Port tester in Python with socket

readme.md

Description

NOTE: These two errnos used in this script may only functional in Windows. You need to modify this script before using this script in *nix systems.

This simple file will allow you to test if a port is available for usage. I recently found that some ports can not be used beacuse of insufficient permission. I wrote this simple script to test how many ports are blocked by sofware firewall installed in my PC. After some search I discovered that it's all Hyper-V's fault. Stop reserving ports, Hyper-V.

Usage

Just simply invoke a Python 3.6+ to run this script.

It will test all available ports (1025-65535) by trying to bind to 0.0.0.0. It will give you a simplified report after testing.

Related links

https://stackoverflow.com/a/54727281
docker/for-win#3171 (comment)

porttest.py

"""
A simple port tester, using socket to bind and see what will happen.
WTFPL
"""

import sys
import socket
import itertools
import errno

available_ports = (1025, 65535)

used_ports = []
failed_ports = []
success_ports = []
host = '0.0.0.0'

def ranges(i):
    """
    Generate a range from list of numbers
    Source: https://stackoverflow.com/a/4629241
    """
    for a, b in itertools.groupby(enumerate(i), lambda pair: pair[1] - pair[0]):
        b = list(b)
        pair = b[0][1], b[-1][1]
        if pair[0] == pair[1]:
                yield (pair[0])
        else:
                yield pair


def try_bind(port: int) -> int:
        """
        Try to bind a port using socket.
        Returns 0 if successfully bind, 1 if the port is used, otherwise returns 2.
        """
        status = 0
        print(f'Testing port {port}...', end='\r')
        s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        try:
                s.bind((host, port))
        except socket.error as e:
                if e.errno == errno.WSAEACCES:
                        failed_ports.append(port)
                        status = 2
                        return status
                elif e.errno == errno.WSAEADDRINUSE:
                        used_ports.append(port)
                        status = 1
                        return status
                else:
                        print(f'\nPort {port} is in a unknown status.')
                        return 3
        
        success_ports.append(port)
        s.close()
        return status


def printout_ranges(r: list):
        counter = 0
        for i in r:
                str = ''
                if counter > 80:
                        print()
                        counter = 0
                if type(i) is int:
                        str += '{} '.format(i)
                else:
                        str += '{}-{} '.format(i[0], i[1])
                counter += len(str)
                print(str, end='')
        print()

def printout():
        print('\r')
        range_s = list(ranges(success_ports))
        range_f = list(ranges(failed_ports))
        range_i = list(ranges(used_ports))
        print(f'You have {len(success_ports)} ports available.')
        print('These ports are:')
        printout_ranges(range_s)
        print()
        print(f'You have {len(used_ports)} ports which are already in use.')
        print('These ports are:')
        printout_ranges(range_i)
        print()
        print(f'You have {len(failed_ports)} ports which can NOT be bound.')
        print(f'If you have WSL 2 or Hyper-V enabled, head to the link below for more details:')
        print('https://github.com/docker/for-win/issues/3171#issuecomment-459205576')
        print('https://stackoverflow.com/a/54727281')
        print('These ports are:')
        printout_ranges(range_f)

if __name__ == "__main__":
    print(f'Testing port from {available_ports[0]} to {available_ports[1]} ...')
    for i in range(available_ports[0], available_ports[1] + 1):
            try_bind(i)
    
    printout()
    sys.exit(0)