xref: /minix3/lib/libc/string/wcsstr.c (revision f14fb602092e015ff630df58e17c2a9cd57d29b3)
1 /*	$NetBSD: wcsstr.c,v 1.5 2012/06/25 22:32:46 abs Exp $	*/
2 
3 /*-
4  * Copyright (c)1999 Citrus Project,
5  * 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  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  *
28  *	citrus Id: wcsstr.c,v 1.2 2000/12/21 05:07:25 itojun Exp
29  */
30 
31 #include <sys/cdefs.h>
32 #if defined(LIBC_SCCS) && !defined(lint)
33 __RCSID("$NetBSD: wcsstr.c,v 1.5 2012/06/25 22:32:46 abs Exp $");
34 #endif /* LIBC_SCCS and not lint */
35 
36 #include <assert.h>
37 #include <wchar.h>
38 
39 wchar_t *
40 #ifdef WCSWCS
wcswcs(const wchar_t * big,const wchar_t * little)41 wcswcs(const wchar_t *big, const wchar_t *little)
42 #else
43 wcsstr(const wchar_t *big, const wchar_t *little)
44 #endif
45 {
46 	const wchar_t *p;
47 	const wchar_t *q;
48 	const wchar_t *r;
49 
50 	_DIAGASSERT(big != NULL);
51 	_DIAGASSERT(little != NULL);
52 
53 	if (!*little)
54 		return __UNCONST(big);
55 	if (wcslen(big) < wcslen(little))
56 		return NULL;
57 
58 	p = big;
59 	q = little;
60 	while (*p) {
61 		q = little;
62 		r = p;
63 		while (*q) {
64 			if (*r != *q)
65 				break;
66 			q++;
67 			r++;
68 		}
69 		if (!*q)
70 			return __UNCONST(p);
71 		p++;
72 	}
73 	return NULL;
74 }
75