SystemTools.cxx

/* Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
   file Copyright.txt or https://cmake.org/licensing#kwsys for details.  */
#ifdef __osf__
#  define _OSF_SOURCE
#  define _POSIX_C_SOURCE 199506L
#  define _XOPEN_SOURCE_EXTENDED
#endif

#if defined(_WIN32) &&                                                        \
  (defined(_MSC_VER) || defined(__WATCOMC__) || defined(__BORLANDC__) ||      \
   defined(__MINGW32__))
#  define KWSYS_WINDOWS_DIRS
#else
#  if defined(__SUNPRO_CC)
#    include <fcntl.h>
#  endif
#endif

#include "kwsysPrivate.h"
#include KWSYS_HEADER(RegularExpression.hxx)
#include KWSYS_HEADER(SystemTools.hxx)
#include KWSYS_HEADER(Directory.hxx)
#include KWSYS_HEADER(FStream.hxx)
#include KWSYS_HEADER(Encoding.h)
#include KWSYS_HEADER(Encoding.hxx)

#include <fstream>
#include <iostream>
#include <set>
#include <sstream>
#include <utility>
#include <vector>

// Work-around CMake dependency scanning limitation.  This must
// duplicate the above list of headers.
#if 0
#  include "Directory.hxx.in"
#  include "Encoding.hxx.in"
#  include "FStream.hxx.in"
#  include "RegularExpression.hxx.in"
#  include "SystemTools.hxx.in"
#endif

#ifdef _MSC_VER
#  pragma warning(disable : 4786)
#endif

#if defined(__sgi) && !defined(__GNUC__)
#  pragma set woff 1375 /* base class destructor not virtual */
#endif

#include <ctype.h>
#include <errno.h>
#ifdef __QNX__
#  include <malloc.h> /* for malloc/free on QNX */
#endif
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>

#if defined(_WIN32) && !defined(_MSC_VER) && defined(__GNUC__)
#  include <strings.h> /* for strcasecmp */
#endif

#ifdef _MSC_VER
#  define umask _umask // Note this is still umask on Borland
#endif

// support for realpath call
#ifndef _WIN32
#  include <limits.h>
#  include <pwd.h>
#  include <sys/ioctl.h>
#  include <sys/time.h>
#  include <sys/wait.h>
#  include <unistd.h>
#  include <utime.h>
#  ifndef __VMS
#    include <sys/param.h>
#    include <termios.h>
#  endif
#  include <signal.h> /* sigprocmask */
#endif

#ifdef __linux
#  include <linux/fs.h>
#endif

// Windows API.
#if defined(_WIN32)
#  include <windows.h>
#  include <winioctl.h>
#  ifndef INVALID_FILE_ATTRIBUTES
#    define INVALID_FILE_ATTRIBUTES ((DWORD)-1)
#  endif
#  if defined(_MSC_VER) && _MSC_VER >= 1800
#    define KWSYS_WINDOWS_DEPRECATED_GetVersionEx
#  endif
#elif defined(__CYGWIN__)
#  include <windows.h>
#  undef _WIN32
#endif

#if !KWSYS_CXX_HAS_ENVIRON_IN_STDLIB_H
extern char** environ;
#endif

#ifdef __CYGWIN__
#  include <sys/cygwin.h>
#endif

// getpwnam doesn't exist on Windows and Cray Xt3/Catamount
// same for TIOCGWINSZ
#if defined(_WIN32) || defined(__LIBCATAMOUNT__) ||                           \
  (defined(HAVE_GETPWNAM) && HAVE_GETPWNAM == 0)
#  undef HAVE_GETPWNAM
#  undef HAVE_TTY_INFO
#else
#  define HAVE_GETPWNAM 1
#  define HAVE_TTY_INFO 1
#endif

#define VTK_URL_PROTOCOL_REGEX "([a-zA-Z0-9]*)://(.*)"
#define VTK_URL_REGEX                                                         \
  "([a-zA-Z0-9]*)://(([A-Za-z0-9]+)(:([^:@]+))?@)?([^:@/]+)(:([0-9]+))?/"     \
  "(.+)?"

