xref: /titanic_41/usr/src/lib/libc/port/gen/strncmp.c (revision d15447b6c777a1b2223924443bf36c9c8efb2ea4)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*	Copyright (c) 1988 AT&T	*/
28 /*	  All Rights Reserved  	*/
29 
30 #pragma ident	"%Z%%M%	%I%	%E% SMI"
31 
32 #include "lint.h"
33 #include <string.h>
34 #include <sys/types.h>
35 
36 /*
37  * Compare strings (at most n bytes)
38  *	returns: s1>s2; >0  s1==s2; 0  s1<s2; <0
39  */
40 int
41 strncmp(const char *s1, const char *s2, size_t n)
42 {
43 	n++;
44 	if (s1 == s2)
45 		return (0);
46 	while (--n != 0 && *s1 == *s2++)
47 		if (*s1++ == '\0')
48 			return (0);
49 	return (n == 0 ? 0 : *(unsigned char *)s1 - *(unsigned char *)--s2);
50 }
51