How to check if a network port is open?

Question

How can I know if a certain port is open/closed on linux ubuntu, not a remote system, using python? How can I list these open ports in python?

• Netstat: Is there a way to integrate netstat output with python?

Answer 1

You can using the socket module to simply check if a port is open or not.

It would look something like this.

import socket sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) result = sock.connect_ex(('127.0.0.1',80)) if result == 0:    print "Port is open" else:    print "Port is not open" sock.close() 

Answer 2

If you want to use this in a more general context, you should make sure, that the socket that you open also gets closed. So the check should be more like this:

import socket from contextlib import closing     def check_socket(host, port):     with closing(socket.socket(socket.AF_INET, socket.SOCK_STREAM)) as sock:         if sock.connect_ex((host, port)) == 0:             print("Port is open")         else:             print("Port is not open")