python - how to receive a socket message with an empty data?

Question

i have a socket client and a socket server.

(the server is in python, and is synchroneous.)

sometimes the clients send an empty string. i'm required to identify this situation, and return a response.

with this code, the server just keeps on waiting, and the client's don't get anything in return, unless it sends something mroe "fat" ;)

how can i capture the empty message? is it at all possible?

that's my server code:

import SocketServer

def multi_threaded_socket_server():

    class MyRequestHandler(SocketServer.BaseRequestHandler):
        def handle(self):
            while True:
                print 'waiting for client calls...'
                received = self.request.recv( PACKET_SIZE )
                (handle request... )

Answer 1

• In TCP, there is no such thing as an empty message, so zero means a peer disconnect.
• In UDP, there is no such thing as a peer disconnect, so zero means an empty datagram.

As you describe a multi-threaded socket server, it would seem to be TCP, in which case your requirement doesn't make sense. You can't send an empty message over TCP. You would have to use a superimposed protocol for everything.