Linux MagazineSeptember 2022的目錄

Dear Reader, A few months ago, I wrote about the need for the open source community to provide a means for the continuity of solo or small-scale open source projects when the maintainer reaches a burnout point or gets busy with something else. Does the project have to die just because the person who started it walks away? Another angle on this problem is the question of scientific software written by research professionals. Some of the most sophisticated software in the world is created by doctoral candidates and other academic scientists. This software isn’t written just to be software – it is written to test a new idea or answer a question related to a research project. Some of these programs represent years of work, but what happens when the…

Slimbook, well known for producing KDE Plasma-powered laptops, has given their Executive series a bit of a refresh by making them available with the Intel 12th Gen Alder Lake CPU. This new iteration adds considerably more power (14 Cores, 20 threads, 24MB cache, and up to 4.80GHz clock speeds), improved battery life, and better graphics (via an integrated Iris Xe 4K chipset). Consumers will find two different models available with this configuration: A 14-inch 3K display, running at a 90Hz refresh rate (at 2880x1800 resolution) and a 16-inch model that sports NVIDIA RTX 3050Ti graphics with 4GB GDDR6 RAM (also at a 90Hz refresh rate). The 14-inch model does get a beefier battery (99WHr), whereas the 16-inch model’s battery is a smaller 82WHr. Both laptops include USB-C Thunderbolt 4, USB…

Linux Magazine www.linux-magazine.com ADMIN HPC http://www.admin-magazine.com/HPC/ Sharing Linux Terminals • Jeff Layton Sometimes sharing a screen between two users is enormously helpful. We look at two terminal sharing tools: screen and tmux. Performance Health Check • Jeff Layton Many HPC systems check the state of a node before running an application, but not very many check that the performance of the node is acceptable before running the job. ADMIN Online http://www.admin-magazine.com/ Three Full-Text Desktop Search Engines • Harald Jele Desktop search engines such as Tracker, DocFetcher, and Recoll help track down files by their content, even in massive datasets. Stretching Devices with Limited Resources • Federico Lucifredi Compressed memory solutions for small memory problems. Portable Home Directory with State-of-the-Art Security • Martin Loschwitz The systemd Homed service makes it easy…

Random Number Sanity Random numbers are important for security. Generally to make random numbers, you grab entropy from somewhere, like the frequency of fingers tapping a keyboard, and use that to generate as many unpredictable numbers as needed. But what if no one’s typing on the keyboard? What if you run out of entropy? Should the system just sit and wait for more? For a long time, the Linux kernel had to choose between locking up the system until it found enough entropy to make truly random numbers and providing numbers anyway, even if they weren’t really random enough. But in 2019, Linus Torvalds wrote a patch that addressed the problem “by actively generating entropy noise using the CPU cycle counter when waiting for the random number generator to initialize.…

Figure 5 shows the reference model of the 5G network. The three main elements are the terminal, the gNodeB, and the core network. The terminal can be a smartphone, an IoT system, a laptop, or any similar device. The gNodeB is the equivalent of a switch in Ethernet, acting below the IP layer. The core network is the equivalent of the ISP network. From bottom to top, the layers of the reference model are: • Physical layer (PHY): deals with all the radio aspects of the communications, such as modulation and demodulation. See the “Radio Aspects” box for a definition of these terms. • Medium Access Control (MAC): defines logical channels over the PHY channels (which are defined by time and frequency). Also performs error correction. • Radio Link Control…

After the resounding success of the Wordle [1] word guessing game, it didn’t take long for the first look-alikes to rear their heads. One of the best is the entertaining Worldle [2] geography game, where the goal is to guess a country based on its shape. After each unsuccessful guess, Worldle helps the player with information about how far the guessed country’s location is from the target and in which direction the target country lies. Not recognizing the outline of the country in Figure 1, a player’s first guess is the Principality of Liechtenstein. The Worldle server promptly tells the player that the target location is 5,371 kilometers away from and to the east of this tiny European state. The player’s second guess is Belarus, but according to the Worldle…

Order online: https://bit.ly/Linux-Newsstand #261/August 2022 USB Boot Live boot was such an exciting idea 15 years ago – just carry a CD with you and boot from anywhere. But old-style boot CDs had some limitations. Today’s USB boot tools solve those problems plus offer a feature that no one even thought about back then: access to several boot images on a single stick. On the DVD: Linux Mint MATE 20.3 and FreeBSD 13.1 #260/July 2022 Privacy If you are really serious about privacy, you’ll need to lean on more than your browser’s no tracking button. Those who need anonymity the most depend on the Tor network – a global project offering safe surfing even in surveillance states. We also look at Portmaster, an application firewall with some useful privacy features.…

