xref: /dragonfly/lib/libc/stdio/asprintf.c (revision b40e316c)
1 /*	$OpenBSD: asprintf.c,v 1.4 1998/06/21 22:13:46 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  * $FreeBSD: src/lib/libc/stdio/asprintf.c,v 1.6 1999/08/28 00:00:55 peter Exp $
30  * $DragonFly: src/lib/libc/stdio/asprintf.c,v 1.4 2004/06/07 17:59:42 hmp Exp $
31  */
32 
33 #include <stdio.h>
34 #include <stdlib.h>
35 #include <errno.h>
36 #include <stdarg.h>
37 
38 int
39 asprintf(char **str, char const *fmt, ...)
40 {
41 	int ret;
42 	va_list ap;
43 	FILE f;
44 
45 	f._file = -1;
46 	f._flags = __SWR | __SSTR | __SALC;
47 	f._bf._base = f._p = (unsigned char *)malloc(128);
48 	if (f._bf._base == NULL) {
49 		*str = NULL;
50 		errno = ENOMEM;
51 		return (-1);
52 	}
53 	f._bf._size = f._w = 127;		/* Leave room for the NUL */
54 	va_start(ap, fmt);
55 	ret = vfprintf(&f, fmt, ap);
56 	va_end(ap);
57 	if (ret < 0) {
58 		free(f._bf._base);
59 		*str = NULL;
60 		errno = ENOMEM;
61 		return (-1);
62 	}
63 	*f._p = '\0';
64 	*str = (char *)f._bf._base;
65 	return (ret);
66 }
67