xref: /illumos-gate/usr/src/lib/libc/port/i18n/wcsstr.c (revision 7a6d80f1660abd4755c68cbd094d4a914681d26e)
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 #include "lint.h"
28 #include <sys/types.h>
29 #include <wchar.h>
30 #include "libc.h"
31 
32 wchar_t *
33 wcsstr(const wchar_t *ws1, const wchar_t *ws2)
34 {
35 	const wchar_t	*os1, *os2;
36 	const wchar_t	*tptr;
37 	wchar_t	c;
38 
39 	os1 = ws1;
40 	os2 = ws2;
41 
42 	if (os1 == NULL || *os2 == L'\0')
43 		return ((wchar_t *)os1);
44 	c = *os2;
45 
46 	while (*os1)
47 		if (*os1++ == c) {
48 			tptr = os1;
49 			while (((c = *++os2) == *os1++) && (c != L'\0'))
50 				;
51 			if (c == L'\0')
52 				return ((wchar_t *)tptr - 1);
53 			os1 = tptr;
54 			os2 = ws2;
55 			c = *os2;
56 		}
57 	return (NULL);
58 }
59