Linux MagazineNovember 2021的目錄

KDE Plasma 5.23 is set for release on October 7, 2021, and it promises several (subtle) improvements across the board. This new release is powered by Qt 5.15 and KDE Frameworks version 5.86. Along with the improvements found in those software stacks, there‘s plenty of goodness to go around within KDE itself. Many of the new features and improvements are all about refinement, so you probably won‘t see anything that‘s mind-blowing or drastic. For example, one of the highlighted new features is that you can specify an alternative accent color from that which is configured by the theme. Other subtle newness includes the ability to choose list or grid view for all Kickoff items (so it no longer only applies to Favorites), a new QML-based Overview effect has been introduced…

In Unix and Linux, best practices call for a strict segregation in the assignment of rights between daily work and administrative tasks. Administrative chores were once reserved for the superuser account. If you are logged in as the superuser, which is normally named root, you are allowed to do everything up to deleting the entire system. Admins at New York University developed Sudo back in 1980 to prevent students from getting unneeded privileges. The name Sudo stands for “Superuser Do.” It lets you give privileges to a user who is a member of the sudo group for limited time or for a specific task. To do this, prepend sudo to a command whose execution requires these privileges. Then enter your user password to authorize it. Sudo became more fashionable in…

Many Linux users are wary of encrypting their data – primarily because most of the available tools don’t offer a graphical user interface, and also – but less often – because of a perceived lack of flexibility in handling encrypted data files. But in the modern era, when high-capacity USB media are easy to find, encryption is becoming more important. Tools such as TrueCrypt or its successor VeraCrypt have a graphical user interface but create containers of a fixed size, without the flexibility to deal with growing volumes. If you store only a few files, you are wasting storage space with a big container. On the other hand, if you create a container that is too small, running out of space will mean a time-consuming overhaul. SiriKali [1] is an…

If you work at the command line, you probably use ls [1] frequently to list directories and their contents. However, it is one of the oldest commands, and many of its options are no longer relevant to modern computer use. In fact, most people can get by with only a small sub-set of its available options. One of several new revamps, lsd (LSDeluxe) [2] (Figure 1) attempts to modernize and simplify ls by assuming a default color code and – apparently – by reducing the number of options and adding options of its own. However, since this is 0.2.21 release, it is hard to be sure exactly what the general release will look like. The lsd release page includes Linux packages for Debian and Gentoo. An alternative is to build…

For most students, lessons in the computer lab are a welcome change from the traditional classroom setting. However, especially for younger elementary students, learning on a computer can also be a distraction, making it hard for teachers to keep a student’s attention on the current lesson. Digital classroom management software can help solve this issue by letting the teacher control the students’ computers to ensure that the screen content does not constantly distract students. Linux offers several open source management solutions for school computer labs, including the well-known Veyon [1]. In this article, I explore another option, Epoptes (Greek for overseer) [2]. Epoptes offers an equally sophisticated client-server solution for managing and monitoring Linux-based computer labs, with the added advantage of being easy to set up and maintain. Functions Epoptes…

We’ve looked at many different tools that can help you manage an ad hoc file transfer across a network or across the Internet. Magic-Wormhole remains one of our favorites, because it requires nothing of the recipient other than the software and some way of telling them the human-readable encryption words used to negotiate both the network protocol and decrypt the transfer. This part is usually accomplished via a secure secondary channel, such as using the Signal messenger client. But this leads to another common use for Signal: sending messages to yourself to act as a cross-device copy and paste buffer for secret wormhole keywords and even passwords and other sets of private information. This isn’t a bad idea if you also delete that data after it’s used, but in our…

We’ve made it through a couple of months without giving in to the temptation of reviewing yet another text editor. But CudaText is worth the break because it genuinely offers some unique features that other text editors don’t. It’s also worth pointing out that this isn’t a text editor designed to help you with NVidia’s GPU processing platform, CUDA, as its name might imply. Cuda-Text is instead an editor written with the Lazarus IDE in the Pascal programming language, a language that might be familiar to anyone who studied computer science in the ‘80s or ‘90s (like me!). This might also help to explain its best feature, because CudaText is truly cross-platform. And we don’t just mean Linux, Windows, and macOS. We mean FreeBSD, OpenBSD, NetBSD, DragonFly BSD, Solaris, and…

