Recently, I was helping another Admin and I wanted to be able to share our screens but our IS department won’t allow for it. Being that we were working in a terminal session I decided to go this route instead.

Needed:
– Screen
– Local account on host computer/server for remote user

Install screen

sudo apt-get install screen

Set the screen binary (/usr/bin/screen) setuid root. By default, screen is installed with the setuid bit turned off, as this is a potential security hole.

sudo chmod +s /usr/bin/screen
sudo chmod 755 /var/run/screen

The host starts screen in a local xterm, using the command screen -S SessionName. The -S switch gives the session a name, which makes multiple screen sessions easier to manage.

screen -S screen-test

The remote user (remote_user) uses SSH to connect to the host computer (host_user).

ssh remote_user@server

The host (host_user) then has to allow multiuser access in the screen session via the command ^A :multiuser on (all ‘screen’ commands start with the screen escape sequence, ^A).

^A
:multiuser on

The host (host_user) must grant permission to the remote user (remote_user) to access the screen session using the command ^A :acladd user_name where user_name is the remote user’s login ID (remote_user).

^A
:acladd remote_user

The remote user can now connect to the hosts ‘screen’ session. The syntax to connect to another user’s screen session is screen -x host_user/sessionname.

screen -x host_user/screen-test