellState *p){
  char *zLine = 0;          /* A single input line */
  char *zSql = 0;           /* Accumulated SQL text */
  i64 nLine;                /* Length of current line */
  i64 nSql = 0;             /* Bytes of zSql[] used */
  i64 nAlloc = 0;           /* Allocated zSql[] space */
  int rc;                   /* Error code */
  int errCnt = 0;           /* Number of errors seen */
  i64 startline = 0;        /* Line number for start of current input */
  QuickScanState qss = QSS_Start; /* Accumulated line status (so far) */

  if( p->inputNesting==MAX_INPUT_NESTING ){
    /* This will be more informative in a later version. */
    sqlite3_fprintf(stderr,"Input nesting limit (%d) reached at line %d."
          " Check recursion.\n", MAX_INPUT_NESTING, p->lineno);
    return 1;
  }
  ++p->inputNesting;
  p->lineno = 0;
  CONTINUE_PROMPT_RESET;
  while( errCnt==0 || !bail_on_error || (p->in==0 && stdin_is_interactive) ){
    fflush(p->out);
    zLine = one_input_line(p->in, zLine, nSql>0);
    if( zLine==0 ){
      /* End of input */
      if( p->in==0 && stdin_is_interactive ) sqlite3_fputs("\n", p->out);
      break;
    }
    if( seenInterrupt ){
      if( p->in!=0 ) break;
      seenInterrupt = 0;
    }
    p->lineno++;
    if( QSS_INPLAIN(qss)
        && line_is_command_terminator(zLine)
        && line_is_complete(zSql, nSql) ){
      memcpy(zLine,";",2);
    }
    qss = quickscan(zLine, qss, CONTINUE_PROMPT_PSTATE);
    if( QSS_PLAINWHITE(qss) && nSql==0 ){
      /* Just swallow single-line whitespace */
      echo_group_input(p, zLine);
      qss = QSS_Start;
      continue;
    }
    if( zLine && (zLine[0]=='.' || zLine[0]=='#') && nSql==0 ){
      CONTINUE_PROMPT_RESET;
      echo_group_input(p, zLine);
      if( zLine[0]=='.' ){
        rc = do_meta_command(zLine, p);
        if( rc==2 ){ /* exit requested */
          break;
        }else if( rc ){
          errCnt++;
        }
      }
      qss = QSS_Start;
      continue;
    }
    /* No single-line dispositions remain; accumulate line(s). */
    nLine = strlen(zLine);
    if( nSql+nLine+2>=nAlloc ){
      /* Grow buffer by half-again increments when big. */
      nAlloc = nSql+(nSql>>1)+nLine+100;
      zSql = realloc(zSql, nAlloc);
      shell_check_oom(zSql);
    }
    if( nSql==0 ){
      i64 i;
      for(i=0; zLine[i] && IsSpace(zLine[i]); i++){}
      assert( nAlloc>0 && zSql!=0 );
      memcpy(zSql, zLine+i, nLine+1-i);
      startline = p->lineno;
      nSql = nLine-i;
    }else{
      zSql[nSql++] = '\n';
      memcpy(zSql+nSql, zLine, nLine+1);
      nSql += nLine;
    }
    if( nSql && QSS_SEMITERM(qss) && sqlite3_complete(zSql) ){
      echo_group_input(p, zSql);
      errCnt += runOneSqlLine(p, zSql, p->in, startline);
      CONTINUE_PROMPT_RESET;
      nSql = 0;
      if( p->outCount ){
        output_reset(p);
        p->outCount = 0;
      }else{
        clearTempFile(p);
      }
      p->bSafeMode = p->bSafeModePersist;
      qss = QSS_Start;
    }else if( nSql && QSS_PLAINWHITE(qss) ){
      echo_group_input(p, zSql);
      nSql = 0;
      qss = QSS_Start;
    }
  }
  if( nSql ){
    /* This may be incomplete. Let the SQL parser deal with that. */
    echo_group_input(p, zSql);
    errCnt += runOneSqlLine(p, zSql, p->in, startline);
    CONTINUE_PROMPT_RESET;
  }
  free(zSql);
  free(zLine);
  --p->inputNesting;
  return errCnt>0;
}

/*
** Return a pathname which is the user's home directory.  A
** 0 return indicates an error of some kind.
*/
static char *find_home_dir(int clearFlag){
  static char *home_dir = NULL;
  if( clearFlag ){
    free(home_dir);
    home_dir = 0;
    return 0;
  }
  if( home_dir ) return home_dir;

#if !defined(_WIN32) && !defined(WIN32) && !defined(_WIN32_WCE) \
     && !defined(__RTP__) && !defined(_WRS_KERNEL) && !defined(SQLITE_WASI)
  {
    struct passwd *pwent;
    uid_t uid = getuid();
    if( (pwent=getpwuid(uid)) != NULL) {
      home_dir = pwent->pw_dir;
    }
  }
#endif

#if defined(_WIN32_WCE)
  /* Windows CE (arm-wince-mingw32ce-gcc) does not provide getenv()
   */
  home_dir = "/";
#else

#if defined(_WIN32) || defined(WIN32)
  if (!home_dir) {
    home_dir = getenv("USERPROFILE");
  }
#endif

  if (!home_dir) {
    home_dir = getenv("HOME");
  }

#if defined(_WIN32) || defined(WIN32)
  if (!home_dir) {
    char *zDrive, *zPath;
    int n;
    zDrive = getenv("HOMEDRIVE");
    zPath = getenv("HOMEPATH");
    if( zDrive && zPath ){
      n = strlen30(zDrive) + strlen30(zPath) + 1;
      home_dir = malloc( n );
      if( home_dir==0 ) return 0;
      sqlite3_snprintf(n, home_dir, "%s%s", zDrive, zPath);
      return home_dir;
    }
    home_dir = "c:\\";
  }
#endif

