DESCRIPTION

     The function fflush forces a write of all buffered data  for
     the  given output or update stream via the stream's underly-
     ing write function.  The open status of the stream is  unaf-
     fected.

     If the stream argument is NULL, fflush flushes all open out-
     put streams.

RETURN VALUES

     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  writ-
          ing.

     The function fflush may also fail and set errno for  any  of
     the errors specified for the routine write(2).

SEE ALSO

     write(2), fopen(3), fclose(3),

CONFORMING TO

     The fflush function conforms  to  ANSI  C3.159-1989  (``ANSI
     C'').