xref: /freebsd/lib/libc/stdio/asprintf.c (revision 6de306ecee3831f48debaad1d0b22418faa48e10)
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 #if defined(LIBC_RCS) && !defined(lint)
31 static char rcsid[] = "$FreeBSD$";
32 #endif /* LIBC_RCS and not lint */
33 
34 #include <stdio.h>
35 #include <stdlib.h>
36 #include <errno.h>
37 #if __STDC__
38 #include <stdarg.h>
39 #else
40 #include <varargs.h>
41 #endif
42 
43 #include "local.h"
44 
45 int
46 #if __STDC__
47 asprintf(char **str, char const *fmt, ...)
48 #else
49 asprintf(str, fmt, va_alist)
50 	char **str;
51 	const char *fmt;
52 	va_dcl
53 #endif
54 {
55 	int ret;
56 	va_list ap;
57 	FILE f;
58 
59 #if __STDC__
60 	va_start(ap, fmt);
61 #else
62 	va_start(ap);
63 #endif
64 	f._file = -1;
65 	f._flags = __SWR | __SSTR | __SALC;
66 	f._bf._base = f._p = (unsigned char *)malloc(128);
67 	if (f._bf._base == NULL) {
68 		*str = NULL;
69 		errno = ENOMEM;
70 		return (-1);
71 	}
72 	f._bf._size = f._w = 127;		/* Leave room for the NULL */
73 	ret = __vfprintf(&f, fmt, ap);		/* Use unlocked __vfprintf */
74 	*f._p = '\0';
75 	va_end(ap);
76 	f._bf._base = reallocf(f._bf._base, f._bf._size + 1);
77 	if (f._bf._base == NULL) {
78 		errno = ENOMEM;
79 		ret = -1;
80 	}
81 	*str = (char *)f._bf._base;
82 	return (ret);
83 }
84