how to register a callback for receiving traps??

Hi All

I need help to understand the callback mechanism for receiving traps.

As per the wiki tutorial in asynchronous application, the
netsnmp_session structure itself has a variable for storing the
callback function name which is called every time a message is
received.

However, when I receive a trap, it maynot be bound to a session so I
need a global handler to process all the incoming traps.

I scrolled through the snmptrapd code and figured out
netsnmp_add_global_traphandler( ) which is used to register a
callback . Is this the way to go ? THis function is a part of the
snmptrap application and not the library itself, so I am not sure.

Can somebody please advice as to how do I capture a trap pdu once i
receive it via snmp_read

thanks
in advance
Shyam