Linux Magazine的March 2022目录

Digital currencies have had quite a lot of buzz around them in recent years, with Bitcoin being the most famous. Satoshi Nakamoto, the mysterious creator of Bitcoin, had the idea to use Bitcoin as a store of value, like gold. For that reason, Bitcoin was designed for the limited purpose of trading and holding value. When Vitalik Buterin and others designed the first version of Ethereum [1], they wanted to extend the blockchain concept to include other kinds of transactions. Ethereum is built around the concept of a smart contract. A smart contract is a program embedded in the blockchain that automatically manages, controls, and documents actions taken for a predetermined purpose. A smart contract allows the creator to implement a contract or agreement without the need for traditional oversight…

Unless you use a version of Fedora released in 2021, you may not have heard of PipeWire [1]. However, by this time next year, PipeWire will likely be installed on your computer. Already, many distributions are starting to carry PipeWire (marked as experimental) in their repositories. Still unfinished and its installation varying, depending on distribution, PipeWire is about to replace PulseAudio as Linux’s main audio server. If you are unwilling to wait until PipeWire becomes a standard part of a Linux installation, here is what you should know. PipeWire was created by Wim Taymans of Red Hat in 2015. Based on an earlier project called PulseVideo, PipeWire was originally intended as a server for capture and playback of audio and video. The video side of the project is still in…

Home automation projects can take advantage of a number of good software packages (e.g., Home Assistant and Node-RED) to manage and monitor sensors and controllable devices. If you are interested in looking at an industrial controls approach to your automation projects, then OpenPLC [1] is a good package to consider. A programmable logic controller (PLC) is a hardened industrial hardware device that manages I/O and logic according to the IEC 61131-3 standard [2]. The OpenPLC open source software runs on a Raspberry Pi, Linux, or Windows PC, and it offers users a great way to learn industrial control concepts, programming languages, and communications protocols. In this article, I introduce IEC 61131-3 programming by creating three small OpenPLC programs that use ladder logic, function blocks, and structured text programming languages. The…

We always joke that the reason why there are so many programming text editors is because creating such a text editor is an ideal first project for programmers, especially when they’re switching to a new language. Because Rust seems to be a popular new language, there are lots of new editors written in Rust. Rust also seems to be one of those languages that’s often mentioned specifically by programmers when they use it, much like Arch users never failing to mention their favorite Linux distribution. All of this is true of Lapce, a new programmer’s editor that proudly wears its Rust editing credentials on its sleeve. But it does this in such a way that makes it worth the installation effort. In particular, it’s fast, simple, and uses edit and…

Back in the mists of time, before Facebook, Twitter, and even Google, Internet users got their news from “newsgroups.” These were secretive enclaves accessed from the terminal where anyone could post, read, and reply to loosely related articles and comments. The great thing about newsgroups was that they were completely decentralized with a web of interconnected servers bouncing messages between themselves. Early ISPs would even have their own news servers, creating an early form of CDN, so that their users could have access to a high performing local news cache. You might reasonably question why this was needed for simple text, but by then text had been supplanted by binaries, albeit encoded as text with uuencode, and Usenet became the go-to location for any kind of file. Remarkably, Usenet still…

Prince of Persia is one of the best 2D platform and adventure games of all time. Originally released in 1989 at the end of the 8-bit era and developed by Jordan Mechner on an Apple II, the game was remarkable for several reasons. The first was its realistic character animation. The sideways animations for the main character and his various enemies were all drawn by hand from actual video footage of Jordan Mechner running, jumping, and sword fighting. This gave the game an uncanny realism that was only matched when motion capture became prevalent many years later. Another reason the game was so compelling was its game play. You start in a palace dungeon with only 60 minutes to escape and save the heroine. Through countless hours of play testing,…

antiX 21 64-bit Based on Debian stable, antiX 21 is designed to be light and efficient. The full installation version available on this month’s DVD is 1.45GB and requires 256MB RAM. However, for older computers, antiX also has a 800MB base version, a 440MB core version, and a 180MB net version. The core and the net versions only install from the command line and without encryption. Both are recommended for those who want total control over the installation, which is necessary for a secure system. From within antiX, users can also set up a live flash drive from which to boot a computer. In addition, antiX is one of the rapidly diminishing number of distributions that still includes a 32-bit version. One of antiX’s standout features is its installer, which…

Futurists and entrepreneurs have long been obsessed with the idea of biometric authentication. Every body is unique – could the unique features of your anatomy be used to prove that you are you? Police departments have used fingerprints to identify suspects for years, and several computer systems now allow fingerprint authentication. But for many researchers, the holy grail for biometric authentication has always been facial recognition. The human brain authenticates humans through facial recognition all the time: That is what happens when you “recognize” someone. Of course, when a camera takes a picture of a person, it is most likely a picture of a face. Your face is looking at your laptop or phone all the time. What could be more convenient than just training your electronic device to look…

