Using APT

Just today I installed Ubuntu Server Edition 12.04 on a machine. It's worth knowing a few apt tricks:

apt-get install pkg_name

apt-get download pkg_name

apt-get update #update repository

apt-get autoremove #remove unnecessary packages

dpkg -s firefox | grep Status #check installation status

apt-cache pkgnames | sort

apt-cache depends firefox #get dependency list

apt-get install -o Acquire::http::Proxy=none #manual proxy setting

echo -e "pkg1 hold\npkg2 hold\npkg3 hold" | dpkg --set-
selections #prevent packages