stdout on end

[plondon]

Hi @raxod502! I'm trying to fire an event after the stdout data has finished streaming. I think I need to hook into something here: https://github.com/raxod502/riju/blame/master/backend/api.js#L328

Do you know of a simple way to do that? Or do you have any advice? Thanks!

[raxod502]

You mean from the frontend? You should probably look for the serviceFailed event for the terminal service.

Or are you talking about modifying the backend? You could set a listener for the EOF event on the stdout stream, but that's approximately equivalent for most realistic use cases to just listening for process termination, which we do already.

[plondon]

Gotcha, yes this is what I'm looking for. However, this event only fires if the language does not have a repl. Any advice on handling languages w/ repls? Much appreciated in advance!

[raxod502]

Ah. You want to tell when the user code has finished executing. Unfortunately there's no real way to do that at least with the current architecture, since it's a single program execution. For example, if you run python3 -i main.py, there's no way to tell when main.py ends and when the repl begins.

Open to suggestions on how that could be changed, but I don't think it's possible without some rearchitecting.

[plondon]

I think it would be possible to use spawnSync instead of spawn in runCode, but an initial pass did not work. I can keep investigating. Glad to know there is no real way to do what I'm trying at the moment!

[raxod502]

If you use spawnSync, then all that's going to happen is the invocation will never terminate. This isn't something you can change at the level of process invocation: you'd have to fundamentally change the semantic interpretation of the repl and run commands, and rewrite them for all existing languages.