-X and multiuser mode

[Rod Nussbaumer]

sunbeam:bomr[/usr1/isac/tools] > screen -v
Screen version 3.09.15 (FAU) 13-Mar-03

This is running on Sun Solaris 8



We use screen primarily for it's multiuser capability, which allows us 
to share access to perpetual telnet sessions that are opened to a number 
of single-purpose black-box devices. There are many people who access 
the devices by attaching to perpetual screen sessions, and any existing 
sessions may have been started by any of the user group.


I would like to be able to issue commands to these long-running screen 
sessions that are running in multi-user mode. The problem is that 
apparently only the originator of the intial session, the owner, is able 
to access the /tmp/S-xxxxxx directory:


sunbeam:bomr[/usr1/isac/tools] > screen -S userxxx/13471.PLC9 -X 'log on'
Cannot opendir /tmp/screens/S-userxxx: Permission denied

(sorry if the above command line wraps...)



Now, I can attach to the specified multiuser session and interactively 
issue the command, no problem.

screen -S userxxx/13471.PLC9 -r

From that I gather that the permission issue is not insurmountable, nor 
is there a real security issue being enforced. Have I missed something 
that would allow me to issue the commands from a non-owner user account? 
I would like to have commands issued from a cron job, to ensure that log 
files are rotated and being properly written.


If this capability is currently unsupported, is it something that could 
be added without a major effort? I would be willing to attempt to add 
the capablility myself, if someone familiar with the code can give some 
general direction to get me started. I have spent an hour or so browsing 
the sources, and didn't see much that looked like what I thought was the 
 right places to work on.

Thanks.

        ---   rod.