/*      $NetBSD: getline.c,v 1.1.1.1 2011/05/12 20:46:50 christos Exp $ */

/*-
 * Copyright (c) 2011 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Christos Zoulas.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include <stddef.h> // for size_t
#include <stdio.h>  // for NULL, FILE, feof, fgetc, etc
#include <stdlib.h> // for malloc, realloc
#include <unistd.h> // for ssize_t

ssize_t getdelim(char **buf, size_t *bufsiz, int delimiter, FILE *fp)
{
  char *ptr, *eptr;

  if (*buf == NULL || *bufsiz == 0) {
    *bufsiz = BUFSIZ;
    if ((*buf = malloc(*bufsiz)) == NULL) {
      return -1;
    }
  }

  for (ptr = *buf, eptr = *buf + *bufsiz;;) {
    int c = fgetc(fp);
    if (c == -1) {
      if (feof(fp)) {
        return ptr == *buf ? -1 : ptr - *buf;
      }
      return -1;
    }
    *ptr++ = c;
    if (c == delimiter) {
      *ptr = '\0';
      return ptr - *buf;
    }
    if (ptr + 2 >= eptr) {
      char *  nbuf;
      size_t  nbufsiz = *bufsiz * 2;
      ssize_t d       = ptr - *buf;
      if ((nbuf = realloc(*buf, nbufsiz)) == NULL) {
        return -1;
      }
      *buf    = nbuf;
      *bufsiz = nbufsiz;
      eptr    = nbuf + nbufsiz;
      ptr     = nbuf + d;
    }
  }
}

ssize_t getline(char **buf, size_t *bufsiz, FILE *fp) { return getdelim(buf, bufsiz, '\n', fp); }

#ifdef TEST
int main(int argc, char *argv[])
{
  char *  p = NULL;
  ssize_t len;
  size_t  n = 0;

  while ((len = getline(&p, &n, stdin)) != -1)
    (void)printf("%zd %s", len, p);
  free(p);
  return 0;
}
#endif
