Linux Magazine的August 2020目录

Listing 1: Installing A screencast is a screenshot with moving pictures. Like a screenshot, a screencast opens up the possibility of explaining complex processes in a way that is more effective than words. Screencasts play an important role in explaining how to use programs in both professional and private contexts. Several screenshot applications inhabit the Linux space, including RecordMyDesktop, SimpleScreenRecorder, and the not-necessarily-intuitive OBS Studio. One screencast tool that was popular in the past and is now making a comeback is Vokoscreen. Volker Kohaupt has been developing the Vokoscreen screencast app since 2013. In 2019, development slowly stopped; after the 2.5.8 release there were no further updates. But in 2020, VokoscreenNG 3.0 was released [1]. The “NG” stands for new generation, and the latest version of Vokoscreen does indeed include…

Apache Guacamole [1] is billed as a clientless HTML5 web application that you can use to access your remote servers and desktops. It’s called clientless, because Guacamole only requires a web browser unlike other remote desktop solutions that require a client to communicate with the server. Although Guacamole only reached the 1.0 milestone (the latest version is 1.1) in 2019, the project has been in development for about a decade. Despite its low version number, the project has a mature code base, which is malleable enough to fit all kinds of deployments. You can use it in simple standalone local networks and also on enterprise networks where it can integrate with other existing resources to enhance security and user management. Guacamole supports all the popular remote desktop protocols including VNC,…

If Linus Torvalds were not already famous for Linux, he would be almost as famous for Git [1]. Within a few years of its first release in 2005, Git had become the dominant version control system in free software, replacing CVS and eclipsing rivals like Mercurial. Part of Git’s popularity is no doubt due to Torvalds’ own reputation, but a large part is also its highly organized structure: Every copy of Git is a complete repository with history and version-tracking tools that operates without a network or centralized server, giving it unmatched flexibility. Author 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,…

Is the desktop really just a metaphor? You bet it is. The software running on your computer doesn’t really look like anything, and that icon you click on inhabits the familiar form of a printer or a camera just to keep you from freaking out. All these metaphorical graphic aids have to come from somewhere, and if you work with Linux, they often come from Gimp. This month we present a Gimp workshop that takes you through the steps of creating a graphical skin for a media player application. Also in this month’s LinuxVoice, we introduce you to Waterfox, a clone of the Mozilla Firefox browser designed for privacy and support for legacy addons. We also show MystiQ, a handy tool for converting multimedia file formats.…

Many users call on the Gimp image editor [1] to crop and touch up their digital photos, but the powerful Gimp has many other uses. For instance, developers and graphic artists use Gimp to create graphic elements for desktop applications. The details of how to tie graphics features into a working application are numerous and depend on the programming language, the desktop system, and the nature of the application. However, the steps for creating basic GUI elements in Gimp are often quite simple and serve as a useful scenario for showcasing Gimp’s impressive toolbox of graphic design tools. This workshop introduces you to some of the tools that graphic artists use to build images in Gimp. In this scenario, I’ll build the skin for a sample media player application. Of…

People are passionate about the kinds of music they enjoy, which is perhaps why there are so many different music players for Linux. From the old school electro minimalism in XMMS to the audiophile prog rock madness of Amarok, there’s something for every kind of listener with every kind of taste. Among this plethora is Audacious, a new favorite of ours. New is perhaps the wrong word for a project that’s been around for 14 years, but it’s the user interface (UI) overhaul in this release that’s made the new version so effective. Audacious 4.0 switches its default graphical toolkit from the ancient GTK2 to the (soon to be deprecated) Qt 5, although in defense of the Qt port, moving to the imminent Qt 6 should be painless. Moving to…

In our day jobs, many of us need to spend a certain amount of time each and every day telling our colleagues what we’ve been working on. This much loved/hated/derided ceremony is known as a “standup,” because in the olden days when developers were working in an office together they would typically all stand up to deliver their summaries. Based on the principles of agile software development, it was meant to be an opportunity to briefly summarize what you’d done, what you’re doing, and whether anything was blocking you. Standing helped to keep the meeting short. These meetings have since become an important part of professional daily life, especially now with the huge increase in the number of people working from home who have to validate their existence. If you’ve…

