Detach a forked process – signals to a disconnected and unref'ed process

[Nickwiz]

I fork a child in a master script using:

const proc = child_process.fork(sub_script, [], {
	// out / err: logfiles
	stdio: ['ignore', out, err, 'ipc'],
	detached: true,
});
proc.on('disconnect', ...);

The child does a startup routine then do process.disconnect().

The master script receives the disconnected event and continue with operations dependent on the spawned child.

Now: If I send a SIGINT or SIGTERM to the master it cleans up and exits. All OK.

But: If I omit the detached: true when forking the child the child process also receives these signals. Even if I do a .unref() in addition to disconnect().

My question is more on the curious side as of why the child get this signal even when both detached and dereferenced?

The proc.subprocess.channel is also undefined.

[bnoordhuis]

That's simply how the UNIX process model works. It's not specific to Node.js.