Posts by Year


Building a 6502 Computer

70 minute read

My notes of building a computer based on the 6502 microprocessor following Ben Eater’s design.


Beware of wilcards paths in sudo commands

7 minute read

Say you want to allow a non-root user on Linux to execute a couple of scripts as root or another user with more privileges. A common way of doing this is to ...


Python tarfile directory traversal

12 minute read

Currently, there’s a lot of hype around the behavior of Python’s tarfile module for extracting archives. In short: tarfile will not sanitize filenames in arc...

Remote debugging Claris Data API

13 minute read

When debugging code that integrates with the Claris FileMaker Data API, it is sometimes helpful to trace a request from your app all the way to the code of t...

Remote debugging NodeJS apps

11 minute read

When you want to debug an application in an environment which is hard to replicate locally and/or you cannot install additional software on the machine it is...



CRTP Certification Review

23 minute read

A couple of days ago I took the exam for the CRTP certification by Pentester Academy. In this review I want to give a quick overview of the course contents, ...



The basics of Logarithms – with examples

26 minute read

Logarithms are widely used in computer science (e.g. for algorithm analyses, floating point number limitations, scaling data, feature transformations). Not c...

Using vi commands in your bash shell

2 minute read

Entering a long shell command and then moving the cursor around to correct parts of it always felt a bit clunky to me. I remembered some of the <ctrl>/...

Basic understanding of IPv4 addresses

16 minute read

In a recent project I needed to anonymize IP addresses in tracking data. While masking a few bits from an IP address is not so interesting, it’s a good excus...

A few updates

8 minute read

After having neglected my blog over the last few months, I want to start posting more frequently again (New Year’s resolutions and all that).


LaTeX mathematics cheat sheet

10 minute read

LaTeX is the de facto standard typesetting system for scientific writing. Find a a cheat sheet with the most frequent used mathematics commands here.

Debugging Jupyter notebooks

5 minute read

While searching for ways to debug code in a Jupyter notebook, I found a lot of outdated posts. So I decided to quickly write up my findings.


Working with FileMaker data in Python

14 minute read

This is an old post. You may also be interested in accessing your FileMaker database via the new Data API. I wrote a Python wrapper to make it easier: python...