Using sudo and screen

The screen program requires write access to the pty of the logged in user. When using sudo, this no longer lines up and you'll get the ever useful error message:

$ screen -R -D
Cannot open your terminal '/dev/pts/0' - please check.

To get around the problem we can use the script program, which usually keeps a record of everything printed to a terminal, to create a new tty owned by the sudo user.

sudo -u popuser script -q -c 'screen -D -R myscreen' /dev/null

Here we sudo into the user we want to run screen, run script with output written to /dev/null, and then forcibly detach and re-attach or create the screen named myscreen.