Examples of problems with integers

Hello! A few days back we talked about problems with floating point numbers. This got me thinking – but what about integers? Of course integers have all kinds of problems too – anytime you represent a number in a small fixed amount of space (like 8/16/32/64 bits), you’re going to run into problems. So I asked on Mastodon again for examples of...

2w

Examples of floating point problems

Hello! I’ve been thinking about writing a zine about how things are represented on computers in bytes, so I was thinking about floating point. I’ve heard a million times about the dangers of floating point arithmetic, like: addition isn’t associative (x + (y + z) is different from (x + y) + z) if you add very big values to very small values,...

3w

Some business graphs for 2022

Hello! I like looking at other independent authors’ business graphs, so I thought I’d share some percentages and graphs of my own this year. Hopefully some of this is useful to other writers who run internet businesses. All of the graphs are about Wizard Zines’ business selling zines – I don’t do sponsorships or consulting or commissions or anything....

4w

New zine: The Pocket Guide to Debugging

Hello! On Monday, we released a new zine: The Pocket Guide to Debugging! It has 47 of my favourite strategies for solving your sneakiest bugs. You can get it for $12 here: https://wizardzines.com/zines/debugging-guide, or get an 12-pack of all my zines here. Here’s the cover: the table of contents Here’s the table of contents!...

Dec 2022

A debugging manifesto

Hello! I’ve been working on a zine about debugging for the last 6 months with my friend Marie, and one of the problems we ran into was figuring out how to explain the right attitude to take when debugging. We ended up writing a short debugging manifesto to start the zine with, and I’m pretty happy with how it came out. Here it is as an image,...

Dec 2022

Tips for analyzing logs

Hello! I’ve been working on writing a zine about debugging for a while now (we’re getting close to finishing it!!!!), and one of the pages is about analyzing logs. I asked for some tips on Mastodon and got WAY more tips than could fit on the page, so I thought I’d write a quick blog post. I’m going to talk about log analysis in the context of...

Dec 2022

A couple of Rust error messages

Hello! I’ve been doing Advent of Code in Rust for the past couple of days, because I’ve never really gotten comfortable with the language and I thought doing some Advent of Code problems might help. My solutions aren’t anything special, but because I’m trying to learn, I’ve been trying to take a slightly more rigorous approach than usual to...

Dec 2022

Making a DNS query in Ruby from scratch

Hello! A while back I wrote a post about how to write a toy DNS resolver in Go. In that post I left out “how to generate and parse DNS queries” because I thought it was boring, but a few people pointed out that they did not know how to parse and generate DNS queries and they were interested in how to do it. This made me curious – how much work...

Nov 2022

Why do domain names sometimes end with a dot?

Hello! When I was writing the zine How DNS Works earlier this year, someone asked me – why do people sometimes put a dot at the end of a domain name? For example, if you look up the IP for example.com by running dig example.com, you’ll see this: $ dig example.com example.com. 5678 IN A 93.184.216.34 dig has put a . to the end of example.com...

Sep 2022

How to send raw network packets in Python with tun/tap

Hello! Recently I’ve been working on a project where I implement a bunch of tiny toy working versions of computer networking protocols in Python without using any libraries, as a way to explain how computer networking works. I’m still working on writing up that project, but today I wanted to talk about how to do the very first step: sending...

Sep 2022