xref: /titanic_51/usr/src/lib/libc/port/gen/strncmp.c (revision 09fe1b16b0d85a4b43987628152f516df3ae9838)
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, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 /*	Copyright (c) 1988 AT&T	*/
30 /*	  All Rights Reserved  	*/
31 
32 
33 #include "synonyms.h"
34 #include <string.h>
35 #include <sys/types.h>
36 
37 /*
38  * Compare strings (at most n bytes)
39  *	returns: s1>s2; >0  s1==s2; 0  s1<s2; <0
40  */
41 int
42 strncmp(const char *s1, const char *s2, size_t n)
43 {
44 	n++;
45 	if (s1 == s2)
46 		return (0);
47 	while (--n != 0 && *s1 == *s2++)
48 		if (*s1++ == '\0')
49 			return (0);
50 	return (n == 0 ? 0 : *(unsigned char *)s1 - *(unsigned char *)--s2);
51 }
52