genericopenlibs/cstdlib/LSTDIO/GETCHAR.C
author andy simpson <andrews@symbian.org>
Fri, 17 Sep 2010 17:50:04 +0100
branchRCL_3
changeset 61 b670675990af
parent 0 e4d67989cc36
permissions -rw-r--r--
Merge Bug 2603 and Bug 3123 plus move exports to rom/bld.inf

/* GETCHAR.C
 * 
 * Portions Copyright (c) 1990-2006 Nokia Corporation and/or its subsidiary(-ies).
 * All rights reserved.
 */

/*
 * Copyright (c) 1990 The Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by the University of California, Berkeley.  The name of the
 * University may not be used to endorse or promote products derived
 * from this software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

/*
FUNCTION
<<getchar>>---read a character (macro)

INDEX
	getchar
INDEX
	_getchar_r

ANSI_SYNOPSIS
	#include <stdio.h>
	int getchar(void);

	int _getchar_r(void *<[reent]>);

TRAD_SYNOPSIS
	#include <stdio.h>
	int getchar();

	int _getchar_r(<[reent]>)
	char * <[reent]>;

DESCRIPTION
<<getchar>> is a macro, defined in <<stdio.h>>.  You can use <<getchar>>
to get the next single character from the standard input stream.
As a side effect, <<getchar>> advances the standard input's
current position indicator.

The alternate function <<_getchar_r>> is a reentrant version.  The
extra argument <[reent]> is a pointer to a reentrancy structure.


RETURNS
The next character (read as an <<unsigned char>>, and cast to
<<int>>), unless there is no more data, or the host system reports a
read error; in either of these situations, <<getchar>> returns <<EOF>>.

You can distinguish the two situations that cause an <<EOF>> result by
using `<<ferror(stdin)>>' and `<<feof(stdin)>>'.

PORTABILITY
ANSI C requires <<getchar>>; it suggests, but does not require, that
<<getchar>> be implemented as a macro.

Supporting OS subroutines required: <<close>>, <<fstat>>, <<isatty>>,
<<lseek>>, <<read>>, <<sbrk>>, <<write>>.
*/

/*
 * A subroutine version of the macro getchar.
 */

#include <stdio_r.h>
#include <reent.h>

#undef getchar

/**
A reentrant version of getchar().
*/
EXPORT_C int
_getchar_r (struct _reent *f)
{
  return getc (_stdin_r (f));
}

#ifndef _REENT_ONLY

/**
Get the next character from stdin.Returns the next character from the
standard input.

@return On Success, the character read is returned as an int. 
		On Failure, returns EOF, if the 'End Of File' is reached or there has
		been an error reading and errno may be set.
*/
EXPORT_C int
getchar (void)
{
  /* CHECK_INIT is called (eventually) by __srefill.  */
  struct _reent *r = _REENT2;
  if (!r)
	return EOF; // Memory for library globals is not allocated (errno not set).
  return _getchar_r (r);
}

#endif