source: trunk/libs/newlib/src/newlib/libc/stdio/clearerr.c

/*
 * 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
<<clearerr>>, <<clearerr_unlocked>>---clear file or stream error indicator

INDEX
        clearerr
INDEX
        clearerr_unlocked

SYNOPSIS
        #include <stdio.h>
        void clearerr(FILE *<[fp]>);

        #define _BSD_SOURCE
        #include <stdio.h>
        void clearerr_unlocked(FILE *<[fp]>);

DESCRIPTION
The <<stdio>> functions maintain an error indicator with each file
pointer <[fp]>, to record whether any read or write errors have
occurred on the associated file or stream.  Similarly, it maintains an
end-of-file indicator to record whether there is no more data in the
file.

Use <<clearerr>> to reset both of these indicators.

See <<ferror>> and <<feof>> to query the two indicators.

<<clearerr_unlocked>> is a non-thread-safe version of <<clearerr>>.
<<clearerr_unlocked>> may only safely be used within a scope
protected by flockfile() (or ftrylockfile()) and funlockfile().  This
function may safely be used in a multi-threaded program if and only
if they are called while the invoking thread owns the (FILE *)
object, as is the case after a successful call to the flockfile() or
ftrylockfile() functions.  If threads are disabled, then
<<clearerr_unlocked>> is equivalent to <<clearerr>>.

RETURNS
<<clearerr>> does not return a result.

PORTABILITY
ANSI C requires <<clearerr>>.

<<clearerr_unlocked>> is a BSD extension also provided by GNU libc.

No supporting OS subroutines are required.
*/

#include <_ansi.h>
#include <stdio.h>
#include "local.h"

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

#undef  clearerr

void
clearerr (FILE * fp)
{
  CHECK_INIT(_REENT, fp);
  _newlib_flockfile_start (fp);
  __sclearerr (fp);
  _newlib_flockfile_end (fp);
}