Von https://askubuntu.com/questions/9135/how-to-backup-settings-and-list-of-installed-packages
A quick way of backing up a list of programs is to run this:
dpkg --get-selections > ~/Package.list sudo cp -R /etc/apt/sources.list* ~/ sudo apt-key exportall > ~/Repo.keys
It will back them up in a format that dpkg can read* for after your reinstall, like this:
sudo apt-key add ~/Repo.keys sudo cp -R ~/sources.list* /etc/apt/ sudo apt-get update sudo apt-get install dselect sudo dselect update sudo dpkg --set-selections < ~/Package.list sudo apt-get dselect-upgrade -y
* You may have to update dpkg's list of available packages or it will just ignore your selections (see this debian bug for more info). You should do this before sudo dpkg –set-selections < ~/Package.list, like this:
apt-cache dumpavail > ~/temp_avail sudo dpkg --merge-avail ~/temp_avail rm ~/temp_avail