/*
Copyright (c) 1994 Cygnus Support.
All rights reserved.

Redistribution and use in source and binary forms are permitted
provided that the above copyright notice and this paragraph are
duplicated in all such forms and that any documentation,
and/or other materials related to such
distribution and use acknowledge that the software was developed
at Cygnus Support, Inc.  Cygnus Support, Inc. may not be used to
endorse or promote products derived from this software without
specific prior written permission.
THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */
/*
FUNCTION
        <<strncasecmp>>---case-insensitive character string compare

INDEX
        strncasecmp

SYNOPSIS
        #include <strings.h>
        int strncasecmp(const char *<[a]>, const char * <[b]>, size_t <[length]>);

DESCRIPTION
        <<strncasecmp>> compares up to <[length]> characters
        from the string at <[a]> to the string at <[b]> in a
        case-insensitive manner.

RETURNS

        If <<*<[a]>>> sorts lexicographically after <<*<[b]>>> (after
        both are converted to lowercase), <<strncasecmp>> returns a
        number greater than zero.  If the two strings are equivalent,
        <<strncasecmp>> returns zero.  If <<*<[a]>>> sorts
        lexicographically before <<*<[b]>>>, <<strncasecmp>> returns a
        number less than zero.

PORTABILITY
<<strncasecmp>> is in the Berkeley Software Distribution.

<<strncasecmp>> requires no supporting OS subroutines. It uses
tolower() from elsewhere in this library.

QUICKREF
        strncasecmp
*/

#include <strings.h>
#include <ctype.h>

int
strncasecmp(const char *s1, const char *s2, size_t n)
{
    int d = 0;
    for (; n != 0; n--) {
        const int c1 = tolower(*(unsigned char *)s1++);
        const int c2 = tolower(*(unsigned char *)s2++);
        if (((d = c1 - c2) != 0) || (c2 == '\0'))
            break;
    }
    return d;
}