#ifdef _MSC_VER
#  include <sys/utime.h>
#else
#  include <utime.h>
#endif

// This is a hack to prevent warnings about these functions being
// declared but not referenced.
#if defined(__sgi) && !defined(__GNUC__)
#  include <sys/termios.h>
namespace KWSYS_NAMESPACE {
class SystemToolsHack
{
public:
  enum
  {
    Ref1 = sizeof(cfgetospeed(0)),
    Ref2 = sizeof(cfgetispeed(0)),
    Ref3 = sizeof(tcgetattr(0, 0)),
    Ref4 = sizeof(tcsetattr(0, 0, 0)),
    Ref5 = sizeof(cfsetospeed(0, 0)),
    Ref6 = sizeof(cfsetispeed(0, 0))
  };
};
}
#endif

#if defined(_WIN32) &&                                                        \
  (defined(_MSC_VER) || defined(__WATCOMC__) || defined(__BORLANDC__) ||      \
   defined(__MINGW32__))
#  include <direct.h>
#  include <io.h>
#  define _unlink unlink
#endif

/* The maximum length of a file name.  */
#if defined(PATH_MAX)
#  define KWSYS_SYSTEMTOOLS_MAXPATH PATH_MAX
#elif defined(MAXPATHLEN)
#  define KWSYS_SYSTEMTOOLS_MAXPATH MAXPATHLEN
#else
#  define KWSYS_SYSTEMTOOLS_MAXPATH 16384
#endif
#if defined(__WATCOMC__)
#  include <direct.h>
#  define _mkdir mkdir
#  define _rmdir rmdir
#  define _getcwd getcwd
#  define _chdir chdir
#endif

#if defined(__BEOS__) && !defined(__ZETA__)
#  include <be/kernel/OS.h>
#  include <be/storage/Path.h>

// BeOS 5 doesn't have usleep(), but it has snooze(), which is identical.
static inline void usleep(unsigned int msec)
{
  ::snooze(msec);
}

// BeOS 5 also doesn't have realpath(), but its C++ API offers something close.
static inline char* realpath(const char* path, char* resolved_path)
{
  const size_t maxlen = KWSYS_SYSTEMTOOLS_MAXPATH;
  snprintf(resolved_path, maxlen, "%s", path);
  BPath normalized(resolved_path, nullptr, true);
  const char* resolved = normalized.Path();
  if (resolved != nullptr) // nullptr == No such file.
  {
    if (snprintf(resolved_path, maxlen, "%s", resolved) < maxlen) {
      return resolved_path;
    }
  }
  return nullptr; // something went wrong.
}
#endif

#ifdef _WIN32
static time_t windows_filetime_to_posix_time(const FILETIME& ft)
{
  LARGE_INTEGER date;
  date.HighPart = ft.dwHighDateTime;
  date.LowPart = ft.dwLowDateTime;

  // removes the diff between 1970 and 1601
  date.QuadPart -= ((LONGLONG)(369 * 365 + 89) * 24 * 3600 * 10000000);

  // converts back from 100-nanoseconds to seconds
  return date.QuadPart / 10000000;
}
#endif

#ifdef KWSYS_WINDOWS_DIRS
#  include <wctype.h>

inline int Mkdir(const std::string& dir)
{
  return _wmkdir(
    KWSYS_NAMESPACE::Encoding::ToWindowsExtendedPath(dir).c_str());
}
inline int Rmdir(const std::string& dir)
{
  return _wrmdir(
    KWSYS_NAMESPACE::Encoding::ToWindowsExtendedPath(dir).c_str());
}
inline const char* Getcwd(char* buf, unsigned int len)
{
  std::vector<wchar_t> w_buf(len);
  if (_wgetcwd(&w_buf[0], len)) {
    size_t nlen = kwsysEncoding_wcstombs(buf, &w_buf[0], len);
    if (nlen == static_cast<size_t>(-1)) {
      return 0;
    }
    if (nlen < len) {
      // make sure the drive letter is capital
      if (nlen > 1 && buf[1] == ':') {
        buf[0] = toupper(buf[0]);
      }
      return buf;
    }
  }
  return 0;
}
inline int Chdir(const std::string& dir)
{
#  if defined(__BORLANDC__)
  return chdir(dir.c_str());
#  else
  return _wchdir(KWSYS_NAMESPACE::Encoding::ToWide(dir).c_str());
#  endif
}
inline void Realpath(const std::string& path, std::string& resolved_path,
                     std::string* errorMessage = 0)
{
  std::wstring tmp = KWSYS_NAMESPACE::Encoding::ToWide(path);
  wchar_t* ptemp;
  wchar_t fullpath[MAX_PATH];
  DWORD bufferLen = GetFullPathNameW(
    tmp.c_str(), sizeof(fullpath) / sizeof(fullpath[0]), fullpath, &ptemp);
  if (bufferLen < sizeof(fullpath) / sizeof(fullpath[0])) {
    resolved_path = KWSYS_NAMESPACE::Encoding::ToNarrow(fullpath);
    KWSYS_NAMESPACE::SystemTools::ConvertToUnixSlashes(resolved_path);
  } else if (errorMessage) {
    if (bufferLen) {
      *errorMessage = "Destination path buffer size too small.";
    } else if (unsigned int errorId = GetLastError()) {
      LPSTR message = nullptr;
      DWORD size = FormatMessageA(
        FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM |
          FORMAT_MESSAGE_IGNORE_INSERTS,
        nullptr, errorId, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
        (LPSTR)&message, 0, nullptr);
      *errorMessage = std::string(message, size);
      LocalFree(message);
    } else {
      *errorMessage = "Unknown error.";
    }

