"ls -s |more" - list directory with sizes "finger" - list active users "du -h" - disk usage, directories sizes h-human readable "df -h" - disk free "grep" - filter output (global regular expression print) "someCommand &>filename.out" - redirection of both outputs to file - "&>" "ps aux |less" - list processes "kill intId" - kill process with given id "killall name" - kill process named ~name "sudo command" - run command as super user "ifconfig" - network interface data "ifdown eth0" - network interface DOWN "ifup eth0" - network interface UP "/etc/init.d/networking restart" - networking restart "lsmod, insmod, modprobe, rmmod" - device drivers list, insert, remove "apt-get install packagename" - install package "apt-get remove packagename" - remove package "pppoeconf, pon dsl-provider, poff dsl-provider, plog" - ppp connection related commands "uname -r" - returns kernel version "find startFolder -name 'searchString'" - finding files named searchString "ed, nano, pico, vi, gedit" - possible editors on the system "dd if=srcPath of=dstpath bs=bytesPerTransfer" - disk copy "tar xzvf packedFile.tar.gz" - unpack .tar.gz archive