--- SystemExit.new([status], [error_message])

    ruby 1.7 feature

    SystemExit 㳰֤ޤ

    ξ硢 status ꤷΤȤߤʤ
    ΤȤСΰ Exception.new 
    ƱǤ

     status ꤵ줿硢λơȤ
    ֥Ȥ status °ꤵޤ(ά 
    0 ꤵޤ)

        e = SystemExit.new(1)
        p e.status

        => 1

