how to listen a port in use ?

[Joseph C. Kopec]

Some simple suggestions:

1. The server listening to the port could signal the Python application 
(perhaps the server even currently produces side effects that the Python 
application could check -- for instance, a log file that logs connections).

2.  Much more intrusively (and efficiency destroying), the Python 
application could listen to the port and forward to the real server.

Ralf Claus wrote:

> Hello,
> how can i listen a port on my computer, if this port is in use ?  I want
> create a script that popup a message window if   anyone connect this port.
> My try with the socket modul do not work.  An error occurs : This port is in
> use !?
> 
> thanks
> 
> Ralf