1 /* $OpenBSD: strncasecmp.c,v 1.4 2004/08/07 00:38:33 deraadt Exp $ */ 2 3 /* 4 * Copyright (c) 1994 Christian E. Hopps 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by Christian E. Hopps. 18 * 4. The name of the author may not be used to endorse or promote products 19 * derived from this software without specific prior written permission 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 22 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 23 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 24 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 26 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 27 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 28 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 29 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 30 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 31 */ 32 #if defined(LIBC_SCCS) && !defined(lint) 33 static char *rcsid = "$Id: strncasecmp.c,v 1.4 2004/08/07 00:38:33 deraadt Exp $"; 34 #endif /* LIBC_SCCS and not lint */ 35 36 #if !defined(_KERNEL) && !defined(_STANDALONE) 37 #include <string.h> 38 #else 39 #include <lib/libkern/libkern.h> 40 #endif 41 42 int 43 strncasecmp(const char *s1, const char *s2, size_t n) 44 { 45 if (n == 0) 46 return 0; 47 48 do { 49 unsigned char c1 = (unsigned char) *s1++; 50 unsigned char c2 = (unsigned char) *s2++; 51 52 if (c1 != c2) { 53 if (c1 >= 'A' && c1 <= 'Z' && 54 c2 >= 'a' && c2 <= 'z') 55 c1 += 'a' - 'A'; 56 else if (c1 >= 'a' && c1 <= 'z' && 57 c2 >= 'A' && c2 <= 'Z') 58 c2 += 'a' - 'A'; 59 if (c1 != c2) 60 return c1 - c2; 61 } 62 if (c1 == 0) 63 break; 64 } while (--n != 0); 65 66 return 0; 67 } 68