strcasecmp.c revision 330897 
1/*-
2 * SPDX-License-Identifier: BSD-4-Clause
3 *
4 * Copyright (c) 1987, 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. 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#include <sys/cdefs.h>
37__FBSDID("$FreeBSD: stable/11/sys/libkern/strcasecmp.c 330897 2018-03-14 03:19:51Z eadler $");
38
39#include <sys/param.h>
40#include <sys/ctype.h>
41#include <sys/libkern.h>
42
43int
44strcasecmp(const char *s1, const char *s2)
45{
46	const u_char *us1 = (const u_char *)s1, *us2 = (const u_char *)s2;
47
48	while (tolower(*us1) == tolower(*us2)) {
49		if (*us1++ == '\0')
50			return (0);
51		us2++;
52	}
53	return (tolower(*us1) - tolower(*us2));
54}
55
56int
57strncasecmp(const char *s1, const char *s2, size_t n)
58{
59
60	if (n != 0) {
61		const u_char *us1 = (const u_char *)s1;
62		const u_char *us2 = (const u_char *)s2;
63
64		do {
65			if (tolower(*us1) != tolower(*us2))
66				return (tolower(*us1) - tolower(*us2));
67			if (*us1++ == '\0')
68				break;
69			us2++;
70		} while (--n != 0);
71	}
72	return (0);
73}
74