1FFLUSH(3)                  Linux Programmer's Manual                 FFLUSH(3)
2
3
4

NAME

6       fflush - flush a stream
7

SYNOPSIS

9       #include <stdio.h>
10
11       int fflush(FILE *stream);
12

DESCRIPTION

14       The  function  fflush()  forces a write of all user-space buffered data
15       for the given output or update stream via the stream's underlying write
16       function.  The open status of the stream is unaffected.
17
18       If  the  stream  argument  is  NULL,  fflush()  flushes all open output
19       streams.
20
21       For a non-locking counterpart, see unlocked_stdio(3).
22

RETURN VALUE

24       Upon successful completion 0 is returned.  Otherwise, EOF  is  returned
25       and the global variable errno is set to indicate the error.
26

ERRORS

28       EBADF  Stream is not an open stream, or is not open for writing.
29
30       The function fflush() may also fail and set errno for any of the errors
31       specified for the routine write(2).
32

NOTES

34       Note that fflush() only flushes the user space buffers provided by  the
35       C  library.   To  ensure that the data is physically stored on disk the
36       kernel buffers must be flushed too, e.g. with sync(2) or fsync(2).
37

CONFORMING TO

39       C89, C99.
40

SEE ALSO

42       fsync(2),   sync(2),   write(2),   fclose(3),   fopen(3),    setbuf(3),
43       unlocked_stdio(3)
44
45
46
47BSD MANPAGE                       1993-11-29                         FFLUSH(3)