Allow tty interraction for started processes

[samodadela]

Feature Request

Allow any started process tty/stdin to be accesses via TUI.

Use Case:

I use process-compose to start processes that require tty. Example: mvn quarkus:dev :app. Those processes are services, but quarkus:dev also opens a tty where you can do things like restart, run tests, etc (you type 's', for example).

Proposed Change:

Allow tty interraction to any started process.
There's already a similar feature (is_foreground), but for some reason processes must be started manually.

Who Benefits From The Change(s)?

Whoever wonders why typing in the TUI does nothing.

Alternative Approaches

Run each process inside tmux?

[F1bonacc1]

Hi @samodadela,

This feature is available since v1.85.0.
https://f1bonacc1.github.io/process-compose/interactive-processes/

[samodadela]

@F1bonacc1 You're right - and it works. I got confused by: https://f1bonacc1.github.io/process-compose/launcher/#foreground-processes

In my mind this seemed like the feature to use (Foreground processes are useful for cases when a full tty access is required (e.g. vim, top, gdb -tui))... but then I read "Foreground process have to be started manually (F7). They can be started multiple times" and since I wanted automatic started...

Thanks!

[samodadela]

I have another question... maybe for another issue? Is it possible to send a key instead of a termination signal? That is send key 'q' so the app exits?

Or is it possible to get the name of the tty so I can send the key using echo?

[F1bonacc1]

I have another question... maybe for another issue? Is it possible to send a key instead of a termination signal? That is send key 'q' so the app exits?

Or is it possible to get the name of the tty so I can send the key using echo?

Neither of those will work the way you're hoping, unfortunately.

Sending a key as a "stop": there's no built-in way to do that today. The shutdown.command option runs a separate command - it doesn't type into the running process's stdin. For an interactive (foreground) process, the way to send q is to attach to it in the TUI and type it in the terminal view.

Echoing to the tty: process-compose keeps the PTY master internally (it's an anonymous fd, so there's no device path to echo to). The slave /dev/pts/N is the process's own terminal, but anything you write there is treated as the program's output and rendered in the view - it doesn't reach the program's stdin. (And TIOCSTI, the old input-injection ioctl, is disabled by default on recent kernels.) So echo q > /dev/pts/N won't send a keystroke.

That said, "send keys to an interactive process" (e.g. to gracefully stop it with a keypress, or script input) is a reasonable thing to want and isn't covered today. Want to open it as a separate feature request so I can track it?

[samodadela]

@F1bonacc1 I tried interactive process but there are some problems - it seems that the tty is not drained until you switch to the processes console in the TUI. I'll open a separate issue. See #508