xref: /freebsd/lib/libc/string/strcasecmp.c (revision 734e82fe33aa764367791a7d603b383996c6b40b)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1987, 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  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  * 3. 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 static char sccsid[] = "@(#)strcasecmp.c	8.1 (Berkeley) 6/4/93";
39 #endif /* LIBC_SCCS and not lint */
40 #include <sys/cdefs.h>
41 #include <strings.h>
42 #include <ctype.h>
43 #include "xlocale_private.h"
44 
45 int
46 strcasecmp_l(const char *s1, const char *s2, locale_t locale)
47 {
48 	const u_char
49 			*us1 = (const u_char *)s1,
50 			*us2 = (const u_char *)s2;
51 	FIX_LOCALE(locale);
52 
53 	while (tolower_l(*us1, locale) == tolower_l(*us2++, locale))
54 		if (*us1++ == '\0')
55 			return (0);
56 	return (tolower_l(*us1, locale) - tolower_l(*--us2, locale));
57 }
58 int
59 strcasecmp(const char *s1, const char *s2)
60 {
61 	return strcasecmp_l(s1, s2, __get_locale());
62 }
63 
64 int
65 strncasecmp_l(const char *s1, const char *s2, size_t n, locale_t locale)
66 {
67 	FIX_LOCALE(locale);
68 	if (n != 0) {
69 		const u_char
70 				*us1 = (const u_char *)s1,
71 				*us2 = (const u_char *)s2;
72 
73 		do {
74 			if (tolower_l(*us1, locale) != tolower_l(*us2++, locale))
75 				return (tolower_l(*us1, locale) - tolower_l(*--us2, locale));
76 			if (*us1++ == '\0')
77 				break;
78 		} while (--n != 0);
79 	}
80 	return (0);
81 }
82 
83 int
84 strncasecmp(const char *s1, const char *s2, size_t n)
85 {
86 	return strncasecmp_l(s1, s2, n, __get_locale());
87 }
88