On localhost, how do I pick a free port number?
问题内容：
I’m trying to play with inter-process communication and since I could not
figure out how to use named pipes under Windows I thought I’ll use network
sockets. Everything happens locally. The server is able to launch slaves in a
separate process and listens on some port. The slaves do their work and submit
the result to the master. How do I figure out which port is available? I
assume I cannot listen on port 80 or 21?
I’m using Python, if that cuts the choices down.
问题答案：
Do not bind to a specific port. Instead, bind to port 0:
sock.bind(('', 0))
The OS will then pick an available port for you. You can get the port that was
chosen using sock.getsockname()[1], and pass it on to the slaves so that
they can connect back.
