stdlib/wcstombs.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 <ctype.h>
  22 #include <stddef.h>
  23 #include <stdio.h>
  24 #include <stdlib.h>
  25 #include <string.h>
  26
  27
  28 /* Convert the `wchar_t' string in PWCS to a multibyte character string
  29    in S, writing no more than N characters.  Return the number of bytes
  30    written, or (size_t) -1 if an invalid `wchar_t' was found.  */
  31 size_t
  32 DEFUN(wcstombs, (s, pwcs, n),
  33       register char *s AND register CONST wchar_t *pwcs AND register size_t n)
  34 {
  35 #if 0
  36   register CONST mb_char *mb;
  37   register int shift = 0;
  38 #endif
  39
  40   register size_t written = 0;
  41   register wchar_t w;
  42
  43   while ((w = *pwcs++) != (wchar_t) '\0')
  44     {
  45       if (isascii (w))
  46         {
  47           /* A normal character.  */
  48           *s++ = (unsigned char) w;
  49           --n;
  50           ++written;
  51         }
  52       else
  53         {
  54 #if 1
  55           written = (size_t) -1;
  56           break;
  57 #else
  58           mb = &_ctype_info->mbchar->mb_chars[w + shift];
  59           if (mb->string == NULL || mb->len == 0)
  60             {
  61               written = (size_t) -1;
  62               break;
  63             }
  64           else if (mb->len > n)
  65             break;
  66           else
  67             {
  68               memcpy ((PTR) s, (CONST PTR) mb->string, mb->len);
  69               s += mb->len;
  70               n -= mb->len;
  71               written += mb->len;
  72               shift += mb->shift;
  73             }
  74 #endif
  75         }
  76     }
  77
  78   /* Terminate the string if it has space.  */
  79   if (n > 0)
  80     *s = '\0';
  81
  82   /* Return the number of characters written (or maybe an error).  */
  83   return written;
  84 }