#!/usr/bin/python
"""
Virt-factory backend code.

Copyright 2006, Red Hat, Inc
Michael DeHaan <mdehaan@redhat.com>
Scott Seago <sseago@redhat.com>
Adrian Likins <alikins@redhat.com>

This software may be freely redistributed under the terms of the GNU
general public license.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
"""

import os
import string
import sys
import traceback

# this is kind of handy, so keep it around for now
# but we really need to fix out server side logging and error
# reporting so we don't need it
def trace_me():
   x = traceback.extract_stack()
   bar = string.join(traceback.format_list(x))
   return bar


def daemonize(pidfile=None):
    """
    Daemonize this process with the UNIX double-fork trick.
    Writes the new PID to the provided file name if not None.
    """

    print pidfile
    pid = os.fork()
    if pid > 0:
       sys.exit(0)
    os.setsid()
    os.umask(0)
    pid = os.fork()


    if pid > 0:
       if pidfile is not None:
          open(pidfile, "w").write(str(pid))
       sys.exit(0)