--- IO.select(reads[, writes[, excepts[, timeout]]])

    select(2) [manual page] ¹Ԥޤ
    reads/writes/exceptsˤϡԤ
    IO (ޤϤΥ֥饹)Υ󥹥󥹤Ϥޤ

    timeout Float ޤ nil(ά
    Υǥե)ꤷޤnil ꤷ
     IO ǥ֤ˤʤޤԤ³ޤ

    ͤϡtimeout ˤ nil 򡢤
    ʤȤ 3 Ǥ֤γǤ//㳰
    ԤΥ֥ȤǤ(ꤷΥ֥å)

    select ƱǤ

