Randall Hopper wrote:
>
> IIRC "UNIX Network Programming" by Stevens (among others) has some code to
> handle this with an explanation into what each fragment does, described
> under starting daemon processes. Vaguely I recall double fork, close all
> your open file descriptors, and sometimes become a process group leader,
> and separate yourself from the controlling terminal.
Daemon, double fork magic in Python:
from socket import *
from time import time, ctime, sleep
from threading import Lock, Thread, Event
import os, sys, asyncore, getopt
def main():
hostname = 'foobar'
SERVERIP = gethostbyname( hostname )
HBPORT = 1667
LISTEN_PORT = 2667
BEATWAIT = 10
hbThread = TaskThread (SERVERIP, HBPORT)
hbThread.start ()
print "Listening ..."
listenServer = Listener(LISTEN_PORT)
while 1:
asyncore.poll()
sleep(0.1)
# do the UNIX double-fork magic, see Stevens' "Advanced
# Programming in the UNIX Environment" for details (ISBN 0201563177)
try:
pid = os.fork()
if pid > 0:
# exit first parent
sys.exit(0)
except OSError, e:
print "fork #1 failed: %d (%s)" % (e.errno, e.strerror)
sys.exit(1)
# decouple from parent environment
os.chdir("/")
os.setsid()
os.umask(0)
# do second fork
try:
pid = os.fork()
if pid > 0:
# exit from second parent, print eventual PID before
print "Daemon PID %d" % pid
sys.exit(0)
except OSError, e:
print "fork #2 failed: %d (%s)" % (e.errno, e.strerror)
sys.exit(1)
# start the daemon main loop
main()
--
----------------------------------------------------------------------
Mark A. Bolstad [EMAIL PROTECTED]
Raytheon Systems Company (410)278-9149
Scientific Visualization Specialist
U.S. Army Research Laboratory - HPC Major Shared Resource Center
----------------------------------------------------------------------
