xref: /freebsd-14.2/lib/libc/stdio/snprintf.c (revision 2403e6d5)
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  *
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 <errno.h>
44 #include <limits.h>
45 #include <stdio.h>
46 #include <stdarg.h>
47 #include "xlocale_private.h"
48 
49 #include "local.h"
50 
51 int
snprintf(char * __restrict str,size_t n,char const * __restrict fmt,...)52 snprintf(char * __restrict str, size_t n, char const * __restrict fmt, ...)
53 {
54 	FILE f = FAKE_FILE;
55 	va_list ap;
56 	size_t on;
57 	int serrno = errno;
58 	int ret;
59 
60 	on = n;
61 	if (n != 0)
62 		n--;
63 	if (n > INT_MAX) {
64 		errno = EOVERFLOW;
65 		*str = '\0';
66 		return (EOF);
67 	}
68 	va_start(ap, fmt);
69 	f._flags = __SWR | __SSTR;
70 	f._bf._base = f._p = (unsigned char *)str;
71 	f._bf._size = f._w = n;
72 	ret = __vfprintf(&f, __get_locale(), serrno, fmt, ap);
73 	if (on > 0)
74 		*f._p = '\0';
75 	va_end(ap);
76 	return (ret);
77 }
78 int
snprintf_l(char * __restrict str,size_t n,locale_t locale,char const * __restrict fmt,...)79 snprintf_l(char * __restrict str, size_t n, locale_t locale,
80 		char const * __restrict fmt, ...)
81 {
82 	FILE f = FAKE_FILE;
83 	va_list ap;
84 	size_t on;
85 	int serrno = errno;
86 	int ret;
87 	FIX_LOCALE(locale);
88 
89 	on = n;
90 	if (n != 0)
91 		n--;
92 	if (n > INT_MAX) {
93 		errno = EOVERFLOW;
94 		*str = '\0';
95 		return (EOF);
96 	}
97 	va_start(ap, fmt);
98 	f._flags = __SWR | __SSTR;
99 	f._bf._base = f._p = (unsigned char *)str;
100 	f._bf._size = f._w = n;
101 	ret = __vfprintf(&f, locale, serrno, fmt, ap);
102 	if (on > 0)
103 		*f._p = '\0';
104 	va_end(ap);
105 	return (ret);
106 }
107