1 /* $OpenBSD: strncmp.c,v 1.7 2003/06/02 23:28:08 millert Exp $ */ 2 3 /* 4 * Copyright (c) 1989 The Regents of the University of California. 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. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 #if defined(LIBC_SCCS) && !defined(lint) 33 /*static char *sccsid = "from: @(#)strncmp.c 5.6 (Berkeley) 1/26/91";*/ 34 static char *rcsid = "$OpenBSD: strncmp.c,v 1.7 2003/06/02 23:28:08 millert Exp $"; 35 #endif /* LIBC_SCCS and not lint */ 36 37 #include <sys/types.h> 38 #if !defined(_KERNEL) && !defined(_STANDALONE) 39 #include <string.h> 40 #else 41 #include <lib/libkern/libkern.h> 42 #endif 43 44 int 45 strncmp(s1, s2, n) 46 register const char *s1, *s2; 47 register size_t n; 48 { 49 50 if (n == 0) 51 return (0); 52 do { 53 if (*s1 != *s2++) 54 return (*(const u_char *)s1 - *(const u_char *)--s2); 55 if (*s1++ == 0) 56 break; 57 } while (--n != 0); 58 return (0); 59 } 60