1 /* $NetBSD: strcasestr.c,v 1.3 2005/11/29 03:12:00 christos Exp $ */ 2 3 /*- 4 * Copyright (c) 1990, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Chris Torek. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 35 #include <sys/cdefs.h> 36 #if defined(LIBC_SCCS) && !defined(lint) 37 __RCSID("$NetBSD: strcasestr.c,v 1.3 2005/11/29 03:12:00 christos Exp $"); 38 #endif /* LIBC_SCCS and not lint */ 39 40 #include "namespace.h" 41 #include <assert.h> 42 #include <ctype.h> 43 #include <string.h> 44 45 /* 46 * Find the first occurrence of find in s, ignore case. 47 */ 48 char * 49 strcasestr(const char *s, const char *find) 50 { 51 char c, sc; 52 size_t len; 53 54 _DIAGASSERT(s != NULL); 55 _DIAGASSERT(find != NULL); 56 57 if ((c = *find++) != 0) { 58 c = tolower((unsigned char)c); 59 len = strlen(find); 60 do { 61 do { 62 if ((sc = *s++) == 0) 63 return (NULL); 64 } while ((char)tolower((unsigned char)sc) != c); 65 } while (strncasecmp(s, find, len) != 0); 66 s--; 67 } 68 return __UNCONST(s); 69 } 70
