xref: /illumos-gate/usr/src/lib/libc/port/locale/strncasecmp.c (revision b819cea2f73f98c5662230cc9affc8cc84f77fcf)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2013 Garrett D'Amore <garrett@damore.org>
24  * Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
25  */
26 
27 /*	Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T	*/
28 /*	  All Rights Reserved  	*/
29 
30 /*
31  * Portions of this source code were derived from Berkeley 4.3 BSD
32  * under license from the Regents of the University of California.
33  */
34 
35 #include "lint.h"
36 #include <sys/types.h>
37 #include <strings.h>
38 #include <ctype.h>
39 #include <locale.h>
40 #include "lctype.h"
41 #include "localeimpl.h"
42 
43 int
44 strncasecmp_l(const char *s1, const char *s2, size_t n, locale_t loc)
45 {
46 	extern int ascii_strncasecmp(const char *s1, const char *s2, size_t n);
47 	const int *cm;
48 	const uchar_t *us1;
49 	const uchar_t *us2;
50 	const struct lc_ctype *lct = loc->ctype;
51 
52 	/*
53 	 * If we are in a locale that uses the ASCII character set
54 	 * (C or POSIX), use the fast ascii_strncasecmp() function.
55 	 */
56 	if (lct->lc_is_ascii)
57 		return (ascii_strncasecmp(s1, s2, n));
58 
59 	cm = lct->lc_trans_lower;
60 	us1 = (const uchar_t *)s1;
61 	us2 = (const uchar_t *)s2;
62 
63 	while (n != 0 && cm[*us1] == cm[*us2++]) {
64 		if (*us1++ == '\0')
65 			return (0);
66 		n--;
67 	}
68 	return (n == 0 ? 0 : cm[*us1] - cm[*(us2 - 1)]);
69 }
70 
71 int
72 strncasecmp(const char *s1, const char *s2, size_t n)
73 {
74 	return (strncasecmp_l(s1, s2, n, uselocale(NULL)));
75 }
76