1FFLUSH(3)                  Linux Programmer's Manual                 FFLUSH(3)
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NAME

6       fflush - flush a stream
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SYNOPSIS

9       #include <stdio.h>
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11       int fflush(FILE *stream);
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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.
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18       If  the  stream  argument  is  NULL,  fflush()  flushes all open output
19       streams.
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21       For a non-locking counterpart, see unlocked_stdio(3).
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RETURN VALUE

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

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

34       C89, C99.
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NOTES

37       Note that fflush() only flushes the user space buffers provided by  the
38       C  library.   To  ensure that the data is physically stored on disk the
39       kernel buffers must be  flushed  too,  for  example,  with  sync(2)  or
40       fsync(2).
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SEE ALSO

43       fsync(2),    sync(2),   write(2),   fclose(3),   fopen(3),   setbuf(3),
44       unlocked_stdio(3)
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COLOPHON

47       This page is part of release 3.22 of the Linux  man-pages  project.   A
48       description  of  the project, and information about reporting bugs, can
49       be found at http://www.kernel.org/doc/man-pages/.
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53GNU                               2009-02-23                         FFLUSH(3)
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