Personal Productivity

A tool to display directory entries, sorted by size, together with their cumulative contribution to the total.

After seeing positive references to it on Linux Weekly News and elsewhere, I bought a copy of “Mastering Emacs” by Mickey Petersen.

What methods are there to connect an external (USB) drive or memory stick to a Linux box most conveniently?

Like many other people, I have struggled with git. It was obviously all very clever, but somehow inexplicably difficult and frustrating to use.

Eventually, I realized that my difficulties stemmed from three misconceptions: areas, where git did something different from what I thought it did, or different from what I was led to believe it did.

Git has been around for going on 20 years, yet people still continue to write “getting-started” and “common-challenges” tutorials. This is mine.

Building open-source software from source is not necessarily hard: after all, typing make is fairly easy. But dealing with the tools and dependencies can be tedious, in particular, if you don’t use them all the time. In this post, I want to describe how to use Docker containers as convenient, clean-room build environments.

When writing programs that do computations, my overwhelming preference is to simply write results to standard output, and to use shell redirection to capture the output in a file. In this way, I am leveraging the shell’s full functionality, in particular filename completion, in the most convenient way possible. For the file format itself, I prefer simple, column-oriented, delimiter-separated flat files. They are completely portable, and can be read and understood by most tools. (They also play well with the usual Unix toolset.)

But this simple approach breaks down, once a program has to write more than one output stream: for example in the case of a simulation run, I may want to capture periodic snapshots of the simulation itself, but also track various calculated metrics as well. These two streams will not fit comfortable into a single flat file. One option is to use a structured file format, the other option is to write to multiple files simultaneously.

QR codes are a two-dimensional equivalent of barcodes: a graphical encoding of information, which in practice means a string of about 4000 alpha-numeric characters (upper-case only) or a little less than 3000 arbitrary bytes.

So, how then are QR codes able to perform magic, such as automatically opening web pages, or sending text messages, or even dealing bitcoin? The answer is: they can’t.

Let’s try to understand what’s going on.

Sharing files across computers on a local, “informal” (home) network is a recurring desire. Yet, at least in the Linux world, one that does not have an obvious, canonical, default solution. Email, cloud storage, or using an USB stick all seem shockingly common.

Processing command-line arguments in ad-hoc python tools is one of those areas where I tend to just hack it together from scratch — simply because the effort of learning and understanding the relevant library packages not only seems to be more work than it is worth, but also and in particular more effort than “just doing it” by hand. I don’t want anything fancy, after all. I just want to get it done.