List all packages that are installed on the system.
ls /var/db/pkg/*
List all packages that i installed.
cat /var/lib/portage/world
Do changes to config files.
dispatch-conf
Install new package.
emerge -av <package-name>
Uninstall package.
emerge -avc <package-name>
Sync repos.
emerge --sync
Update all packages in @world.
emerge -avuDU @world
Uninstall unused dependencies.
emerge -ac