stdlib/wctomb.c

   1 /* Copyright (C) 1991, 1992, 1995 Free Software Foundation, Inc.
   2 This file is part of the GNU C Library.
   3
   4 The GNU C Library is free software; you can redistribute it and/or
   5 modify it under the terms of the GNU Library General Public License as
   6 published by the Free Software Foundation; either version 2 of the
   7 License, or (at your option) any later version.
   8
   9 The GNU C Library is distributed in the hope that it will be useful,
  10 but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12 Library General Public License for more details.
  13
  14 You should have received a copy of the GNU Library General Public
  15 License along with the GNU C Library; see the file COPYING.LIB.  If
  16 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
  17 Cambridge, MA 02139, USA.  */
  18
  19 #include <ansidecl.h>
  20 #include "../locale/localeinfo.h"
  21 #include <stddef.h>
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24 #include <string.h>
  25 #include <ctype.h>
  26
  27
  28 extern long int _mb_shift;      /* Defined in mbtowc.c.  */
  29
  30 /* Convert WCHAR into its multibyte character representation,
  31    putting this in S and returning its length.  */
  32 int
  33 DEFUN(wctomb, (s, wchar), register char *s AND wchar_t wchar)
  34 {
  35 #if 0
  36   register CONST mb_char *mb;
  37
  38   if (_ctype_info->mbchar == NULL)
  39     mb = NULL;
  40   else
  41     mb = _ctype_info->mbchar->mb_chars;
  42 #endif
  43
  44   /* If S is NULL, just say if we're shifted or not.  */
  45   if (s == NULL)
  46     return _mb_shift != 0;
  47
  48   if (wchar == (wchar_t) '\0')
  49     {
  50       _mb_shift = 0;
  51       /* See ANSI 4.4.1.1, line 21.  */
  52       if (s != NULL)
  53         *s = '\0';
  54       return 1;
  55     }
  56   else /* if (mb == NULL) */
  57     {
  58       if ((wchar_t) (char) wchar == wchar && isascii ((char) wchar))
  59         {
  60           /* A normal ASCII character translates to itself.  */
  61           if (s != NULL)
  62             *s = (char) wchar;
  63           return 1;
  64         }
  65       return -1;
  66     }
  67
  68 #if 1
  69   return -1;
  70 #else
  71   mb += wchar + _mb_shift;
  72   if (mb->string == NULL || mb->len == 0)
  73     return -1;
  74   memcpy((PTR) s, (CONST PTR) mb->string, mb->len + 1);
  75   _mb_shift += mb->shift;
  76   return mb->len;
  77 #endif
  78 }