FFLUSH
Section: Linux Programmer's Manual (3)
Updated: 2009-02-23
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NAME
fflush - flush a stream
SYNOPSIS
#include <stdio.h>
int fflush(FILE *stream);
DESCRIPTION
The function
fflush()
forces a write of all user-space buffered data for the given output or update
stream
via the stream's underlying write function.
The open status of the stream is unaffected.
If the
stream
argument is NULL,
fflush()
flushes
all
open output streams.
For a non-locking counterpart, see
unlocked_stdio(3).
RETURN VALUE
Upon successful completion 0 is returned.
Otherwise,
EOF
is returned and
errno
is set to indicate the error.
ERRORS
- EBADF
-
Stream
is not an open stream, or is not open for writing.
The function
fflush()
may also fail and set
errno
for any of the errors specified for
write(2).
CONFORMING TO
C89, C99.
NOTES
Note that
fflush()
only flushes the user space buffers provided by the C library.
To ensure that the data is physically stored on disk
the kernel buffers must be flushed too, for example, with
sync(2)
or
fsync(2).
SEE ALSO
fsync(2),
sync(2),
write(2),
fclose(3),
fopen(3),
setbuf(3),
unlocked_stdio(3)
COLOPHON
This page is part of release 3.22 of the Linux
man-pages
project.
A description of the project,
and information about reporting bugs,
can be found at
http://www.kernel.org/doc/man-pages/.