newlib-cygwin/newlib/libc/stdio/getchar.c

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2000-02-18 03:39:52 +08:00
/*
* 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>>.
*/
#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "%W% (Berkeley) %G%";
#endif /* LIBC_SCCS and not lint */
/*
* A subroutine version of the macro getchar.
*/
#include <stdio.h>
#include <reent.h>
#include "local.h"
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#undef getchar
int
_getchar_r (f)
struct _reent *f;
{
_REENT_SMALL_CHECK_INIT(_stdin_r (f));
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return getc (_stdin_r (f));
}
#ifndef _REENT_ONLY
int
getchar ()
{
/* CHECK_INIT is called (eventually) by __srefill. */
return _getchar_r (_REENT);
}
#endif