from typing import Callable, Iterable, Tuple _Reader = Callable[[int], bytes] STDIN_FILENO: int STDOUT_FILENO: int STDERR_FILENO: int CHILD: int def openpty() -> Tuple[int, int]: ... def master_open() -> Tuple[int, str]: ... def slave_open(tty_name: str) -> int: ... def fork() -> Tuple[int, int]: ... def spawn(argv: str | Iterable[str], master_read: _Reader = ..., stdin_read: _Reader = ...) -> int: ...