.Undo of deleted file
      Undo line command is avail for the file deleted by line command.
      Deleted files by DOS command is not undoable.
      Undo line command support also Move/Rename line command.
      Delete line command has other variation,Not undoable(z),
      Delete also ReadOnly file(/) and Both undoable and del ReadOnly(0).

     directory and undeletability.
     +---+-------+---------------+
     |cmd|undo   | For ReadOnly  |
     +---+-------+---------------+
     | d |Avail  | Error         |
     | / |Avail  | Deleted       |
     | z |N/A    | Error         |
     | 0 |N/A    | Deleted       |
     +---+-------+---------------+