https://blog.ef67daisuki.club/2017/01/trainscanner%e3%81%ae%e7%b4%b9%e4%bb%8b%e3%81%a8ubuntu-16-10%e3%81%a7%e3%81%ae%e5%b0%8e%e5%85%a5%e6%96%b9%e6%b3%95/