1 /* $NetBSD: strcasestr.c,v 1.1.1.1 2014/06/13 01:48:21 christos 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 36 #if defined(LIBC_SCCS) && !defined(lint) 37 __RCSID("NetBSD: strcasestr.c,v 1.3 2005/11/29 03:12:00 christos Exp "); 38 __RCSID("NetBSD: strncasecmp.c,v 1.2 2007/06/04 18:19:27 christos Exp "); 39 #endif /* LIBC_SCCS and not lint */ 40 41 #include "file.h" 42 43 #include <assert.h> 44 #include <ctype.h> 45 #include <string.h> 46 47 static int 48 _strncasecmp(const char *s1, const char *s2, size_t n) 49 { 50 if (n != 0) { 51 const unsigned char *us1 = (const unsigned char *)s1, 52 *us2 = (const unsigned char *)s2; 53 54 do { 55 if (tolower(*us1) != tolower(*us2++)) 56 return tolower(*us1) - tolower(*--us2); 57 if (*us1++ == '\0') 58 break; 59 } while (--n != 0); 60 } 61 return 0; 62 } 63 64 /* 65 * Find the first occurrence of find in s, ignore case. 66 */ 67 char * 68 strcasestr(const char *s, const char *find) 69 { 70 char c, sc; 71 size_t len; 72 73 if ((c = *find++) != 0) { 74 c = tolower((unsigned char)c); 75 len = strlen(find); 76 do { 77 do { 78 if ((sc = *s++) == 0) 79 return (NULL); 80 } while ((char)tolower((unsigned char)sc) != c); 81 } while (_strncasecmp(s, find, len) != 0); 82 s--; 83 } 84 return (char *)(intptr_t)(s); 85 } 86