The progressive digitalization of all areas of life makes it difficult to cope with the growing flood of data. Many users like to share photos taken with their smartphones or webcams, music and video files, and even PDF documents on the Internet. However, all of these file formats contain metadata that can be read with various programs and often reveals private information about the file’s creator. Before you publish files on the Internet, you should first check for unwanted metadata and remove sensitive information to protect your privacy. This article looks at some Linux tools that will help you delete metadata from your files at the push of a button. The Purpose of Metadata Metadata is usually generated on the basis of defined specifications and intended to record certain characteristics…

Most of the IT industry has consolidated around Intelequivalent processors with the x86 and (related) AMD64 architectures. But just two decades ago, several other processor manufacturers and architectures were fighting for a place in the market. Many of these processors (including MIPS, PowerPC, Alpha, and SPARC) followed a set of principles for processor design known as Reduced Instruction Set Computer (RISC). RISC systems live on today, most notably in the ARM architecture used in today’s in smartphones, Raspberry Pis, Hardware Options The ESP32-C3-DevKitC-02 board, which features a RISC-V core, is available in mail order shops for prices starting at around EUR10 (Figure 1). Chinese manufacturer Espressif has added a RISC-Vbased ESP32-C3 to its well-known and successful ESP32 model; it has slightly slower performance than the classic model, but it is…

Without light, nothing can be seen in photography, but with just a little background light and light brushes, you can create interesting motifs. For long exposures, you need a camera with manual adjustment and a tripod. A flashlight or laser pointer is sufficient to paint simple patterns or lettering into an on-going exposure. If you like to experiment, you might want to work with LEDs to achieve particularly interesting light graphics. I was interested in a creative approach and in trying out what can be achieved with modern pixel elements and clever programming. The idea of a light stick for light painting was born. In this article, I use a Raspberry Pi Pico to build a Micro-Python programmable LED light stick. The control does not require much in the line…

The way we control a desktop environment has not changed significantly since the early days of Gnome, KDE, and Xfce, even if Gnome in particular tends to take a swipe at the paradigms every now and then. Even early interface role models like GEM or the Xerox Alto operating system, the forefather of all graphical user interfaces, used graphical elements such as windows, scrollbars, or menus. Every now and then, however, it is useful to step off the familiar path and try something new. The Fly-Pie [1] extension for the Gnome desktop is a candidate for an offthe-beaten-path excursion. In contrast to more heavily keyboard-oriented approaches such as the Gnome Shell’s activity overview or launchers like Kupfer [2], Fly-Pie is aimed at users who prefer to keep their hands on…

There are many ways to track and manage a collection of things, from a simple file in your Documents folder or an open source database lovingly handcrafted from SQL to desktop applications or even spreadsheets. But there’s nothing better than finding a tool that’s been developed by someone with the same passion for a specific kind of collection. This is what Kavita is. It’s a self-hosted, web-based collection manager built specifically for manga, comics, and books. It’s not really limited to items like these, and you can create a collection out of anything, but text-based graphical items will be able to take advantage of integrated bookmarks, browser-based reading, and the search functionality, plus the image thumbnails used to view a collection will look more uniform. The project has been built…

We’re used to seeing new terminal emulators appear but not for terminal emulators to appear fully formed and ready to use. Yet this is the case with the brilliantly named Tabby, both for the key you frequently use on the command line and because, we presume, it’s a name not dissimilar to that other flashy new terminal emulator, Kitty. But there’s a good reason why Tabby has appeared almost fully formed and perfectly usable from day one, and that is because it was already an established project under the name of Terminus. Tabby hopes, as did Terminus, to be a terminal emulator for the modern age. In being so, Tabby offers lots of performance and convenience features that your default terminal from the 1970s might otherwise be lacking. These differences…

There are few open source projects that not only broaden the possibilities for their users but also kickstart an entire software ecosystem. Blender is one of those projects, as is Krita, but so too is the amazing VCV Rack (now often abbreviated to Rack). VCV Rack is a virtual modular synthesizer where different modules can be connected to one another to create an infinite variety of sounds, effects, drums, noises, note sequences, controller responses, and physical devices. What was most remarkable about this project was that it spawned a huge library of first-and third-party modules that could be added to your virtual racks, many of them modeled on real hardware that might cost hundreds or thousands of dollars but instead given away for free in their virtual form. There was…

Around the turn of the millenium, the proprietary BeOS included many features that made it stand out from other operating systems. Despite a determined effort, it never gained a commercial foothold. However, it did capture some enthusiastic fans. After production ceased in 2002, a half dozen attempts to continue or clone BeOS sprang up, of which only Haiku exists today (Figure 1). Although officially in its third beta, in 2022, Haiku is a stable operating system with a somewhat archaic look to its icons and widgets. However, with a little help from Plasma applications and standard software like LibreOffice, it is generally usable for modern computing purposes. Its speed is compelling, and even some minor features, like the ability to tab multiple applications in a single window or the use…

