--- Socket.unpack_sockaddr_in(addr)      ruby 1.7 feature

    åȥɥ쥹¤Τ pack ʸ 
    unpack ɥ쥹֤ޤ֤ͤ [port, ipaddr] 
    Ǥ

        require 'socket'
        p Socket.unpack_sockaddr_in(Socket.pack_sockaddr_in("echo", "localhost"))
        => [7, "127.0.0.1"]