All of us who work in publishing know that advertising is an essential part of the business model. Without advertising, much of what we all enjoy writing or reading simply couldn’t be financed. At its best, such as in this magazine or on our website, content creators and advertisers work together to the benefit of everyone. The quality subject matter drives a specific set of advertiser needs. But at its worst, the hyper-competitive arms race between advertisers and ad-cynical content consumers has turned parts of the Internet into a tracking, privacy, and bloatware combat zone, where the only probable outcome seems to be mutually assured destruction. The answer for many is installing an ad-blocker, which takes out both the good and the bad. They’re typically installed per device or per…

Preview Newsletter The Linux Magazine Preview is a monthly email newsletter that gives you a sneak peek at the next issue, including links to articles posted online. Sign up at: https://bit.ly/Linux-Update Approximate UK / Europe Aug 08 USA / Canada Sep 04 Australia Oct 05 On Sale Date…

Ubuntu Studio 20.04 LTS 64-bit Ubuntu Studio is a version of Ubuntu that is outfitted and tuned for creative artists. Onboard the default configuration, you’ll find tools for photographers, graphic artists, video production specialists, and audio engineers. Although most of these applications are also available for other Linux systems, Ubuntu Studio ties them neatly into a complete package and manages configuration settings for seamless access. For audiophiles, Ubuntu Studio boots up with the Jack low-latency audio and midi server, the Ardour digital audio workstation, the Carla virtual patchbay, and a variety of sequencers and synthesizers. Graphic artists will find the Blender 3D creation suite and the PikoPixel pixel art studio. Photographers will appreciate the Darktable virtual light table and darkroom app, and video makers will find a ready-made collection of…

Linux Professional Institute (LPI) has launched FOSSlife, a website for those “who care about the FOSS community and want to follow the trends, tools, projects, programs, and people who define the FOSS experience.” The new website will offer recent news and articles on FOSS technology and advocacy (https://www.lpi.org/articles/welcome-fosslife-new-web-magazine-born). FOSSlife is intended to be a destination and resource for experts as well as those just starting out on their open source journey. “It is our mission to promote the use of free and open source by elevating the people who work with it. FOSSlife fits perfectly into this mission, as it helps us share, bundle, and disseminate knowledge about free and open source software and inspire people who are searching for their own approach in gaining this expertise,” said G. Matthew…

Many webcam manufacturers still don’t take Linux seriously, which means that kernel modules for many cameras are often created by freelance developers. In some cases, the manufacturer even changes the chipset during a production run without informing the Linux community. The result of all this uncertainty is that webcam operations in Linux are somewhat unpredictable. A specific system might work out-of-the-box for some cameras but have troubles with others. Users today, however, are accustomed to more seamless hardware configuration. If you, or anyone who depends on you for Linux advice, is having trouble with getting a webcam to work in Linux, one option is to replace the on-board webcam utility shipped with your distro with an alternative application. Guvcview and QtCAM are powerful alternative tools that are suitable for all…

PHP is great. It feels approachable and intuitive, and it allows you to write a working application with just a handful of lines of code. PHP basics are relatively easy to master, and there are plenty of books and online resources that can help. As with any programming language, things can get rather hairy sooner or later. But even with basic PHP knowledge, you can build simple yet useful applications. As you progress, you’ll notice that many PHP applications share a lot of common code. With time, you may even build your own library of reusable PHP blocks that can significantly reduce the amount of effort required to build an application. Personal Note I’m not a programmer by any stretch of the imagination. I like writing simple applications and tools…

