wcsmbs/wcsnlen.c

   1 /* Copyright (C) 1998-2017 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1998.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <wchar.h>
  20
  21 #ifdef WCSNLEN
  22 # define __wcsnlen WCSNLEN
  23 #endif
  24
  25 /* Return length of string S at most maxlen.  */
  26 size_t
  27 __wcsnlen (const wchar_t *s, size_t maxlen)
  28 {
  29   size_t len = 0;
  30
  31   while (maxlen > 0 && s[len] != L'\0')
  32     {
  33       ++len;
  34       if (--maxlen == 0 || s[len] == L'\0')
  35         return len;
  36       ++len;
  37       if (--maxlen == 0 || s[len] == L'\0')
  38         return len;
  39       ++len;
  40       if (--maxlen == 0 || s[len] == L'\0')
  41         return len;
  42       ++len;
  43       --maxlen;
  44     }
  45
  46   return len;
  47 }
  48 #ifndef WCSNLEN
  49 weak_alias (__wcsnlen, wcsnlen)
  50 #endif