APFS (like many modern file systems but unlike its predecessor HFS+) supports copy-on-write. This means you can logically copy a file – it looks and behaves like a distinct file – but it doesn’t immediately copy the file’s contents on disk – it merely shares them with the original. Only if and as you modify… Read more
A few weeks ago, Axel Roest published a simple web server comparison, that turned out to not be doing what it was thought to be doing. Figuring that out was a very interesting discussion that warrants a retrospective, to look at which parts were particularly helpful and which not so much. Tangentially, I want to… Read more
The following code prints the Fibonacci sequence. You’ve probably seen it before. It’s one of the simplest and most well-known examples of a sliding window operation – where the next value depends on the preceding two (or more) values. While almost all programs do not calculate the Fibonacci sequence, many do contain similar sliding-window algorithms.… Read more
Most people don’t have any idea what the true cost of server electricity use is. This is for many reasons, but I want to highlight the main factors. Usage is hidden In leasing / colo arrangements electricity cost is often flat-rated, and/or bundled up with many other costs. Many hosts don’t provide electricity usage reporting… Read more
I’ve been taking screenshots on Macs for more than thirty years. I thought I was pretty much a power user. I’ve known forever that you can do not just the whole screen (⇧⌘3) but a specific target area (⇧⌘4), and of course the space trick for capturing a window (including menus!). But what I didn’t know is… Read more
I only just learned that the venerable basename and dirname are no longer necessary, let-alone the horrible string splitting required for teasing apart names from file extensions. Zsh has some awesomely convenient expansion modifiers which do it all! e.g. given the path “/Users/me/Documents/Work.zip”: $file:t → Work.zip $file:h → /Users/me/Documents $file:r → /Users/me/Documents/Work $file:e → zip… Read more
It’s always bemused me that I did better in electronic engineering than computer science. I studied them simultaneously, receiving degrees in both after five years (some classes counted towards both, thus why it wasn’t seven or eight years). I grew up playing on, dabbling with, and programming computers. From BASIC II to Hypercard to RealBasic… Read more