I have made a backup of my entire computer and I reinstalled the OS right now. I know I should have listed dpkg -l to obtain a list of packages, but I have not done so. I only made a tarball of the entire disk.
I wonder how I can find a list of packages based on this data. I would like to have the same packages installed that I had on my previous set-up. But there seems no longer a way to gain a list of packages, since I already reinstalled Ubuntu on the computer and only have the tarball back-up.