let main() = 
  if Array.length Sys.argv > 1 then
    let module D = Disk.Opendisk(struct let name = Sys.argv.(1) end) in
    let () = D.print() in
    D.close() 
  else (prerr_endline "Usage: showdisk <diskname>"; exit 1)
  in
Printexc.catch (Unix.handle_unix_error main) ();;