xref: /freebsd-11.0-release/lib/libc/locale/collcmp.c

/*
 * Copyright (C) 1996 by Andrey A. Chernov, Moscow, Russia.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <ctype.h>
#include <string.h>
#include <limits.h>
#include <locale.h>

int collate_range_cmp (c1, c2)
	int c1, c2;
{
	int as1, as2, al1, al2;
	static char s1[2], s2[2];

	c1 &= UCHAR_MAX;
	c2 &= UCHAR_MAX;
	if (c1 == c2)
		return (0);

	as1 = isascii(c1);
	as2 = isascii(c2);
	al1 = isalpha(c1);
	al2 = isalpha(c2);

	if (as1 || as2 || al1 || al2) {
		if ((as1 && as2) || (!al1 && !al2))
			return (c1 - c2);
		if (al1 && !al2) {
			if (isupper(c1))
				return ('A' - c2);
			else
				return ('a' - c2);
		} else if (al2 && !al1) {
			if (isupper(c2))
				return (c1 - 'A');
			else
				return (c1 - 'a');
		}
	}

	s1[0] = c1;
	s2[0] = c2;
	return strcoll(s1, s2);
}