Invokes the directory (dir or ls) operation of the FTP utility.
    The DIRECTORY/FTP command writes a listing of the contents of
    the specified remote directory to the local host over a TCP/IP
    connection by invoking the FTP utility.

    The format is:

    $ DIR/FTP nodename"username password"::directory_pathname

    If the directory path name is omitted, the contents of the user's
    home directory are displayed. If only the node name is entered,
    the contents of the ANONYMOUS directory are displayed.