wcsmbs/btowc.c

   1 /* Copyright (C) 1996, 1997, 1998, 1999 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Ulrich Drepper <drepper@gnu.org>, 1996.
   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 #include <limits.h>
  26
  27
  28 wint_t
  29 __btowc (c)
  30      int c;
  31 {
  32   wchar_t result;
  33   struct __gconv_step_data data;
  34   unsigned char inbuf[1];
  35   const unsigned char *inptr = inbuf;
  36   size_t dummy;
  37   int status;
  38
  39   /* If the parameter does not fit into one byte or it is the EOF value
  40      we can give the answer now.  */
  41   if (c < SCHAR_MIN || c > UCHAR_MAX || c == EOF)
  42     return WEOF;
  43
  44   /* Tell where we want the result.  */
  45   data.__outbuf = (unsigned char *) &result;
  46   data.__outbufend = data.__outbuf + sizeof (wchar_t);
  47   data.__invocation_counter = 0;
  48   data.__internal_use = 1;
  49   data.__is_last = 1;
  50   data.__statep = &data.__state;
  51
  52   /* Make sure we start in the initial state.  */
  53   memset (&data.__state, '\0', sizeof (mbstate_t));
  54
  55   /* Make sure we use the correct function.  */
  56   update_conversion_ptrs ();
  57
  58   /* Create the input string.  */
  59   inbuf[0] = c;
  60
  61   status = (*__wcsmbs_gconv_fcts.towc->__fct) (__wcsmbs_gconv_fcts.towc, &data,
  62                                                &inptr, inptr + 1, &dummy, 0);
  63   /* The conversion failed.  */
  64   if (status != __GCONV_OK && status != __GCONV_FULL_OUTPUT
  65       && status != __GCONV_EMPTY_INPUT)
  66     result = WEOF;
  67
  68   return result;
  69 }
  70 weak_alias (__btowc, btowc)