ubuntu debian backup restore packages

packages.sh

#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