xref: /freebsd/lib/libc/string/strcasecmp.c (revision a9029fbb59bf682ed0d57511a4a5bf06b17f7e80)
1 /*
2  * Copyright (c) 1987, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Copyright (c) 2011 The FreeBSD Foundation
6  * All rights reserved.
7  * Portions of this software were developed by David Chisnall
8  * under sponsorship from the FreeBSD Foundation.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 4. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34 
35 #if defined(LIBC_SCCS) && !defined(lint)
36 static char sccsid[] = "@(#)strcasecmp.c	8.1 (Berkeley) 6/4/93";
37 #endif /* LIBC_SCCS and not lint */
38 #include <sys/cdefs.h>
39 __FBSDID("$FreeBSD$");
40 
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 	if (s1 == s2)
52 		return (0);
53 
54 	FIX_LOCALE(locale);
55 
56 	while (tolower_l(*us1, locale) == tolower_l(*us2++, locale))
57 		if (*us1++ == '\0')
58 			return (0);
59 	return (tolower_l(*us1, locale) - tolower_l(*--us2, locale));
60 }
61 int
62 strcasecmp(const char *s1, const char *s2)
63 {
64 	return strcasecmp_l(s1, s2, __get_locale());
65 }
66 
67 int
68 strncasecmp_l(const char *s1, const char *s2, size_t n, locale_t locale)
69 {
70 	FIX_LOCALE(locale);
71 
72 	const u_char
73 			*us1 = (const u_char *)s1,
74 			*us2 = (const u_char *)s2;
75 
76 	/* use a bitwise or to avoid an additional branch instruction */
77 	if ((s1 == s2) | (n == 0))
78 		return (0);
79 
80 
81 	do {
82 		if (tolower_l(*us1, locale) != tolower_l(*us2++, locale))
83 			return (tolower_l(*us1, locale) - tolower_l(*--us2, locale));
84 		if (*us1++ == '\0')
85 			break;
86 	} while (--n != 0);
87 	return (0);
88 }
89 
90 int
91 strncasecmp(const char *s1, const char *s2, size_t n)
92 {
93 	return strncasecmp_l(s1, s2, n, __get_locale());
94 }
95