--- Etc.getgrgid(gid)
    /etc/groupե(뤤ϡEtc.getpwnam)򸡺
    gid򥰥롼IDȤ륰롼ץȥ֤ͤgroup
    ¤ΤǰʲΥФġ

      struct group
        name        # 롼̾(ʸ)
        passwd      # 롼פΥѥ(ʸ)
        gid         # 롼ID()
        mem         # 롼ץ̾
      end

    ܺ٤getgrgid(3) [manual page]򻲾ȤΤȡ

