« usbkill » is an anti-forensic kill-switch that waits for a change on your USB ports and then immediately shuts down your computer.

JSON is everywhere on the Internet. Servers spend a lot of time parsing it. We need a fresh approach. The simdjson library uses commonly available SIMD instructions and microparallel algorithms to parse JSON 2.5x faster than anything else out there.

A while back I bought a DYMO LabelManager Plug N Play Label Maker to help organize things. Before I bought it I had done some cursory searching and saw there were Linux drivers, and I set up CUPS, fixed permissions (of course), and installed the DYMO drivers, but nothing was showing up.

Well, turns out there’s a reason for that – the LabelManager PnP actually labels itself as a HID device, not a printer! (lsusb -v to peep the details)…

Luckily, with a bit of searching, I found a nice little Python 3 script called dymoprint (github) that reverse-engineered the USB protocol and works perfectly. Another dev subsequently wrote a Perl script that generates 64px tall bitmaps to the printer. (I have lots of existing image generation code to build a Python version of this, but honestly, the first dymoprint script does just about everything I want, which is just to print some simple labels).

I saw that someone else did get it to run on CUPS – it looks like you have to set up modeswitching, but I haven’t tested that personally.

ncdu (NCurses Disk Usage) is a disk utility for Unix systems. Its name refers to its similar purpose to the du utility, but ncdu uses a text-based user interface under the [n]curses programming library.[2] Users can navigate the list using the arrow keys and delete files that are taking up too much space by pressing the 'd' key. Version 1.09 and later can export the file listing in JSON format.

Using a terminal from 1976 as home automation hub, because why not?

Shuf is a Linux and Unix command-line utility that puts its input text in random order to generate output consisting of random permutations of the input. In simple terms, it just shuffles the input of either text file or standard input passed through the command line.

10 years ago, systemd was announced and swiftly rose to become one of the most persistently controversial and polarizing pieces of software in recent history, and especially in the GNU/Linux world. The quality and nature of debate has not improved in the least from the major flame wars around 2012-2014, and systemd still remains poorly understood and understudied from both a technical and social level despite paradoxically having disproportionate levels of attention focused on it.

I am writing this essay both for my own solace, so I can finally lay it to rest, but also with the hopes that my analysis can provide some context to what has been a decade-long farce, and not, as in Benno Rice’s now famous characterization, tragedy.

A new way to see and navigate directory trees

Delta provides language syntax-highlighting, within-line insertion/deletion detection, and restructured diff output for git on the command line.

A cat(1) clone with syntax highlighting and Git integration.

bat supports syntax highlighting for a large number of programming and markup languages
Git integration
Show non-printable characters
Automatic paging
File concatenation

The proc filesystem is an important feature of Linux that you can't ignore. proc is a pseudo or virtual filesystem that provides an interface to kernel data structures. In other words, proc isn't an actual filesystem in the real-world sense; rather, it resides only in memory and not on a disk. It is automatically mounted by the system.

Most of its contents are regular files and directories, so you can use most regular Linux tools to navigate the proc filesystem. The examples in this article should run the same on any Linux distribution.

Did you ever want to match a regex, but all you had was a fat32 driver? Ever wanted to serialize your regex DFAs into one of the most widely supported formats used by over 3 billion devices? Are directory loops your thing?

Worry no more, with regex2fat this has become easier than ever before! With just a little regex2fat '[YOUR] F{4}VOUR{1,7}E (R[^E]G)*EX HERE.' /dev/whatever, you will have a fat32 regex DFA of your favourite regex. For example, to see whether the string 'Y FFFFVOURRE EX HEREM' would match, just mount it and check if '/Y/SPACE/F/F/F/F/V/O/U/R/R/E/SPACE/E/X/SPACE/H/E/R/E/M/MATCH' exists.

If you’re trying to learn Docker you will first have to master its various terminal commands. This guide aims to help you get started with basic docker commands.

systemd has become a mainstay for the Linux world, but one of the things that still seems to stick around is cron jobs. It’s understandable, as cron is a tool that we have been using for a long time. Change is hard, but I think systemd Timers make the change well worth it. Here are a few reasons why…

I've now learned that grep can, halfway through grepping in a file, think
the file is suddenly binary and stop returning results.

xsv is a command line program for indexing, slicing, analyzing, splitting and joining CSV files. Commands should be simple, fast and composable:

Simple tasks should be easy.
Performance trade offs should be exposed in the CLI interface.
Composition should not come at the expense of performance.

The first and second open source migration waves were periods of rapid expansion for companies that rose up to provide commercial assurances for Linux and the open source databases, like Red Hat, MongoDB, and Cloudera. Or platforms that made it easier to host open source workloads in a reliable, consistent, and flexible manner via the cloud, like Amazon Web Services, Google Cloud, and Microsoft Azure.

This trend will continue in the third wave of open source migration, as organizations interested in reducing cost without sacrificing development speed will look to migrate more of their applications to open source. They’ll need a new breed of vendor—akin to Red Hat or AWS—to provide the commercial assurances they need to do it safely.

Ncdu is a command line tool to view and analyse disk space usage on linux. It can drill down into directories and report space used by individual directories. This way it is very easy to track down space consuming files/directories. It actually allows the user to do this much faster than even a gui file manager. On the server ofcourse gui tools are not present.

SSHHeatmap

Generates a heatmap of IPs that made failed SSH login attempts on linux systems, using /var/log/auth.log to get failed attempts. Uses the ipinfo.io library to fetch the IP address coordinates, and folium to generate the heatmap

The xpipe command reads input from stdin and splits it by the given number of bytes, lines, or if matching the given pattern. It then invokes the given utility repeatedly, feeding it the generated data chunks as input.

You can think of it as a Unix love-child of the split(1), tee(1), and xargs(1) commands.

It's usefulness might best be illustrated by an example. Suppose you have a file 'certs.pem' containing a number of x509 certificates in PEM format, and you wish to extract e.g., the subject and validity dates from each.

The openssl s_client(1) utility can only accept a single certificate at a time, so you'll have to first split the input into individual files containing exactly one cert, then repeatedly run the s_client(1) command against each file.

And, let's be honest, you probably have to google how to use sed(1) or awk(1) to extract subsequent blocks from a flip-flop pattern.

xpipe(1) can do the job for you in a single command: