child_process "pipe"s what are they really at the OS level, can they be used outside of Node.JS?

[segevfiner]

The Node.JS docs state:

'pipe': Create a pipe between the child process and the parent process. The parent end of the pipe is exposed to the parent as a property on the child_process object as subprocess.stdio[fd]. Pipes created for fds 0, 1, and 2 are also available as subprocess.stdin, subprocess.stdout and subprocess.stderr, respectively. Currently, these are not actual Unix pipes and therefore the child process can not use them by their descriptor files, e.g. /dev/fd/2 or /dev/stdout.
– https://nodejs.org/docs/latest-v16.x/api/child_process.html#optionsstdio

So what are they really? At the OS level? I'm looking for a way for a child_process to have a file descriptor/pipe it can monitor for closure to know when its parent process has terminated. But since those are not real file descriptors, I have no idea how I can use them from a child process that isn't Node.JS, or if it is even possible ATM. e.g. Can a Python process read from a stdio > 2 spawned from a Node.JS parent?

[bnoordhuis]

They're UNIX sockets. Specifically, one end of a socketpair(2).

[Antonius-S]

But how it works on Windows?

[bnoordhuis]

Named pipes.

[Antonius-S]

Okay, and how to use it with non-Node processes? What name, what the protocol is?