openbsd-compat/bsd-asprintf.c

   1 /*
   2  * Copyright (c) 2004 Darren Tucker.
   3  *
   4  * Based originally on asprintf.c from OpenBSD:
   5  * Copyright (c) 1997 Todd C. Miller <Todd.Miller@courtesan.com>
   6  *
   7  * Permission to use, copy, modify, and distribute this software for any
   8  * purpose with or without fee is hereby granted, provided that the above
   9  * copyright notice and this permission notice appear in all copies.
  10  *
  11  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  12  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  13  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  14  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  15  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  16  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  17  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  18  */
  19
  20 #include "includes.h"
  21
  22 #ifndef HAVE_VASPRINTF
  23
  24 #include <errno.h>
  25 #include <stdarg.h>
  26 #include <stdlib.h>
  27
  28 #ifndef VA_COPY
  29 # ifdef HAVE_VA_COPY
  30 #  define VA_COPY(dest, src) va_copy(dest, src)
  31 # else
  32 #  ifdef HAVE___VA_COPY
  33 #   define VA_COPY(dest, src) __va_copy(dest, src)
  34 #  else
  35 #   define VA_COPY(dest, src) (dest) = (src)
  36 #  endif
  37 # endif
  38 #endif
  39
  40 #define INIT_SZ 128
  41
  42 int
  43 vasprintf(char **str, const char *fmt, va_list ap)
  44 {
  45         int ret = -1;
  46         va_list ap2;
  47         char *string, *newstr;
  48         size_t len;
  49
  50         VA_COPY(ap2, ap);
  51         if ((string = malloc(INIT_SZ)) == NULL)
  52                 goto fail;
  53
  54         ret = vsnprintf(string, INIT_SZ, fmt, ap2);
  55         if (ret >= 0 && ret < INIT_SZ) { /* succeeded with initial alloc */
  56                 *str = string;
  57         } else if (ret == INT_MAX || ret < 0) { /* Bad length */
  58                 free(string);
  59                 goto fail;
  60         } else {        /* bigger than initial, realloc allowing for nul */
  61                 len = (size_t)ret + 1;
  62                 if ((newstr = realloc(string, len)) == NULL) {
  63                         free(string);
  64                         goto fail;
  65                 } else {
  66                         va_end(ap2);
  67                         VA_COPY(ap2, ap);
  68                         ret = vsnprintf(newstr, len, fmt, ap2);
  69                         if (ret >= 0 && (size_t)ret < len) {
  70                                 *str = newstr;
  71                         } else { /* failed with realloc'ed string, give up */
  72                                 free(newstr);
  73                                 goto fail;
  74                         }
  75                 }
  76         }
  77         va_end(ap2);
  78         return (ret);
  79
  80 fail:
  81         *str = NULL;
  82         errno = ENOMEM;
  83         va_end(ap2);
  84         return (-1);
  85 }
  86 #endif
  87
  88 #ifndef HAVE_ASPRINTF
  89 int asprintf(char **str, const char *fmt, ...)
  90 {
  91         va_list ap;
  92         int ret;
  93
  94         *str = NULL;
  95         va_start(ap, fmt);
  96         ret = vasprintf(str, fmt, ap);
  97         va_end(ap);
  98
  99         return ret;
 100 }
 101 #endif