fflush

FFLUSH(3)		  Linux Programmer’s Manual		    FFLUSH(3)



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 the global variable 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 the routine write(2).

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, e.g. with sync(2) or fsync(2).

CONFORMING TO
       The function fflush() conforms to ANSI X3.159-1989 (‘‘ANSI C’’).

SEE ALSO
       fsync(2),   sync(2),   write(2),	  fclose(3),   fopen(3),   setbuf(3),
       unlocked_stdio(3)



BSD MANPAGE			  1993-11-29			    FFLUSH(3)