snprintf.c revision 31969 
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		"$Id: snprintf.c,v 1.6 1997/12/24 12:31:31 ache Exp $";
43#endif /* LIBC_SCCS and not lint */
44
45#include <stdio.h>
46#if __STDC__
47#include <stdarg.h>
48#else
49#include <varargs.h>
50#endif
51
52#if __STDC__
53int
54snprintf(char *str, size_t n, char const *fmt, ...)
55#else
56int
57snprintf(str, n, fmt, va_alist)
58	char *str;
59	size_t n;
60	char *fmt;
61	va_dcl
62#endif
63{
64	int ret;
65	va_list ap;
66	FILE f;
67
68	if ((int)n < 1)
69		return (EOF);
70	n--;
71#if __STDC__
72	va_start(ap, fmt);
73#else
74	va_start(ap);
75#endif
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;
80	ret = vfprintf(&f, fmt, ap);
81	*f._p = 0;
82	va_end(ap);
83	if (ret == EOF)
84		return (ret);
85	return (ret > (int)n ? n : ret);
86}
87