#endif /* !_WIN32_WCE */

  if( home_dir ){
    i64 n = strlen(home_dir) + 1;
    char *z = malloc( n );
    if( z ) memcpy(z, home_dir, n);
    home_dir = z;
  }

  return home_dir;
}

/*
** On non-Windows platforms, look for $XDG_CONFIG_HOME.
** If ${XDG_CONFIG_HOME}/sqlite3/sqliterc is found, return
** the path to it.  If there is no $(XDG_CONFIG_HOME) then
** look for $(HOME)/.config/sqlite3/sqliterc and if found
** return that.  If none of these are found, return 0.
**
** The string returned is obtained from sqlite3_malloc() and
** should be freed by the caller.
*/
static char *find_xdg_config(void){
#if defined(_WIN32) || defined(WIN32) || defined(_WIN32_WCE) \
     || defined(__RTP__) || defined(_WRS_KERNEL)
  return 0;
#else
  char *zConfig = 0;
  const char *zXdgHome;

  zXdgHome = getenv("XDG_CONFIG_HOME");
  if( zXdgHome==0 ){
    const char *zHome = getenv("HOME");
    if( zHome==0 ) return 0;
    zConfig = sqlite3_mprintf("%s/.config/sqlite3/sqliterc", zHome);
  }else{
    zConfig = sqlite3_mprintf("%s/sqlite3/sqliterc", zXdgHome);
  }
  shell_check_oom(zConfig);
  if( access(zConfig,0)!=0 ){
    sqlite3_free(zConfig);
    zConfig = 0;
  }
  return zConfig;
#endif
}

/*
** Read input from the file given by sqliterc_override.  Or if that
** parameter is NULL, take input from the first of find_xdg_config()
** or ~/.sqliterc which is found.
**
** Returns the number of errors.
*/
static void process_sqliterc(
  ShellState *p,                  /* Configuration data */
  const char *sqliterc_override   /* Name of config file. NULL to use default */
){
  char *home_dir = NULL;
  const char *sqliterc = sqliterc_override;
  char *zBuf = 0;
  FILE *inSaved = p->in;
  int savedLineno = p->lineno;

  if( sqliterc == NULL ){
    sqliterc = zBuf = find_xdg_config();
  }
  if( sqliterc == NULL ){
    home_dir = find_home_dir(0);
    if( home_dir==0 ){
      eputz("-- warning: cannot find home directory;"
            " cannot read ~/.sqliterc\n");
      return;
    }
    zBuf = sqlite3_mprintf("%s/.sqliterc",home_dir);
    shell_check_oom(zBuf);
    sqliterc = zBuf;
  }
  p->in = sqlite3_fopen(sqliterc,"rb");
  if( p->in ){
    if( stdin_is_interactive ){
      sqlite3_fprintf(stderr,"-- Loading resources from %s\n", sqliterc);
    }
    if( process_input(p) && bail_on_error ) exit(1);
    fclose(p->in);
  }else if( sqliterc_override!=0 ){
    sqlite3_fprintf(stderr,"cannot open: \"%s\"\n", sqliterc);
    if( bail_on_error ) exit(1);
  }
  p->in = inSaved;
  p->lineno = savedLineno;
  sqlite3_free(zBuf);
}

/*
** Show available command line options
*/
static const char zOptions[] =
  "   --                   treat no subsequent arguments as options\n"
#if defined(SQLITE_HAVE_ZLIB) && !defined(SQLITE_OMIT_VIRTUALTABLE)
  "   -A ARGS...           run \".archive ARGS\" and exit\n"
#endif
  "   -append              append the database to the end of the file\n"
  "   -ascii               set output mode to 'ascii'\n"
  "   -bail                stop after hitting an error\n"
  "   -batch               force batch I/O\n"
  "   -box                 set output mode to 'box'\n"
  "   -column              set output mode to 'column'\n"
  "   -cmd COMMAND         run \"COMMAND\" before reading stdin\n"
  "   -csv                 set output mode to 'csv'\n"
#if !defined(SQLITE_OMIT_DESERIALIZE)
  "   -deserialize         open the database using sqlite3_deserialize()\n"
#endif
  "   -echo                print inputs before execution\n"
  "   -init FILENAME       read/process named file\n"
  "   -[no]header          turn headers on or off\n"
#if defined(SQLITE_ENABLE_MEMSYS3) || defined(SQLITE_ENABLE_MEMSYS5)
  "   -heap SIZE           Size of heap for memsys3 or memsys5\n"
#endif
  "   -help                show this message\n"
  "   -html                set output mode to HTML\n"
  "   -interactive         force interactive I/O\n"
  "   -json                set output mode to 'json'\n"
  "   -line                set output mode to 'line'\n"
  "   -list                set output mode to 'list'\n"
  "   -lookaside SIZE N    use N entries of SZ bytes for lookaside memory\n"
  "   -markdown            set output mode to 'markdown'\n"
#if !defined(SQLITE_OMIT_DESERIALIZE)
  "   -maxsize N           maximum size for a --deserialize database\n"
#endif
  "   -memtrace            trace all memory allocations and deallocations\n"
  "   -mmap N              default mmap size set to N\n"
#ifdef SQLITE_ENABLE_MULTIPLEX
  "   -multiplex           enable the multiplexor VFS\n"
#endif
  "   -newline SEP         set output row separator. Default: '\\n'\n"
  "   -nofollow            refuse to open symbolic links to database files\n"
  "   -nonce STRING        set the safe-mode escape nonce\n"
  "   -no-rowid-in-view    Disable rowid-in-view using sqlite3_config()\n"
  "   -nullvalue TEXT      set text string for NULL values. Default ''\n"
  "   -pagecache SIZE N    use N slots of SZ bytes each for page cache memory\n"
  "   -pcachetrace         trace all page cache operations\n"
  "   -quote               set output mode to 'quote'\n"
  "   -readonly            open the database read-only\n"
  "   -safe                enable safe-mode\n"
  "   -separator SEP       set output column separator. Default: '|'\n"
#ifdef SQLITE_ENABLE_SORTER_REFERENCES
  "   -sorterref SIZE      sorter references threshold size\n"
#endif
  "   -stats               print memory stats before each finalize\n"
  "   -table               set output mode to 'table'\n"
  "   -tabs                set output mode to 'tabs'\n"
  "   -unsafe-testing      allow unsafe commands and modes for testing\n"
  "   -version             show SQLite version\n"
  "   -vfs NAME            use NAME as the default VFS\n"
  "   -vfstrace            enable tracing of all VFS calls\n"
#ifdef SQLITE_HAVE_ZLIB
  "   -zip                 open the file as a ZIP Archive\n"
#endif
;
static void usage(int showDetail){
  sqlite3_fprintf(stderr,"Usage: %s [OPTIONS] [FILENAME [SQL]]\n"
       "FILENAME is the name of an SQLite database. A new database is created\n"
       "if the file does not previously exist. Defaults to :memory:.\n", Argv0);
  if( showDetail ){
    sqlite3_fprintf(stderr,"OPTIONS include:\n%s", zOptions);
  }else{
    eputz("Use the -help option for additional information\n");
  }
  exit(0);
}

