strstr.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
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#pragma ident	"%Z%%M%	%I%	%E% SMI"
28
29/*
30 * Get matching substring
31 */
32#include <string.h>
33
34#pragma weak strstr = _strstr
35
36char *
37_strstr(s1, s2)
38	register char *s1, *s2;
39{
40	int s2len = strlen(s2);	/* length of the second string */
41	/*
42	 * If the length of the second string is 0,
43	 *  return the first argument.
44	 */
45	if (s2len == 0)
46		return (s1);
47
48	while (strlen(s1) >= s2len) {
49		if (strncmp(s1, s2, s2len) == 0)
50			return (s1);
51		s1++;
52	}
53	return (0);
54}
55