SIGINT (Ctrl-C) always quits shell while running in Node

[AtkinsSJ]

This code, which we use to intercept Ctrl-C, unconditionally terminates Phoenix:

phoenix/src/pty/NodeStdioPTT.js

Lines 32 to 35 in f7f2ded

	if (input.length === 1 && (input[0] === signals.SIGINT || input[0] === signals.SIGQUIT)) {
	process.exit(1);
	return;
	}

This means we never allow Phoenix to handle that itself, either to terminate a running foreground process, or cancel the user's current command input.

I couldn't figure out how to make this work correctly. I think we should remove that code (or maybe limit it to the kill signals - side note, I get the impression our SIG values are wrong?) and then handle the signals inside readline() somehow, but I'm not sure. @KernelDeimos Any thoughts?

[KernelDeimos]

We need to make sure it's possible to exit the shell. Any bugs related to not being able to exit the shell are very frustrating. I'd recommend this:

• temporarily for development: create an async poll interval; as soon as the file /some/path/exit-shell exists, then process.exit(1)
• remove this and see what happens when you type Ctrl+C
• add SIGINT handling to readline so we can exit the shell when no child process is running

[KernelDeimos]

side note, I get the impression our SIG values are wrong?

signals.js has SIGINT: 2 and SIGQUIT: 3. I believe these are correct, but none of the other signals (like SIGWINCH) are in there yet.

[AtkinsSJ]

side note, I get the impression our SIG values are wrong?

signals.js has SIGINT: 2 and SIGQUIT: 3. I believe these are correct, but none of the other signals (like SIGWINCH) are in there yet.

Those do seem correct actually... I'm not sure what made me think they weren't, but something was behaving oddly.

[AtkinsSJ]

OK, I think my issue was that Ctrl-C makes Node give us the input 3, which is the ETX character, not SIGINT. But we interpreted it as a signal:

phoenix/src/pty/NodeStdioPTT.js

Lines 32 to 35 in f7f2ded

	if (input.length === 1 && (input[0] === signals.SIGINT || input[0] === signals.SIGQUIT)) {
	process.exit(1);
	return;
	}

It just happens that SIGQUIT is also 3, so the code seemed to work. I just misunderstood what Node was passing us there.