    resolved_path = "";
  } else {
    resolved_path = path;
  }
}
#else
#  include <sys/types.h>

#  include <fcntl.h>
#  include <unistd.h>
inline int Mkdir(const std::string& dir)
{
  return mkdir(dir.c_str(), 00777);
}
inline int Rmdir(const std::string& dir)
{
  return rmdir(dir.c_str());
}
inline const char* Getcwd(char* buf, unsigned int len)
{
  return getcwd(buf, len);
}

inline int Chdir(const std::string& dir)
{
  return chdir(dir.c_str());
}
inline void Realpath(const std::string& path, std::string& resolved_path,
                     std::string* errorMessage = nullptr)
{
  char resolved_name[KWSYS_SYSTEMTOOLS_MAXPATH];

  errno = 0;
  char* ret = realpath(path.c_str(), resolved_name);
  if (ret) {
    resolved_path = ret;
  } else if (errorMessage) {
    if (errno) {
      *errorMessage = strerror(errno);
    } else {
      *errorMessage = "Unknown error.";
    }

    resolved_path = "";
  } else {
    // if path resolution fails, return what was passed in
    resolved_path = path;
  }
}
#endif

#if !defined(_WIN32) && defined(__COMO__)
// Hack for como strict mode to avoid defining _SVID_SOURCE or _BSD_SOURCE.
extern "C" {
extern FILE* popen(__const char* __command, __const char* __modes) __THROW;
extern int pclose(FILE* __stream) __THROW;
extern char* realpath(__const char* __restrict __name,
                      char* __restrict __resolved) __THROW;
extern char* strdup(__const char* __s) __THROW;
extern int putenv(char* __string) __THROW;
}
#endif

namespace KWSYS_NAMESPACE {

double SystemTools::GetTime(void)
{
#if defined(_WIN32) && !defined(__CYGWIN__)
  FILETIME ft;
  GetSystemTimeAsFileTime(&ft);
  return (429.4967296 * ft.dwHighDateTime + 0.0000001 * ft.dwLowDateTime -
          11644473600.0);
#else
  struct timeval t;
  gettimeofday(&t, nullptr);
  return 1.0 * double(t.tv_sec) + 0.000001 * double(t.tv_usec);
#endif
}

/* Type of character storing the environment.  */
#if defined(_WIN32)
typedef wchar_t envchar;
#else
typedef char envchar;
#endif

/* Order by environment key only (VAR from VAR=VALUE).  */
struct kwsysEnvCompare
{
  bool operator()(const envchar* l, const envchar* r) const
  {
#if defined(_WIN32)
    const wchar_t* leq = wcschr(l, L'=');
    const wchar_t* req = wcschr(r, L'=');
    size_t llen = leq ? (leq - l) : wcslen(l);
    size_t rlen = req ? (req - r) : wcslen(r);
    if (llen == rlen) {
      return wcsncmp(l, r, llen) < 0;
    } else {
      return wcscmp(l, r) < 0;
    }
#else
    const char* leq = strchr(l, '=');
    const char* req = strchr(r, '=');
    size_t llen = leq ? static_cast<size_t>(leq - l) : strlen(l);
    size_t rlen = req ? static_cast<size_t>(req - r) : strlen(r);
    if (llen == rlen) {
      return strncmp(l, r, llen) < 0;
    } else {
      return strcmp(l, r) < 0;
    }
#endif
  }
};

class kwsysEnvSet : public std::set<const envchar*, kwsysEnvCompare>
{
public:
  class Free
  {
    const envchar* Env;

  public:
    Free(const envchar* env)
      : Env(env)
    {
    }
    ~Free() { free(const_cast<envchar*>(this->Env)); }

