Telling Textual App how to ignore or pass-through certain keystroke sequences to originating stdin

[evanpolster]

Use Case: We have a requirement that when we run long-running jobs from a terminal (like a lengthy build) we must do it from inside a tmux session. That is because our security configuration sets an user-input inactivity timeout on our connection and kicks us out before the job has finished. The tmux session allows us to reconnect to the system and reattach to the terminal session (i.e. the still running build) as if we were never detached to begin with.

I tried this morning to run my Textual app (which indeed wraps our long-running build) inside a tmux session and it appears to work correctly which is potentially very powerful.

The only thing I can't figure out how to do is send the tmux magical 'detach' keystroke sequence (e.g. Ctrl-B D) from inside the Textual app in order to get out of the tmux session and back up into the original default terminal (i.e. from where I ran tmux new-session to begin with).

As Textual appears to do with Ctrl-C, is there any way to tell the Textual app to pass through certain key sequences from its intercepted stdin back to the command-line's stdin (i.e. the terminal session from where the Textual app was started)?

If not, is there a key sequence that can push the Textual App to the background (kinda like an equivalent to Ctrl-Z on Linux shell )?

[davep]

To clarify on the Ctrl+C front: that's something that's handled by Textual itself -- it's not that the key combination gets passed "up" and the operating system kills the application.

On your more general point, just to check I'm understanding things correctly: you want some way to start a tmux session, running a Textual app, and have it detach right away so you can come back to it later? (I ask only because Ctrl+B D works right now with Textual apps, if you're the one pressing it). If that's the case, would it not make more sense to create a detached session to start with?

I'm not really much of a tmux user but I believe this should work just fine:

$ tmux new-session -d my-textual-application-here

then later you can:

$ tmux attach

to attach to the session and view and interact with the application.

Testing that here now and it all works fine.

[evanpolster]

You are correct. I apparently had my tmux detach key sequence set to Ctrl-a d and not the default of Ctrl-b d

Thanks, as usual, for your excellent answer and apologies for the disruption.

[davep]

Not at all disruptive, glad you got the answer one way or another. 🙂