As a result of the COVID-19 pandemic, many employees have exchanged the office for their home to accommodate social distancing guidelines. In addition to getting used to working from home, many telecommuters must also deal with security issues when contacting colleagues or accessing company servers. While large corporations may take care of these issues for their employees, self-employed telecommuters and small businesses need to find their own solution. WireGuard [1], the modern virtual private network (VPN) tunnel software developed by security researcher Jason Donenfeld, offers an easy-to-implement solution that relies on encryption to secure the connection between two endpoints. WireGuard found its way into the Linux kernel 5.6 at the end of March at the same time WireGuard v1.0.0 was released. The VPN program is now available for all common…

The Raspberry Pi has a hard time with small displays because support from Raspbian is surprisingly poor. Creating and implementing suitable interfaces is difficult with a dearth of off-the-shelf programs for controlling small displays. I’m quietly confident that the PyPortal intelligent touchscreen by Adafruit is a better solution. Figure 1: The front of the intelligent PyPortal display. The resistive touchscreen requires a certain amount of pressure before it reacts. PyPortal (Figure 1) is a small 3.2-inch networkable resistive touch display with an integrated microprocessor [1]. At $55 (EUR59), it is not exactly cheap, but considering its components, the price seems reasonable. A correspondingly sized 3.2-inch display plus a Pi Zero W with an SD card, at about the same price, will serve as a comparison with the PyPortal configuration. PyPortal…

Multimedia content is available on the web and on data carriers in many formats. Often, your chosen media player doesn’t understand all of them. This means that you will find numerous tools on Linux that convert audio or video formats. Although these tools offer a great deal of flexibility through numerous options, they are often confusing, especially to newcomers. MystiQ [1] follows a different strategy. The program converts multimedia files, no matter whether you need to change the format of an audio file or a movie, but it keeps to the essentials. That makes it possible to convert any content with just a few mouse clicks and without extensive training. The numerous presets that you can apply to frequently used video and audio formats make the program easier to use.…

If there’s one tool you rely on when writing these pages (other than a text editor, of course), it’s the tool you use to make screenshots. It’s not until you start taking lots of them, under all kinds of circumstances, that you realize there’s a big difference between the old Windows equivalent of pressing PrtScn and hoping for the best, and something advanced enough to make your life easier. Specifically, it helps if a screenshot tool is unobtrusive, allows for a timer, saves with a sensible file name, remembers the save directory, works with OpenGL/compositing, and can grab a user-defined section of the screen. It’s amazing how many screenshot tools there are, and yet how few can do all of this. For a long time, my favorite screenshot tool was…

As has been written many times in these pages, the version control tool, Git, has become almost as transformative within the computing industry as Linux itself. That they’re both the product of Linus Torvalds’ brain is remarkable, but it might explain why they can both be prone to logarithmic complexity. On the surface, Git is relatively straightforward to use. The commands to create a new branch, stage modified files, commit changes, and push those changes back are easy to understand and will mostly be all you need. But as soon as a project reaches a certain level of maturity, when the commits start conflicting and the blame log starts growing, the complexity becomes corporeal. This is where a GUI can help, both by enforcing a set process to the way…

Veloren is the beginnings of a beautiful, open world, open source, voxel-rendered, massively multiplayer online role-playing game (MMORPG). It’s a game that was initially inspired by another game, Cube World, during the latter’s seemingly moribund development. But Veloren has been able to generate enough momentum of its own to move beyond its original inspiration (and escape the negativity surrounding Cube World’s early beta release) to become what looks like an incredibly promising title. You can’t help but notice that the graphics have taken a huge chunk of inspiration from Minecraft, especially if Minecraft is the only voxel-rendered game you know. But Veloren uses this graphical style simply as a toolkit for its game mechanic, because it allows for huge procedurally generated worlds that can be easily generated and rendered. It’s…

Teleprompters have become an important tool in television and politics. The goal of a teleprompter is to display text to the speaker in a way that gives the viewer the impression the speaker is improvising. The recent rise of platforms such as YouTube or Dailymotion has democratized video production, which means that more and more private video bloggers have an occasional need for teleprompters to deliver essays, speeches, and other presentations. You don’t need expensive equipment to integrate a teleprompter with your video creations. Armed with just a Raspberry Pi and the free Imaginary Teleprompter [1] software, you will have the same capabilities as speakers at a political event or on TV. For Everyone Listing 1: Installing Figure 1: The Imaginary Teleprompter editor window looks like the interface of a…

