Searching Available Packages
On Debian/Ubuntu
apt-cache search $name
On CentOS/Fedora
apt-cache search $name
On Gentoo
emerge -s $name
Installing Packages
On Debian/Ubuntu
apt-get install $name
On Gentoo
emerge -av $name
Upgrading Packages / System
On Debian/Ubuntu
apt-get update apt-get upgrade
On Gentoo
emerge --sync emerge -avuDN @world
Searching Installed Packages
On Debian/Ubuntu
dpkg -l |grep $name
On Gentoo
equery l '*$name*'
Removing Packages
On Debian/Ubuntu
apt-get remove $name
On Gentoo
emerge -Cv $name
Purging Packages
On Debian/Ubuntu, and use the dpkg output to then dpkg --purge.
apt-get autoremove dpkg -l | grep '^rc' dpkg --purge $name
Re-Packaging
On Debian/Ubuntu.
apt-get install dpkg-repack dpkg-repack $name