Wiki.Cyli.Org

This assumes you have your machine set up and have screen installed;

• Find out if Screen is installed 'setuid' or not, run; 'ls -l $(which screen)' and look for an 's' in the permissions field, like '-rwxr-sr-x'.
• If you don't see that 's', run 'sudo chmod u+s /usr/bin/screen' and 'sudo chmod 755 /var/run/screen'.
• As the user that want's to share a screen (amy in this case), run 'screen -d -m -S shared ; screen -S shared -X multiuser on ; screen -S shared -X acladd bob'
• Give the user bob instruction to run 'screen -x amy/shared'
• At this point, both Amy and Bob should see the same screen, either user can type - if Amy runs something like 'sudo echo “Hello”', she will be able to type her password, sudo will hide it from both users (it may echo the asterisk character).