1 /* $OpenBSD: strcasestr.c,v 1.4 2015/08/31 02:53:57 guenther Exp $ */
2 /* $NetBSD: strcasestr.c,v 1.2 2005/02/09 21:35:47 kleink Exp $ */
3
4 /*-
5 * Copyright (c) 1990, 1993
6 * The Regents of the University of California. All rights reserved.
7 *
8 * This code is derived from software contributed to Berkeley by
9 * Chris Torek.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. Neither the name of the University nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36 #include <ctype.h>
37 #include <string.h>
38
39 /*
40 * Find the first occurrence of find in s, ignore case.
41 */
42 char *
strcasestr(const char * s,const char * find)43 strcasestr(const char *s, const char *find)
44 {
45 char c, sc;
46 size_t len;
47
48 if ((c = *find++) != 0) {
49 c = (char)tolower((unsigned char)c);
50 len = strlen(find);
51 do {
52 do {
53 if ((sc = *s++) == 0)
54 return (NULL);
55 } while ((char)tolower((unsigned char)sc) != c);
56 } while (strncasecmp(s, find, len) != 0);
57 s--;
58 }
59 return ((char *)s);
60 }
61 DEF_WEAK(strcasestr);
62