sed -i "s@http://ppa.launchpad.net@https://launchpad.proxy.ustclug.org@g" /etc/apt/sources.list.d/*.list
sed -i "s@http://mirrors.aliyun.com@https://mirrors.aliyun.com@g" /etc/apt/sources.list sed -i "s@http://archive.ubuntu.com@https://mirrors.aliyun.com@g" /etc/apt/sources.list