xref: /freebsd/lib/libc/locale/collcmp.c (revision ebbd4fa8c8427d3dd847ba33c45c996e0500e6ff)
1 /*
2  * Copyright (C) 1996 by Andrey A. Chernov, Moscow, Russia.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #define ASCII_COMPATIBLE_COLLATE        /* see share/colldef */
31 
32 #include <string.h>
33 #include "collate.h"
34 #ifndef ASCII_COMPATIBLE_COLLATE
35 #include <ctype.h>
36 #endif
37 
38 /*
39  * Compare two characters converting collate information
40  * into ASCII-compatible range, it allows to handle
41  * "[a-z]"-type ranges with national characters.
42  */
43 
44 int __collate_range_cmp (c1, c2)
45 	int c1, c2;
46 {
47 	static char s1[2], s2[2];
48 	int ret;
49 #ifndef ASCII_COMPATIBLE_COLLATE
50 	int as1, as2, al1, al2;
51 #endif
52 
53 	c1 &= UCHAR_MAX;
54 	c2 &= UCHAR_MAX;
55 	if (c1 == c2)
56 		return (0);
57 
58 #ifndef ASCII_COMPATIBLE_COLLATE
59 	as1 = isascii(c1);
60 	as2 = isascii(c2);
61 	al1 = isalpha(c1);
62 	al2 = isalpha(c2);
63 
64 	if (as1 || as2 || al1 || al2) {
65 		if ((as1 && as2) || (!al1 && !al2))
66 			return (c1 - c2);
67 		if (al1 && !al2) {
68 			if (isupper(c1))
69 				return ('A' - c2);
70 			else
71 				return ('a' - c2);
72 		} else if (al2 && !al1) {
73 			if (isupper(c2))
74 				return (c1 - 'A');
75 			else
76 				return (c1 - 'a');
77 		}
78 	}
79 #endif
80 	s1[0] = c1;
81 	s2[0] = c2;
82 	if ((ret = strcoll(s1, s2)) != 0)
83 		return (ret);
84 	return (c1 - c2);
85 }
86