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 (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
24 */
25
26 /* Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T */
27 /* All Rights Reserved */
28
29 /*
30 * Portions of this source code were derived from Berkeley 4.3 BSD
31 * under license from the Regents of the University of California.
32 */
33
34 #include "lint.h"
35 #include <sys/types.h>
36 #include <strings.h>
37
38 /*
39 * This array is designed for mapping upper and lower case letter
40 * together for a case independent comparison. The mappings are
41 * based upon ascii character sequences.
42 */
43
44 extern const char strcase_charmap[];
45
46 int
ascii_strncasecmp(const char * s1,const char * s2,size_t n)47 ascii_strncasecmp(const char *s1, const char *s2, size_t n)
48 {
49 const unsigned char *cm = (const unsigned char *)strcase_charmap;
50 const unsigned char *us1 = (const unsigned char *)s1;
51 const unsigned char *us2 = (const unsigned char *)s2;
52
53 while (n != 0 && cm[*us1] == cm[*us2++]) {
54 if (*us1++ == '\0')
55 return (0);
56 n--;
57 }
58 return (n == 0 ? 0 : cm[*us1] - cm[*(us2 - 1)]);
59 }
60