/*
** Internal check:  Verify that the SQLite is uninitialized.  Print a
** error message if it is initialized.
*/
static void verify_uninitialized(void){
  if( sqlite3_config(-1)==SQLITE_MISUSE ){
    sputz(stdout, "WARNING: attempt to configure SQLite after"
          " initialization.\n");
  }
}

/*
** Initialize the state information in data
*/
static void main_init(ShellState *data) {
  memset(data, 0, sizeof(*data));
  data->normalMode = data->cMode = data->mode = MODE_List;
  data->autoExplain = 1;
#ifdef _WIN32
  data->crlfMode = 1;
#endif
  data->pAuxDb = &data->aAuxDb[0];
  memcpy(data->colSeparator,SEP_Column, 2);
  memcpy(data->rowSeparator,SEP_Row, 2);
  data->showHeader = 0;
  data->shellFlgs = SHFLG_Lookaside;
  sqlite3_config(SQLITE_CONFIG_LOG, shellLog, data);
#if !defined(SQLITE_SHELL_FIDDLE)
  verify_uninitialized();
#endif
  sqlite3_config(SQLITE_CONFIG_URI, 1);
  sqlite3_config(SQLITE_CONFIG_MULTITHREAD);
  sqlite3_snprintf(sizeof(mainPrompt), mainPrompt,"sqlite> ");
  sqlite3_snprintf(sizeof(continuePrompt), continuePrompt,"   ...> ");
}

/*
** Output text to the console in a font that attracts extra attention.
*/
#if defined(_WIN32) || defined(WIN32)
static void printBold(const char *zText){
#if !SQLITE_OS_WINRT
  HANDLE out = GetStdHandle(STD_OUTPUT_HANDLE);
  CONSOLE_SCREEN_BUFFER_INFO defaultScreenInfo;
  GetConsoleScreenBufferInfo(out, &defaultScreenInfo);
  SetConsoleTextAttribute(out,
         FOREGROUND_RED|FOREGROUND_INTENSITY
  );
#endif
  sputz(stdout, zText);
#if !SQLITE_OS_WINRT
  SetConsoleTextAttribute(out, defaultScreenInfo.wAttributes);
#endif
}
#else
static void printBold(const char *zText){
  sqlite3_fprintf(stdout, "\033[1m%s\033[0m", zText);
}
#endif

/*
** Get the argument to an --option.  Throw an error and die if no argument
** is available.
*/
static char *cmdline_option_value(int argc, char **argv, int i){
  if( i==argc ){
    sqlite3_fprintf(stderr,
            "%s: Error: missing argument to %s\n", argv[0], argv[argc-1]);
    exit(1);
  }
  return argv[i];
}

static void sayAbnormalExit(void){
  if( seenInterrupt ) eputz("Program interrupted.\n");
}

#ifndef SQLITE_SHELL_IS_UTF8
#  if (defined(_WIN32) || defined(WIN32)) \
   && (defined(_MSC_VER) || (defined(UNICODE) && defined(__GNUC__)))
#    define SQLITE_SHELL_IS_UTF8          (0)
#  else
#    define SQLITE_SHELL_IS_UTF8          (1)
#  endif
#endif

#ifdef SQLITE_SHELL_FIDDLE
#  define main fiddle_main
#endif

#if SQLITE_SHELL_IS_UTF8
int SQLITE_CDECL main(int argc, char **argv){
#else
int SQLITE_CDECL wmain(int argc, wchar_t **wargv){
  char **argv;
#endif
#ifdef SQLITE_DEBUG
  sqlite3_int64 mem_main_enter = 0;
#endif
  char *zErrMsg = 0;
#ifdef SQLITE_SHELL_FIDDLE
#  define data shellState
#else
  ShellState data;
#endif
  const char *zInitFile = 0;
  int i;
  int rc = 0;
  int warnInmemoryDb = 0;
  int readStdin = 1;
  int nCmd = 0;
  int nOptsEnd = argc;
  int bEnableVfstrace = 0;
  char **azCmd = 0;
  const char *zVfs = 0;           /* Value of -vfs command-line option */
#if !SQLITE_SHELL_IS_UTF8
  char **argvToFree = 0;
  int argcToFree = 0;
#endif
  setvbuf(stderr, 0, _IONBF, 0); /* Make sure stderr is unbuffered */

#ifdef SQLITE_SHELL_FIDDLE
  stdin_is_interactive = 0;
  stdout_is_console = 1;
  data.wasm.zDefaultDbName = "/fiddle.sqlite3";
#else
  stdin_is_interactive = isatty(0);
  stdout_is_console = isatty(1);
#endif
  atexit(sayAbnormalExit);
#ifdef SQLITE_DEBUG
  mem_main_enter = sqlite3_memory_used();
#endif
#if !defined(_WIN32_WCE)
  if( getenv("SQLITE_DEBUG_BREAK") ){
    if( isatty(0) && isatty(2) ){
      char zLine[100];
      sqlite3_fprintf(stderr,
            "attach debugger to process %d and press ENTER to continue...",
            GETPID());
      if( sqlite3_fgets(zLine, sizeof(zLine), stdin)!=0
       && cli_strcmp(zLine,"stop")==0
      ){
        exit(1);
      }
    }else{
#if defined(_WIN32) || defined(WIN32)
#if SQLITE_OS_WINRT
      __debugbreak();
#else
      DebugBreak();
#endif
#elif defined(SIGTRAP)
      raise(SIGTRAP);
#endif
    }
  }
#endif
  /* Register a valid signal handler early, before much else is done. */
#ifdef SIGINT
  signal(SIGINT, interrupt_handler);
#elif (defined(_WIN32) || defined(WIN32)) && !defined(_WIN32_WCE)
  if( !SetConsoleCtrlHandler(ConsoleCtrlHandler, TRUE) ){
    eputz("No ^C handler.\n");
  }
#endif

