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