Re: How to use groups from the command line (or at all)?

[Neal Fultz]

Once you have started a screen session, and then made a group inside
it, it will put you in the groups "windowlist" (C-A ") - at that point
you can start new shells the normal way (C-A c). To switch out of the
group to the default one, either switch by number to a shell, or go
into the windowlist and hit backspace.

I would describe this feature as more of a UI navigation tweak so that
you don't have 30 shells in your status bar. I wouldn't  be surprised
if it's not fully implemented for scripting externally via the -X
flag. You might (or might not) have more luck using the :source <file>
command. Another idea would be to pass in data via environment
variables.

HTH




On Tue, May 30, 2023 at 10:18 AM Tim Landscheidt <tim@tim-landscheidt.de> wrote:
>
> Hi,
>
> background: I use Screen 4.09.00 to control Emacs either in
> a local GUI terminal or an SSH client from my phone by using
> a command à la:
>
> | screen -dRS emacs_gnus sh -c 'pidof emacs || emacs -nw -f gnus'
>
> I want to customize Emacs's browse-url et al. so that they
> do the Right Thing™ depending on which device I'm controll-
> ing Emacs from.  My current game plan is to enhance the com-
> mand above so that prior to executing Screen, it notes the
> controlling device in some file /var/run/user/…  that I can
> then read in Emacs and act upon its contents.  But it would
> be more appropriate and better reusable code to consider
> this information a "property" of the Screen session.  Look-
> ing at the Screen manual, at first I thought I might store
> the information in a register, but groups ("local", "de-
> vice1", "device2", etc.) appear to be more fitting.
>
> So I launch a test session:
>
> | $ screen -dRS test
>
> and, in another terminal, I try to assign the session to a
> group and (unsuccessfully) query its name:
>
> | $ screen -S test -X group local
> | $ screen -S test -X group
> | $
>
> Rereading the manual, I note that it says: "Once a new group
> is created, it will act as a container for windows and even
> other groups."  So I assume that I need to create the group
> before using it:
>
> | $ screen -S test -X screen -t local //group
> | $
>
> This causes the "test" session to show a screen with the
> title "Group: local" and leaves me without a clue how to re-
> turn to my shell prompt.  But even though it did something,
> it did not succeed to assign the session to something query-
> able from the command line:
>
> | $ screen -S test -X group local
> | $ screen -S test -X group
> | $ screen -S test -ls
> | There is a screen on:
> |         64047.test      (Attached)
> | 1 Socket in /run/screen/S-tim.
> | $
>
> So (how) can I create a group, assign a session to it, and
> query the group a session is assigned to?
>
> TIA,
> Tim
>