#if USE_SYSTEM_SQLITE+0!=1
  if( cli_strncmp(sqlite3_sourceid(),SQLITE_SOURCE_ID,60)!=0 ){
    sqlite3_fprintf(stderr,
          "SQLite header and source version mismatch\n%s\n%s\n",
          sqlite3_sourceid(), SQLITE_SOURCE_ID);
    exit(1);
  }
#endif
  main_init(&data);

  /* On Windows, we must translate command-line arguments into UTF-8.
  ** The SQLite memory allocator subsystem has to be enabled in order to
  ** do this.  But we want to run an sqlite3_shutdown() afterwards so that
  ** subsequent sqlite3_config() calls will work.  So copy all results into
  ** memory that does not come from the SQLite memory allocator.
  */
#if !SQLITE_SHELL_IS_UTF8
  sqlite3_initialize();
  argvToFree = malloc(sizeof(argv[0])*argc*2);
  shell_check_oom(argvToFree);
  argcToFree = argc;
  argv = argvToFree + argc;
  for(i=0; i<argc; i++){
    char *z = sqlite3_win32_unicode_to_utf8(wargv[i]);
    i64 n;
    shell_check_oom(z);
    n = strlen(z);
    argv[i] = malloc( n+1 );
    shell_check_oom(argv[i]);
    memcpy(argv[i], z, n+1);
    argvToFree[i] = argv[i];
    sqlite3_free(z);
  }
  sqlite3_shutdown();
#endif

  assert( argc>=1 && argv && argv[0] );
  Argv0 = argv[0];

#ifdef SQLITE_SHELL_DBNAME_PROC
  {
    /* If the SQLITE_SHELL_DBNAME_PROC macro is defined, then it is the name
    ** of a C-function that will provide the name of the database file.  Use
    ** this compile-time option to embed this shell program in larger
    ** applications. */
    extern void SQLITE_SHELL_DBNAME_PROC(const char**);
    SQLITE_SHELL_DBNAME_PROC(&data.pAuxDb->zDbFilename);
    warnInmemoryDb = 0;
  }
#endif

  /* Do an initial pass through the command-line argument to locate
  ** the name of the database file, the name of the initialization file,
  ** the size of the alternative malloc heap, options affecting commands
  ** or SQL run from the command line, and the first command to execute.
  */
#ifndef SQLITE_SHELL_FIDDLE
  verify_uninitialized();
#endif
  for(i=1; i<argc; i++){
    char *z;
    z = argv[i];
    if( z[0]!='-' || i>nOptsEnd ){
      if( data.aAuxDb->zDbFilename==0 ){
        data.aAuxDb->zDbFilename = z;
      }else{
        /* Excess arguments are interpreted as SQL (or dot-commands) and
        ** mean that nothing is read from stdin */
        readStdin = 0;
        nCmd++;
        azCmd = realloc(azCmd, sizeof(azCmd[0])*nCmd);
        shell_check_oom(azCmd);
        azCmd[nCmd-1] = z;
      }
      continue;
    }
    if( z[1]=='-' ) z++;
    if( cli_strcmp(z, "-")==0 ){
      nOptsEnd = i;
      continue;
    }else if( cli_strcmp(z,"-separator")==0
     || cli_strcmp(z,"-nullvalue")==0
     || cli_strcmp(z,"-newline")==0
     || cli_strcmp(z,"-cmd")==0
    ){
      (void)cmdline_option_value(argc, argv, ++i);
    }else if( cli_strcmp(z,"-init")==0 ){
      zInitFile = cmdline_option_value(argc, argv, ++i);
    }else if( cli_strcmp(z,"-interactive")==0 ){
    }else if( cli_strcmp(z,"-batch")==0 ){
      /* Need to check for batch mode here to so we can avoid printing
      ** informational messages (like from process_sqliterc) before
      ** we do the actual processing of arguments later in a second pass.
      */
      stdin_is_interactive = 0;
    }else if( cli_strcmp(z,"-utf8")==0 ){
    }else if( cli_strcmp(z,"-no-utf8")==0 ){
    }else if( cli_strcmp(z,"-no-rowid-in-view")==0 ){
      int val = 0;
      sqlite3_config(SQLITE_CONFIG_ROWID_IN_VIEW, &val);
      assert( val==0 );
    }else if( cli_strcmp(z,"-heap")==0 ){
#if defined(SQLITE_ENABLE_MEMSYS3) || defined(SQLITE_ENABLE_MEMSYS5)
      const char *zSize;
      sqlite3_int64 szHeap;

