ubuntu 18.04更换源

1 剪切现有源

mv /etc/apt/sources.list ~/sources.list.backup

2 修改源

sudo vim /etc/apt/sources.list

把下面阿里云的源地址复制进去

deb http://cn.archive.ubuntu.com/ubuntu bionic main multiverse restricted universe
deb http://cn.archive.ubuntu.com/ubuntu bionic-updates main multiverse restricted universe
deb http://cn.archive.ubuntu.com/ubuntu bionic-security main multiverse restricted universe
deb http://cn.archive.ubuntu.com/ubuntu bionic-proposed main multiverse restricted universe

使源生效

sudo apt-get update