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

   1 /*
   2 FUNCTION
   3         <<wcsrchr>>---wide-character string scanning operation
   4
   5 ANSI_SYNOPSIS
   6         #include <wchar.h>
   7         wchar_t *wcsrchr(const wchar_t *<[s]>, wchar_t <[c]>);
   8
   9 TRAD_SYNOPSIS
  10         #include <wchar.h>
  11         wchar_t *wcsrchr(<[s]>, <[c]>
  12         const wchar_t *<[s]>;
  13         wchar_t <[c]>;
  14
  15 DESCRIPTION
  16         The <<wcsrchr>> function locates the last occurrence of <[c]> in the
  17         wide-character string pointed to by <[s]>. The value of <[c]> must be a
  18         character representable as a type wchar_t and must be a wide-character
  19         code corresponding to a valid character in the current locale.
  20         The terminating null wide-character code is considered to be part of
  21         the wide-character string.
  22
  23 RETURNS
  24         Upon successful completion, <<wcsrchr>> returns a pointer to the
  25         wide-character code or a null pointer if <[c]> does not occur in the
  26         wide-character string.
  27
  28 PORTABILITY
  29 <<wcsrchr>> is ISO/IEC 9899/AMD1:1995 (ISO C).
  30 No supporting OS subroutines are required.
  31 */
  32
  33 /*      $NetBSD: wcsrchr.c,v 1.1 2000/12/23 23:14:37 itojun Exp $       */
  34
  35 /*-
  36  * Copyright (c)1999 Citrus Project,
  37  * All rights reserved.
  38  *
  39  * Redistribution and use in source and binary forms, with or without
  40  * modification, are permitted provided that the following conditions
  41  * are met:
  42  * 1. Redistributions of source code must retain the above copyright
  43  *    notice, this list of conditions and the following disclaimer.
  44  * 2. Redistributions in binary form must reproduce the above copyright
  45  *    notice, this list of conditions and the following disclaimer in the
  46  *    documentation and/or other materials provided with the distribution.
  47  *
  48  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  49  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  50  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  51  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  52  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  53  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  54  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  55  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  56  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  57  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  58  * SUCH DAMAGE.
  59  *
  60  *      citrus Id: wcsrchr.c,v 1.2 2000/12/21 05:07:25 itojun Exp
  61  */
  62
  63 #include <_ansi.h>
  64 #include <stddef.h>
  65 #include <wchar.h>
  66
  67 wchar_t *
  68 _DEFUN (wcsrchr, (s, c),
  69         _CONST wchar_t * s _AND
  70         wchar_t c)
  71 {
  72   _CONST wchar_t *p;
  73
  74   p = s;
  75   while (*p)
  76     p++;
  77   while (s <= p)
  78     {
  79       if (*p == c)
  80         {
  81           /* LINTED interface specification */
  82           return (wchar_t *) p;
  83         }
  84       p--;
  85     }
  86   return NULL;
  87 }