xref: /freebsd/lib/libc/stdio/vasprintf.c (revision d74e86d9e30043893d6b308468008b65640ddcae)
1 /*	$OpenBSD: vasprintf.c,v 1.4 1998/06/21 22:13:47 millert Exp $	*/
2 
3 /*
4  * Copyright (c) 1997 Todd C. Miller <Todd.Miller@courtesan.com>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. The name of the author may not be used to endorse or promote products
16  *    derived from this software without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
19  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
20  * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
21  * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
22  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
23  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
24  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
25  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
26  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
27  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28  */
29 
30 #if defined(LIBC_RCS) && !defined(lint)
31 static char rcsid[] = "$Id: vasprintf.c,v 1.9 1998/07/08 00:44:56 peter Exp $";
32 #endif /* LIBC_RCS and not lint */
33 
34 #include <stdio.h>
35 #include <stdlib.h>
36 #include <errno.h>
37 
38 int
39 vasprintf(str, fmt, ap)
40 	char **str;
41 	const char *fmt;
42 	_BSD_VA_LIST_ ap;
43 {
44 	int ret;
45 	FILE f;
46 
47 	f._file = -1;
48 	f._flags = __SWR | __SSTR | __SALC;
49 	f._bf._base = f._p = (unsigned char *)malloc(128);
50 	if (f._bf._base == NULL) {
51 		*str = NULL;
52 		errno = ENOMEM;
53 		return (-1);
54 	}
55 	f._bf._size = f._w = 127;		/* Leave room for the NULL */
56 	ret = vfprintf(&f, fmt, ap);
57 	*f._p = '\0';
58 	f._bf._base = reallocf(f._bf._base, f._bf._size + 1);
59 	if (f._bf._base == NULL) {
60 		errno = ENOMEM;
61 		ret = -1;
62 	}
63 	*str = (char *)f._bf._base;
64 	return (ret);
65 }
66