Toolserver:Screen

Problem: when you log off, the programs that were running under your session quit.

Solution: run the programs under screen.

Quick-start

Log in to a terminal (for instance, use PuTTY and log in to login.toolserver.org).

Type

$ screen

at a terminal. You will get a new shell prompt. Now run your program here. (When running php scripts in the console, GET and POST variables cannot be used.) When you want to log off, type CTRL+A CTRL+D. You will see:

[screen detached]

and you're back at the old shell prompt. Now log off; your programs will continue running in screen's virtual terminal. When you want to get them back, log in again and run

$ screen -r

This will resume a detached screen. To terminate a screen, resume it with screen -r and then press CTRL+A CTRL+K, or simply exit the shell, and screen will exit automatically.

If you are running multiple sessions, CTRL+A \ will end the session.

If you don't want to accidentally close something important, you may want to use CTRL-D instead. CTRL-D is not specific to screen, it's specific more to tty. It won't work in other programs like vi.

Other features

Opening multiple windows

Type CTRL+A c. A new screen will open. You can switch between screens with CTRL+A #, where # is the screen to switch to (starting from 0). All screens under the same session are detached and reattached together.

List all open windows

Type CTRL+A w.

For a detailed overview of screen, see the manual page screen(1).

Always use screen on login

By changing your ~/.bash_profile to somewhat like

#!/bin/bash
if [ -f ~/.bashrc ]; then
        source ~/.bashrc
fi
exec screen -D -R

you will always reattach to the same screen session (or create a new one if there's no screen running). With CTRL+C d you will detach the screen and log out. Use CTRL+d or type exit to close a screen. With the last screen closed you will log out.

If ~/.bash_profile did not exist in prior you have to make it executable: chmod +x ~/.bash_profile.