wcsmbs/btowc.c

   1 /* Copyright (C) 1996, 1997, 1998 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Ulrich Drepper, <drepper@gnu.ai.mit.edu>
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Library General Public License as
   7    published by the Free Software Foundation; either version 2 of the
   8    License, or (at your option) any later version.
   9
  10    The GNU C Library 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 GNU
  13    Library General Public License for more details.
  14
  15    You should have received a copy of the GNU Library General Public
  16    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  17    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  18    Boston, MA 02111-1307, USA.  */
  19
  20 #include <gconv.h>
  21 #include <stdio.h>
  22 #include <string.h>
  23 #include <wchar.h>
  24 #include <wcsmbsload.h>
  25
  26
  27 wint_t
  28 __btowc (c)
  29      int c;
  30 {
  31   char buf[sizeof (wchar_t)];
  32   struct gconv_step_data data;
  33   char inbuf[1];
  34   const char *inptr = inbuf;
  35   size_t dummy;
  36   int status;
  37
  38   /* If the parameter does not fit into one byte or it is the EOF value
  39      we can give the answer now.  */
  40   if (c < -128 || c > 127 || c == EOF)
  41     return WEOF;
  42
  43   /* Tell where we want the result.  */
  44   data.outbuf = (char *) buf;
  45   data.outbufend = data.outbuf + sizeof (wchar_t);
  46   data.invocation_counter = 0;
  47   data.internal_use = 1;
  48   data.is_last = 1;
  49   data.statep = &data.__state;
  50
  51   /* Make sure we start in the initial state.  */
  52   memset (&data.__state, '\0', sizeof (mbstate_t));
  53
  54   /* Make sure we use the correct function.  */
  55   update_conversion_ptrs ();
  56
  57   /* Create the input string.  */
  58   inbuf[0] = c;
  59
  60   status = (*__wcsmbs_gconv_fcts.towc->fct) (__wcsmbs_gconv_fcts.towc, &data,
  61                                              &inptr, inptr + 1, &dummy, 0);
  62   /* The conversion failed.  */
  63   if (status != GCONV_OK && status != GCONV_FULL_OUTPUT
  64       && status != GCONV_EMPTY_INPUT)
  65     return WEOF;
  66
  67   return *(wchar_t *)buf;
  68 }
  69 weak_alias (__btowc, btowc)