dpkg-query -L package
# or if not installed
apt-file list package
apt-cache search string
# alias 'search' in stretchbang
aptitude search '?and(~i, ~Araring-backports)'
# list installed with backport upgrades
aptitude search '~Abackports ?not(~S ~i ~Abackports)'
# list all available backport packages (installed or not)
apt-cache policy packname
# or just
apt-cache policy
# some sort of repository status
sudo apt update && sudo apt dist-upgrade
# alias 'up' in stretchbang
sudo apt install -t stretch-backports packname
sudo apt install --no-install-recommends packname
# only the main dependencies (packages in the Depends field) are installed.
sudo apt autoremove # removes unused deps
sudo apt autoclean # clears downloaded cache
https://wiki.debian.org/DontBreakDebian
sudo /usr/sbin/dmidecode --type memory
inxi -F -c 0