subprocess-util/unix_sock_input.py

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#!/usr/bin/env python3
# -*- coding: utf-8 -*-
2023-01-10 22:13:56 +01:00
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()