pscan — Multi-threaded port-scanner

Building a network port-scanner from scratch with Python. From implementing the core socket module, to learning about locking threads.

Python Sockets CLI

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// what it does

This is a simple port scanner written in Python. It allows you to scan a range of ports on a specified host to check which ports are open.

terminal

usage: portscanner [-h] [--start START] [--end END] [host]

positional arguments: host hostname or IPv4 address

options:

-h, --help show help message and exit

--start START start of the port range to be scanned

--end END end of the port range to be scanned

example usage: python3 portscanner.py --start 0 --end 1000 example.com

// roadmap

✓ Implement Python socket module

✓ Make the first socket connection

✓ Scanning multiple ports

✓ Upgrade loops to threads

✓ Error handling

✓ Adding argparse

// devlog

Posts written while building this, in order.

Building a port scanner with Python

How I went about building a simple network port scanner from scratch with Python.

10 May
2026

Upgrading the port scanner with multi-threading

Switching out the loop logic for multi-threading, handling errors, and adding argparse.

12 May
2026