collcmp.c revision 18331 
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: collcmp.c,v 1.5 1996/08/14 19:47:02 ache Exp $
27 */
28
29#include <ctype.h>
30#include <string.h>
31#include <limits.h>
32#include <locale.h>
33
34/*
35 * Compare two characters converting collate information
36 * into ASCII-compatible range, it allows to handle
37 * "[a-z]"-type ranges with national characters.
38 */
39
40int collate_range_cmp (c1, c2)
41	int c1, c2;
42{
43	int as1, as2, al1, al2, ret;
44	static char s1[2], s2[2];
45
46	c1 &= UCHAR_MAX;
47	c2 &= UCHAR_MAX;
48	if (c1 == c2)
49		return (0);
50
51	as1 = isascii(c1);
52	as2 = isascii(c2);
53	al1 = isalpha(c1);
54	al2 = isalpha(c2);
55
56	if (as1 || as2 || al1 || al2) {
57		if ((as1 && as2) || (!al1 && !al2))
58			return (c1 - c2);
59		if (al1 && !al2) {
60			if (isupper(c1))
61				return ('A' - c2);
62			else
63				return ('a' - c2);
64		} else if (al2 && !al1) {
65			if (isupper(c2))
66				return (c1 - 'A');
67			else
68				return (c1 - 'a');
69		}
70	}
71
72	s1[0] = c1;
73	s2[0] = c2;
74	if ((ret = strcoll(s1, s2)) != 0)
75		return (ret);
76	return (c1 - c2);
77}
78