Notes on Screen

It is a good idea to use screen sessions

On super computers like those at IU, it is essential to use a screen session for submitting interactive jobs. Screen basically emulates a user sitting at the computer screen. It accepts output and can give input. However, you can detach from screen sessions and log out from the computer without causing running jobs to terminate.

Here are some notes provided by IU's Knowledge Base

When you can't re-attach to your screen session after a lost connection

In some cases, your previous screen session may not have detached properly when you lost your connection. If this happens, you can detach your session manually.

To see your existing screen sessions, enter:

 screen -list

This will display a list of your current screen sessions. For instance, if you had one attached and one dead screen, you would see:

 There are screens on: 25542.pts-28.hostname (Dead ???) 1636.pts-21.hostname (Attached) Remove dead screens with 'screen -wipe'. 2 Sockets in /tmp/screens/S-username.

To detach an attached screen, enter:

 screen -D

If you have more than one attached screen, you can specify a particular screen to detach. For example, to detach the screen in the above example, you would enter:

 screen -D 1636.pts-21.hostname

Once you've done this, you can resume the screen by entering the screen -r command.

(In the above example, the dead screen isn't causing problems, but you should probably enter the screen -wipe command to get rid of it.)