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 */
42char *
43strcasestr(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}
61DEF_WEAK(strcasestr);
62