First, let’s make the list. You’ll be doing all of this in a Terminal Session:
dpkg –get-selections | grep -v deinstall > ubuntu-files
Now you’ve got a list of all of your installed debs in a fairly small file. In my case, I simply moved this file to a thumb-drive. You could also store it on a seperate partition or on a disk somewhere. Heck, it’s not that big, email it to your gmail account.
So now you’ve got this list and all is well, until you’re Ubuntu install either dies or has to be reinstalled for some reason. Go ahead and do the base install.
Once you’ve got Ubuntu back up and running, copy your ubuntu-files back into your home directory and do the following:
sudo apt-get update
sudo apt-get dist-upgrade
dpkg –set-selections < ubuntu-files
Now you’ve told your system what it needs to install, so let’s install it all.
sudo dselect
This will open up a dselect session. Type ‘I‘ and allow dselect to install of the the packages listed in your ubuntu-files document. When it’s finished, type ‘Q‘ and hit the ENTER key to exit dselect.