newlib-cygwin/newlib/libc/string/wmemcmp.c

89 lines
2.9 KiB
C

/*
FUNCTION
<<wmemcmp>>---compare wide-characters in memory
ANSI_SYNOPSIS
#include <wchar.h>
int wmemcmp(const wchar_t *<[s1]>, const wchar_t *<[s2]>, size_t <[n]>);
TRAD_SYNOPSIS
int wmemcmp(<[s1]>, <[s2]>, <[n]>
const wchar_t *<[s1]>;
const wchar_t *<[s2]>;
size_t <[n]>;
DESCRIPTION
The <<wmemcmp>> function compares the first <[n]> wide-characters of the
object pointed to by <[s1]> to the first <[n]> wide-characters of the
object pointed to by <[s2]>. This function is not affected by locale
and all wchar_t values are treated identically. The null wide-character
and wchar_t values not corresponding to valid characters are not treated
specially.
If <[n]> is zero, <[s1]> and <[s2]> must be a valid pointers and the
function behaves as if the two objects compare equal.
RETURNS
The <<wmemcmp>> function returns an integer greater than, equal to,
or less than zero, accordingly as the object pointed to by <[s1]> is
greater than, equal to, or less than the object pointed to by <[s2]>.
PORTABILITY
<<wmemcmp>> is ISO/IEC 9899/AMD1:1995 (ISO C).
No supporting OS subroutines are required.
*/
/* $NetBSD: wmemcmp.c,v 1.1 2000/12/23 23:14:37 itojun Exp $ */
/*-
* Copyright (c)1999 Citrus Project,
* 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 AND CONTRIBUTORS ``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 AUTHOR 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.
*
* citrus Id: wmemcmp.c,v 1.2 2000/12/20 14:08:31 itojun Exp
*/
#include <_ansi.h>
#include <wchar.h>
int
_DEFUN (wmemcmp, (s1, s2, n),
_CONST wchar_t * s1 _AND
_CONST wchar_t * s2 _AND
size_t n)
{
size_t i;
for (i = 0; i < n; i++)
{
if (*s1 != *s2)
{
/* wchar might be unsigned */
return *s1 > *s2 ? 1 : -1;
}
s1++;
s2++;
}
return 0;
}