1.備份
sudo cp /etc/apt/sources.list /etc/apt/sources.bak1
#第一個參數時拷貝的文件路徑和文件名稱,第二個是拷貝到(粘貼)的文件路徑和文件名
2.更改權限
sudo chmod 777 /etc/apt/sources.list
3.更改鏡像內容
清空原來的內容
> /etc/apt/sources.list
sudo vi /etc/apt/sources.list
1 #阿里源 2 deb http://mirrors.aliyun.com/ubuntu/ bionic main restricted universe multiverse 3 deb http://mirrors.aliyun.com/ubuntu/ bionic-security main restricted universe multiverse 4 deb http://mirrors.aliyun.com/ubuntu/ bionic-updates main restricted universe multiverse 5 deb http://mirrors.aliyun.com/ubuntu/ bionic-proposed main restricted universe multiverse 6 deb http://mirrors.aliyun.com/ubuntu/ bionic-backports main restricted universe multiverse 7 deb-src http://mirrors.aliyun.com/ubuntu/ bionic main restricted universe multiverse 8 deb-src http://mirrors.aliyun.com/ubuntu/ bionic-security main restricted universe multiverse 9 deb-src http://mirrors.aliyun.com/ubuntu/ bionic-updates main restricted universe multiverse 10 deb-src http://mirrors.aliyun.com/ubuntu/ bionic-proposed main restricted universe multiverse 11 deb-src http://mirrors.aliyun.com/ubuntu/ bionic-backports main restricted universe multiverse 12 #網易源 13 deb http://mirrors.163.com/ubuntu/ bionic main restricted universe multiverse 14 deb http://mirrors.163.com/ubuntu/ bionic-security main restricted universe multiverse 15 deb http://mirrors.163.com/ubuntu/ bionic-updates main restricted universe multiverse 16 deb http://mirrors.163.com/ubuntu/ bionic-proposed main restricted universe multiverse 17 deb http://mirrors.163.com/ubuntu/ bionic-backports main restricted universe multiverse 18 deb-src http://mirrors.163.com/ubuntu/ bionic main restricted universe multiverse 19 deb-src http://mirrors.163.com/ubuntu/ bionic-security main restricted universe multiverse 20 deb-src http://mirrors.163.com/ubuntu/ bionic-updates main restricted universe multiverse 21 deb-src http://mirrors.163.com/ubuntu/ bionic-proposed main restricted universe multiverse 22 deb-src http://mirrors.163.com/ubuntu/ bionic-backports main restricted universe multiverse 23 #清華源 24 deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic main restricted universe multiverse 25 deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic main restricted universe multiverse 26 deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-updates main restricted universe multiverse 27 deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-updates main restricted universe multiverse 28 deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-backports main restricted universe multiverse 29 deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-backports main restricted universe multiverse 30 deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-security main restricted universe multiverse 31 deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-security main restricted universe multiverse 32 deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-proposed main restricted universe multiverse 33 deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-proposed main restricted universe multiverse 34 #中科大源 35 deb https://mirrors.ustc.edu.cn/ubuntu/ bionic main restricted universe multiverse 36 deb-src https://mirrors.ustc.edu.cn/ubuntu/ bionic main restricted universe multiverse 37 deb https://mirrors.ustc.edu.cn/ubuntu/ bionic-updates main restricted universe multiverse 38 deb-src https://mirrors.ustc.edu.cn/ubuntu/ bionic-updates main restricted universe multiverse 39 deb https://mirrors.ustc.edu.cn/ubuntu/ bionic-backports main restricted universe multiverse 40 deb-src https://mirrors.ustc.edu.cn/ubuntu/ bionic-backports main restricted universe multiverse 41 deb https://mirrors.ustc.edu.cn/ubuntu/ bionic-security main restricted universe multiverse 42 deb-src https://mirrors.ustc.edu.cn/ubuntu/ bionic-security main restricted universe multiverse 43 deb https://mirrors.ustc.edu.cn/ubuntu/ bionic-proposed main restricted universe multiverse 44 deb-src https://mirrors.ustc.edu.cn/ubuntu/ bionic-proposed main restricted universe multiverse
4.更新源列表
sudo apt-get update
#這個命令，會訪問源列表里的每個網址，並讀取軟件列表，然后保存在本地電腦。
我們在新立得軟件包管理器里看到的軟件列表，都是通過update命令更新的。
5.更新軟件
sudo apt-get upgrade
#這個命令，會把本地已安裝的軟件，與剛下載的軟件列表里對應軟件進行對比，如果發現已安裝的軟件版本太低，
就會提示你更新。如果你的軟件都是最新版本，會提示：
升級了 0 個軟件包，新安裝了 0 個軟件包，要卸載 0 個軟件包，有 0 個軟件包未被升級。