xref: /netbsd-src/lib/libc/string/wcsncmp.c (revision 76c7fc5f6b13ed0b1508e6b313e88e59977ed78e)
1 /*	$NetBSD: wcsncmp.c,v 1.9 2012/06/25 22:32:46 abs 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. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 #if defined(LIBC_SCCS) && !defined(lint)
34 #if 0
35 static char sccsid[] = "@(#)strncmp.c	8.1 (Berkeley) 6/4/93";
36 #else
37 __RCSID("$NetBSD: wcsncmp.c,v 1.9 2012/06/25 22:32:46 abs Exp $");
38 #endif
39 #endif /* LIBC_SCCS and not lint */
40 
41 #include <assert.h>
42 #include <wchar.h>
43 #include "runetype_local.h"
44 
45 int
46 wcsncmp(const wchar_t *s1, const wchar_t *s2, size_t n)
47 {
48 
49 	_DIAGASSERT(s1 != NULL);
50 	_DIAGASSERT(s2 != NULL);
51 
52 	if (n == 0)
53 		return (0);
54 	do {
55 		if (*s1 != *s2++) {
56 			/* XXX assumes wchar_t = int */
57 			return (*(const __nbrune_t *)s1 -
58 			    *(const __nbrune_t *)--s2);
59 		}
60 		if (*s1++ == 0)
61 			break;
62 	} while (--n != 0);
63 	return (0);
64 }
65