--- clone
--- dup

    쥷ФƱ IO 򻲾Ȥ뿷 IO ֥Ȥ֤ޤ
    (ȤƤե뵭һҤ dup(2) [manual page] ޤ)
    clone κݤ self ϰö flush ޤ

    ե꡼ IO  clone Ʊͤ˥ե꡼줿 IO ֤ޤ
    dup Ƥե꡼Ƥʤ IO ֤ޤ

