1 /* $NetBSD: strcmp.c,v 1.3 2013/07/01 20:51:59 joerg Exp $ */
2
3 /*-
4 * Copyright (c) 1990, 1993
5 * The Regents of the University of California. 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. 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 #include <sys/cdefs.h>
36 #if defined(LIBC_SCCS) && !defined(lint)
37 #if 0
38 static char sccsid[] = "@(#)strcmp.c 8.1 (Berkeley) 6/4/93";
39 #else
40 __RCSID("$NetBSD: strcmp.c,v 1.3 2013/07/01 20:51:59 joerg Exp $");
41 #endif
42 #endif /* LIBC_SCCS and not lint */
43
44 #if !defined(_KERNEL) && !defined(_STANDALONE)
45 #include <assert.h>
46 #include <string.h>
47 #else
48 #include <lib/libkern/libkern.h>
49 #endif
50
51 #undef strcmp
52
53 /*
54 * Compare strings.
55 */
56 int
strcmp(const char * s1,const char * s2)57 strcmp(const char *s1, const char *s2)
58 {
59
60 _DIAGASSERT(s1 != NULL);
61 _DIAGASSERT(s2 != NULL);
62
63 while (*s1 == *s2++)
64 if (*s1++ == 0)
65 return (0);
66 return (*(const unsigned char *)s1 - *(const unsigned char *)--s2);
67 }
68