Write to/ read from process in gdscript

:information_source: Attention Topic was automatically imported from the old Question2Answer platform.
:bust_in_silhouette: Asked By 0rube
:warning: Old Version Published before Godot 3 was released.

How can I read and write to a process in gdscript, after starting it with OS.execute(...)?

Java-Example:

    Process process = builder.start();

    OutputStream stdin = process.getOutputStream(); // <- Eh?
    InputStream stdout = process.getInputStream();

    BufferedReader reader = new BufferedReader(new InputStreamReader(stdout));
    BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(stdin));

    writer.write("Sup buddy");
    writer.flush();
    writer.close();

    Scanner scanner = new Scanner(stdout);
    while (scanner.hasNextLine()) {
        System.out.println(scanner.nextLine());
    }