    Free(const Free&) = delete;
    Free& operator=(const Free&) = delete;
  };

  const envchar* Release(const envchar* env)
  {
    const envchar* old = nullptr;
    iterator i = this->find(env);
    if (i != this->end()) {
      old = *i;
      this->erase(i);
    }
    return old;
  }
};

#ifdef _WIN32
struct SystemToolsPathCaseCmp
{
  bool operator()(std::string const& l, std::string const& r) const
  {
#  ifdef _MSC_VER
    return _stricmp(l.c_str(), r.c_str()) < 0;
#  elif defined(__GNUC__)
    return strcasecmp(l.c_str(), r.c_str()) < 0;
#  else
    return SystemTools::Strucmp(l.c_str(), r.c_str()) < 0;
#  endif
  }
};
#endif

/**
 * SystemTools static variables singleton class.
 */
class SystemToolsStatic
{
public:
  typedef std::map<std::string, std::string> StringMap;
#if KWSYS_SYSTEMTOOLS_USE_TRANSLATION_MAP
  /**
   * Path translation table from dir to refdir
   * Each time 'dir' will be found it will be replace by 'refdir'
   */
  StringMap TranslationMap;
#endif
#ifdef _WIN32
  static std::string GetCasePathName(std::string const& pathIn);
  static std::string GetActualCaseForPathCached(std::string const& path);
  static const char* GetEnvBuffered(const char* key);
  std::map<std::string, std::string, SystemToolsPathCaseCmp> PathCaseMap;
  std::map<std::string, std::string> EnvMap;
#endif
#ifdef __CYGWIN__
  StringMap Cyg2Win32Map;
#endif

  /**
   * Actual implementation of ReplaceString.
   */
  static void ReplaceString(std::string& source, const char* replace,
                            size_t replaceSize, const std::string& with);

  /**
   * Actual implementation of FileIsFullPath.
   */
  static bool FileIsFullPath(const char*, size_t);

  /**
   * Find a filename (file or directory) in the system PATH, with
   * optional extra paths.
   */
  static std::string FindName(
    const std::string& name,
    const std::vector<std::string>& path = std::vector<std::string>(),
    bool no_system_path = false);
};

#ifdef _WIN32
std::string SystemToolsStatic::GetCasePathName(std::string const& pathIn)
{
  std::string casePath;

  // First check if the file is relative. We don't fix relative paths since the
  // real case depends on the root directory and the given path fragment may
  // have meaning elsewhere in the project.
  if (!SystemTools::FileIsFullPath(pathIn)) {
    // This looks unnecessary, but it allows for the return value optimization
    // since all return paths return the same local variable.
    casePath = pathIn;
    return casePath;
  }

  std::vector<std::string> path_components;
  SystemTools::SplitPath(pathIn, path_components);

  // Start with root component.
  std::vector<std::string>::size_type idx = 0;
  casePath = path_components[idx++];
  // make sure drive letter is always upper case
  if (casePath.size() > 1 && casePath[1] == ':') {
    casePath[0] = toupper(casePath[0]);
  }
  const char* sep = "";

  // If network path, fill casePath with server/share so FindFirstFile
  // will work after that.  Maybe someday call other APIs to get
  // actual case of servers and shares.
  if (path_components.size() > 2 && path_components[0] == "//") {
    casePath += path_components[idx++];
    casePath += "/";
    casePath += path_components[idx++];
    sep = "/";
  }

  // Convert case of all components that exist.
  bool converting = true;
  for (; idx < path_components.size(); idx++) {
    casePath += sep;
    sep = "/";

    if (converting) {
      // If path component contains wildcards, we skip matching
      // because these filenames are not allowed on windows,
      // and we do not want to match a different file.
      if (path_components[idx].find('*') != std::string::npos ||
          path_components[idx].find('?') != std::string::npos) {
        converting = false;
      } else {
        std::string test_str = casePath;
        test_str += path_components[idx];
        WIN32_FIND_DATAW findData;
        HANDLE hFind =
          ::FindFirstFileW(Encoding::ToWide(test_str).c_str(), &findData);
        if (INVALID_HANDLE_VALUE != hFind) {
          path_components[idx] = Encoding::ToNarrow(findData.cFileName);
          ::FindClose(hFind);
        } else {
          converting = false;
        }
      }
    }

    casePath += path_components[idx];
  }
  return casePath;
}

std::string SystemToolsStatic::GetActualCaseForPathCached(std::string const& p)
{
  // Check to see if actual case has already been called
  // for this path, and the result is stored in the PathCaseMap
  auto& pcm = SystemTools::Statics->PathCaseMap;
  {
    auto itr = pcm.find(p);
    if (itr != pcm.end()) {
      return itr->second;
    }
  }
  std::string casePath = SystemToolsStatic::GetCasePathName(p);
  if (casePath.size() <= MAX_PATH) {
    pcm[p] = casePath;
  }
  return casePath;
}
#endif

