/*
 * Copyright (c) 2001 Sendmail, Inc. and its suppliers.
 *      All rights reserved.
 *
 * By using this file, you agree to the terms and conditions set
 * forth in the LICENSE file which can be found at the top level of
 * the sendmail distribution.
 *
 */

#include <sm/gen.h>
SM_RCSID("@(#)$Id: strrevcmp.c,v 1.2 2001/08/27 22:21:51 gshapiro Exp $")

#include <sm/config.h>
#include <sm/string.h>
#include <string.h>

/* strcasecmp.c */
extern const unsigned char charmap[];

/*
**  SM_STRREVCASECMP -- compare two strings starting at the end (ignore case)
**
**      Parameters:
**              s1 -- first string.
**              s2 -- second string.
**
**      Returns:
**              strcasecmp(reverse(s1), reverse(s2))
*/

int
sm_strrevcasecmp(s1, s2)
        const char *s1, *s2;
{
        register int i1, i2;

        i1 = strlen(s1) - 1;
        i2 = strlen(s2) - 1;
        while (i1 >= 0 && i2 >= 0 &&
               charmap[(unsigned char) s1[i1]] ==
               charmap[(unsigned char) s2[i2]])
        {
                --i1;
                --i2;
        }
        if (i1 < 0)
        {
                if (i2 < 0)
                        return 0;
                else
                        return -1;
        }
        else
        {
                if (i2 < 0)
                        return 1;
                else
                        return (charmap[(unsigned char) s1[i1]] -
                                charmap[(unsigned char) s2[i2]]);
        }
}
/*
**  SM_STRREVCMP -- compare two strings starting at the end
**
**      Parameters:
**              s1 -- first string.
**              s2 -- second string.
**
**      Returns:
**              strcmp(reverse(s1), reverse(s2))
*/

int
sm_strrevcmp(s1, s2)
        const char *s1, *s2;
{
        register int i1, i2;

        i1 = strlen(s1) - 1;
        i2 = strlen(s2) - 1;
        while (i1 >= 0 && i2 >= 0 && s1[i1] == s2[i2])
        {
                --i1;
                --i2;
        }
        if (i1 < 0)
        {
                if (i2 < 0)
                        return 0;
                else
                        return -1;
        }
        else
        {
                if (i2 < 0)
                        return 1;
                else
                        return s1[i1] - s2[i2];
        }
}