src/text_file.c

   1 /*
   2  * Copyright (C) 2003-2010 The Music Player Daemon Project
   3  * http://www.musicpd.org
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  18  */
  19
  20 #include "config.h"
  21 #include "text_file.h"
  22
  23 #include <assert.h>
  24 #include <string.h>
  25
  26 char *
  27 read_text_line(FILE *file, GString *buffer)
  28 {
  29         enum {
  30                 max_length = 512 * 1024,
  31                 step = 1024,
  32         };
  33
  34         gsize length = 0, i;
  35         char *p;
  36
  37         assert(file != NULL);
  38         assert(buffer != NULL);
  39
  40         if (buffer->allocated_len < step)
  41                 g_string_set_size(buffer, step);
  42
  43         while (buffer->len < max_length) {
  44                 p = fgets(buffer->str + length,
  45                           buffer->allocated_len - length, file);
  46                 if (p == NULL) {
  47                         if (length == 0 || ferror(file))
  48                                 return NULL;
  49                         break;
  50                 }
  51
  52                 i = strlen(buffer->str + length);
  53                 length += i;
  54                 if (i < step - 1 || buffer->str[length - 1] == '\n')
  55                         break;
  56
  57                 g_string_set_size(buffer, length + step);
  58         }
  59
  60         /* remove the newline characters */
  61         if (buffer->str[length - 1] == '\n')
  62                 --length;
  63         if (buffer->str[length - 1] == '\r')
  64                 --length;
  65
  66         g_string_set_size(buffer, length);
  67         return buffer->str;
  68 }