[Ubuntu]源修改为国内的阿里云镜像源

#备份默认的源
sudo cp /etc/apt/sources.list /etc/apt/sources.list.bak
#修改为国内的阿里云镜像源
sudo sed -i "s/archive.ubuntu.com/mirrors.aliyun.com/g" /etc/apt/sources.list
#删除#开头的注释行
sudo sed -i '/^#/d' /etc/apt/sources.list
#更新 apt-get 源
sudo apt update
sudo apt upgrade