The SHOW PORT command displays information about a port. The output
    includes the type of port and one of these possible states:

    o  Full or <barcode> -- The port contains a cartridge. The bar code
       value of the cartridge occupying the port appears if the media
       robot is capable of reading cartridge bar codes.

    o  Empty -- The port contains no cartridge and is available for
       use.

    o  Unavailable -- The port is unavailable for use.

    Format

    SHOW [ROBOT robot_name] PORT [[[port_number]|[port_number-port_number]],...]