Subprocess.stdio

Extra file descriptors passed to the stdio option.

Entries beyond index 2 are number for "pipe" and "socket-fd" slots and, on POSIX, for slots where a raw file descriptor was supplied (the same fd is returned). On POSIX, reading this property transfers ownership of any "pipe" fds to the caller, who is then responsible for closing them; the subprocess will not close them. "socket-fd" and raw-fd slots are likewise caller-owned. Other slots — including raw fds on Windows — are null.