asprintf.c revision a27d2baa0c1a2ec70f47ea9199b1dd6762c8a349 
1/*	$OpenBSD: asprintf.c,v 1.15 2005/10/10 12:00:52 espie Exp $	*/
2
3/*
4 * Copyright (c) 1997 Todd C. Miller <Todd.Miller@courtesan.com>
5 *
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 */
18
19#include <stdio.h>
20#include <stdlib.h>
21#include <string.h>
22#include <errno.h>
23#include <stdarg.h>
24#include "local.h"
25
26int
27asprintf(char **str, const char *fmt, ...)
28{
29	int ret;
30	va_list ap;
31	FILE f;
32	unsigned char *_base;
33
34	f._file = -1;
35	f._flags = __SWR | __SSTR | __SALC;
36	f._bf._base = f._p = (unsigned char *)malloc(128);
37	if (f._bf._base == NULL)
38		goto err;
39	f._bf._size = f._w = 127;		/* Leave room for the NUL */
40	va_start(ap, fmt);
41	ret = vfprintf(&f, fmt, ap);
42  va_end(ap);
43	if (ret == -1)
44		goto err;
45	*f._p = '\0';
46	_base = realloc(f._bf._base, ret + 1);
47	if (_base == NULL)
48		goto err;
49	*str = (char *)_base;
50	return (ret);
51
52err:
53	if (f._bf._base) {
54		free(f._bf._base);
55		f._bf._base = NULL;
56	}
57	*str = NULL;
58	errno = ENOMEM;
59	return (-1);
60}
61