Fedora Linux has been available for desktops, servers, and even IoT devices. However, if you wanted to install the OS on the Raspberry Pi 4 device, you were out of luck – until now. With the upcoming release of Fedora 37, support for the devices might well finally become a reality. Although not official, it has become a proposed change and will be implemented if it receives approval from the Fedora Engineering Steering Committee. The reason the Raspberry Pi 4 has yet to be supported by Fedora Linux has been the lack of accelerated graphics. However, with upstream work on the kernel and Mesa (specifically the V3D GPU for both OpenGL ES and Vulkan), it’s now just a matter of enabling support. The one caveat is that support for WiFi…

Manjaro is an Arch-based, rolling-release Linux distribution aimed at users who want the power and flexibility of Arch, without complications. The latest release, version 21.3.0, includes plenty of newness, in the form of the Calamares installer (which now supports LUKS partitions), Gnome 42 (which includes Libadwaita), KDE Plasma 5.24 (which includes the new Overview), Xfce 4.16 (which now supports fractional scaling), and Linux kernel 5.15 LTS. The Gnome edition of Manjaro 21.3.0 includes both GTK 4 and Libadwaita, which offers improved performance, a modern UI style, and plenty of new user interface elements. The Plasma edition makes it possible to more easily move panels around and stick them to any edge you like. The Xfce edition received quite a number of updates, especially in the area of compositing and GLX.…

Probably the first thing that comes to mind when talking about a mobile network is the radio technology that makes it possible. These functions are all contained in the PHY layer and are some of the most specialized parts of the network that require their own hardware. For digital radio transmission, we start with a baseband signal (Figure 6), which is made up of one or several electric signals that represent digital bits. The spectrum of this signal (its Fourier transform) is centered around 0 Hz and has a limited bandwidth. You can then modulate this signal, i.e., transform it such that its central frequency is at a specific given frequency. You can also modulate several different streams of bits in adjacent frequencies, which is called Frequency Division Multiple Access…

Laser cutting mainly used to be the purview of hard-headed business owners with solid financial backing and a business plan to make sure the laser paid for its upkeep. And there were hobbyists who were more interested in the arts and crafts side of laser cutting and saw the laser as a tool for cutting and engraving materials such as wood, cloth, and acrylics in the scope of their arts and crafts projects. The trouble was, many people were more than a little worried about the Heath Robinson-style, low-budget lasers they could purchase at the time. The foundations of the laser world were to be shaken though, when FLUX – an organization founded by a “group of passionate young engineers and designers,” as the manufacturer itself states – launched the…

Some of the best articles are the ones that don’t just teach about a tool – they teach about the reason for the tool. When you read one of those articles, you aren’t just learning about Linux: You are learning about some other aspect of life on Earth that brings value to the reading experience. This month we feature one such article. You’ll learn about the Manuskript editor and novel-writing tool, but you’ll also get an introduction to the snowflake method, an outlining technique that takes the intimidation out of writing long fiction works. And while we’re on the subject of creating things in original ways, how about building a slide presentation using the Go programming language? Read on for a study of Presentation as Code.…

Sparkling gems and new releases from the world of Free and Open Source Software Virtual whiteboard Lorien There are reasons why whiteboards are synonymous with places of learning: They’re brilliant for education and brainstorming, they’re dynamic and adaptable, and they’re collaborative. It’s no surprise then that whiteboard functionality has been digitized, not just in schools with touchscreens, but also online where complex information can be presented on a virtual canvas that scrolls left and right and zooms out. A similar idea has been used with note-taking applications on the desktop. These usually mimic a notepad interface for drawing sketches and adding mental doodles rather than finding a way to map more complex ideas across a larger canvas. Even Apple’s own note-taking application works in the same way with the next…

Users, developers, and vendors meet at Linux events around the world. We at Linux Magazine are proud to sponsor the Featured Events shown here. For other events near you, check our extensive events calendar online at https://www.linux-magazine.com/events. If you know of another Linux event you would like us to add to our calendar, please send a message with all the details to info@linux-magazine.com. NOTICE Be sure to check the event website before booking any travel, as many events are being canceled or converted to virtual events due to the effects of COVID-19. DrupalCon Prague 2022 Date: September 20-23, 2022 Location: Prague, Czech Republic Website: https://events.drupal.org/prague2022 Be part of the future of Drupal! Brought to you by the Drupal Association, DrupalCon Europe will be held September 20-23 in Prague. Join us in…

Rocky Linux 9 is now available and is a landmark release for several reasons. First off, there has been a surge in Rocky Linux deployments, putting it ahead of CentOS Stream and AlmaLinux. But more than that, Rocky Linux includes several security enhancements and networking features to help make it a best-in-class open source operating system for businesses of all sizes. In the new release, you’ll find SHA-1 message digest for cryptographic purposes has been deprecated (as the cryptographic hash functions are no longer considered secure). In addition, you’ll find OpenSSL 3.0.1 (which includes provider concept, a new versioning scheme, an improved HTTP/HTTPS client, support for new protocols/formats/algorithms, and more), OpenSSH version 8.7p1 (which includes the replacement of the SCP/RCP protocol with the more predictable SFTP protocol), SELinux performance improvements,…

