Question

I have a bunch of servers, on which I run experiments using screen. The procedure is the following :

1. ssh to server XXX
2. launch screen
3. start experiments in a few tabs
4. detach screen
5. disconnect from the server

While the experiments are running, I can easily find on which servers they are by sshing to all servers and listing my running processes (using top or ps).

However, once the experiments are finished, how could I find on which servers I have a screen session opened (so that I can have a look at the output, relaunch them, etc.) ?

PS: my experiments do print their output to files, too… but this is not the point of my question.

Answer 1

To list all of the screen sessions for a user, run the following command as that user:

screen -ls 

To see all screen sessions on a specific machine you can do:

ls -laR /var/run/screen/ 

I get this on my machine:

gentle ~ # ls -laR /var/run/screen/  /var/run/screen/: total 1 drwxrwxr-x  4 root utmp   96 Mar  1  2005 . drwxr-xr-x 10 root root  840 Feb  1 03:10 .. drwx------  2 josh users  88 Jan 13 11:33 S-josh drwx------  2 root root   48 Feb 11 10:50 S-root  /var/run/screen/S-josh: total 0 drwx------ 2 josh users 88 Jan 13 11:33 . drwxrwxr-x 4 root utmp  96 Mar  1  2005 .. prwx------ 1 josh users  0 Feb 11 10:41 12931.pts-0.gentle  /var/run/screen/S-root: total 0 drwx------ 2 root root 48 Feb 11 10:50 . drwxrwxr-x 4 root utmp 96 Mar  1  2005 .. 

This is a rather brilliantly Unixy use of Unix Sockets wrapped in filesystem permissions to handle security, state, and streams.