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

   1 /*
   2 FUNCTION
   3         <<wcscmp>>---compare two wide-character strings
   4
   5 ANSI_SYNOPSIS
   6         #include <wchar.h>
   7         int wcscmp(const wchar_t *<[s1]>, *<[s2]>);
   8
   9 TRAD_SYNOPSIS
  10         int wcscmp(<[s1]>, <[s2]>
  11         const wchar_t *<[s1]>, <[s2]>;
  12
  13 DESCRIPTION
  14         The <<wcscmp>> function compares the wide-character string pointed to
  15         by <[s1]> to the wide-character string pointed to by <[s2]>.
  16
  17         The sign of a non-zero return value is determined by the sign of the
  18         difference between the values of the first pair of wide-character codes
  19         that differ in the objects being compared.
  20
  21 RETURNS
  22         Upon completion, <<wcscmp>> returns an integer greater than, equal to
  23         or less than 0, if the wide-character string pointed to by <[s1]> is
  24         greater than, equal to or less than the wide-character string pointed
  25         to by <[s2]> respectively.
  26
  27 PORTABILITY
  28 <<wcscmp>> is ISO/IEC 9899/AMD1:1995 (ISO C).
  29 No supporting OS subroutines are required.
  30 */
  31
  32 /*      $NetBSD$        */
  33
  34 /*-
  35  * Copyright (c) 1990, 1993
  36  *      The Regents of the University of California.  All rights reserved.
  37  *
  38  * This code is derived from software contributed to Berkeley by
  39  * Chris Torek.
  40  *
  41  * Redistribution and use in source and binary forms, with or without
  42  * modification, are permitted provided that the following conditions
  43  * are met:
  44  * 1. Redistributions of source code must retain the above copyright
  45  *    notice, this list of conditions and the following disclaimer.
  46  * 2. Redistributions in binary form must reproduce the above copyright
  47  *    notice, this list of conditions and the following disclaimer in the
  48  *    documentation and/or other materials provided with the distribution.
  49  * 3. Neither the name of the University nor the names of its contributors
  50  *    may be used to endorse or promote products derived from this software
  51  *    without specific prior written permission.
  52  *
  53  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  54  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  55  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  56  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  57  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  58  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  59  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  60  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  61  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  62  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  63  * SUCH DAMAGE.
  64  */
  65
  66 #include <_ansi.h>
  67 #include <wchar.h>
  68
  69 /*
  70  * Compare strings.
  71  */
  72 int
  73 _DEFUN (wcscmp, (s1, s2),
  74         _CONST wchar_t * s1 _AND
  75         _CONST wchar_t * s2)
  76 {
  77
  78   while (*s1 == *s2++)
  79     if (*s1++ == 0)
  80       return (0);
  81   return (*s1 - *--s2);
  82 }