      zSize = cmdline_option_value(argc, argv, ++i);
      szHeap = integerValue(zSize);
      if( szHeap>0x7fff0000 ) szHeap = 0x7fff0000;
      verify_uninitialized();
      sqlite3_config(SQLITE_CONFIG_HEAP, malloc((int)szHeap), (int)szHeap, 64);
#else
      (void)cmdline_option_value(argc, argv, ++i);
#endif
    }else if( cli_strcmp(z,"-pagecache")==0 ){
      sqlite3_int64 n, sz;
      sz = integerValue(cmdline_option_value(argc,argv,++i));
      if( sz>70000 ) sz = 70000;
      if( sz<0 ) sz = 0;
      n = integerValue(cmdline_option_value(argc,argv,++i));
      if( sz>0 && n>0 && 0xffffffffffffLL/sz<n ){
        n = 0xffffffffffffLL/sz;
      }
      verify_uninitialized();
      sqlite3_config(SQLITE_CONFIG_PAGECACHE,
                    (n>0 && sz>0) ? malloc(n*sz) : 0, sz, n);
      data.shellFlgs |= SHFLG_Pagecache;
    }else if( cli_strcmp(z,"-lookaside")==0 ){
      int n, sz;
      sz = (int)integerValue(cmdline_option_value(argc,argv,++i));
      if( sz<0 ) sz = 0;
      n = (int)integerValue(cmdline_option_value(argc,argv,++i));
      if( n<0 ) n = 0;
      verify_uninitialized();
      sqlite3_config(SQLITE_CONFIG_LOOKASIDE, sz, n);
      if( sz*n==0 ) data.shellFlgs &= ~SHFLG_Lookaside;
    }else if( cli_strcmp(z,"-threadsafe")==0 ){
      int n;
      n = (int)integerValue(cmdline_option_value(argc,argv,++i));
      verify_uninitialized();
      switch( n ){
         case 0:  sqlite3_config(SQLITE_CONFIG_SINGLETHREAD);  break;
         case 2:  sqlite3_config(SQLITE_CONFIG_MULTITHREAD);   break;
         default: sqlite3_config(SQLITE_CONFIG_SERIALIZED);    break;
      }
    }else if( cli_strcmp(z,"-vfstrace")==0 ){
      vfstrace_register("trace",0,(int(*)(const char*,void*))sqlite3_fputs,
                        stderr,1);
      bEnableVfstrace = 1;
#ifdef SQLITE_ENABLE_MULTIPLEX
    }else if( cli_strcmp(z,"-multiplex")==0 ){
      extern int sqlite3_multiplex_initialize(const char*,int);
      sqlite3_multiplex_initialize(0, 1);
#endif
    }else if( cli_strcmp(z,"-mmap")==0 ){
      sqlite3_int64 sz = integerValue(cmdline_option_value(argc,argv,++i));
      verify_uninitialized();
      sqlite3_config(SQLITE_CONFIG_MMAP_SIZE, sz, sz);
#if defined(SQLITE_ENABLE_SORTER_REFERENCES)
    }else if( cli_strcmp(z,"-sorterref")==0 ){
      sqlite3_int64 sz = integerValue(cmdline_option_value(argc,argv,++i));
      verify_uninitialized();
      sqlite3_config(SQLITE_CONFIG_SORTERREF_SIZE, (int)sz);
#endif
    }else if( cli_strcmp(z,"-vfs")==0 ){
      zVfs = cmdline_option_value(argc, argv, ++i);
#ifdef SQLITE_HAVE_ZLIB
    }else if( cli_strcmp(z,"-zip")==0 ){
      data.openMode = SHELL_OPEN_ZIPFILE;
#endif
    }else if( cli_strcmp(z,"-append")==0 ){
      data.openMode = SHELL_OPEN_APPENDVFS;
#ifndef SQLITE_OMIT_DESERIALIZE
    }else if( cli_strcmp(z,"-deserialize")==0 ){
      data.openMode = SHELL_OPEN_DESERIALIZE;
    }else if( cli_strcmp(z,"-maxsize")==0 && i+1<argc ){
      data.szMax = integerValue(argv[++i]);
#endif
    }else if( cli_strcmp(z,"-readonly")==0 ){
      data.openMode = SHELL_OPEN_READONLY;
    }else if( cli_strcmp(z,"-nofollow")==0 ){
      data.openFlags = SQLITE_OPEN_NOFOLLOW;
#if !defined(SQLITE_OMIT_VIRTUALTABLE) && defined(SQLITE_HAVE_ZLIB)
    }else if( cli_strncmp(z, "-A",2)==0 ){
      /* All remaining command-line arguments are passed to the ".archive"
      ** command, so ignore them */
      break;
#endif
    }else if( cli_strcmp(z, "-memtrace")==0 ){
      sqlite3MemTraceActivate(stderr);
    }else if( cli_strcmp(z, "-pcachetrace")==0 ){
      sqlite3PcacheTraceActivate(stderr);
    }else if( cli_strcmp(z,"-bail")==0 ){
      bail_on_error = 1;
    }else if( cli_strcmp(z,"-nonce")==0 ){
      free(data.zNonce);
      data.zNonce = strdup(cmdline_option_value(argc, argv, ++i));
    }else if( cli_strcmp(z,"-unsafe-testing")==0 ){
      ShellSetFlag(&data,SHFLG_TestingMode);
    }else if( cli_strcmp(z,"-safe")==0 ){
      /* no-op - catch this on the second pass */
    }
  }
#ifndef SQLITE_SHELL_FIDDLE
  if( !bEnableVfstrace ) verify_uninitialized();
#endif


#ifdef SQLITE_SHELL_INIT_PROC
  {
    /* If the SQLITE_SHELL_INIT_PROC macro is defined, then it is the name
    ** of a C-function that will perform initialization actions on SQLite that
    ** occur just before or after sqlite3_initialize(). Use this compile-time
    ** option to embed this shell program in larger applications. */
    extern void SQLITE_SHELL_INIT_PROC(void);
    SQLITE_SHELL_INIT_PROC();
  }
#else
  /* All the sqlite3_config() calls have now been made. So it is safe
  ** to call sqlite3_initialize() and process any command line -vfs option. */
  sqlite3_initialize();
#endif

  if( zVfs ){
    sqlite3_vfs *pVfs = sqlite3_vfs_find(zVfs);
    if( pVfs ){
      sqlite3_vfs_register(pVfs, 1);
    }else{
      sqlite3_fprintf(stderr,"no such VFS: \"%s\"\n", zVfs);
      exit(1);
    }
  }

  if( data.pAuxDb->zDbFilename==0 ){
#ifndef SQLITE_OMIT_MEMORYDB
    data.pAuxDb->zDbFilename = ":memory:";
    warnInmemoryDb = argc==1;
#else
    sqlite3_fprintf(stderr,
                    "%s: Error: no database filename specified\n", Argv0);
    return 1;
#endif
  }
  data.out = stdout;
#ifndef SQLITE_SHELL_FIDDLE
  sqlite3_appendvfs_init(0,0,0);
#endif

  /* Go ahead and open the database file if it already exists.  If the
  ** file does not exist, delay opening it.  This prevents empty database
  ** files from being created if a user mistypes the database name argument
  ** to the sqlite command-line tool.
  */
  if( access(data.pAuxDb->zDbFilename, 0)==0 ){
    open_db(&data, 0);
  }

  /* Process the initialization file if there is one.  If no -init option
  ** is given on the command line, look for a file named ~/.sqliterc and
  ** try to process it.
  */
  process_sqliterc(&data,zInitFile);

