newlib/libc/stdio/getwchar.c

   1 /*-
   2  * Copyright (c) 2002 Tim J. Robbins.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  24  * SUCH DAMAGE.
  25  */
  26
  27 /*
  28 FUNCTION
  29 <<getwchar>>, <<getwchar_unlocked>>---read a wide character from standard input
  30
  31 INDEX
  32         getwchar
  33 INDEX
  34         getwchar_unlocked
  35 INDEX
  36         _getwchar_r
  37 INDEX
  38         _getwchar_unlocked_r
  39
  40 SYNOPSIS
  41         #include <wchar.h>
  42         wint_t getwchar(void);
  43
  44         #define _GNU_SOURCE
  45         #include <wchar.h>
  46         wint_t getwchar_unlocked(void);
  47
  48         #include <wchar.h>
  49         wint_t _getwchar_r(struct _reent *<[reent]>);
  50
  51         #include <wchar.h>
  52         wint_t _getwchar_unlocked_r(struct _reent *<[reent]>);
  53
  54 DESCRIPTION
  55 <<getwchar>> function or macro is the wide character equivalent of
  56 the <<getchar>> function.  You can use <<getwchar>> to get the next
  57 wide character from the standard input stream.  As a side effect,
  58 <<getwchar>> advances the standard input's current position indicator.
  59
  60 <<getwchar_unlocked>> is a non-thread-safe version of <<getwchar>>.
  61 <<getwchar_unlocked>> may only safely be used within a scope
  62 protected by flockfile() (or ftrylockfile()) and funlockfile().  This
  63 function may safely be used in a multi-threaded program if and only
  64 if they are called while the invoking thread owns the (FILE *)
  65 object, as is the case after a successful call to the flockfile() or
  66 ftrylockfile() functions.  If threads are disabled, then
  67 <<getwchar_unlocked>> is equivalent to <<getwchar>>.
  68
  69 The alternate functions <<_getwchar_r>> and <<_getwchar_unlocked_r>> are
  70 reentrant versions of the above.  The extra argument <[reent]> is a pointer to
  71 a reentrancy structure.
  72
  73 RETURNS
  74 The next wide character cast to <<wint_t>>, unless there is no more
  75 data, or the host system reports a read error; in either of these
  76 situations, <<getwchar>> returns <<WEOF>>.
  77
  78 You can distinguish the two situations that cause an <<WEOF>> result by
  79 using `<<ferror(stdin)>>' and `<<feof(stdin)>>'.
  80
  81 PORTABILITY
  82 <<getwchar>> is required by C99.
  83
  84 <<getwchar_unlocked>> is a GNU extension.
  85 */
  86
  87 #include <_ansi.h>
  88 #include <reent.h>
  89 #include <stdio.h>
  90 #include <wchar.h>
  91 #include "local.h"
  92
  93 #undef getwchar
  94
  95 wint_t
  96 _getwchar_r (struct _reent *ptr)
  97 {
  98   return _fgetwc_r (ptr, stdin);
  99 }
 100
 101 /*
 102  * Synonym for fgetwc(stdin).
 103  */
 104 wint_t
 105 getwchar (void)
 106 {
 107   _REENT_SMALL_CHECK_INIT (_REENT);
 108   return fgetwc (stdin);
 109 }