xref: /freebsd/lib/libc/string/strcasecmp.c (revision 3047fefe49f57a673de8df152c199de12ec2c6d3)
1 /*
2  * Copyright (c) 1987, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #if defined(LIBC_SCCS) && !defined(lint)
35 static char sccsid[] = "@(#)strcasecmp.c	8.1 (Berkeley) 6/4/93";
36 #endif /* LIBC_SCCS and not lint */
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD$");
39 
40 #include <strings.h>
41 #include <ctype.h>
42 
43 typedef unsigned char u_char;
44 
45 int
46 strcasecmp(s1, s2)
47 	const char *s1, *s2;
48 {
49 	const u_char
50 			*us1 = (const u_char *)s1,
51 			*us2 = (const u_char *)s2;
52 
53 	while (tolower(*us1) == tolower(*us2++))
54 		if (*us1++ == '\0')
55 			return (0);
56 	return (tolower(*us1) - tolower(*--us2));
57 }
58 
59 int
60 strncasecmp(s1, s2, n)
61 	const char *s1, *s2;
62 	size_t n;
63 {
64 	if (n != 0) {
65 		const u_char
66 				*us1 = (const u_char *)s1,
67 				*us2 = (const u_char *)s2;
68 
69 		do {
70 			if (tolower(*us1) != tolower(*us2++))
71 				return (tolower(*us1) - tolower(*--us2));
72 			if (*us1++ == '\0')
73 				break;
74 		} while (--n != 0);
75 	}
76 	return (0);
77 }
78