1 /* $Id: compat_strcasestr.c,v 1.5 2020/06/15 01:37:15 schwarze Exp $ */ 2 /* $NetBSD: strcasestr.c,v 1.3 2005/11/29 03:12:00 christos 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 #include "config.h" 36 37 #include <sys/types.h> 38 #include <ctype.h> 39 #include <string.h> 40 41 #define __UNCONST(a) ((void *)(unsigned long)(const void *)(a)) 42 43 /* 44 * Find the first occurrence of find in s, ignore case. 45 */ 46 char * 47 strcasestr(const char *s, const char *find) 48 { 49 char c, sc; 50 size_t len; 51 52 if ((c = *find++) != 0) { 53 c = tolower((unsigned char)c); 54 len = strlen(find); 55 do { 56 do { 57 if ((sc = *s++) == 0) 58 return (NULL); 59 } while ((char)tolower((unsigned char)sc) != c); 60 } while (strncasecmp(s, find, len) != 0); 61 s--; 62 } 63 return __UNCONST(s); 64 } 65