  /* Make a second pass through the command-line argument and set
  ** options.  This second pass is delayed until after the initialization
  ** file is processed so that the command-line arguments will override
  ** settings in the initialization file.
  */
  for(i=1; i<argc; i++){
    char *z = argv[i];
    if( z[0]!='-' || i>=nOptsEnd ) continue;
    if( z[1]=='-' ){ z++; }
    if( cli_strcmp(z,"-init")==0 ){
      i++;
    }else if( cli_strcmp(z,"-html")==0 ){
      data.mode = MODE_Html;
    }else if( cli_strcmp(z,"-list")==0 ){
      data.mode = MODE_List;
    }else if( cli_strcmp(z,"-quote")==0 ){
      data.mode = MODE_Quote;
      sqlite3_snprintf(sizeof(data.colSeparator), data.colSeparator, SEP_Comma);
      sqlite3_snprintf(sizeof(data.rowSeparator), data.rowSeparator, SEP_Row);
    }else if( cli_strcmp(z,"-line")==0 ){
      data.mode = MODE_Line;
    }else if( cli_strcmp(z,"-column")==0 ){
      data.mode = MODE_Column;
    }else if( cli_strcmp(z,"-json")==0 ){
      data.mode = MODE_Json;
    }else if( cli_strcmp(z,"-markdown")==0 ){
      data.mode = MODE_Markdown;
    }else if( cli_strcmp(z,"-table")==0 ){
      data.mode = MODE_Table;
    }else if( cli_strcmp(z,"-box")==0 ){
      data.mode = MODE_Box;
    }else if( cli_strcmp(z,"-csv")==0 ){
      data.mode = MODE_Csv;
      memcpy(data.colSeparator,",",2);
#ifdef SQLITE_HAVE_ZLIB
    }else if( cli_strcmp(z,"-zip")==0 ){
      data.openMode = SHELL_OPEN_ZIPFILE;
#endif
    }else if( cli_strcmp(z,"-append")==0 ){
      data.openMode = SHELL_OPEN_APPENDVFS;
#ifndef SQLITE_OMIT_DESERIALIZE
    }else if( cli_strcmp(z,"-deserialize")==0 ){
      data.openMode = SHELL_OPEN_DESERIALIZE;
    }else if( cli_strcmp(z,"-maxsize")==0 && i+1<argc ){
      data.szMax = integerValue(argv[++i]);
#endif
    }else if( cli_strcmp(z,"-readonly")==0 ){
      data.openMode = SHELL_OPEN_READONLY;
    }else if( cli_strcmp(z,"-nofollow")==0 ){
      data.openFlags |= SQLITE_OPEN_NOFOLLOW;
    }else if( cli_strcmp(z,"-ascii")==0 ){
      data.mode = MODE_Ascii;
      sqlite3_snprintf(sizeof(data.colSeparator), data.colSeparator,SEP_Unit);
      sqlite3_snprintf(sizeof(data.rowSeparator), data.rowSeparator,SEP_Record);
    }else if( cli_strcmp(z,"-tabs")==0 ){
      data.mode = MODE_List;
      sqlite3_snprintf(sizeof(data.colSeparator), data.colSeparator,SEP_Tab);
      sqlite3_snprintf(sizeof(data.rowSeparator), data.rowSeparator,SEP_Row);
    }else if( cli_strcmp(z,"-separator")==0 ){
      sqlite3_snprintf(sizeof(data.colSeparator), data.colSeparator,
                       "%s",cmdline_option_value(argc,argv,++i));
    }else if( cli_strcmp(z,"-newline")==0 ){
      sqlite3_snprintf(sizeof(data.rowSeparator), data.rowSeparator,
                       "%s",cmdline_option_value(argc,argv,++i));
    }else if( cli_strcmp(z,"-nullvalue")==0 ){
      sqlite3_snprintf(sizeof(data.nullValue), data.nullValue,
                       "%s",cmdline_option_value(argc,argv,++i));
    }else if( cli_strcmp(z,"-header")==0 ){
      data.showHeader = 1;
      ShellSetFlag(&data, SHFLG_HeaderSet);
     }else if( cli_strcmp(z,"-noheader")==0 ){
      data.showHeader = 0;
      ShellSetFlag(&data, SHFLG_HeaderSet);
    }else if( cli_strcmp(z,"-echo")==0 ){
      ShellSetFlag(&data, SHFLG_Echo);
    }else if( cli_strcmp(z,"-eqp")==0 ){
      data.autoEQP = AUTOEQP_on;
    }else if( cli_strcmp(z,"-eqpfull")==0 ){
      data.autoEQP = AUTOEQP_full;
    }else if( cli_strcmp(z,"-stats")==0 ){
      data.statsOn = 1;
    }else if( cli_strcmp(z,"-scanstats")==0 ){
      data.scanstatsOn = 1;
    }else if( cli_strcmp(z,"-backslash")==0 ){
      /* Undocumented command-line option: -backslash
      ** Causes C-style backslash escapes to be evaluated in SQL statements
      ** prior to sending the SQL into SQLite.  Useful for injecting
      ** crazy bytes in the middle of SQL statements for testing and debugging.
      */
      ShellSetFlag(&data, SHFLG_Backslash);
    }else if( cli_strcmp(z,"-bail")==0 ){
      /* No-op.  The bail_on_error flag should already be set. */
    }else if( cli_strcmp(z,"-version")==0 ){
      sqlite3_fprintf(stdout, "%s %s (%d-bit)\n",
            sqlite3_libversion(), sqlite3_sourceid(), 8*(int)sizeof(char*));
      return 0;
    }else if( cli_strcmp(z,"-interactive")==0 ){
      /* Need to check for interactive override here to so that it can
      ** affect console setup (for Windows only) and testing thereof.
      */
      stdin_is_interactive = 1;
    }else if( cli_strcmp(z,"-batch")==0 ){
      /* already handled */
    }else if( cli_strcmp(z,"-utf8")==0 ){
      /* already handled */
    }else if( cli_strcmp(z,"-no-utf8")==0 ){
      /* already handled */
    }else if( cli_strcmp(z,"-no-rowid-in-view")==0 ){
      /* already handled */
    }else if( cli_strcmp(z,"-heap")==0 ){
      i++;
    }else if( cli_strcmp(z,"-pagecache")==0 ){
      i+=2;
    }else if( cli_strcmp(z,"-lookaside")==0 ){
      i+=2;
    }else if( cli_strcmp(z,"-threadsafe")==0 ){
      i+=2;
    }else if( cli_strcmp(z,"-nonce")==0 ){
      i += 2;
    }else if( cli_strcmp(z,"-mmap")==0 ){
      i++;
    }else if( cli_strcmp(z,"-memtrace")==0 ){
      i++;
    }else if( cli_strcmp(z,"-pcachetrace")==0 ){
      i++;
#ifdef SQLITE_ENABLE_SORTER_REFERENCES
    }else if( cli_strcmp(z,"-sorterref")==0 ){
      i++;
#endif
    }else if( cli_strcmp(z,"-vfs")==0 ){
      i++;
    }else if( cli_strcmp(z,"-vfstrace")==0 ){
      i++;
#ifdef SQLITE_ENABLE_MULTIPLEX
    }else if( cli_strcmp(z,"-multiplex")==0 ){
      i++;
#endif
    }else if( cli_strcmp(z,"-help")==0 ){
      usage(1);
    }else if( cli_strcmp(z,"-cmd")==0 ){
      /* Run commands that follow -cmd first and separately from commands
      ** that simply appear on the command-line.  This seems goofy.  It would
      ** be better if all commands ran in the order that they appear.  But
      ** we retain the goofy behavior for historical compatibility. */
      if( i==argc-1 ) break;
      z = cmdline_option_value(argc,argv,++i);
      if( z[0]=='.' ){
        rc = do_meta_command(z, &data);
        if( rc && bail_on_error ) return rc==2 ? 0 : rc;
      }else{
        open_db(&data, 0);
        rc = shell_exec(&data, z, &zErrMsg);
        if( zErrMsg!=0 ){
          shellEmitError(zErrMsg);
          if( bail_on_error ) return rc!=0 ? rc : 1;
        }else if( rc!=0 ){
          sqlite3_fprintf(stderr,"Error: unable to process SQL \"%s\"\n", z);
          if( bail_on_error ) return rc;
        }
      }
#if !defined(SQLITE_OMIT_VIRTUALTABLE) && defined(SQLITE_HAVE_ZLIB)
    }else if( cli_strncmp(z, "-A", 2)==0 ){
      if( nCmd>0 ){
        sqlite3_fprintf(stderr,"Error: cannot mix regular SQL or dot-commands"
              " with \"%s\"\n", z);
        return 1;
      }
      open_db(&data, OPEN_DB_ZIPFILE);
      if( z[2] ){
        argv[i] = &z[2];
        arDotCommand(&data, 1, argv+(i-1), argc-(i-1));
      }else{
        arDotCommand(&data, 1, argv+i, argc-i);
      }
      readStdin = 0;
      break;
#endif
    }else if( cli_strcmp(z,"-safe")==0 ){
      data.bSafeMode = data.bSafeModePersist = 1;
    }else if( cli_strcmp(z,"-unsafe-testing")==0 ){
      /* Acted upon in first pass. */
    }else{
      sqlite3_fprintf(stderr,"%s: Error: unknown option: %s\n", Argv0, z);
      eputz("Use -help for a list of options.\n");
      return 1;
    }
    data.cMode = data.mode;
  }

