xref: /freebsd/stand/libsa/strcasecmp.c (revision 397e83df75e0fcd0d3fcb95ae4d794cb7600fc89)
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. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #include "stand.h"
31 #include <string.h>
32 
33 int
34 strcasecmp(const char *s1, const char *s2)
35 {
36 	const u_char
37 			*us1 = (const u_char *)s1,
38 			*us2 = (const u_char *)s2;
39 
40 	while (tolower(*us1) == tolower(*us2++))
41 		if (*us1++ == '\0')
42 			return (0);
43 	return (tolower(*us1) - tolower(*--us2));
44 }
45 
46 int
47 strncasecmp(const char *s1, const char *s2, size_t n)
48 {
49 	if (n != 0) {
50 		const u_char
51 				*us1 = (const u_char *)s1,
52 				*us2 = (const u_char *)s2;
53 
54 		do {
55 			if (tolower(*us1) != tolower(*us2++))
56 				return (tolower(*us1) - tolower(*--us2));
57 			if (*us1++ == '\0')
58 				break;
59 		} while (--n != 0);
60 	}
61 	return (0);
62 }
63