--- fcntl(cmd[, arg])

    IOФƥƥॳ fcntl ¹Ԥޤ
    ǽξܺ٤fcntl(2) [manual page]򻲾ȤƤ

    arg λˤϤͤtrue ޤ false ξϤ줾
     1 ޤ 0 ʸξˤ pack ¤ΤȤߤʤƤ
    ޤ fcntl(2) [manual page] Ϥޤarg ξά
     0 Ǥ

    cmd ФƻǤͤϡźե饤֥ fcntl.so  
    Fcntl ⥸塼뤬󶡤Ƥޤ

    fcntl(2) ֤֤ͤޤfcntl(2) μ¹Ԥ˼
    㳰 Errno::EXXX ȯޤ

