gl/mbtowc-impl.h

   1 /* Convert multibyte character to wide character.
   2    Copyright (C) 2011-2023 Free Software Foundation, Inc.
   3    Written by Bruno Haible <bruno@clisp.org>, 2011.
   4
   5    This file is free software: you can redistribute it and/or modify
   6    it under the terms of the GNU Lesser General Public License as
   7    published by the Free Software Foundation; either version 2.1 of the
   8    License, or (at your option) any later version.
   9
  10    This file 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
  13    GNU Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public License
  16    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  17
  18 /* We don't need a static internal state, because the encoding is not state
  19    dependent, and when mbrtowc returns (size_t)(-2). we throw the result
  20    away. */
  21
  22 int
  23 mbtowc (wchar_t *pwc, const char *s, size_t n)
  24 {
  25   if (s == NULL)
  26     return 0;
  27   else
  28     {
  29       mbstate_t state;
  30       wchar_t wc;
  31       size_t result;
  32
  33       memset (&state, 0, sizeof (mbstate_t));
  34       result = mbrtowc (&wc, s, n, &state);
  35       if (result == (size_t)-1 || result == (size_t)-2)
  36         {
  37           errno = EILSEQ;
  38           return -1;
  39         }
  40       if (pwc != NULL)
  41         *pwc = wc;
  42       return (wc == 0 ? 0 : result);
  43     }
  44 }