nullmailer-queuec.py

#!/usr/bin/env python3

import socket
import sys

SERVER_SOCKET = '/run/nullmailer/queued.sock'

# reference implementation from docs.python.org; will be in v3.9
if not hasattr(socket.socket, 'send_fds'):
    import array
    def send_fds(sock, msg, fds):
        ancdata = [(socket.SOL_SOCKET, socket.SCM_RIGHTS, array.array("i", fds).tobytes())]
        return sock.sendmsg([msg], ancdata)
    socket.socket.send_fds = send_fds

sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
try:
    sock.connect(SERVER_SOCKET)
except socket.error as msg:
    print(msg)
    sys.exit(255)

ret = 255
try:
    sock.send_fds((1).to_bytes(4, 'big'), [sys.stdin.fileno()])
    ret = int.from_bytes(sock.recv(1024), 'big')
finally:
    sock.close()

sys.exit(ret)