#!/usr/local/bin/python
#
# Copyright (c) 2003-2005 Maxim Sobolev. All rights reserved.
# Copyright (c) 2006-2014 Sippy Software, Inc. All rights reserved.
#
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without modification,
# are permitted provided that the following conditions are met:
#
# 1. Redistributions of source code must retain the above copyright notice, this
# list of conditions and the following disclaimer.
#
# 2. Redistributions in binary form must reproduce the above copyright notice,
# this list of conditions and the following disclaimer in the documentation and/or
# other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
# ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
# ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

import os, sys

def daemonize(logfile = None):
    # Fork once
    if os.fork() != 0:
        os._exit(0)
    # Create new session
    os.setsid()
    if os.fork() != 0:
        os._exit(0)
    os.chdir('/')
    fd = os.open('/dev/null', os.O_RDWR)
    os.dup2(fd, sys.__stdin__.fileno())
    if logfile != None:
        fake_stdout = file(logfile, 'a', 1)
        sys.stdout = fake_stdout
        sys.stderr = fake_stdout
        fd = fake_stdout.fileno()
    os.dup2(fd, sys.__stdout__.fileno())
    os.dup2(fd, sys.__stderr__.fileno())
    if logfile == None:
        os.close(fd)

Add previously missing file.