fflush

NAME

       fflush, fpurge - flush a stream

SYNOPSIS

       #include <stdio.h>

       int fflush( FILE *stream);
       int fpurge( FILE *stream);

DESCRIPTION

       The  function  fflush  forces a write of all 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. (Does this happen under Linux?)

       The function fpurge erases any input or output buffered in
       the given stream.  For output streams  this  discards  any
       unwritten  output.   For  input  streams this discards any
       input read from the underlying object but not yet obtained
       via  getc(3);  this  includes  any  text  pushed  back via
       ungetc.

RETURN VALUES

       Upon successful completion 0 is returned.  Otherwise,  EOF
       is  returned and the global variable errno is set to indi-
       cate the error.

ERRORS

       EBADF  Stream is not an open stream, or, in  the  case  of
              fflush, not a stream open for writing.

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

BUGS

       Linux may not support fpurge.

SEE ALSO

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

STANDARDS

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