Frænkïbøï

Category: Programming

  • Raspberry Pi 4, WS2801 & Apple HomeKit

    Raspberry Pi 4, WS2801 & Apple HomeKit

    Intro In this post, I’m going to explain how to connect a WS2801 RGB-LED-strip to the RPi 4B and Apple HomeKit. I’m writing this during the 2020 Covid-19 quarantine. I had lots of time to spend, obviously, so I started this project. It started as a simple wood project and then I wanted to add…

  • Howto: WordPress Child Themes

    Last week, I had to make some HTML/CSS/PHP changes to a wordpress blog. I remembered, that the last time I made something like that, all of my changes made directly to the running theme have been overwritten by a theme update. So this time, I really wanted to make things right, make it the wordpress…

  • WordPress Spam on Attachment Pages

    The other day I recognized in the dashboard of one of my pages, that I had 1600 something unanswered comments. ALTHOUGH I completely disabled comments on my page. I used a fancy theme together with a bunch of plugins to enable a Flickr’ish kind of gallery display with a lightbox. It turns out that wordpress…

  • iMacros enhanced using Javascript

    Introduction The other day, I had to automate interactions on a web page, for testing purposes. I stumbled across the iMacros Firefox extension, which turned out to be very mighty. Basics With iMacros you can automate sequences of events on web pages in order to test them in terms of behavior and/or performance. The extension…

  • Howto find memory leaks using code injection via LD_PRELOAD

    Introduction I recently had to find a memory leak in a huge C/C++ application running on linux. Unfortunately, I was not able to use valgrind, because the application was too slow when running inside the valgrind VM. So I decided to write my own memory debugging library. The key idea is to overwrite/replace the original…

  • Need ldd on windows?

    Hey there, if you might ever need something like ldd on windows to figure out the dependencies on dynamic libraries of some binary, the following link could interest you: http://www.dependencywalker.com/

  • GDB command

    Hey folks, I’ve just discovered another neat feature of gdb: command. I was in a situation where I needed to watch a certain variable on each breakpoint hit. Generally, this is pretty easy in gdb using its watch-feature. Unfortunately, the variable under consideration was a QString. Now, we already have some experience with those little…

  • Print QStrings in GDB

    If you will ever have to go through the hell of debugging Qt-applications, you might face the problem of printing the contents of QString objects. If you call print on a QString object in gdb, the output will most probably look like the following: {static null = {}, static shared_null = {ref = {_q_value =…