lib/compat/vasprintf.c

   1 /*
   2  * libcompat - system compatibility library
   3  *
   4  * Copyright © 2010 Guillem Jover <guillem@debian.org>
   5  *
   6  * This is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This 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 General Public License
  17  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  18  */
  19
  20 #include <config.h>
  21
  22 #include <stdarg.h>
  23 #include <stdio.h>
  24 #include <stdlib.h>
  25
  26 #include "compat.h"
  27
  28 int
  29 vasprintf(char **strp, char const *fmt, va_list args)
  30 {
  31         va_list args_copy;
  32         int needed, n;
  33         char *str;
  34
  35         va_copy(args_copy, args);
  36         needed = vsnprintf(NULL, 0, fmt, args_copy);
  37         va_end(args_copy);
  38
  39         if (needed < 0) {
  40                 *strp = NULL;
  41                 return -1;
  42         }
  43
  44         str = malloc(needed + 1);
  45         if (str == NULL) {
  46                 *strp = NULL;
  47                 return -1;
  48         }
  49
  50         n = vsnprintf(str, needed + 1, fmt, args);
  51         if (n < 0) {
  52                 free(str);
  53                 str = NULL;
  54         }
  55
  56         *strp = str;
  57
  58         return n;
  59 }