There are many modern compatibility conversions of old classic games. They often require the original data files but have a re-engineered game engine written for modern compilers and graphics engines. Many are brilliant, but most of the interest in playing them comes from nostalgia and revisiting a misspent youth. Very few can live up to modern playability standards, but Descent and its immediate sequel, Descent 2, are possible exceptions. Originally released in 1995 and 1996 for the PC and original Play-Station, both games were the first to realize the potential in giving the player “six degrees of freedom.” Doom, which had revolutionized the first-person shooter, offered four or five degrees of freedom: movement left and right (1), movement forwards and backwards (2), movement up and down (3), and rotation (4).…

Gnu Privacy Guard [1] (sometimes called GnuPG or just GPG) has long served the open source community as a tool for encrypting email and other documents. GnuPG, which is based on the OpenPGP standard, uses the familiar asymmetric key exchange approach, with a public key to encrypt the message and a private key to decrypt it. The public key is shared with other users, and the private key is kept secret by the message receiver. As long as no one discovers the private key, only the message receiver will be able to read the message. GnuPG is thus a powerful tool for ensuring confidential communication – as long as the private key stays private. But protecting a private key is not as easy as it sounds. If you store the…

Redcore Linux [1] (Figure 1) is a Gentoo [2] derivative designed to give users some of the optimization of Gentoo with an easier install. It is a successor to Kogaion Linux, which in later releases was also based on Gentoo. However, after five years of development, the RogentOS Development Group, Kogaion’s owner, discontinued it in November 2016. In response, Ghiunhan Mamut, a member of RogentOS, created Redcore Linux. With Redcore featured in this month’s download DVD, Mamut agreed to answer our questions. Mamut discovered free software around the turn of the millennium. Unusually, his high school ran Mandrake Linux, one of the earliest user-friendly distributions, rather than Windows. Later, when he bought his first home computer, he thought it natural to install Linux himself. “Back then,” he recalls, “the free…

Many of our day-to-day desktop applications, such as email and chat clients, text editing, music playback, and more have switched to become web applications. This puts a resource strain on our web browsers but also a cognitive strain on our brains as we struggle between using these applications and more traditional web searches and page views in a browser with dozens of tabs open. One possible solution to this is to offload these “Software as a Service” types of pages to a separate application, one that might even be able to aggregate shared functionality to make things even simpler. This is what Ferdi hopes to do, with an emphasis on applications that help us to communicate. Ferdi does this via its own online service, but it’s also possible to use…

Pigiron is a command-line utility that brings unity to the world of MIDI and Open Source Control (OSC). MIDI is the protocol used to send and receive musical notes and data, usually between your computer and a synthesizer. OSC was designed to be MIDI’s successor, but in many ways it was over engineered. Instead of the specific commands provided by MIDI, for example, such as note on, note off, and velocity, OSC is entirely dynamic. Applications and hardware create their own commands and publish these as a kind of API. This complexity makes it unintuitive compared to MIDI and might explain why MIDI is still so common. But OSC has become widely adopted when flexibility and power are required for cross-device communication, performance, and automation. All it really needs is…

Over the past 40 years, the MIDI specification has enabled physical controllers, hardware synthesizers, software synthesizers, audio applications, and numerous other hardware categories to talk to one another. This is an incredible achievement for a protocol born before TCP/IP. Even today, MIDI has never been more popular. Which is why it’s particularly bemusing that there isn’t a decent open source settings librarian for MIDI devices. Librarians are essential if you want to save a set of MIDI values for a device and also for computer-driven archival and patch management. MIDI devices are usually limited in their storage capacity and userinterface design, which means you often need to save your data to a computer. The easiest way to generate this data is usually via a system-exclusive data dump from your hardware,…

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System76 (https://system76.com/) is not just one of the most popular makers of Linuxonly hardware, they‘re also really good at pushing all of the boundaries and reinventing all of the wheels. This latest move might not push or reinvent, but it certainly gives consumers options for more mobile power. But this isn‘t news, right? The Pangolin was already available with an AMD Ryzen processor. This is a situation where out with the old, in with the new applies because the company is upping the Ryzen ante by offering the 15" Pangolin with a Ryzen 7 5700U CPU. Of course, along with this much-improved CPU comes a slightly steeper price. The previous Ryzen model starts at $1,199 and the new version starts at $1,398 (due to the $199 CPU upgrade). Both iterations…

The small and inconspicuous Nitrokey Pro 2 is a digital door opener: You can use the Nitrokey’s password safe to securely lock up your access credentials, and you can generate one-time passwords for more secure logins to online services. An integrated OpenPGP card lets you encrypt and sign emails. (See the article on the OpenPGP smartcard starting on p. 18 in this issue.) You can purchase the Nitrokey Pro 2 for around EUR50 via the manufacturer’s online shop [1] (Figure 1). The online shop is also where you will find the Nitrokey Storage 2, which provides the same functions as the Nitrokey Pro 2 but also includes encrypted storage capacity ranging from 16 to 64GB. Depending on how much storage you need, the Nitrokey Storage 2 costs somewhere between EUR109…