// adds the elements of the env variable path to the arg passed in
void SystemTools::GetPath(std::vector<std::string>& path, const char* env)
{
  size_t const old_size = path.size();
#if defined(_WIN32) && !defined(__CYGWIN__)
  const char pathSep = ';';
#else
  const char pathSep = ':';
#endif
  if (!env) {
    env = "PATH";
  }
  std::string pathEnv;
  if (!SystemTools::GetEnv(env, pathEnv)) {
    return;
  }

  // A hack to make the below algorithm work.
  if (!pathEnv.empty() && pathEnv.back() != pathSep) {
    pathEnv += pathSep;
  }
  std::string::size_type start = 0;
  bool done = false;
  while (!done) {
    std::string::size_type endpos = pathEnv.find(pathSep, start);
    if (endpos != std::string::npos) {
      path.push_back(pathEnv.substr(start, endpos - start));
      start = endpos + 1;
    } else {
      done = true;
    }
  }
  for (std::vector<std::string>::iterator i = path.begin() + old_size;
       i != path.end(); ++i) {
    SystemTools::ConvertToUnixSlashes(*i);
  }
}

#if defined(_WIN32)
const char* SystemToolsStatic::GetEnvBuffered(const char* key)
{
  std::string env;
  if (SystemTools::GetEnv(key, env)) {
    std::string& menv = SystemTools::Statics->EnvMap[key];
    if (menv != env) {
      menv = std::move(env);
    }
    return menv.c_str();
  }
  return nullptr;
}
#endif

const char* SystemTools::GetEnv(const char* key)
{
#if defined(_WIN32)
  return SystemToolsStatic::GetEnvBuffered(key);
#else
  return getenv(key);
#endif
}

const char* SystemTools::GetEnv(const std::string& key)
{
#if defined(_WIN32)
  return SystemToolsStatic::GetEnvBuffered(key.c_str());
#else
  return getenv(key.c_str());
#endif
}

bool SystemTools::GetEnv(const char* key, std::string& result)
{
#if defined(_WIN32)
  const std::wstring wkey = Encoding::ToWide(key);
  const wchar_t* wv = _wgetenv(wkey.c_str());
  if (wv) {
    result = Encoding::ToNarrow(wv);
    return true;
  }
#else
  const char* v = getenv(key);
  if (v) {
    result = v;
    return true;
  }
#endif
  return false;
}

bool SystemTools::GetEnv(const std::string& key, std::string& result)
{
  return SystemTools::GetEnv(key.c_str(), result);
}

bool SystemTools::HasEnv(const char* key)
{
#if defined(_WIN32)
  const std::wstring wkey = Encoding::ToWide(key);
  const wchar_t* v = _wgetenv(wkey.c_str());
#else
  const char* v = getenv(key);
#endif
  return v != nullptr;
}

bool SystemTools::HasEnv(const std::string& key)
{
  return SystemTools::HasEnv(key.c_str());
}

#if KWSYS_CXX_HAS_UNSETENV
/* unsetenv("A") removes A from the environment.
   On older platforms it returns void instead of int.  */
static int kwsysUnPutEnv(const std::string& env)
{
  size_t pos = env.find('=');
  if (pos != std::string::npos) {
    std::string name = env.substr(0, pos);
    unsetenv(name.c_str());
  } else {
    unsetenv(env.c_str());
  }
  return 0;
}

#elif defined(__CYGWIN__) || defined(__GLIBC__)
/* putenv("A") removes A from the environment.  It must not put the
   memory in the environment because it does not have any "=" syntax.  */
static int kwsysUnPutEnv(const std::string& env)
{
  int err = 0;
  size_t pos = env.find('=');
  size_t const len = pos == std::string::npos ? env.size() : pos;
  size_t const sz = len + 1;
  char local_buf[256];
  char* buf = sz > sizeof(local_buf) ? (char*)malloc(sz) : local_buf;
  if (!buf) {
    return -1;
  }
  strncpy(buf, env.c_str(), len);
  buf[len] = 0;
  if (putenv(buf) < 0 && errno != EINVAL) {
    err = errno;
  }
  if (buf != local_buf) {
    free(buf);
  }
  if (err) {
    errno = err;
    return -1;
  }
  return 0;
}