The business of distributions centers around the packaging and testing of applications. However, many distributions have grown so large that their daily activities rival those of Apple and Google. How are distros organized? How are they run? How do they make decisions? What relationships do they have with other free software organizations? This month, Distro Walk touches on a few of these questions through a sample of news items from different distributions. These not only give a glimpse into the complexity of modern distributions, but also show how their daily business might inspire developers to offer their services or help users decide which distribution best suits their philosophy. Arch Linux The process is defined on the project DeveloperWiki [2]. The project leader’s role is defined as making decisions when no…

Without special aids, people with vision impairments can find using a computer difficult. While icons can be sufficiently enlarged to make them readable, word processors and spreadsheets are a major hurdle. The fonts in the documents are almost always too small to be read and deciphering text is also difficult due to the smooth transitions in serif or cursive fonts. In this case, programs that read the text out loud can help. These programs convert letters into linguistically adapted phonemes and then play them back via the computer’s sound system with an installed voice. On Linux, there are various screen readers for this purpose that are based on text-to-speech programs such as eSpeak or Festival. Solutions based on the popular eSpeak have the disadvantage of a synthetic computer voice: It…

Mozilla’s Firefox web browser has been massively popular in the past. Although for a long time the browser was one of the most frequently used web navigators, Google’s Chrome browser and its open source counterpart Chromium have now outpaced it – not least because of faster response times. Firefox also lost some of its popularity because of changes to the browser. The integration of services such as Pocket, interface changes, and the fact that telemetry data are collected have left many users concerned about their privacy and feeling restricted in terms of usage options. Also consider that for many privacy-conscious users, Chrome or Chromium are not an alternative because of the integration of many Google services with these browsers. All of this makes Waterfox an interesting alternative. Waterfox is a…

My longtime favorite terminal emulator is Konsole running ZSH. Konsole is obviously an important part of the KDE Plasma desktop and integrates perfectly with color themes and font selection. But it’s also fast and functional, with native split support, tabbed views, key control over profile swapping, and an unlimited scrollback. But this doesn’t mean there aren’t better terminal emulators out there. Some that we’ve previously looked at have been seriously impressive, such as the GPU-accelerated Alacritty. But Viter could be another candidate for one simple reason: It’s a terminal emulator that attempts to use Vim key bindings alongside similar normal edit and detached command modes for terminal interaction. While Bash does have a setting for Vim key bindings, and there are various other hacks you can try, none of these…

If you’re looking for a slightly more ambitious Git GUI than the excellent Guitar (above), GitQlient can be a great option. In particular, it’s considerably faster, especially when dealing with larger projects, and can open more than one project at a time. We tested this with a local Git clone of the Ardour DAW repository, which is a large project with thousands of commits over its 15 year history. Parsing this history took Guitar around 60 seconds on our system, while GitQlient took less than 5 seconds. To be fair, GitQlient appears to only load enough commits to populate the list view until you scroll down (as most apps should), but it shows that it’s a potentially more ambitious tool developed to be used with larger projects. The ambition in…

Despite the humongous processing and graphics advances made in the last 35 years, and the fact that the genre is still popular, the humble platform game still has the same basic mechanics as 1983’s Manic Miner. You move left and right and jump to negotiate a path across one platform to another while avoiding enemies and pitfalls. Whether it’s playing Moss in virtual reality, or New Super Mario Bros. U Deluxe on the Nintendo Switch, the vast majority of platform games use this same premise. Which is why it’s a totally legitimate endeavor for Super Bombinhas to unashamedly pursue that old addictive gameplay style in the 21st century. Pursue is the operative word here, because the game is far from complete. There are currently six playable stages, complete with artwork,…