1 /* $OpenBSD: strncmp.c,v 1.6 1998/06/27 01:21:10 mickey 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. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. 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 /*static char *sccsid = "from: @(#)strncmp.c 5.6 (Berkeley) 1/26/91";*/ 38 static char *rcsid = "$OpenBSD: strncmp.c,v 1.6 1998/06/27 01:21:10 mickey Exp $"; 39 #endif /* LIBC_SCCS and not lint */ 40 41 #include <sys/types.h> 42 #if !defined(_KERNEL) && !defined(_STANDALONE) 43 #include <string.h> 44 #else 45 #include <lib/libkern/libkern.h> 46 #endif 47 48 int 49 strncmp(s1, s2, n) 50 register const char *s1, *s2; 51 register size_t n; 52 { 53 54 if (n == 0) 55 return (0); 56 do { 57 if (*s1 != *s2++) 58 return (*(const u_char *)s1 - *(const u_char *)--s2); 59 if (*s1++ == 0) 60 break; 61 } while (--n != 0); 62 return (0); 63 } 64