check if all default packages are installed from the Ubuntu manifest

Question

My Ubuntu is running somewhat slow sometimes. Now I would like to check if all packages are still installed, maybe I uninstalled an important package.

How can I re-check if all initial packages are still installed?

Answer 1

There is a full list in the manifest file of each distribution at http://releases.ubuntu.com

To generate a list use

cd /tmp/
# 14.10: $ wget http://old-releases.ubuntu.com/releases/utopic/ubuntu-14.10-desktop-amd64.manifest
# 16.04.2: $ wget http://releases.ubuntu.com/releases/xenial/ubuntu-16.04.2-desktop-amd64.manifest
# for 16.10: 
wget http://releases.ubuntu.com/releases/16.10/ubuntu-16.10-desktop-amd64.manifest \
     -q -O - | cut -f 1 > packages.manifest.list
# compare it with the list generated by 
dpkg --get-selections  | cut -f 1 > packages.installed.list
# from moreutils you can use combine:
combine packages.manifest.list not packages.installed.list > packages.diff.list

For 32 bit use another manifest with the ending desktop-i386.manifest:

wget http://releases.ubuntu.com/utopic/ubuntu-14.10-desktop-i386.manifest -q -O - | cut -f 1 > packages.manifest.list 

Now just figure out how to ignore those packages that are removed upon installation, such as GParted, Ubiquity, various language packs, etc.:

IGNORE="language-pack|ubiquity|linux-|locale-|spell-|-help-|hyphen-|l10n|wbrazilian|wfrench|witalian|wportuguese|wspanish|mythes-"
cat packages.diff.list |egrep -v '('$IGNORE')' |less

(full list of removed packages here)