[RndTbl] Screen

Sean Cody sean at tinfoilhat.ca
Fri Jun 12 13:05:21 CDT 2015

On 2015-06-12 08:18, Kevin McGregor wrote:
> I've been using 'screen' (yay!). Mostly fine, getting used to it. But
> then this happened:
> # screen -r
> There are screens on:
>         20900.pts-13.server      (Dead ???)
>         29291.pts-1.server       (Dead ???)
> Remove dead screens with 'screen -wipe'.
> There is no screen to be resumed.
> What sort of things cause this?

Screen process died abnormally and didn't trap right to remove... sudden 
reboots etc.

> I'm guessing it means both screen
> sessions are completely toast, and the list above is just due to some
> leftover lock files or something.

Yup.  Those first digits in the screen name may be the process ID 
(depends on configuration) so you can see if any of those PIDs are 
parents to any running processes... odds are the subprocesses were 
either killed/died/zombied.

Screen -wipe just well... removes those files.

They are what screen uses to inform itself how to attach to sessions.
You can check them out in /tmp/
You'll find a folder for each session and a named pipe (which is the 
connection point for the screen client to an existing session).

Glad you are playing aroudn with the tool.  It is extremely powerful and 
enabling... especially for long running processes/reports.  You can use 
it to do training etc... I explain it as WebEx before that was a thing.

Hope that helps,

P.S. A BSD alternative is tmux and it's AWESOME.

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