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# daemon code from ASPN
import os
import sys
def daemonize(pidfile, home):
"""
Detach this process from the controlling terminal and run it in the
background as a daemon.
"""
UMASK = 0
WORKDIR = "/"
REDIRECT_TO = getattr(os, 'devnull', '/dev/null')
MAXFD = 1024
try:
pid = os.fork()
except OSError, e:
raise Exception("%s [%d]" % (e.strerror, e.errno))
if (pid == 0): # The first child.
os.setsid()
try:
pid = os.fork() # Fork a second child.
except OSError, e:
raise Exception, "%s [%d]" % (e.strerror, e.errno)
if (pid == 0): # The second child.
os.chdir(WORKDIR)
os.umask(UMASK)
else:
os._exit(0) # Exit parent (the first child) of the second child.
else:
os._exit(0) # Exit parent of the first child.
#import resource # Resource usage information.
#maxfd = resource.getrlimit(resource.RLIMIT_NOFILE)[1]
#if (maxfd == resource.RLIM_INFINITY):
# maxfd = MAXFD
# Iterate through and close all file descriptors.
#for fd in range(3, maxfd):
# try:
# os.close(fd)
# except OSError: # ERROR, fd wasn't open to begin with (ignored)
# pass
# This call to open is guaranteed to return the lowest file descriptor,
# which will be 0 (stdin), since it was closed above.
#os.open(REDIRECT_TO, os.O_RDWR) # standard input (0)
# Duplicate standard input to standard output and standard error.
#os.dup2(0, 1) # standard output (1)
#os.dup2(0, 2) # standard error (2)
f = open(pidfile, 'w')
f.write('%d\n' % (os.getpid(),))
f.write('%s\n' % (home,))
f.close()
def is_running(pidfile):
try:
f = open(pidfile, 'r')
except IOError:
return False
pid = int(f.readline())
f.close()
try:
os.kill(pid, 0)
except OSError:
# no such process
return False
return True
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