  if( !readStdin ){
    /* Run all arguments that do not begin with '-' as if they were separate
    ** command-line inputs, except for the argToSkip argument which contains
    ** the database filename.
    */
    for(i=0; i<nCmd; i++){
      if( azCmd[i][0]=='.' ){
        rc = do_meta_command(azCmd[i], &data);
        if( rc ){
          if( rc==2 ) rc = 0;
          goto shell_main_exit;
        }
      }else{
        open_db(&data, 0);
        echo_group_input(&data, azCmd[i]);
        rc = shell_exec(&data, azCmd[i], &zErrMsg);
        if( zErrMsg || rc ){
          if( zErrMsg!=0 ){
            shellEmitError(zErrMsg);
          }else{
            sqlite3_fprintf(stderr,
                            "Error: unable to process SQL: %s\n", azCmd[i]);
          }
          sqlite3_free(zErrMsg);
          if( rc==0 ) rc = 1;
          goto shell_main_exit;
        }
      }
    }
  }else{
    /* Run commands received from standard input
    */
    if( stdin_is_interactive ){
      char *zHome;
      char *zHistory;
      int nHistory;
#if CIO_WIN_WC_XLATE
# define SHELL_CIO_CHAR_SET (stdout_is_console? " (UTF-16 console I/O)" : "")
#else
# define SHELL_CIO_CHAR_SET ""
#endif
      sqlite3_fprintf(stdout,
            "SQLite version %s %.19s%s\n" /*extra-version-info*/
            "Enter \".help\" for usage hints.\n",
            sqlite3_libversion(), sqlite3_sourceid(), SHELL_CIO_CHAR_SET);
      if( warnInmemoryDb ){
        sputz(stdout, "Connected to a ");
        printBold("transient in-memory database");
        sputz(stdout, ".\nUse \".open FILENAME\" to reopen on a"
              " persistent database.\n");
      }
      zHistory = getenv("SQLITE_HISTORY");
      if( zHistory ){
        zHistory = strdup(zHistory);
      }else if( (zHome = find_home_dir(0))!=0 ){
        nHistory = strlen30(zHome) + 20;
        if( (zHistory = malloc(nHistory))!=0 ){
          sqlite3_snprintf(nHistory, zHistory,"%s/.sqlite_history", zHome);
        }
      }
      if( zHistory ){ shell_read_history(zHistory); }
#if HAVE_READLINE || HAVE_EDITLINE
      rl_attempted_completion_function = readline_completion;
#elif HAVE_LINENOISE
      linenoiseSetCompletionCallback(linenoise_completion, NULL);
#endif
      data.in = 0;
      rc = process_input(&data);
      if( zHistory ){
        shell_stifle_history(2000);
        shell_write_history(zHistory);
        free(zHistory);
      }
    }else{
      data.in = stdin;
      rc = process_input(&data);
    }
  }
#ifndef SQLITE_SHELL_FIDDLE
  /* In WASM mode we have to leave the db state in place so that
  ** client code can "push" SQL into it after this call returns. */
#ifndef SQLITE_OMIT_VIRTUALTABLE
  if( data.expert.pExpert ){
    expertFinish(&data, 1, 0);
  }
#endif
 shell_main_exit:
  free(azCmd);
  set_table_name(&data, 0);
  if( data.db ){
    session_close_all(&data, -1);
    close_db(data.db);
  }
  for(i=0; i<ArraySize(data.aAuxDb); i++){
    sqlite3_free(data.aAuxDb[i].zFreeOnClose);
    if( data.aAuxDb[i].db ){
      session_close_all(&data, i);
      close_db(data.aAuxDb[i].db);
    }
  }
  find_home_dir(1);
  output_reset(&data);
  data.doXdgOpen = 0;
  clearTempFile(&data);
#if !SQLITE_SHELL_IS_UTF8
  for(i=0; i<argcToFree; i++) free(argvToFree[i]);
  free(argvToFree);
#endif
  free(data.colWidth);
  free(data.zNonce);
  /* Clear the global data structure so that valgrind will detect memory
  ** leaks */
  memset(&data, 0, sizeof(data));
  if( bEnableVfstrace ){
    vfstrace_unregister("trace");
  }
#ifdef SQLITE_DEBUG
  if( sqlite3_memory_used()>mem_main_enter ){
    sqlite3_fprintf(stderr,"Memory leaked: %u bytes\n",
          (unsigned int)(sqlite3_memory_used()-mem_main_enter));
  }
#endif
#else /* SQLITE_SHELL_FIDDLE... */
  shell_main_exit:
#endif
  return rc;
}


