handle stale pid file

hbc

@@ -26,6 +26,7 @@ import syslog
 
 PORT = 50003
 INTERVAL = 10
+PIDFILE = '/tmp/hbc.pid'
 DBG = True
 
 sock = None
@@ -260,12 +261,32 @@ if msgonly:
 # 
 syslog.openlog(logoption=syslog.LOG_PID, facility=syslog.LOG_DAEMON)
 if fdaemon:
-	print "daemoinizing... %s" % os.getpid()
 
+	pidfile = daemon.pidfile.TimeoutPIDLockFile(PIDFILE, acquire_timeout=-1)
+	try:
+		opid = pidfile.read_pid()
+	except:
+		opid = None
+	if verbose: print "opid %s" % opid
+
+	if opid:
+		try:
+			os.kill(opid, 0)
+			is_running = True
+		except:
+			is_running = False
+		if verbose: print "is_running  %s" % is_running 
+		if is_running:
+			print "process still alive %s" % opid
+			sys.exit(1)
+		print "warning: stale pid file removed"
+		os.unlink(PIDFILE)
+
+	print "daemoinizing... %s" % os.getpid()
 	context = daemon.DaemonContext(
 		working_directory='/tmp',
 		umask=0o002,
-		pidfile=daemon.pidfile.TimeoutPIDLockFile('/tmp/hbc.pid', acquire_timeout=-1),
+		pidfile=pidfile,
 		)
 
 	context.signal_map = {