xref: /openbsd/lib/libc/stdio/asprintf.c (revision f2dfb0a4)
1 /*	$OpenBSD: asprintf.c,v 1.3 1998/02/07 20:51:21 tholo 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. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *	This product includes software developed by Todd C. Miller.
18  * 4. The name of the author may not be used to endorse or promote products
19  *    derived from this software without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
22  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
23  * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
24  * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
25  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
26  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
27  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
28  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
29  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
30  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31  */
32 
33 #if defined(LIBC_SCCS) && !defined(lint)
34 static char rcsid[] = "$OpenBSD: asprintf.c,v 1.3 1998/02/07 20:51:21 tholo Exp $";
35 #endif /* LIBC_SCCS and not lint */
36 
37 #include <stdio.h>
38 #include <stdlib.h>
39 #include <errno.h>
40 #if __STDC__
41 #include <stdarg.h>
42 #else
43 #include <varargs.h>
44 #endif
45 
46 int
47 #if __STDC__
48 asprintf(char **str, char const *fmt, ...)
49 #else
50 asprintf(str, fmt, va_alist)
51 	char **str;
52 	const char *fmt;
53 	va_dcl
54 #endif
55 {
56 	int ret;
57 	va_list ap;
58 	FILE f;
59 
60 #if __STDC__
61 	va_start(ap, fmt);
62 #else
63 	va_start(ap);
64 #endif
65 	f._file = -1;
66 	f._flags = __SWR | __SSTR | __SALC;
67 	f._bf._base = f._p = (unsigned char *)malloc(128);
68 	if (f._bf._base == NULL) {
69 		*str = NULL;
70 		errno = ENOMEM;
71 		return (-1);
72 	}
73 	f._bf._size = f._w = 127;		/* Leave room for the NULL */
74 	ret = vfprintf(&f, fmt, ap);
75 	*f._p = '\0';
76 	va_end(ap);
77 	f._bf._base = realloc(f._bf._base, f._bf._size + 1);
78 	if (f._bf._base == NULL) {
79 		errno = ENOMEM;
80 		ret = -1;
81 	}
82 	*str = (char *)f._bf._base;
83 	return (ret);
84 }
85