.\" Copyright (c) 1990 The Regents of the University of California.
.\" All rights reserved.
.\"
.\" This code is derived from software contributed to Berkeley by
.\" Chris Torek.
.\"
.\" %sccs.include.redist.man%
.\"
.\"	@(#)fflush.3	5.1 (Berkeley) 03/05/91
.\"
.TH FFLUSH 3 ""
.UC 7
.SH NAME
fflush, fpurge \- flush a stream
.SH SYNOPSIS
.nf
.ft B
#include <stdio.h>

int
fflush(FILE *stream);

int
fpurge(FILE *stream);
.ft R
.fi
.SH DESCRIPTION
.I Fflush
writes any buffered data for the given output
.I stream
via the stream's underlying write function.
The stream remains open.
.PP
If the
.I stream
argument is NULL,
.I fflush
flushes
.I all
open output streams.
.PP
.I Fpurge
erases any input or output buffered in the given
.IR stream .
For output streams this discards any unwritten output.
For input streams this discards any input read from the underlying object
but not yet obtained via
.IR getc ;
this includes any text pushed back via
.IR ungetc .
.SH "RETURN VALUE"
Upon successful completion 0 is returned.
Otherwise,
.B EOF
is returned and the global variable
.I errno
is set to indicate the error.
.SH ERRORS
.TP 15
[EBADF]
.I Stream
is not an open stream, or, in the case of
.IR fflush ,
not a stream open for writing.
.PP
.I Fflush
may also fail and set
.I errno
for any of the errors specified for the routine
.IR write (2).
.SH "SEE ALSO"
write(2), fopen(3), fclose(3), setbuf(3)
.SH STANDARDS
.I Fflush
conforms to ANSI X3.159-1989 (``ANSI C'').