#!/usr/bin/env python3 # -*- coding: utf-8 -*- import socket from pathlib import Path def wait_until_command_received(socket_file: Path, commands: list[bytes]) -> bytes: """ Creates a UNIX socket at socket_file. Accepts connections on the UNIX socket, until one client sends one of the given commands as first message. Closes the UNIX socket. :returns: The command that was received. """ # INSPIRATION: https://pymotw.com/3/socket/uds.html print(f'Listening on socket {socket_file}') sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM) sock.bind(str(socket_file)) sock.listen(1) command = accept_loop_until_command_received(sock, commands) print(f'Closing socket {socket_file}') sock.close() socket_file.unlink(missing_ok=False) return command def accept_loop_until_command_received(sock: socket.socket, commands: list[bytes]) -> bytes: """ Uses an open UNIX socket. Accepts connections on the UNIX socket, until one client sends one of the given commands as first message. Does not close the UNIX socket. :returns: The command that was received. """ bufsize = max([len(cmd) for cmd in commands]) + len(b'\n') while True: connection, client_address = sock.accept() try: b: bytes = connection.recv(bufsize) for cmd in commands: if b == cmd: print(f'Received "{cmd}".') return cmd print(f'Received unknown message: {b}') except Exception as e: print(f'Error while reading message: {e}') finally: connection.close()