The SHOW DRIVE command shows the status of drives. One of these
    possible states is reported:
    o  Full or <barcode> -- The drive contains a cartridge. The bar code
       value of the cartridge occupying the drive appears if the media
       robot is capable of reading cartridge bar codes.
    o  Empty -- The drive contains no cartridge, and is available for
       use.
    o  Unavailable -- The drive is unavailable for use.
    Format
    SHOW [ROBOT robot_name] DRIVE [[[drv_number]|[drv_number-drv_number]],...]
1 – Parameters
    robot_name - The name for the media robot.
    drv_number - An integer value indicating the physical drive in the robot.
2 – Example
    The following example shows the status of drive 0 in the default
    robot identified by the MRU_ROBOT logical:
    $ ROBOT SHOW DRIVE 0
    DRIVE:          0               Empty