apt
Table of Contents
1. Removed packages with configuration files left
List of all removed packages that may have configuration files left on the system (if any)
apt list '~c'
Assuming you want to purge all of them in one go, you can use the following command
apt purge '~c'
2. Removing obsolete and locally created packages
List of all “Obsolete and Locally Created Packages” can be listed and purged with these commands
apt list '~o'
Assuming you want to purge all of them in one go, you can use the following command
apt purge '~o'
3. List packages not coming from Debian origin
apt list '?narrow(?installed, ?not(?origin(Debian)))'
4. Check for updates without warnings
apt -qq list --upgradeable