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      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 (at) 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
    102