xref: /freebsd/lib/libc/locale/collcmp.c (revision df7f5d4de4592a8948a25ce01e5bddfbb7ce39dc)
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  * $Id$
27  */
28 
29 #define ASCII_COMPATIBLE_COLLATE        /* see usr.bin/colldef/data */
30 
31 #include <string.h>
32 #include "collate.h"
33 #ifndef ASCII_COMPATIBLE_COLLATE
34 #include <ctype.h>
35 #endif
36 
37 /* Temporary backward compatibility */
38 
39 int collate_range_cmp (c1, c2)
40 	int c1, c2;
41 {
42 	return __collate_range_cmp(c1, c2);
43 }
44 
45 
46 /*
47  * Compare two characters converting collate information
48  * into ASCII-compatible range, it allows to handle
49  * "[a-z]"-type ranges with national characters.
50  */
51 
52 int __collate_range_cmp (c1, c2)
53 	int c1, c2;
54 {
55 	static char s1[2], s2[2];
56 	int ret;
57 #ifndef ASCII_COMPATIBLE_COLLATE
58 	int as1, as2, al1, al2;
59 #endif
60 
61 	c1 &= UCHAR_MAX;
62 	c2 &= UCHAR_MAX;
63 	if (c1 == c2)
64 		return (0);
65 
66 #ifndef ASCII_COMPATIBLE_COLLATE
67 	as1 = isascii(c1);
68 	as2 = isascii(c2);
69 	al1 = isalpha(c1);
70 	al2 = isalpha(c2);
71 
72 	if (as1 || as2 || al1 || al2) {
73 		if ((as1 && as2) || (!al1 && !al2))
74 			return (c1 - c2);
75 		if (al1 && !al2) {
76 			if (isupper(c1))
77 				return ('A' - c2);
78 			else
79 				return ('a' - c2);
80 		} else if (al2 && !al1) {
81 			if (isupper(c2))
82 				return (c1 - 'A');
83 			else
84 				return (c1 - 'a');
85 		}
86 	}
87 #endif
88 	s1[0] = c1;
89 	s2[0] = c2;
90 	if ((ret = strcoll(s1, s2)) != 0)
91 		return (ret);
92 	return (c1 - c2);
93 }
94