Computing/Linux/Process Control

It is very easy to run background processes on Linux boxes without causing inconvenience to others. Every process is assigned a priority level which on Linux ranges from -20 to 20, with the default level being 0. Although it might seem a bit backward, -20 is actually the highest priority a process can have, while 20 is the lowest. To control process priority, you use the "nice" and "renice" commands. For example: $ nice -n 20 ./mysimulation args Otherwise, if you want to renice a process which is already running: $ renice 20 pid where pid is process id of the program you are running.

If you want your simulations to run even after you log out, use nohup: $ nohup mysimulation args & Another option is to use screen. It is a full-screen manager that multiplexes physical terminal between several processes. To start a process using screen: $ screen mysimulation To detach the process window and switch back to shell, type C-a d (press and hold , hit , release both and hit ). If you want to get back to your program (say to check output), then simply reattach: $ screen -r You can get more info from screen manual page: $ man screen