compat/getdelim.c

   1 /*****************************************************************************
   2  * getdelim.c: POSIX getdelim() and getline() replacements
   3  *****************************************************************************
   4  * Copyright © 2010 Rémi Denis-Courmont
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU Lesser General Public License as published by
   8  * the Free Software Foundation; either version 2.1 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  19  *****************************************************************************/
  20
  21 #ifdef HAVE_CONFIG_H
  22 # include <config.h>
  23 #endif
  24
  25 #include <stdio.h>
  26 #include <stdlib.h>
  27
  28 ssize_t getdelim (char **restrict lineptr, size_t *restrict n,
  29                   int delimiter, FILE *restrict stream)
  30 {
  31     char *ptr = *lineptr;
  32     size_t size = (ptr != NULL) ? *n : 0;
  33     size_t len = 0;
  34
  35     for (;;)
  36     {
  37         if ((size - len) <= 2)
  38         {
  39             size = size ? (size * 2) : 256;
  40             ptr = realloc (*lineptr, size);
  41             if (ptr == NULL)
  42                 return -1;
  43             *lineptr = ptr;
  44             *n = size;
  45         }
  46
  47         int c = fgetc (stream);
  48         if (c == -1)
  49         {
  50             if (len == 0 || ferror (stream))
  51                 return -1;
  52             break; /* EOF */
  53         }
  54         ptr[len++] = c;
  55         if (c == delimiter)
  56             break;
  57     }
  58
  59     ptr[len] = '\0';
  60     return len;
  61 }
  62
  63 ssize_t getline (char **restrict lineptr, size_t *restrict n,
  64                  FILE *restrict stream)
  65 {
  66     return getdelim (lineptr, n, '\n', stream);
  67 }