collcmp.c revision 17576 
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 <ctype.h>
28#include <string.h>
29#include <limits.h>
30#include <locale.h>
31
32int collate_range_cmp (c1, c2)
33	int c1, c2;
34{
35	int as1, as2, al1, al2;
36	static char s1[2], s2[2];
37
38	c1 &= UCHAR_MAX;
39	c2 &= UCHAR_MAX;
40	if (c1 == c2)
41		return (0);
42
43	as1 = isascii(c1);
44	as2 = isascii(c2);
45	al1 = isalpha(c1);
46	al2 = isalpha(c2);
47
48	if (as1 || as2 || al1 || al2) {
49		if ((as1 && as2) || (!al1 && !al2))
50			return (c1 - c2);
51		if (al1 && !al2) {
52			if (isupper(c1))
53				return ('A' - c2);
54			else
55				return ('a' - c2);
56		} else if (al2 && !al1) {
57			if (isupper(c2))
58				return (c1 - 'A');
59			else
60				return (c1 - 'a');
61		}
62	}
63
64	s1[0] = c1;
65	s2[0] = c2;
66	return strcoll(s1, s2);
67}
68