# Synchronize your Gentoo Portage tree.
# List which list of packages would require you to install libreoffice without actually installing them:
emerge -pv app-office/libreoffice
# Remove the Gentoo Portage - package named dev-lang/ruby but not its dependencies:
emerge -C dev-lang/ruby
# Remove a Gentoo Portage - package along with its post-install unrequired dependencies:
emerge -cav category/package-atom
# Update your Gentoo system (might be neccessary after use flag changes)
emerge -uDN @world
# Clean up system from unneeded packages/dependencies.