To list all non-free Linux packages that are installed on your Linux Mint system, use this one-liner. This prints out a list of all non-free packages that are installed on a system.
jason@jason-virtual-machine ~ $ dpkg-query -W -f '${Section}/${Package}\n' | grep -E '^(contrib|multiverse|non-free|partner|restricted)/' | sort contrib/kernel/virtualbox-guest-dkms contrib/misc/virtualbox-guest-utils contrib/x11/virtualbox-guest-x11 |
Another way is to install the vrms package.
jason@jason-virtual-machine ~ $ sudo apt install vrms |
Then run it to list all of the offending non-free packages.
jason@jason-virtual-machine ~ $ vrms Contrib packages installed on jason-virtual-machine virtualbox-guest-dkms x86 virtualization solution - guest addition module so virtualbox-guest-utils x86 virtualization solution - non-X11 guest utilities virtualbox-guest-x11 x86 virtualization solution - X11 guest utilities 3 contrib packages, 0.1% of 2297 installed packages |
Very useful if the Linux system that is in use at your home or work is desired to be free of non-free binary blobs.