ubuntu 18.04更改国内源——清华源_清华大学出版社源18.04

替换系统下/etc/apt/sources.list文件里面的内容

 
sudo passwd root        #切换root,同时设置root密码
输入你的密码
cd /etc/apt/    #进入apt目录
cp sources.list sources.list.bak   #备份一份
echo ``>sources.list               #清空内容
vi sources.list                    #编辑文件

粘贴以下内容：

# 默认注释了源码镜像以提高 apt update 速度，如有需要可自行取消注释
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic main restricted universe multiverse
# deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic main restricted universe multiverse
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-updates main restricted universe multiverse
# deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-updates main restricted universe multiverse
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-backports main restricted universe multiverse
# deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-backports main restricted universe multiverse
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-security main restricted universe multiverse
# deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-security main restricted universe multiverse
 
# 预发布软件源，不建议启用
# deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-proposed main restricted universe multiverse
# deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-proposed main restricted universe multiverse

上面的是清华大学的源，可以到这里验证：ubuntu | 镜像站使用帮助 | 清华大学开源软件镜像站 | Tsinghua Open Source Mirror

再运行：

sudo apt-get update
sudo apt-get upgrade