我正在运行Ubuntu 11.10和GNU屏幕版本“ 4.00.03jw4”，并且正在尝试使用多用户模式。
以下过程对我有用：
as user "first_user"
> sudo chmod u+s /usr/bin/screen
> sudo chmod 755 /var/run/screen
and only after that can you do
> screen -S session_name
or if you've already created a screen session,
> screen -r session_name
and inside of screen:
>^A:multiuser on
>^A:acladd second_user "#?"
and if you want second_user to only be an observer
>^A:aclchg second_user -w "#?"
now you can, as user "second_user", do
> screen -x first_user/
to connect
when you're all done, …