OnCommandLookup is the TGetEvent event handler triggered when a client makes a query to the WhoIs server. OnCommandLookup is used during execution of the threaded client connection, and allows the server to implement the specifics operations needed to resolve the WhoIs query. OnCommandLookup is the event handler used to respond to execution of the TIdWHOIS.WhoIs method on the client. 

AThread is the thread for the client connection. ALookup is the domain query to be resolved by the WhoIs server. 

A server implementation must assign a procedure to the event handler to allow responding to the event notification. The procedure is responsible for all aspects of resolving the WhoIs query in ALookup, and writing appropriate return values or error messages to the client connection in AContext.

TGetEvent 

TIdContext 

TIdWhois.WhoIs