Test of sending file descriptors to another process using AF_UNIX

af_unix_send_fd.py

from socket import *
import struct

#Open a file (opens itself now)
this_script = open(__file__, 'r')

#List of file descriptors to send
fd_list = [this_script.fileno()]

#Prepare ancillary data
cmsg_level, cmsg_type, cmsg_data = SOL_SOCKET, SCM_RIGHTS, struct.pack('I'*len(fd_list), *fd_list)
anc_data = [(cmsg_level, cmsg_type, cmsg_data)]

#Socket to connect to
socket_path = '/tmp/fd_test.sock'


#Seek to a known location
this_script.seek(420)

print('File descriptors', fd_list)
with socket(AF_UNIX, SOCK_SEQPACKET) as target:
	target.connect(socket_path)
	target.sendmsg([b'Yo! Have some file descriptors =)'], anc_data)