-def createDaemon():
- """Detach a process from the controlling terminal and run it in the
- background as a daemon.
-
- """
- UMASK = 077
- WORKDIR = "/"
- # Default maximum for the number of available file descriptors.
- if 'SC_OPEN_MAX' in os.sysconf_names:
- try:
- MAXFD = os.sysconf('SC_OPEN_MAX')
- if MAXFD < 0:
- MAXFD = 1024
- except OSError:
- MAXFD = 1024
- else:
- MAXFD = 1024
- # The standard I/O file descriptors are redirected to /dev/null by default.
- #REDIRECT_TO = getattr(os, "devnull", "/dev/null")
- REDIRECT_TO = constants.LOG_NODESERVER
- 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:
- # exit() or _exit()? See below.
- os._exit(0) # Exit parent (the first child) of the second child.
- else:
- os._exit(0) # Exit parent of the first child.
- 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(0, maxfd):
- try:
- os.close(fd)
- except OSError: # ERROR, fd wasn't open to begin with (ignored)
- pass
- os.open(REDIRECT_TO, os.O_RDWR|os.O_CREAT|os.O_APPEND, 0600)
- # Duplicate standard input to standard output and standard error.
- os.dup2(0, 1) # standard output (1)
- os.dup2(0, 2) # standard error (2)
- return(0)
-
-