INTERFACE OSSupport;

IMPORT FileWr, OSError;

TYPE
  T <: FileWr.T;

PROCEDURE Sync(wr: T) RAISES {OSError.E};
   (* Flushes "wr".  The attempt to write all modified data
      to stable storage ... to whatever extent permitted by
      the OS.  *)
   (* "wr" must be a file writer *)

PROCEDURE Truncate(wr: T) RAISES {OSError.E};
   (* Truncates the specified writer at the currernt position. *)
   (* "wr" must be a file writer *)

END OSSupport.