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

   1 /*
   2 FUNCTION
   3         <<wcsnlen>>---get fixed-size wide character string length
   4
   5 INDEX
   6         wcsnlen
   7
   8 ANSI_SYNOPSIS
   9         #include <wchar.h>
  10         size_t wcsnlen(const wchar_t *<[s]>, size_t <[maxlen]>);
  11
  12 TRAD_SYNOPSIS
  13         #include <wchar.h>
  14         size_t wcsnlen(<[s]>, <[maxlen]>)
  15         wchar_t *<[s]>;
  16         size_t <[maxlen]>;
  17
  18 DESCRIPTION
  19         The <<wcsnlen>> function computes the number of wide character codes
  20         in the wide character string pointed to by <[s]> not including the
  21         terminating L'\0' wide character but at most <[maxlen]> wide
  22         characters.
  23
  24 RETURNS
  25         <<wcsnlen>> returns the length of <[s]> if it is less then <[maxlen]>,
  26         or <[maxlen]> if there is no L'\0' wide character in first <[maxlen]>
  27         characters.
  28
  29 PORTABILITY
  30 <<wcsnlen>> is GNU extension..
  31 <<wcsnlen>> requires no supporting OS subroutines.
  32 */
  33
  34 /*
  35  * Copyright (c) 2003, Artem B. Bityuckiy (dedekind@mail.ru).
  36  *
  37  * Redistribution and use in source and binary forms, with or without
  38  * modification, are permitted provided that the above copyright notice,
  39  * this condition statement, and the following disclaimer are retained
  40  * in any redistributions of the source code.
  41  *
  42  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  43  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  44  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  45  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  46  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  47  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  48  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  49  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  50  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  51  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  52  * SUCH DAMAGE.
  53  */
  54
  55 #include <_ansi.h>
  56 #include <sys/types.h>
  57 #include <wchar.h>
  58
  59 size_t
  60 _DEFUN(wcsnlen, (s, maxlen),
  61                  _CONST wchar_t *s _AND
  62                  size_t maxlen)
  63 {
  64   _CONST wchar_t *p;
  65
  66   p = s;
  67   while (*p && maxlen-- > 0)
  68     p++;
  69
  70   return (size_t)(p - s);
  71 }
  72
  73
  74