xref: /netbsd-src/lib/libc/stdio/vsnprintf.c (revision 5aefcfdc06931dd97e76246d2fe0302f7b3fe094)
1 /*	$NetBSD: vsnprintf.c,v 1.15 2000/10/19 09:47:43 kleink Exp $	*/
2 
3 /*-
4  * Copyright (c) 1990, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * This code is derived from software contributed to Berkeley by
8  * Chris Torek.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *	This product includes software developed by the University of
21  *	California, Berkeley and its contributors.
22  * 4. Neither the name of the University nor the names of its contributors
23  *    may be used to endorse or promote products derived from this software
24  *    without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36  * SUCH DAMAGE.
37  */
38 
39 #include <sys/cdefs.h>
40 #if defined(LIBC_SCCS) && !defined(lint)
41 #if 0
42 static char sccsid[] = "@(#)vsnprintf.c	8.1 (Berkeley) 6/4/93";
43 #else
44 __RCSID("$NetBSD: vsnprintf.c,v 1.15 2000/10/19 09:47:43 kleink Exp $");
45 #endif
46 #endif /* LIBC_SCCS and not lint */
47 
48 #include "namespace.h"
49 
50 #include <assert.h>
51 #include <errno.h>
52 #include <stdio.h>
53 
54 #ifdef __weak_alias
55 __weak_alias(vsnprintf,_vsnprintf)
56 #endif
57 
58 int
59 vsnprintf(str, n, fmt, ap)
60 	char *str;
61 	size_t n;
62 	const char *fmt;
63 	_BSD_VA_LIST_ ap;
64 {
65 	int ret;
66 	FILE f;
67 
68 	_DIAGASSERT(n == 0 || str != NULL);
69 	_DIAGASSERT(fmt != NULL);
70 
71 	if ((int)n < 0) {
72 		errno = EINVAL;
73 		return (-1);
74 	}
75 
76 	f._file = -1;
77 	f._flags = __SWR | __SSTR;
78 	f._bf._base = f._p = (unsigned char *)str;
79 	f._bf._size = f._w = n - 1;
80 	ret = vfprintf(&f, fmt, ap);
81 	*f._p = 0;
82 	return (ret);
83 }
84