ubuntu package maintenance

# https://help.ubuntu.com/community/AptGet/Howto
# run after changing /etc/apt/sources.list or /etc/apt/preferences
apt-get update

# upgrade all installed packages
apt-get upgrade

# upgrade all installed packages with "smart" conflict resolution
apt-get dist-upgrade

# Diagnostic tool. It does an update of the package lists and checks for broken dependencies
apt-get check

# Fix Broken Packages
apt-get -f install

# removes .deb files for packages that are no longer installed 
apt-get autoclean

# removes .deb files for all packages
apt-get clean

# removes packages that were installed by other packages and are no longer needed.
apt-get autoremove