Package repositories on Ubuntu Server
Package repositories
Update the package repositories from sources with the latest versions
sudo apt-get update
A list of repositories, that the server will check for packages, is stored at /etc/apt/sources.list
cat /etc/apt/sources.list
Extra repositories can be added to /etc/apt/sources.list.d
Package information
Search for available packages (eg. mysql); to search only by the package name, use -n tag.
sudo apt-cache search mysql
sudo apt-cache search -n mysql
Get the package information (eg. mysql-server-5.6)
sudo apt-cache show mysql-server-5.6
Install/uninstall a package
Install a package || without prompting use tag -y || for quiet install use tag -qq
sudo apt-get install -y mysql-server-5.6
Uninstall a package ('purge' removes the configuration, 'remove' removes only the package)
sudo apt-get purge mysql-server-5.6
After uninstalling use autoremove to remove any dependencies that are not in use by other packages
sudo apt-get autoremove
List all installed packages
Get a list of packages installed locally (the -v tag "inverts" grep to return non-matching lines)
dpkg --get-selections | grep -v deinstall
Get a list of a specific package installed
dpkg --get-selections | grep mysql
Alternatively, simply use
dpkg -l
Get just the packages which were expressly installed (not just installed as dependencies)
aptitude search '~i!~M'