xref: /illumos-gate/usr/src/lib/libc/port/i18n/wcswcs.c (revision 201ceb75ab95f9bf1f42ea1dc9ab363b43ba47cf)
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 (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*	Copyright (c) 1986 AT&T	*/
28 /*	  All Rights Reserved  	*/
29 
30 /*
31  * Returns a pointer to the first occurrnce of ws1 in ws2.
32  */
33 
34 #pragma weak _wcswcs = wcswcs
35 
36 #include "lint.h"
37 #include <stdlib.h>
38 
39 wchar_t *
40 wcswcs(const wchar_t *ws1, const wchar_t *ws2)
41 {
42 	const wchar_t *s1, *s2;
43 	const wchar_t *tptr;
44 	wchar_t c;
45 
46 	s1 = ws1;
47 	s2 = ws2;
48 
49 	if (s2 == NULL || *s2 == 0)
50 		return ((wchar_t *)s1);
51 	c = *s2;
52 
53 	while (*s1)
54 		if (*s1++ == c) {
55 			tptr = s1;
56 			while ((c = *++s2) == *s1++ && c)
57 				;
58 			if (c == 0)
59 				return ((wchar_t *)tptr - 1);
60 			s1 = tptr;
61 			s2 = ws2;
62 			c = *s2;
63 		}
64 	return (NULL);
65 }
66