Software
aptitude is a high-level interface to the package manager
apt-get
Configuration of the Advanced Packaging Tool (APT) system repositories is stored in the /etc/apt/sources.list configuration file.
To enable the universe repository, remove the # in /etc/apt/sources.list for universe repositories.
After editing the /etc/apt/sources.list file, run the following command to take the changes to take effect
# apt-get update
To update all software to latest level
# apt-get upgrade
To disable apt-get asking for the installaion CD each time, comment out the CD entry in /etc/apt/sources.list file
To Remove automatically all unused packages which are installed with packageX
# apt-get autoremove packageX
To update the whole distribution of Ubuntu
# apt-get dist-upgrade
To find out which package a file belongs to
apt-get install apt-file apt-file update apt-file search /path/to/file
To list installed packages
# dpkg --list
To remove a package
# dpkg --remove package_name
Some packages, such as lynx, will install configuration files. If you wish these to be removed along with the package you can use the more brutal '--purge' flag:
# dpkg --purge package_name
To re-configure a package.
# dpkg-reconfigure slapd
To upgrade one version of ubuntu to newver version
# do-release-upgrade
To see the locations of all the files installed as part of the package,
# dpkg -L <packagename>