# Reinstall or install on another system
dpkg --get-selections | sed -e 's/hold$/install/' > yourpkgs.list

dpkg --set-selections < yourpkgs.list
apt-get dselect-upgrade


# Remove packages selected for removal (deinstallation) / Remove lingering packages
dpkg --get-selections | sed -e 's/deinstall$/purge/' | dpkg --set-selections
apt-get dselect-upgrade


# List packages selected for removal (deinstallation) / List lingering packages
dpkg -l | grep '^rc' or dpkg --get-selections | grep deinstall


# Place a hold on a package
echo "<package> hold" | dpkg --set-selections


# Search for installed package
dpkg -l | grep 'package'

Try the following if long package names gets truncated
export COLUMNS=200; dpkg -l | grep 'package'


# List files in package
dpkg -L <package>

Use the following if the package isn't installed on your system
dpkg -c <package-file>


# Find package owning the specified file
dpkg -S <file>