--- TCPSocket.open(host, service [local_host, local_serice])
--- TCPSocket.new(host, service [local_host, local_serice])
    hostǻꤷۥȤserviceǻꤷݡȤ³
    Ȥ֤ޤhostϥۥ̾ޤoctet decimal
    ˤ륤󥿡ͥåȥɥ쥹򼨤ʸservice
    /etc/services(ޤNIS)ϿƤ륵
    ӥ̾ݡֹǤ

    ruby 1.7 feature:
     local_host, local_service ꤷ硢Υɥ쥹
    Фbind(2) [manual page]ޤ

