以下过程适合我：

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,do 
> sudo chmod u-s /usr/bin/screen
> sudo chmod 775 /var/run/screen

because running screen suid root is a security risk

这令人沮丧.我一直在努力寻找,但我找不到更好的方法.有吗？