source: kBuild/trunk/src/grep/lib/wctomb-impl.h

/* Convert wide character to multibyte character.
   Copyright (C) 2011-2021 Free Software Foundation, Inc.
   Written by Bruno Haible <[email protected]>, 2011.

   This file is free software: you can redistribute it and/or modify
   it under the terms of the GNU Lesser General Public License as
   published by the Free Software Foundation; either version 2.1 of the
   License, or (at your option) any later version.

   This file is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public License
   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */

int
wctomb (char *s, wchar_t wc)
{
  if (s == NULL)
    return 0;
  else
    {
      mbstate_t state;
      size_t result;

      memset (&state, 0, sizeof (mbstate_t));
      result = wcrtomb (s, wc, &state);
      if (result == (size_t)-1)
        return -1;
      return result;
    }
}