xref: /freebsd/lib/libc/stdio/snprintf.c (revision 97759ccc715c4b365432c16d763c50eecfcb1100)
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 int
49 snprintf(char * __restrict str, size_t n, char const * __restrict fmt, ...)
50 {
51 	size_t on;
52 	int ret;
53 	va_list ap;
54 	FILE f = FAKE_FILE;
55 
56 	on = n;
57 	if (n != 0)
58 		n--;
59 	if (n > INT_MAX) {
60 		errno = EOVERFLOW;
61 		*str = '\0';
62 		return (EOF);
63 	}
64 	va_start(ap, fmt);
65 	f._flags = __SWR | __SSTR;
66 	f._bf._base = f._p = (unsigned char *)str;
67 	f._bf._size = f._w = n;
68 	ret = __vfprintf(&f, __get_locale(), fmt, ap);
69 	if (on > 0)
70 		*f._p = '\0';
71 	va_end(ap);
72 	return (ret);
73 }
74 int
75 snprintf_l(char * __restrict str, size_t n, locale_t locale,
76 		char const * __restrict fmt, ...)
77 {
78 	size_t on;
79 	int ret;
80 	va_list ap;
81 	FILE f = FAKE_FILE;
82 	FIX_LOCALE(locale);
83 
84 	on = n;
85 	if (n != 0)
86 		n--;
87 	if (n > INT_MAX) {
88 		errno = EOVERFLOW;
89 		*str = '\0';
90 		return (EOF);
91 	}
92 	va_start(ap, fmt);
93 	f._flags = __SWR | __SSTR;
94 	f._bf._base = f._p = (unsigned char *)str;
95 	f._bf._size = f._w = n;
96 	ret = __vfprintf(&f, locale, fmt, ap);
97 	if (on > 0)
98 		*f._p = '\0';
99 	va_end(ap);
100 	return (ret);
101 }
102