xref: /freebsd/lib/libc/stdio/snprintf.c (revision 3750ccefb8629a08890bfbae894dd6bc6a7483b4)
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 #include <errno.h>
41 #include <limits.h>
42 #include <stdio.h>
43 #include <stdarg.h>
44 #include "xlocale_private.h"
45 
46 #include "local.h"
47 
48 #undef snprintf	/* _FORTIFY_SOURCE */
49 
50 int
51 snprintf(char * __restrict str, size_t n, char const * __restrict fmt, ...)
52 {
53 	FILE f = FAKE_FILE;
54 	va_list ap;
55 	size_t on;
56 	int serrno = errno;
57 	int ret;
58 
59 	on = n;
60 	if (n != 0)
61 		n--;
62 	if (n > INT_MAX) {
63 		errno = EOVERFLOW;
64 		*str = '\0';
65 		return (EOF);
66 	}
67 	va_start(ap, fmt);
68 	f._flags = __SWR | __SSTR;
69 	f._bf._base = f._p = (unsigned char *)str;
70 	f._bf._size = f._w = n;
71 	ret = __vfprintf(&f, __get_locale(), serrno, fmt, ap);
72 	if (on > 0)
73 		*f._p = '\0';
74 	va_end(ap);
75 	return (ret);
76 }
77 int
78 snprintf_l(char * __restrict str, size_t n, locale_t locale,
79 		char const * __restrict fmt, ...)
80 {
81 	FILE f = FAKE_FILE;
82 	va_list ap;
83 	size_t on;
84 	int serrno = errno;
85 	int ret;
86 	FIX_LOCALE(locale);
87 
88 	on = n;
89 	if (n != 0)
90 		n--;
91 	if (n > INT_MAX) {
92 		errno = EOVERFLOW;
93 		*str = '\0';
94 		return (EOF);
95 	}
96 	va_start(ap, fmt);
97 	f._flags = __SWR | __SSTR;
98 	f._bf._base = f._p = (unsigned char *)str;
99 	f._bf._size = f._w = n;
100 	ret = __vfprintf(&f, locale, serrno, fmt, ap);
101 	if (on > 0)
102 		*f._p = '\0';
103 	va_end(ap);
104 	return (ret);
105 }
106