snprintf.c revision 72373 
1/*-
2 * Copyright (c) 1990, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * Chris Torek.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 *    must display the following acknowledgement:
18 *	This product includes software developed by the University of
19 *	California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 *    may be used to endorse or promote products derived from this software
22 *    without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 */
36
37#if defined(LIBC_SCCS) && !defined(lint)
38#if 0
39static char sccsid[] = "@(#)snprintf.c	8.1 (Berkeley) 6/4/93";
40#endif
41static const char rcsid[] =
42  "$FreeBSD: head/lib/libc/stdio/snprintf.c 72373 2001-02-11 22:06:43Z deischen $";
43#endif /* LIBC_SCCS and not lint */
44
45#include <limits.h>
46#include <stdio.h>
47#if __STDC__
48#include <stdarg.h>
49#else
50#include <varargs.h>
51#endif
52
53#include "local.h"
54
55#if __STDC__
56int
57snprintf(char *str, size_t n, char const *fmt, ...)
58#else
59int
60snprintf(str, n, fmt, va_alist)
61	char *str;
62	size_t n;
63	char *fmt;
64	va_dcl
65#endif
66{
67	size_t on;
68	int ret;
69	va_list ap;
70	FILE f;
71
72	on = n;
73	if (n != 0)
74		n--;
75	if (n > INT_MAX)
76		n = INT_MAX;
77#if __STDC__
78	va_start(ap, fmt);
79#else
80	va_start(ap);
81#endif
82	f._file = -1;
83	f._flags = __SWR | __SSTR;
84	f._bf._base = f._p = (unsigned char *)str;
85	f._bf._size = f._w = n;
86	ret = __vfprintf(&f, fmt, ap);
87	if (on > 0)
88		*f._p = '\0';
89	va_end(ap);
90	return (ret);
91}
92