Creating a website is a lot of trouble – especially if you just have a few files you wish to publish online. You could type in all the HTML codes by hand, or you could employ a graphic design tool that looks simple but still might be more effort than you want to spend. Another easier option is to use Pandoc [1]. Pandoc is a universal document converter. You can give Pandoc a text file in any of several markup formats, and it will convert the document to any of several output formats. One common scenario is to format a text file using the simple and expressive Markdown markup language and then use Pandoc to convert the file to an HTML page. Pandoc is a command-line tool, so it allows…

Suppose you have hundreds or even thousands of photos that you want to present on a web page. If the images use the original camera resolution, they could severely slow down or even paralyze a website populated with this data. Optimizing the images can save bandwidth on the network and space on the storage medium. With a large number of images, a batch processing tool such as imgp [1] comes in handy. The command-line tool, formerly known as imgd and written in Python, provides functions for resizing images in JPEG and PNG formats, as well as converting from PNG to JPEG, rotating the images, and removing metadata. Even with thousands of files, imgp does its job at lightning speed. The developer, Arun Prakash Jana, achieves this through multicore processing, an…

Sometimes you need to copy the same ISO image to several USB storage devices. Since most available tools only let you write to one media at a time, this process can be a time-consuming task. With Popsicle [1], you can flash an image to multiple media simultaneously. Installation Originally written for the Ubuntu derivative Pop!_OS, you can find Popsicle in the repositories for Arch Linux and its derivatives. For other distributions, Popsicle’s GitHub page [1] provides the source code and detailed installation instructions. In addition, Popsicle is available as a Flatpak [2]. Operation After installation, you will find a launcher in your desktop’s Start menu. Popsicle does not require any configuration and supports intuitive use. Upon start-up, a small dialog opens prompting you to select the desired file for flashing…

The IT industry has been obsessed with security for years, so you’d think all our systems would be really, really secure by now. Seriously, though, doesn’t it sometimes seem that things are getting worse? In the great security arms race, the attackers are innovating just as quickly as the defenders. What can you do to stay safe? Install updates, don’t click on strange links, and tune in to your firewall. One reason some users tend to avoid configuring firewalls is that they are just too complicated. The Uncomplicated Firewall (ufw) was developed as an attempt to demystify firewall configuration. Ufw, which was created by Ubuntu but is supported in many other GTK-based Linux systems, is a simplified interface for configuring netfilter, the firewall system built down deep into Linux. We’ll…

The Tuned service is a daemon that can control, or tune, certain performance-affecting hardware characteristics on your computer. This can help you squeeze the most from your machine when you need it for a specific application or simply for battery life. While it is possible to start by creating your own configuration for the tasks you need to perform, the service comes prepackaged with profiles for certain tasks. These are split into two categories: power-saving modes and performance-boosting modes. Performance-boosting modes are useful when running virtualization software or when you want the best possible network performance. Power saving will help prolong battery life or keep your hardware from overheating. You can define and switch between profiles using configuration files, but there is a better way – an application called Tuned…

Until recently, it was an inconvenience that you couldn’t properly edit PDF documents on Linux. But it was also a seldom-required function that could usually be sidestepped by using LibreOffice or a web form. Recent events have changed this with everyone from local schools to doctors’ offices wanting a PDF edited, or signed, or added to and reshuffled, all of which can be a challenge on Linux. Our PDF tools have improved – and KDE Plasma’s Okular is a good example of a PDF viewer that can now do things such as annotations and filling out forms in a meaningful way – but they’re still a long way from the capabilities of Adobe Acrobat. While there still isn’t a tool that can do everything we need from a PDF editor,…

There can’t be many people who haven’t heard of the game Among Us, especially if you’ve been around young adults over the past 12 months. It’s an ingenious 2D, topdown game set on a space station. As you might expect from a game with a young following, it is also fundamentally online multiplayer. At the start of each round, each player appears on the station in the cafeteria. One player is designated the imposter, and all the other players are regular crewmates, none of whom know who the imposter is. Crewmates need to perform tasks while the imposter attempts to “kill” them, but if anyone gets a whiff of who the imposter might be, they can summon a discussion, and everyone votes to try and tease the identity of the…