#elif defined(_WIN32)
/* putenv("A=") places "A=" in the environment, which is as close to
   removal as we can get with the putenv API.  We have to leak the
   most recent value placed in the environment for each variable name
   on program exit in case exit routines access it.  */

static kwsysEnvSet kwsysUnPutEnvSet;

static int kwsysUnPutEnv(std::string const& env)
{
  std::wstring wEnv = Encoding::ToWide(env);
  size_t const pos = wEnv.find('=');
  size_t const len = pos == std::string::npos ? wEnv.size() : pos;
  wEnv.resize(len + 1, L'=');
  wchar_t* newEnv = _wcsdup(wEnv.c_str());
  if (!newEnv) {
    return -1;
  }
  kwsysEnvSet::Free oldEnv(kwsysUnPutEnvSet.Release(newEnv));
  kwsysUnPutEnvSet.insert(newEnv);
  return _wputenv(newEnv);
}

#else
/* Manipulate the "environ" global directly.  */
static int kwsysUnPutEnv(const std::string& env)
{
  size_t pos = env.find('=');
  size_t const len = pos == std::string::npos ? env.size() : pos;
  int in = 0;
  int out = 0;
  while (environ[in]) {
    if (strlen(environ[in]) > len && environ[in][len] == '=' &&
        strncmp(env.c_str(), environ[in], len) == 0) {
      ++in;
    } else {
      environ[out++] = environ[in++];
    }
  }
  while (out < in) {
    environ[out++] = 0;
  }
  return 0;
}
#endif

#if KWSYS_CXX_HAS_SETENV

/* setenv("A", "B", 1) will set A=B in the environment and makes its
   own copies of the strings.  */
bool SystemTools::PutEnv(const std::string& env)
{
  size_t pos = env.find('=');
  if (pos != std::string::npos) {
    std::string name = env.substr(0, pos);
    return setenv(name.c_str(), env.c_str() + pos + 1, 1) == 0;
  } else {
    return kwsysUnPutEnv(env) == 0;
  }
}

bool SystemTools::UnPutEnv(const std::string& env)
{
  return kwsysUnPutEnv(env) == 0;
}

#else

/* putenv("A=B") will set A=B in the environment.  Most putenv implementations
   put their argument directly in the environment.  They never free the memory
   on program exit.  Keep an active set of pointers to memory we allocate and
   pass to putenv, one per environment key.  At program exit remove any
   environment values that may still reference memory we allocated.  Then free
   the memory.  This will not affect any environment values we never set.  */

#  ifdef __INTEL_COMPILER
#    pragma warning disable 444 /* base has non-virtual destructor */
#  endif

class kwsysEnv : public kwsysEnvSet
{
public:
  ~kwsysEnv()
  {
    for (iterator i = this->begin(); i != this->end(); ++i) {
#  if defined(_WIN32)
      const std::string s = Encoding::ToNarrow(*i);
      kwsysUnPutEnv(s);
#  else
      kwsysUnPutEnv(*i);
#  endif
      free(const_cast<envchar*>(*i));
    }
  }
  bool Put(const char* env)
  {
#  if defined(_WIN32)
    const std::wstring wEnv = Encoding::ToWide(env);
    wchar_t* newEnv = _wcsdup(wEnv.c_str());
#  else
    char* newEnv = strdup(env);
#  endif
    Free oldEnv(this->Release(newEnv));
    this->insert(newEnv);
#  if defined(_WIN32)
    return _wputenv(newEnv) == 0;
#  else
    return putenv(newEnv) == 0;
#  endif
  }
  bool UnPut(const char* env)
  {
#  if defined(_WIN32)
    const std::wstring wEnv = Encoding::ToWide(env);
    Free oldEnv(this->Release(wEnv.c_str()));
#  else
    Free oldEnv(this->Release(env));
#  endif
    return kwsysUnPutEnv(env) == 0;
  }
};

static kwsysEnv kwsysEnvInstance;

bool SystemTools::PutEnv(const std::string& env)
{
  return kwsysEnvInstance.Put(env.c_str());
}

bool SystemTools::UnPutEnv(const std::string& env)
{
  return kwsysEnvInstance.UnPut(env.c_str());
}

#endif

const char* SystemTools::GetExecutableExtension()
{
#if defined(_WIN32) || defined(__CYGWIN__) || defined(__VMS)
  return ".exe";
#else
  return "";