Take advantage of the Model inheritance provided by polymodel.PolyModel to
have Club, School, Sponsor, and Organization actually inherit from the Group
Model class, rather than being composed via ReferenceProperties.
Patch by: Todd Larsen
Review by: Pawel Solyga, Sverre Rabbelier, Augie Fackler
Review URL: http://codereviews.googleopensourceprograms.com/606
import os
import sys
if os.name == 'posix':
def become_daemon(our_home_dir='.', out_log='/dev/null', err_log='/dev/null'):
"Robustly turn into a UNIX daemon, running in our_home_dir."
# First fork
try:
if os.fork() > 0:
sys.exit(0) # kill off parent
except OSError, e:
sys.stderr.write("fork #1 failed: (%d) %s\n" % (e.errno, e.strerror))
sys.exit(1)
os.setsid()
os.chdir(our_home_dir)
os.umask(0)
# Second fork
try:
if os.fork() > 0:
os._exit(0)
except OSError, e:
sys.stderr.write("fork #2 failed: (%d) %s\n" % (e.errno, e.strerror))
os._exit(1)
si = open('/dev/null', 'r')
so = open(out_log, 'a+', 0)
se = open(err_log, 'a+', 0)
os.dup2(si.fileno(), sys.stdin.fileno())
os.dup2(so.fileno(), sys.stdout.fileno())
os.dup2(se.fileno(), sys.stderr.fileno())
# Set custom file descriptors so that they get proper buffering.
sys.stdout, sys.stderr = so, se
else:
def become_daemon(our_home_dir='.', out_log=None, err_log=None):
"""
If we're not running under a POSIX system, just simulate the daemon
mode by doing redirections and directory changing.
"""
os.chdir(our_home_dir)
os.umask(0)
sys.stdin.close()
sys.stdout.close()
sys.stderr.close()
if err_log:
sys.stderr = open(err_log, 'a', 0)
else:
sys.stderr = NullDevice()
if out_log:
sys.stdout = open(out_log, 'a', 0)
else:
sys.stdout = NullDevice()
class NullDevice:
"A writeable object that writes to nowhere -- like /dev/null."
def write(self, s):
pass