vlc backup

[cnawfal]

hello i am trying to build a back up system using VLC. From a sat source i am sending channels using dvblast. and in a reception a i am using vlc to translate a chanel from one multicast address to an other one (for other purposes) the cl is : cvlc -vv udp://@239.100.100.4:5000 --sout='#standard{access=udp,mux=ts,dst=239.5.5.5:1234}' . Now what i want is that : when i stop the source (dvblast) i was expecting to get a special message from vlc to tell me that it can not connect to the source or something and then use this message to launch a new stream from onather server
the problem is that vlc doent give me any msg even if i use the verbosity
is their a way to get the messages from vlc?
any suggestions ?
or if vlc can not, do someone know any tool in command line linux which can alert me when their is no streams sent ?