#ifdef SQLITE_SHELL_FIDDLE
/* Only for emcc experimentation purposes. */
int fiddle_experiment(int a,int b){
  return a + b;
}

/*
** Returns a pointer to the current DB handle.
*/
sqlite3 * fiddle_db_handle(){
  return globalDb;
}

/*
** Returns a pointer to the given DB name's VFS. If zDbName is 0 then
** "main" is assumed. Returns 0 if no db with the given name is
** open.
*/
sqlite3_vfs * fiddle_db_vfs(const char *zDbName){
  sqlite3_vfs * pVfs = 0;
  if(globalDb){
    sqlite3_file_control(globalDb, zDbName ? zDbName : "main",
                         SQLITE_FCNTL_VFS_POINTER, &pVfs);
  }
  return pVfs;
}

/* Only for emcc experimentation purposes. */
sqlite3 * fiddle_db_arg(sqlite3 *arg){
    sqlite3_fprintf(stdout, "fiddle_db_arg(%p)\n", (const void*)arg);
    return arg;
}

/*
** Intended to be called via a SharedWorker() while a separate
** SharedWorker() (which manages the wasm module) is performing work
** which should be interrupted. Unfortunately, SharedWorker is not
** portable enough to make real use of.
*/
void fiddle_interrupt(void){
  if( globalDb ) sqlite3_interrupt(globalDb);
}

/*
** Returns the filename of the given db name, assuming "main" if
** zDbName is NULL. Returns NULL if globalDb is not opened.
*/
const char * fiddle_db_filename(const char * zDbName){
    return globalDb
      ? sqlite3_db_filename(globalDb, zDbName ? zDbName : "main")
      : NULL;
}

/*
** Completely wipes out the contents of the currently-opened database
** but leaves its storage intact for reuse. If any transactions are
** active, they are forcibly rolled back.
*/
void fiddle_reset_db(void){
  if( globalDb ){
    int rc;
    while( sqlite3_txn_state(globalDb,0)>0 ){
      /*
      ** Resolve problem reported in
      ** https://sqlite.org/forum/forumpost/0b41a25d65
      */
      sqlite3_fputs("Rolling back in-progress transaction.\n", stdout);
      sqlite3_exec(globalDb,"ROLLBACK", 0, 0, 0);
    }
    rc = sqlite3_db_config(globalDb, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0);
    if( 0==rc ) sqlite3_exec(globalDb, "VACUUM", 0, 0, 0);
    sqlite3_db_config(globalDb, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0);
  }
}

/*
** Uses the current database's VFS xRead to stream the db file's
** contents out to the given callback. The callback gets a single
** chunk of size n (its 2nd argument) on each call and must return 0
** on success, non-0 on error. This function returns 0 on success,
** SQLITE_NOTFOUND if no db is open, or propagates any other non-0
** code from the callback. Note that this is not thread-friendly: it
** expects that it will be the only thread reading the db file and
** takes no measures to ensure that is the case.
*/
int fiddle_export_db( int (*xCallback)(unsigned const char *zOut, int n) ){
  sqlite3_int64 nSize = 0;
  sqlite3_int64 nPos = 0;
  sqlite3_file * pFile = 0;
  unsigned char buf[1024 * 8];
  int nBuf = (int)sizeof(buf);
  int rc = shellState.db
    ? sqlite3_file_control(shellState.db, "main",
                           SQLITE_FCNTL_FILE_POINTER, &pFile)
    : SQLITE_NOTFOUND;
  if( rc ) return rc;
  rc = pFile->pMethods->xFileSize(pFile, &nSize);
  if( rc ) return rc;
  if(nSize % nBuf){
    /* DB size is not an even multiple of the buffer size. Reduce
    ** buffer size so that we do not unduly inflate the db size when
    ** exporting. */
    if(0 == nSize % 4096) nBuf = 4096;
    else if(0 == nSize % 2048) nBuf = 2048;
    else if(0 == nSize % 1024) nBuf = 1024;
    else nBuf = 512;
  }
  for( ; 0==rc && nPos<nSize; nPos += nBuf ){
    rc = pFile->pMethods->xRead(pFile, buf, nBuf, nPos);
    if(SQLITE_IOERR_SHORT_READ == rc){
      rc = (nPos + nBuf) < nSize ? rc : 0/*assume EOF*/;
    }
    if( 0==rc ) rc = xCallback(buf, nBuf);
  }
  return rc;
}

/*
** Trivial exportable function for emscripten. It processes zSql as if
** it were input to the sqlite3 shell and redirects all output to the
** wasm binding. fiddle_main() must have been called before this
** is called, or results are undefined.
*/
void fiddle_exec(const char * zSql){
  if(zSql && *zSql){
    if('.'==*zSql) puts(zSql);
    shellState.wasm.zInput = zSql;
    shellState.wasm.zPos = zSql;
    process_input(&shellState);
    shellState.wasm.zInput = shellState.wasm.zPos = 0;
  }
}
#endif /* SQLITE_SHELL_FIDDLE */
