The following are lines from ~rsyncer/.ssh/authorized-keys on my dbclone host – which gathers database backups from various hosts.

from="x8dtu.example.org,10.1.1.1",command="/usr/local/sbin/rrsync -ro /usr/home/rsyncer/backups/bacula-database/postgresql/" ssh-ed25519
AAAAC3thisisalsonotmyrealpublickeybcxpFeUMAC2LOitdpRb9l0RoW7vt5hnzwt rsyncer@x8dtu.example.org

The above appears on two lines to make it easier to read without horizontal scrolling – in the file, it’s all on one line.

This says:

• when an ssh connection comes in from a client at x8dtu.example.org, or 10.1.1.1
• run /usr/local/sbin/rrsync -ro /usr/home/rsyncer/backups/bacula-database/postgresql/
• and that client must have this key (as shown)
• rsyncer@x8dtu.example.org is a comment, and has no effect

"What kind of script is it?"

• "A Bäsch script."
  "Bash?"
• "No, its German cousin."
  "???"
• "???"

Become an irreplaceable 10x developer in 30 seconds flat

Why learn actual skills when you can just look impressive instead?

Introducing rust-stakeholder - a CLI tool that generates absolutely meaningless but impressive-looking terminal output to convince everyone you're a coding genius without writing a single line of useful code.

https://github.com/giacomo-b/rust-stakeholder

Yesterday I learned that #ghostty, the terminal emulator supports custom shaders. So here is a little retro/crt shader: https://gist.github.com/lukad/d979a36ed9a83020bd6fa3fa0d5d7c89

blinry - I also learned that the "grep" command is called like that because it performs the same function as running "g/re/p" in the original editor "ed" (and "QED" before that, I think): It gets all lines from a file that match the regular expression "re", and prints them!

And through that same heritage, :g/re/p still works in my Neovim today! ^_^ I love learning stuff like this!~

Glances is a cross-platform system monitoring tool written in Python

List system USB buses and devices; a lib and modern cross-platform lsusb that attempts to maintain compatibility with, but also add new features. Includes a macOS system_profiler SPUSBDataType parser module and libusb profiler for non-macOS systems/gathering more verbose information.

The project started as a quick replacement for the barely working lsusb script and a Rust project to keep me up to date! Like most fun projects, it quickly experienced feature creep as I developed it into a cross-platform replacement for lsusb.

Merge, tail, search, filter, and query log files with ease.

No server. No setup. Still featureful.

via @pty

A data hoarder’s dream come true: bundle any web page into a single HTML file. You can finally replace that gazillion of open tabs with a gazillion of .html files stored somewhere on your precious little drive.

Unlike the conventional “Save page as”, monolith not only saves the target document, it embeds CSS, image, and JavaScript assets all at once, producing a single HTML5 document that is a joy to store and share.

If compared to saving websites with wget -mpk, this tool embeds all assets as data URLs and therefore lets browsers render the saved page exactly the way it was on the Internet, even when no network connection is available.

An interactive replacer for ripgrep.

This is an interactive command line tool to make find and replacement easy. It uses ripgrep to find, and then provides you with a simple interface to see the replacements in real-time and conditionally replace matches.

Some features:

⚡ Super fast search results
✨ Interactive interface for selecting which matches should be replaced or not
🕶️ Live preview of the replacements
🧠 Replace using capturing groups (e.g., when using /foo (\w+)/ replace with bar $1)
🦀 and more!

[diff is] the seed crystal of all workable open collaboration, and people living without it don’t even have the language to recognize how bad they’ve got it.

The Modern Port Scanner. Find ports quickly (3 seconds at its fastest). Run scripts through our scripting engine (Python, Lua, Shell supported).
✨ Features

Scans all 65k ports in 3 seconds.
Full scripting engine support. Automatically pipe results into Nmap, or use our scripts (or write your own) to do whatever you want.
Adaptive learning. RustScan improves the more you use it. No bloated machine learning here, just basic maths.
The usuals you would expect. IPv6, CIDR, file input and more.
Automatically pipes ports into Nmap.

conorh@mastodon.sdf.org - During lunch a friend mentioned that you can just supply a HTTP URL to vim on the command line and it would use curl to download that resource and allow you to edit the content. I jokingly asked whether if you enter :w it would then issue a HTTP POST back to the origin which is of course ridiculous.

It issues a PUT

A fast, simple TUI for interacting with systemd services and their logs.

systemctl-tui can quickly browse service status and logs, and start/stop/restart services. It aims to do a small number of things well.

Well, today I learned that if you add the Ethernet header – 36 bytes – then an MTU of 1500 plus that header is 1536 bytes, which is 12288 bits, which takes 2^12 microseconds to transmit at 3Mb/second, and because the Xerox Alto computer for which Ethernet was invented had an internal data path that ran at 3Mhz, then you could just write the bits into the Alto’s memory at the precise speed at which they arrived, saving the very-expensive-then cost of extra silicon for an interface or any buffering hardware.

task spooler is a Unix batch system where the tasks spooled run one after the other. The amount of jobs to run at once can be set at any time. Each user in each system has his own job queue. The tasks are run in the correct context (that of enqueue) from any shell/process, and its output/results can be easily watched. It is very useful when you know that your commands depend on a lot of RAM, a lot of disk use, give a lot of output, or for whatever reason it's better not to run them all at the same time, while you want to keep your resources busy for maximum benfit. Its interface allows using it easily in scripts. 

For your first contact, you can read an article at linux.com, which I like as overview, guide and examples (original url). On more advanced usage, don't neglect the TRICKS file in the package.

Synonym is a small utility tool to find synonyms directly from the command line.
It is using the thesaurus.altervista.org API to query for words.

List of supported languages:

en, fr, cs, el, es, da, de, hu, it, no, pl, pt, ro, ru, sk

It’s been known for years now that SSH servers can (and should) be hardened by removing weak default algorithms. For example, recent versions of OpenSSH ship with algorithms suspected of being back-doored by the NSA (i.e.: ECDSA with the NIST P-curves), along with other algorithms with sub-128bit security levels.

But did you know that client software can be hardened too?
Why Harden Client Software?

In a world where all servers are properly hardened, there would be no need to re-configure client software. However, server hardening is unfortunately more rare than it should be, and you can only do it for machines you directly control. In that case, it’s very useful to upgrade your client’s defaults so you have assurance that only strong connections will be made.

What explains the popularity of terminals with 80×24 and 80×25 displays? A recent blog post "80x25" motivated me to investigate this. The source of 80-column lines is clearly punch cards, as commonly claimed. But why 24 or 25 lines? There are many theories, but I found a simple answer: IBM, in particular its dominance of the terminal market. In 1971, IBM introduced a terminal with an 80×24 display (the 3270) and it soon became the best-selling terminal, forcing competing terminals to match its 80×24 size. The display for the IBM PC added one more line to its screen, making the 80×25 size standard in the PC world. The impact of these systems remains decades later: 80-character lines are still a standard, along with both 80×24 and 80×25 terminal windows.

In this blog post, I'll discuss this history in detail, including some other systems that played key roles. The CRT terminal market essentially started with the IBM 2260 Display Station in 1965, built from curious technologies such as sonic delay lines. This led to the popular IBM 3270 display and then widespread, inexpensive terminals such as the DEC VT100. In 1981, IBM released a microcomputer called the DataMaster. While the DataMaster is mostly forgotten, it strongly influenced the IBM PC, including the display. This post also studies reports on the terminal market from the 1970s and 1980s; these make it clear that market forces, not technological forces, led to the popularity of various display sizes.