1/*	$OpenBSD: snprintf.c,v 1.14 2005/10/10 12:00:52 espie Exp $ */
2/*-
3 * Copyright (c) 1990, 1993
4 *	The Regents of the University of California.  All rights reserved.
5 *
6 * This code is derived from software contributed to Berkeley by
7 * Chris Torek.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 *    notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 *    notice, this list of conditions and the following disclaimer in the
16 *    documentation and/or other materials provided with the distribution.
17 * 3. Neither the name of the University nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34#include <limits.h>
35#include <stdio.h>
36#include <string.h>
37#include <stdarg.h>
38#include "local.h"
39
40int
41snprintf(char *str, size_t n, const char *fmt, ...)
42{
43	va_list ap;
44	int ret;
45	char dummy;
46	FILE f;
47	struct __sfileext fext;
48
49	/* While snprintf(3) specifies size_t stdio uses an int internally */
50	if (n > INT_MAX)
51		n = INT_MAX;
52	/* Stdio internals do not deal correctly with zero length buffer */
53	if (n == 0) {
54		str = &dummy;
55		n = 1;
56	}
57	_FILEEXT_SETUP(&f, &fext);
58	f._file = -1;
59	f._flags = __SWR | __SSTR;
60	f._bf._base = f._p = (unsigned char *)str;
61	f._bf._size = f._w = n - 1;
62	va_start(ap, fmt);
63	ret = __vfprintf(&f, fmt, ap);
64	va_end(ap);
65	*f._p = '\0';
66	return (ret);
67}
68