[PLUG] Connect BT keyboard to headless Raspberry

[Eric House]

On Sat, Jan 22, 2022 at 12:00 PM <plug-request at pdxlinux.org> wrote:

> I am not entirely sure what you did here. What are the two commands that
> you used to connect to the same screen session and how did you start that
> initial screen session? I thought the original scenario  was a keyboard
> attached to the Pi. You login via the keyboard and start a screen session.
> Granted this has to be done blindly because you don't have a display
> connected to the Pi. Then from the Ipad you ssh to the Pi and connect to
> the screen session started from the Pi keyboard. This has only one ssh
> session involved.
>

That was the original scenario, but I'm trying to confirm that screen can
do what I want before figuring out how to get the keyboard to connect over
BT. (For some reason it connects when its session will be directed to tmux
but not when it'll be directed to screen. I'm punting on figuring out why.)

So I'm working with two connections via ssh. If I can get them to do what I
want I'll figure out how to get the keyboard to connect instead of one of
them. Am I wrong to expect the keyboard's session to behave the same
(modulo that I can't see it)?

Anyway, I've tried setting up the initial session (with 'screen -dmS main')
from a @reboot in my user's crontab and from the commandline of the first
ssh connection after a reboot. In both cases subsequent sessions
established with 'screen -x main' that coexist are not mirrored. I assume
that if one of them were the keyboard, and I used that keyboard to open a
new window , I would not see that window in the terminal -- just as I don't
when both connections are via ssh.

BTW, I've read that screen provides a typing lock on a per-window basis:
first to open a window is the only one allowed to type there until moving
away from the window. That screen's designers were thinking that way
suggests (at least to me) that they weren't interested in mirroring at all.
So I'm surprised that people describe using screen in scenarios that
require mirroring. Or perhaps I'm misunderstanding.

Thanks,

--Eric