xref: /openbsd-src/sys/lib/libkern/strcmp.c (revision 443998a44aec1b782e28ea78ab54ad82e5be4c96)
1 /*	$OpenBSD: strcmp.c,v 1.6 1998/06/27 01:21:05 mickey Exp $	*/
2 
3 /*-
4  * Copyright (c) 1990 The Regents of the University of California.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to Berkeley by
8  * Chris Torek.
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  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *	This product includes software developed by the University of
21  *	California, Berkeley and its contributors.
22  * 4. Neither the name of the University nor the names of its contributors
23  *    may be used to endorse or promote products derived from this software
24  *    without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36  * SUCH DAMAGE.
37  */
38 
39 #if defined(LIBC_SCCS) && !defined(lint)
40 /*static char *sccsid = "from: @(#)strcmp.c	5.5 (Berkeley) 1/26/91";*/
41 static char *rcsid = "$OpenBSD: strcmp.c,v 1.6 1998/06/27 01:21:05 mickey Exp $";
42 #endif /* LIBC_SCCS and not lint */
43 
44 #include <sys/types.h>
45 #if !defined(_KERNEL) && !defined(_STANDALONE)
46 #include <string.h>
47 #else
48 #include <lib/libkern/libkern.h>
49 #endif
50 
51 /*
52  * Compare strings.
53  */
54 int
55 strcmp(s1, s2)
56 	register const char *s1, *s2;
57 {
58 	while (*s1 == *s2++)
59 		if (*s1++ == 0)
60 			return (0);
61 	return (*(const u_char *)s1 - *(const u_char *)--s2);
62 }
63