vasprintf.c revision f582340a6a48588aa50da17e1620e8f91b146941 
1/*	$OpenBSD: vasprintf.c,v 1.13 2006/01/06 18:53:04 millert 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 "local.h"
24
25int
26vasprintf(char **str, const char *fmt, __va_list ap)
27{
28	int ret;
29	FILE f;
30	struct __sfileext fext;
31	unsigned char *_base;
32
33	_FILEEXT_SETUP(&f, &fext);
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	ret = __vfprintf(&f, fmt, ap);
41	if (ret == -1)
42		goto err;
43	*f._p = '\0';
44	_base = realloc(f._bf._base, ret + 1);
45	if (_base == NULL)
46		goto err;
47	*str = (char *)_base;
48	return (ret);
49
50err:
51	free(f._bf._base);
52	*str = NULL;
53	errno = ENOMEM;
54	return (-1);
55}
56