Condor or HTcondor is an open source project at the University of Wisconsin’s Computer Science Department, which is a high-throughput computing software framework for coarse-grained distributed parallelization of computationally intensive tasks, a.k.a., a cluster management system.


For a complete manual with tutorials and examples please check the manual.


However, there is always the possibility that we have to use a machine without condor installed. I was stuck in this embarrassment when interning at IBM Research Lab – Ireland. The purpose of this tutorial is to find a substitute which is more widely used. The right tool we would like to use is GNU Screen.


This tutorial will have some basic and frequent-used commands introduced as below (PC/Mac resp.).


Start a new screen session:


Detach from the current screen session (leave session temporarily):

Ctrl/Command + a + d

List all screen sessions:

screen -ls

Return to a screen session:

screen –r +sessionID

Kill the current session:


Start a new screen session:

pkill screen


killall screen

More screen commands are available to use, and for a complete manual of the command “screen”, please type

man screen

or check here.


Any comment or question is welcome.