def daemonize()

in deploy/daemon.py [0:0]

• 30 lines of code
• 5 McCabe index (conditional complexity)

    def daemonize(self):
        """Deamonize class. UNIX double fork mechanism."""

        try: 
            pid = os.fork() 
            if pid > 0:
                # exit first parent
                sys.exit(0) 
        except OSError as err: 
            sys.stderr.write('fork #1 failed: {0}\n'.format(err))
            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
                sys.exit(0) 
        except OSError as err: 
            sys.stderr.write('fork #2 failed: {0}\n'.format(err))
            sys.exit(1) 
    
        # redirect standard file descriptors
        sys.stdout.flush()
        sys.stderr.flush()
        si = open(os.devnull, 'r')
        so = open(os.devnull, 'a+')
        se = open(os.devnull, 'a+')

        os.dup2(si.fileno(), sys.stdin.fileno())
        os.dup2(so.fileno(), sys.stdout.fileno())
        os.dup2(se.fileno(), sys.stderr.fileno())
    
        # write pidfile
        atexit.register(self.delpid)

        pid = str(os.getpid())
        with open(self.pidfile,'w+') as f:
            f.write(pid + '\n')