Using an old VFD serial communication display for use with Arduino based microcontrollers.

The TURN Server is a VoIP media traffic NAT traversal server and gateway. It can be used as a general-purpose network traffic TURN server and gateway, too.

On-line management interface (over telnet or over HTTPS) for the TURN server is available.

The implementation also includes some extra experimental features.

Das STUN-Protokoll erkennt Clients, die sich bspw. hinter einem Router oder einer Firewall befinden und eine NAT-Adresse haben. Mit Hilfe des STUN-Servers können NAT-Clients ihre öffentliche IP-Adresse erfahren und sind anschließend in der Lage eine direkte Kommunikationsverbindung zwischen (zwei) Teilnehmern herzustellen. Um die Übermittlung der IP-Adresse an externe Anbieter zu vermeiden, könnt ihr einen eigenen STUN- / TURN-Server betreiben. Alternativ könnt ihr natürlich auch einfach bestehende STUN-Server wählen, die öffentlich zur Verfügung gestellt werden.

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.

How to wire up laptop screen backlights: https://youtu.be/Y2KK4YiOO1o
DIY Secondary Screen (from laptop screen): https://youtu.be/CfirQC99xPc
Dual Screen Laptop Project: https://youtu.be/J2aY6cvk-WI
DIY Smart Mirror: https://youtu.be/puFSdfIRNIw
CCTV from laptop webcams: https://youtu.be/CouxmNqxO4A
Media PC project: https://youtu.be/e3fnsGHe8eE

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

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.

On any given day, we handle around 15% of daily retail trading volume across all stock exchanges in India. Billions of requests generated in the process are handled by a suite of systems we have built in-house. Also, we are very particular on self-hosting as many dependencies as possible, everything from CRMs to large databases, Kafka clusters, mail servers etc.

To aid these primary systems, there are a large number of ancillary workloads that run, covering everything from real-time trades, document processing, KYC, and account opening, legal and compliance, complex, large scale P&L and number crunching, and a wide range of backoffice workloads. The systems are spread across a hybrid setup; physical racks across two different data centres (where exchange leased lines terminate) and AWS. All of this means that we have a lot of dynamic workloads and dissimilar systems and environments, bare metal to Kubernetes clusters, to be monitored independently.

I’ve been writing about running Docker on Raspberry Pi for five years now and things have got a lot easier than when I started back in the day. There’s now no need to patch the kernel, use a bespoke OS, or even build Go and Docker from scratch.

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

As part two (see previous attempt) of my ongoing series in ‘computational necromancy,’ I’ve spent the last year and a half or so constructing my own 1/10-scale, binary-compatible, cycle-accurate Cray-1. This project falls purely into the “because I can!” category – I was poking around the internet one day looking for a Cray emulator and came up dry, so I decided to do something about it. Luckily, the Cray-1 hardware reference manual turned out to be useful enough that implementing most of this was pretty straightforward. The Cray-1 is one of those iconic machines that just makes you say “Now that‘s a super computer!” Sure, your iPhone is 10X faster, and it’s completely useless to own one, but admit it . . you really want one, don’t you?

Resource monitor that shows usage and stats for processor, memory, disks, network and processes.

Let me add some technical things to this blog and talk a little bit about the things I learned while preparing our own Youtube live streams.