lib/getline.c

   1 /*
   2  * This program is free software; you can redistribute it and/or
   3  * modify it under the terms of the GNU General Public License
   4  * as published by the Free Software Foundation; either version 2
   5  * of the License, or (at your option) any later version.
   6  *
   7  * This program is distributed in the hope that it will be useful,
   8  * but WITHOUT ANY WARRANTY; without even the implied warranty of
   9  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  10  * GNU General Public License for more details.
  11  *
  12  * You should have received a copy of the GNU General Public License
  13  * along with this program; if not, write to the Free Software
  14  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  15  *
  16  * See the COPYING file for license information.
  17  *
  18  * Guillaume Chazarain <guichaz@yahoo.fr>
  19  */
  20
  21 /**************************************************************
  22  * getline() is a GNU extension so here is an implementation. *
  23  **************************************************************/
  24
  25 #include <stdlib.h>             /* malloc(), realloc() */
  26 #include <string.h>             /* strchr() */
  27 #include "./getline.h"
  28
  29 /* We don't handle errno. */
  30
  31 ssize_t getline(char **lineptr, size_t * n, FILE * stream)
  32 {
  33     size_t buf_size, real_size = 0;
  34     char *buf;
  35     int c;
  36
  37     if (!n || !lineptr || !stream)
  38         return -1;
  39
  40     /* Initialize the buffer. */
  41     if (*lineptr == NULL || *n == 0) {
  42         buf_size = 128;
  43         buf = malloc(buf_size);
  44     } else {
  45         buf_size = *n;
  46         buf = *lineptr;
  47     }
  48
  49     do {
  50         if (real_size == buf_size) {
  51             /* Buffer too small, enlarge it. */
  52             buf_size *= 2;
  53             buf = realloc(buf, buf_size);
  54         }
  55
  56         c = getc(stream);
  57
  58         buf[real_size] = (char) c;
  59         real_size++;
  60
  61     } while (c != '\n' && c != EOF);
  62
  63     if (c == '\n')
  64         /* We keep the '\n'. */
  65         real_size++;
  66
  67     buf = realloc(buf, real_size + 1);
  68     buf[real_size] = '\0';
  69
  70     *lineptr = buf;
  71     *n = real_size + 1;
  72
  73     return (ssize_t) real_size;
  74 }