xref: /netbsd/lib/libc/string/wcsncmp.c (revision bf9ec67e)
1 /*	$NetBSD: wcsncmp.c,v 1.3 2001/01/05 12:13:13 itojun Exp $	*/
2 
3 /*
4  * Copyright (c) 1989, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *	This product includes software developed by the University of
18  *	California, Berkeley and its contributors.
19  * 4. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #include <sys/cdefs.h>
37 #if defined(LIBC_SCCS) && !defined(lint)
38 #if 0
39 static char sccsid[] = "@(#)strncmp.c	8.1 (Berkeley) 6/4/93";
40 #else
41 __RCSID("$NetBSD: wcsncmp.c,v 1.3 2001/01/05 12:13:13 itojun Exp $");
42 #endif
43 #endif /* LIBC_SCCS and not lint */
44 
45 #include <assert.h>
46 #include <wchar.h>
47 
48 int
49 wcsncmp(s1, s2, n)
50 	const wchar_t *s1, *s2;
51 	size_t n;
52 {
53 
54 	_DIAGASSERT(s1 != NULL);
55 	_DIAGASSERT(s2 != NULL);
56 
57 	if (n == 0)
58 		return (0);
59 	do {
60 		if (*s1 != *s2++) {
61 			/* XXX assumes wchar_t = int */
62 			return (*(const unsigned int *)s1 -
63 			    *(const unsigned int *)--s2);
64 		}
65 		if (*s1++ == 0)
66 			break;
67 	} while (--n != 0);
68 	return (0);
69 }
70