Configuring UNIX screen

Working with Víctor this morning. Getting UNIX screen set up on the project server. UNIX screen is notoriously difficult to set up and outstanding useful once you do. Happily, our session this morning went smoothly. We followed the six steps in Phil Hollenback's linux.com article here and only had to insert one additional step, for a total of seven. What worked for us:


1. Set the screen binary userid bit to true. Our starting conditions showed that the groupid bit was set to true on the screen binary upon installation but that the userid bit (in the first triplet of permissions settings) was not. So we were required to go through this first step.

2. Set the permissions on the /var/usr/screen directory to 755. Hollenback doesn't list this step in his article so we had to insert it here. But it was relatively easy to figure out because screen barked. The only unusual thing here is that /var/usr/screen was setting to the more-liberal 775 immediately after installation. Which means that by resetting permissions to 755 we actually restricted the directory's access further. But it did work. Everything else is easy.

3. First user starts a session. Example: Víctor runs screen -S Abjad

4. First user turns multiuser mode on: Víctor runs ctrl-A :multiuser on

5. First user adds second user: Víctor types ctrl-A :acladd tbaca

6. Second user attaches to first user's screen session: Trevor types screen -x vadan/Abjad


That's it. Extremely useful.