xref: /freebsd/lib/libc/stdio/asprintf.c (revision ee2ea5ceafed78a5bd9810beb9e3ca927180c226)
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 
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
32 
33 #include <stdio.h>
34 #include <stdlib.h>
35 #include <errno.h>
36 #if __STDC__
37 #include <stdarg.h>
38 #else
39 #include <varargs.h>
40 #endif
41 
42 #include "local.h"
43 
44 int
45 #if __STDC__
46 asprintf(char **str, char const *fmt, ...)
47 #else
48 asprintf(str, fmt, va_alist)
49 	char **str;
50 	const char *fmt;
51 	va_dcl
52 #endif
53 {
54 	int ret;
55 	va_list ap;
56 	FILE f;
57 
58 #if __STDC__
59 	va_start(ap, fmt);
60 #else
61 	va_start(ap);
62 #endif
63 	f._file = -1;
64 	f._flags = __SWR | __SSTR | __SALC;
65 	f._bf._base = f._p = (unsigned char *)malloc(128);
66 	if (f._bf._base == NULL) {
67 		*str = NULL;
68 		errno = ENOMEM;
69 		return (-1);
70 	}
71 	f._bf._size = f._w = 127;		/* Leave room for the NULL */
72 	ret = __vfprintf(&f, fmt, ap);		/* Use unlocked __vfprintf */
73 	*f._p = '\0';
74 	va_end(ap);
75 	f._bf._base = reallocf(f._bf._base, f._bf._size + 1);
76 	if (f._bf._base == NULL) {
77 		errno = ENOMEM;
78 		ret = -1;
79 	}
80 	*str = (char *)f._bf._base;
81 	return (ret);
82 }
83