1/* $NetBSD: strncmp.c,v 1.3 2018/02/04 20:22:17 mrg Exp $ */
2
3/*
4 * Copyright (c) 1989, 1993
5 * The Regents of the University of California. 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#include <sys/cdefs.h>
33#if defined(LIBC_SCCS) && !defined(lint)
34#if 0
35static char sccsid[] = "@(#)strncmp.c 8.1 (Berkeley) 6/4/93";
36#else
37__RCSID("$NetBSD: strncmp.c,v 1.3 2018/02/04 20:22:17 mrg Exp $");
38#endif
39#endif /* LIBC_SCCS and not lint */
40
41#if !defined(_KERNEL) && !defined(_STANDALONE)
42#include <assert.h>
43#include <string.h>
44#else
45#include <lib/libkern/libkern.h>
46#endif
47
48int
49strncmp(const char *s1, const char *s2, size_t n)
50{
51
52 if (n == 0)
53 return (0);
54 do {
55 if (*s1 != *s2++)
56 return (*(const unsigned char *)s1 -
57 *(const unsigned char *)--s2);
58 if (*s1++ == 0)
59 break;
60 } while (--n != 0);
61 return (0);
62}
63