Many users of Debian or its derivatives are aware of only a handful of tools. When troubleshooting or searching for a package to install, most rely on the Debian web pages for each package. The more expert may use Bruce Byfield is a computer journalist and a freelance writer and editor specializing in free and open source software. In addition to his writing projects, he also teaches live and e-learning courses. In his spare time, Bruce writes about Northwest Coast art (http://brucebyfield.wordpress.com). He is also co-founder of Prentice Pieces, a blog about writing and fantasy at https://prenticepieces.com/. apt-cache. However, these tools give limited information. For more demanding needs, a better alternative is Debian Goodies [1], a collection of small scripts that allow users to probe the details of packages without…

Hyperscale data centers are seeking more visibility into network performance for better manageability. This challenge is made more difficult as the number of switches and servers grow, and as data flows evolve to 100Gbps and higher. Knowing where network congestion is and how it is affecting data flows and service level agreements (SLAs) is critical. Inband Network Telemetry (INT) is an open specification from the P4 open source community [1]. The goal of INT is to allow the collection and reporting of packets as they flow through the network. Intel has brought this capability to the Linux open source community with Host Inband Network Telemetry (Host-INT). The Host-INT framework can collect some very valuable data on network conditions – such as latency and packet drops – that would be very…

The way distributions deliver software is changing. New package formats such as Flatpak and Snap are becoming more widespread, and containers are becoming increasingly important even for casual desktop users. There are many reasons for this. Developers want to see their software quickly reach users without having to create packages in different formats. Some approaches also allow multiple software versions to be installed simultaneously. Sandboxing as a security feature also plays a role. In addition, not all software can be easily packaged and kept up-to-date using traditional package formats. This is especially true for distributions such as Kali Linux which ship hundreds of highly specialized applications. Many of these specialized applications are unavailable in the Debian repository. Others are difficult to package because they rely on outdated libraries that hardly…

One thing people love about open source is the spirit of innovation. If you can visualize a solution, you can build it yourself. Users all around the world have been expanding and extending the Linux experience for years, so at this point, you don’t even have to be a coder – you can choose a solution from the great gallery of components that are available right now in the Linux universe. We serve up a pair of desktop innovations in this month’s Linux Voice: Fly-Pie, a new way to think about desktop menus, and CopyQ, a souped up clipboard with some special features. Also inside: We introduce you to PhotoPrism, a cool tool that brings the power of artificial intelligence to your photo library.…

Regardless of whether you use Linux, macOS, or Windows, the clipboard is one of the most frequently used tools on the desktop. It is a buffer provided by the operating system that temporarily stores, for instance, text snippets which can then be copied and pasted into other applications. The various desktop environments often have clipboard managers that extend the possibilities of the clipboard. In contrast to the operating system’s own clipboard, which resides in RAM and whose contents thus disappear at the next reboot, these small tools help preserve a configurable number of texts beyond a reboot. In KDE Plasma, the corresponding application is known as Klipper, which is loosely derived from the clipboard. You populate the clipboard by pressing Ctrl+X, Ctrl+C, or by selecting something with the mouse and…

Git starts off easy. You clone repositories, create branches, and push back changes to your shared code without troubling the documentation. It works like you might expect a version control system to work, and most projects can subsist like this, perhaps with a smattering of rebase and cherry picking. But with Git, it’s only a matter of time before a fog of war descends over your project, turning your muscle memory commands into increasingly intricate knots that become almost impossible to untangle. It’s then that you wish you’d used some kind of smart client to make better sense of it all. This is what lazygit attempts to be. Lazygit runs from, and takes over, your terminal, filling the area with five or six different panes. When first launched, it gamely…

This is a bit of a cautious find because its most obvious use is to help people gain unauthorized access to a network, which is an action we absolutely don’t condone. But neither do we condone security through obscurity because, in our experience, it’s always helpful to know what kinds of tools are out there and what they do, especially when they have actual utility. This is the case with ReverseSSH, a project with a particularly descriptive name. ReverseSSH is a modified version of the same SSH server binary that many of us rely on every day to make connections between our various servers, Raspberry Pis, and home automation systems. ReverseSSH has been modified to allow anyone with physical access to a system, and presumably a way to get the…

This is an exciting time for Linux gamers because so much is happening to make gaming on Linux better. This is of course mostly thanks to Valve, which has been lavishing attention on Linux, Wine, and its Proton compatibility layer in preparation for the release of its Steam Deck handheld gaming PC. But there are plenty of other developments too, and Gamebuntu is one of them. It’s the brainchild of Rudra Saraswat, a developer based in India who’s also responsible for the Ubuntu Unity Remix distribution and, at the time of writing, is still only 12 years old! Gamebuntu is a comprehensive Bash script with a graphical front end that aggregates the installation of everything and anything related to gaming. It’s designed for people new to Linux who might install…