src/stdlib/mblen.c

   1 /*
   2  * mblen: determine the length of a multibyte character.
   3  * Copyright (C) 2009 Nick Bowler.
   4  *
   5  * License LGPLv3+: GNU LGPL version 3 or later.  See COPYING.LIB for terms.
   6  * See <http://www.gnu.org/licenses/lgpl.html> if you did not receive a copy.
   7  * This is free software: you are free to change and redistribute it.
   8  * There is NO WARRANTY, to the extent permitted by law.
   9  */
  10 #include <stdlib.h>
  11 #include <wchar.h>
  12 #include <cstd/locale.h>
  13
  14 int (mblen)(const char *s, size_t n)
  15 {
  16         wint_t wc;
  17         char *end;
  18
  19         wc = __cstd_conv->decode(s, &end, n);
  20         if (wc == WEOF)
  21                 return -1;
  22         if (wc == 0)
  23                 return 0;
  24         return end - s;
  25 }