toolchain/gcc/newlib/libc/string/wmemcmp.c

   1 /*
   2 FUNCTION
   3         <<wmemcmp>>---compare wide-characters in memory
   4
   5 ANSI_SYNOPSIS
   6         #include <wchar.h>
   7         int wmemcmp(const wchar_t *<[s1]>, const wchar_t *<[s2]>, size_t <[n]>);
   8
   9 TRAD_SYNOPSIS
  10         int wmemcmp(<[s1]>, <[s2]>, <[n]>
  11         const wchar_t *<[s1]>;
  12         const wchar_t *<[s2]>;
  13         size_t <[n]>;
  14
  15 DESCRIPTION
  16         The <<wmemcmp>> function compares the first <[n]> wide-characters of the
  17         object pointed to by <[s1]> to the first <[n]> wide-characters of the
  18         object pointed to by <[s2]>. This function is not affected by locale
  19         and all wchar_t values are treated identically. The null wide-character
  20         and wchar_t values not corresponding to valid characters are not treated
  21         specially.
  22
  23         If <[n]> is zero, <[s1]> and <[s2]> must be a valid pointers and the
  24         function behaves as if the two objects compare equal.
  25
  26 RETURNS
  27         The <<wmemcmp>> function returns an integer greater than, equal to,
  28         or less than zero, accordingly as the object pointed to by <[s1]> is
  29         greater than, equal to, or less than the object pointed to by <[s2]>.
  30
  31 PORTABILITY
  32 <<wmemcmp>> is ISO/IEC 9899/AMD1:1995 (ISO C).
  33 No supporting OS subroutines are required.
  34 */
  35
  36 /*      $NetBSD: wmemcmp.c,v 1.1 2000/12/23 23:14:37 itojun Exp $       */
  37
  38 /*-
  39  * Copyright (c)1999 Citrus Project,
  40  * All rights reserved.
  41  *
  42  * Redistribution and use in source and binary forms, with or without
  43  * modification, are permitted provided that the following conditions
  44  * are met:
  45  * 1. Redistributions of source code must retain the above copyright
  46  *    notice, this list of conditions and the following disclaimer.
  47  * 2. Redistributions in binary form must reproduce the above copyright
  48  *    notice, this list of conditions and the following disclaimer in the
  49  *    documentation and/or other materials provided with the distribution.
  50  *
  51  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  52  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  53  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  54  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  55  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  56  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  57  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  58  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  59  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  60  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  61  * SUCH DAMAGE.
  62  *
  63  *      citrus Id: wmemcmp.c,v 1.2 2000/12/20 14:08:31 itojun Exp
  64  */
  65
  66 #include <_ansi.h>
  67 #include <wchar.h>
  68
  69 int
  70 _DEFUN (wmemcmp, (s1, s2, n),
  71         _CONST wchar_t * s1 _AND
  72         _CONST wchar_t * s2 _AND
  73         size_t n)
  74 {
  75   size_t i;
  76
  77   for (i = 0; i < n; i++)
  78     {
  79       if (*s1 != *s2)
  80         {
  81           /* wchar might be unsigned */
  82           return *s1 > *s2 ? 1 : -1;
  83         }
  84       s1++;
  85       s2++;
  86     }
  87   return 0;
  88 }