how can a feed a file list into dpkg --get?

Question

I can use dpkg --get-selections | grep -v deinstall | cut -f 1 | tr '\n' ' ' > listpackages.txt

to fill a file with all my installed packages.

Is there a to install using dpkg or apt and reference the listpackages.txt file created above?

I want to be able to backup what I have installed as a package list, reinstall my distro and finally in one command install everything I had installed on the previous version.

-thanks u2!

Answer 1

Use the --set-selections flag to do this.

To export the package list from one system: dpkg --get-selections followed by whatever filtering you want.

To re-import the list to another system, pipe it into dpkg --set-selections, and then run aptitude install. The dpkg --set-selections command will only queue the install process; you then actually have to execute it.

Answer 2

apt-get install `cat listpackages.txt`