compat/asprintf.c

   1 /*
   2  * Copyright (c) 2006 Nicholas Marriott <nicholas.marriott@gmail.com>
   3  *
   4  * Permission to use, copy, modify, and distribute this software for any
   5  * purpose with or without fee is hereby granted, provided that the above
   6  * copyright notice and this permission notice appear in all copies.
   7  *
   8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  12  * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
  13  * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
  14  * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  15  */
  16
  17 #include <sys/types.h>
  18
  19 #include <err.h>
  20 #include <stdarg.h>
  21 #include <stdio.h>
  22 #include <string.h>
  23 #include <stdlib.h>
  24
  25 int
  26 asprintf(char **ret, const char *fmt, ...)
  27 {
  28         va_list ap;
  29         int     n;
  30
  31         va_start(ap, fmt);
  32         n = vasprintf(ret, fmt, ap);
  33         va_end(ap);
  34
  35         return (n);
  36 }
  37
  38 int
  39 vasprintf(char **ret, const char *fmt, va_list ap)
  40 {
  41         int      n;
  42         va_list  ap2;
  43
  44         va_copy(ap2, ap);
  45
  46         if ((n = vsnprintf(NULL, 0, fmt, ap)) < 0)
  47                 goto error;
  48
  49         *ret = malloc(n + 1);
  50         if (*ret == NULL)
  51                 errx(1, "vasprintf: malloc failed");
  52         if ((n = vsnprintf(*ret, n + 1, fmt, ap2)) < 0) {
  53                 free(*ret);
  54                 goto error;
  55         }
  56         va_end(ap2);
  57
  58         return (n);
  59
  60 error:
  61         va_end(ap2);
  62         *ret = NULL;
  63         return (-1);
  64 }