xref: /freebsd/lib/libc/stdio/snprintf.c (revision b9f654b163bce26de79705e77b872427c9f2afa1)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1990, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Copyright (c) 2011 The FreeBSD Foundation
8  * All rights reserved.
9  * Portions of this software were developed by David Chisnall
10  * under sponsorship from the FreeBSD Foundation.
11  *
12  * This code is derived from software contributed to Berkeley by
13  * Chris Torek.
14  *
15  * Redistribution and use in source and binary forms, with or without
16  * modification, are permitted provided that the following conditions
17  * are met:
18  * 1. Redistributions of source code must retain the above copyright
19  *    notice, this list of conditions and the following disclaimer.
20  * 2. Redistributions in binary form must reproduce the above copyright
21  *    notice, this list of conditions and the following disclaimer in the
22  *    documentation and/or other materials provided with the distribution.
23  * 3. Neither the name of the University nor the names of its contributors
24  *    may be used to endorse or promote products derived from this software
25  *    without specific prior written permission.
26  *
27  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
28  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
29  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
30  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
31  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
32  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
33  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
34  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
35  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
36  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37  * SUCH DAMAGE.
38  */
39 
40 #if defined(LIBC_SCCS) && !defined(lint)
41 static char sccsid[] = "@(#)snprintf.c	8.1 (Berkeley) 6/4/93";
42 #endif /* LIBC_SCCS and not lint */
43 #include <sys/cdefs.h>
44 __FBSDID("$FreeBSD$");
45 
46 #include <errno.h>
47 #include <limits.h>
48 #include <stdio.h>
49 #include <stdarg.h>
50 #include "xlocale_private.h"
51 
52 #include "local.h"
53 
54 int
55 snprintf(char * __restrict str, size_t n, char const * __restrict fmt, ...)
56 {
57 	size_t on;
58 	int ret;
59 	va_list ap;
60 	FILE f = FAKE_FILE;
61 
62 	on = n;
63 	if (n != 0)
64 		n--;
65 	if (n > INT_MAX) {
66 		errno = EOVERFLOW;
67 		*str = '\0';
68 		return (EOF);
69 	}
70 	va_start(ap, fmt);
71 	f._flags = __SWR | __SSTR;
72 	f._bf._base = f._p = (unsigned char *)str;
73 	f._bf._size = f._w = n;
74 	ret = __vfprintf(&f, __get_locale(), fmt, ap);
75 	if (on > 0)
76 		*f._p = '\0';
77 	va_end(ap);
78 	return (ret);
79 }
80 int
81 snprintf_l(char * __restrict str, size_t n, locale_t locale,
82 		char const * __restrict fmt, ...)
83 {
84 	size_t on;
85 	int ret;
86 	va_list ap;
87 	FILE f = FAKE_FILE;
88 	FIX_LOCALE(locale);
89 
90 	on = n;
91 	if (n != 0)
92 		n--;
93 	if (n > INT_MAX) {
94 		errno = EOVERFLOW;
95 		*str = '\0';
96 		return (EOF);
97 	}
98 	va_start(ap, fmt);
99 	f._flags = __SWR | __SSTR;
100 	f._bf._base = f._p = (unsigned char *)str;
101 	f._bf._size = f._w = n;
102 	ret = __vfprintf(&f, locale, fmt, ap);
103 	if (on > 0)
104 		*f._p = '\0';
105 	va_end(ap);
106 	return (ret);
107 }
108