1 /* $NetBSD: strcasestr.c,v 1.1.1.2 2015/01/02 20:34:27 christos Exp $ */ 2 3 /* NetBSD: strcasestr.c,v 1.3 2005/11/29 03:12:00 christos Exp */ 4 5 /*- 6 * Copyright (c) 1990, 1993 7 * The Regents of the University of California. All rights reserved. 8 * 9 * This code is derived from software contributed to Berkeley by 10 * Chris Torek. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 */ 36 37 #if defined(LIBC_SCCS) && !defined(lint) 38 __RCSID("NetBSD: strcasestr.c,v 1.3 2005/11/29 03:12:00 christos Exp "); 39 __RCSID("NetBSD: strncasecmp.c,v 1.2 2007/06/04 18:19:27 christos Exp "); 40 #endif /* LIBC_SCCS and not lint */ 41 42 #include "file.h" 43 44 #include <assert.h> 45 #include <ctype.h> 46 #include <string.h> 47 48 static int 49 _strncasecmp(const char *s1, const char *s2, size_t n) 50 { 51 if (n != 0) { 52 const unsigned char *us1 = (const unsigned char *)s1, 53 *us2 = (const unsigned char *)s2; 54 55 do { 56 if (tolower(*us1) != tolower(*us2++)) 57 return tolower(*us1) - tolower(*--us2); 58 if (*us1++ == '\0') 59 break; 60 } while (--n != 0); 61 } 62 return 0; 63 } 64 65 /* 66 * Find the first occurrence of find in s, ignore case. 67 */ 68 char * 69 strcasestr(const char *s, const char *find) 70 { 71 char c, sc; 72 size_t len; 73 74 if ((c = *find++) != 0) { 75 c = tolower((unsigned char)c); 76 len = strlen(find); 77 do { 78 do { 79 if ((sc = *s++) == 0) 80 return (NULL); 81 } while ((char)tolower((unsigned char)sc) != c); 82 } while (_strncasecmp(s, find, len) != 0); 83 s--; 84 } 85 return (char *)(intptr_t)(s); 86 } 87