Screen is a Linux tool to run multiple virtual terminal from a command line. It is useful when you need to run long processes and you need to close your SSH client. Screen is really life saver.
Start a new Screen
Detach from Screen (left screen running in background)
$ ctrl a d
View running virtual terminal in background
$ screen -ls
There are screens on:
5311.pts-0.langkawi (08/23/2013 05:27:39 PM) (Detached) 5253.pts-0.langkawi (08/23/2013 05:27:09 PM) (Detached) 2 Sockets in /var/run/screen/S-ubuntu.
Resume existing Screen
$ screen -r 5253.pts-0.langkawi
To exit or close Screen, go inside the Screen and type
ctrl + a k.