Ubuntu 16.04 is a bit slow to download software, because the default is to download software from abroad, then replace it with a better fast update source in China (that is, the server where these software are located). Generally, a lot of Baidu Ubuntu update sources can come out directly. At this time, it is best to find an update source that is consistent with your own Ubuntu version. My Ubuntu version is 16.04. The following is a better update source I found.
1. Find domestic mirror sources
https://mirrors.tuna.tsinghua.edu.cn/help/ubuntu/
2. Configure the source list source
The sources.list comes with the system, and the source is from Ubuntu's official website! The installation package is relatively slow, so it is best to switch to domestic
linuxidc.com@ubuntu:~$ cd /etc/apt
linuxidc.com@ubuntu:/etc/apt$ sudo cp sources.list sources.list.bak
linuxidc.com@ubuntu:/etc/apt$ vim sources.list
# The source image is commented by default to improve the speed of apt update, if necessary, you can uncomment it yourself
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial main restricted universe multiverse
# deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial main restricted universe multiverse
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-updates main restricted universe multiverse
# deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-updates main restricted universe multiverse
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-backports main restricted universe multiverse
# deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-backports main restricted universe multiverse
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-security main restricted universe multiverse
# deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-security main restricted universe multiverse
# Pre-release software source, it is not recommended to enable
# deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-proposed main restricted universe multiverse
# deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-proposed main restricted universe multiverse
3. Update source
linuxidc.com@ubuntu:/etc/apt$ sudo apt-get update
命中: 1 http://mirrors.aliyun.com/ubuntu great InRelease
命中: 2 http://mirrors.aliyun.com/ubuntu xenial-updates InRelease
命中: 3 http://mirrors.aliyun.com/ubuntu xenial-backports InRelease
命中: 4 http://mirrors.aliyun.com/ubuntu xenial-security InRelease
Reading package list... done
Test: install sl package
linuxidc.com@ubuntu:/etc/apt$ sudo apt-get install sl
linuxidc.com@ubuntu:/etc/apt$ sl
4. Some other commands
sudo apt-get update update source
sudo apt-get install package install package
sudo apt-get remove package remove package
sudo apt-cache search package Search for packages
sudo apt-cache show package Get information about the package, such as description, size, version, etc.
sudo apt-get install package --reinstall to reinstall the package
sudo apt-get -f install to fix the installation
sudo apt-get remove package --purge removes packages, including configuration files, etc.
sudo apt-get build-dep package install related compilation environment
sudo apt-get upgrade to update installed packages
sudo apt-get dist-upgrade upgrade system
sudo apt-cache depends package to understand which packages are depended on using this package
sudo apt-cache rdepends package to see which packages depend on the package
sudo apt-get source package to download the source code of the package
sudo apt-get clean && sudo apt-get autoclean clean useless packages
sudo apt-get check to check for broken dependencies