emerge is primarily used for installing Portage-packages emerge [options] [action] [ebuild | tbz2file | file | @set | atom] ... emerge --sync [repo | alias] ... emerge --info [atom] emerge --search somestring emerge --help | --version
emerge --sync is a deprecated(?) command. emaint with the corresponding option should be used. emerge --oneshot avoids adding a package to the world file (/var/lib/portage/world).