#! /usr/bin/python
# -*- test-case-name: twisted.python.test.test_sendmsg -*-
# Copyright (c) Twisted Matrix Laboratories.
# See LICENSE for details.

import sys, os
from struct import unpack

# This makes me sad. Why aren't things nice?
sys.path.insert(0, __file__.rsplit('/', 4)[0])

from twisted.python.sendmsg import recv1msg

def recvfd(socketfd):
"""
Receive a file descriptor from a L{send1msg} message on the given C{AF_UNIX}
socket.

@param socketfd: An C{AF_UNIX} socket, attached to another process waiting
to send sockets via the ancillary data mechanism in L{send1msg}.

@param fd: C{int}

@return: a 2-tuple of (new file descriptor, description).

@rtype: 2-tuple of (C{int}, C{str})
"""
data, flags, ancillary = recv1msg(socketfd)
[(cmsg_level, cmsg_type, packedFD)] = ancillary
# cmsg_level and cmsg_type really need to be SOL_SOCKET / SCM_RIGHTS, but
# since those are the *only* standard values, there's not much point in
# checking.
[unpackedFD] = unpack("i", packedFD)
return (unpackedFD, data)


if __name__ == '__main__':
fd, description = recvfd(int(sys.argv[1]))
os.write(fd, "Test fixture data: %s.\n" % (description,))
os.close(fd)