KaOS was first created in 2013 as a Linux distribution that focuses on the KDE Desktop Environment. The original goal was to create a highly polished KDE experience, which the developers achieved quite well. And with the latest release, that experience is made even better with the addition of KDE Plasma 5.25 and a number of other additions and enhancements. As to what else has been added to KaOS, you’ll see KDE Frameworks 5.95, KDE Gear 22.04.2, Calamares 3.3, LibreOffice as the default office suite (a change from Calligra), Linux kernel 5.17 (which adds improved support for GPUs), and a new package selection addition to the onboarding Welcome screen. Of course, at the heart of KaOS 2022.06 is KDE Plasma 5.25, which adds a host of improvements, including improved gesture…

SpiralLinux (https://spirallinux.github.io/) is Debian-based Linux distribution with spins for Cinnamon, Xfce, Gnome, KDE Plasma, Mate, Budgie, LXQt, and Builder (which uses the IceWM window manager for experienced users to fully configure the system to meet their needs). Each of these spins (minus “Builder”) offers a simplified Linux experience that uses the official Debian Stable package repositories. SpiralLinux includes Flatpak support built-in as well as a GUI front end for managing Flatpak packages. The distribution uses the Btrfs filesystem which includes an optimal sub-partition with Zstd transparent compression and built-in support for automatic Snapper snapshots and even zRAM swap support. According to the developer, “Great effort has been expended in polishing the SpiralLinux default configuration for all the major desktop environments using the packages and mechanisms that Debian itself provides,” said…

In 5G, the main core network functions are: • User Plane Function (UPF): contains all the functions that are directly related with connecting the terminal with the Internet. Among these functions are routing and forwarding, Network Address Translation (NAT), packet filtering, Deep Packet Inspection (for lawful communication interception; yes, this function is defined in the standard [1]) and, of course, billing. These functions compose the user plane. All the other functions of a 5G network are called control plane functions and are needed to support the correct operation of the user plane. • Access and Mobility Management Function (AMF): performs the roaming functionality, that is, the required operations for reassigning serving gNodeBs to the terminal and doing the handover such that the user plane can always provide connectivity to the…

While recently doing a small project, I was amazed by how much web scraping I could do with just one line of Bash. I used the text-based Lynx browser [1] and then piped the output to a grep search. Figure 1 shows the oneline Bash example that scrapes the current snow depth from the Sunshine Village Snow Forecast web page. In this article, I will introduce some techniques to easily scrape web pages, and then I will create a desktop notification script that provides the daily snow forecast. The Lynx Text Browser For my Bash web scraping, I started out by looking at using command-line tools such as curl [2] with the html2text [3] utility. This technique definitely works, but I found that using the Lynx browser offers a one-step…

As you are probably aware, laser cutters are precision instruments. What you may not have been aware of up to this point is that the laser beam is deflected by mirrors to the laser head. Any knocks the laser’s packaging took en route to its new owner are likely to cause some misalignment issues. You may get lucky and not need to align the mirrors on your machine, and you may not. We were not so lucky and had to align the first reflecting mirror (Figure 5), which involves removing a large number of Allen screws before you can start the alignment. It sounds complicated, but if we managed it, we’re sure you can, too. Here’s what you need to do: 1. Mirror one: With the laser switched off, attach…

Growing Linux Desktop There is a story about the game of chess and how it was invented centuries ago. After the game was invented, the ruler of the country was so happy that he offered the inventor a reward for their efforts. The inventor requested a grain of rice on the first square, two grains on the second square, four grains on the third square, and so forth. The ruler, speaking quickly, said “Let it be done.” The problem was that there was not enough grain in the entire kingdom. Today we might think of this as “two to the 64th power,” a number so large that it is fairly unimaginable. Even two to the 32nd is over four billion, and, if you start with a number greater than two,…

We are always looking for good articles on Linux and the tools of the Linux environment. Although we will consider any topic, the following themes are of special interest: • System administration• Useful tips and tools• Security, both news and techniques• Product reviews, especially from real-world experience• Community news and projects If you have an idea, send a proposal with an outline, an estimate of the length, a description of your background, and contact information to edit@linux-magazine.com. The technical level of the article should be consistent with what you normally read in Linux Magazine. Remember that Linux Magazine is read in many countries, and your article may be translated into one of our sister publications. Therefore, it is best to avoid using slang and idioms that might not be understood…

The IoT revolution offers infinite possibilities, but hardware specs and system requirements can vary. The Yocto project will help you build a custom Linux system, regardless of the hardware. + 22 years of Linux Magazine! Next month's issue will include the new Linux Magazine Archive DVD, featuring every article we've ever printed from issues 1 to 262. Secure your copy today by subscribing to the DVD edition of Linux Magazine: https://bit.ly/Linux-Magazine-DVD Approximate UK / Europe Sep 03 USA / Canada Sep 30 Australia Oct 31 On Sale Date Please note: On sale dates are approximate and may be delayed because of logistical issues.…