Linux MagazineFebruary 2022的目錄

The Parrot OS home page [1] lists four major concerns: security, software freedom, a lightweight system, and cross-platform portability. To these concerns, it also adds a thorough development stack and the goal “to push newbies into good habits.” Of all these concerns, Parrot is best known for being security conscious. However, it succeeds in all of these concerns to a degree. In particular, by making privacy and security tools part of the standard install, Parrot is probably most successful in pushing all users – not just newbies – into better security habits. Based on Debian Testing, Parrot OS is a rolling release, with packages updated as soon as they have been tested, although official releases are periodically released as well. It also offers a choice of MATE or KDE Plasma…

The European soccer championship a year ago was quite a flop for Germany, with what used to be a World Cup-winning squad, but one scene from the Czech Republic’s match against Scotland still sticks in my mind. The Scots goalkeeper had run far out of the goal, which Czech player Patrik Schick noticed while hovering at the halfway line. Schick quickly fired the ball into the out-of-bounds goalkeeper’s goal with an eye-catching arcing shot. Since then, I’ve been trying to replicate this feat in my position as striker for the amateur team “Beer Fit” in San Francisco, though without any success so far. This is what prompted me to turn this into a video game written in Go for my Programming Snapshot column. The underlying physics for the chip shot…

A picture is worth a thousand words, and sometimes, a visual image of your network can save you hours of troubleshooting. Skydive [1] is an open source network analyzer designed to provide a graphical representation of the IT components and how they interact. I’m not talking about wiring but about the data flows between the nodes. Skydive stores this information in a central location. You can interact with Skydive using a web interface, the command line, or an API. Skydive consists of a central analyzer and many agents (Figure 1). The agents run on Linux hosts and report network configuration and statistics to the analyzer. The analyzer listens to feedback from its agents and stores the input in a database. Gradually, the analyzer gets to know the entire topology and…

If you’ve tried browsing the Internet recently without some form of ad blocking, it can be a real shock. There are pop-ups everywhere, invasive AI chats, endorsements inserted into text, site takeovers, slide-downs, slide-ins, and every other kind of invasive, attention-grabbing mechanic you can imagine. It’s truly a sorry state because many great content sites – such as our own – obviously rely on advertising to fund the work they do, but the Wild West of click-throughs has broken any possible kind of compromise. Because most people don’t run any kind of ad blocker, they must think the Internet is a very different kind of place than those of us who do, which perhaps explains why they may also be unconcerned about other aspects of the Internet, such as a…

Over the years, we’ve looked at many different shell environments. The vast majority of these attempt to make you more productive either by mimicking the way you might work with a programming language, such as with Microsoft’s PowerShell, or old Unix systems with Bash, or even modern search-based shells such as fish. None that we’ve looked at so far have attempted to make you feel more “cozy,” but that’s exactly what Dune has been developed to do. Cozy in this sense does need a little qualification, because it’s not the kind of cozy you might get from lounging around an open fire with a good book. Instead, it’s the kind of cozy you might feel if you were a developer who wants your command line environment to behave more like…

Space Station 14 is a unique top-down multiplayer game set on a space station. It’s a remake of a cult classic called Space Station 13, but this version is completely open source and still under active development. The developers consider the game to be in an alpha state, and it can feel that way when it comes to trying to understand what’s happening and what your overall objective might be. But the developers are also asking for people to test the game and contribute to the community, so it’s definitely worth giving it a go. Once installed, you first need to connect to a server with other players, which will then download whatever assets are being used by that particular game instance. You then get to choose a character to…

Security researchers at Sansec (https://sansec.io/research/cronrat) have found a new stealth attack that targets Linux servers and uses a non-existent calendar day to stay off the radar. This remote access Trojan (RAT) masks the actions of the attack by using the date February 31 and targets Linux-based web stores to trigger online payment skimmer threats. The new CronRAT attack can execute fileless malware, launch malware in separate subsystems, control servers disguised as Dropbear SSH services, hide payloads in legitimate cron tasks, and run anti-tampering commands. CronRAT bypasses browser-based security scans and has already been discovered in live online stores. The threat was injected into servers via a Magecart (payment skimming) attack. This attack is made possible because cron only checks for a date format and not that the date of the…

First released in 1992, the Portable Document Format (PDF) shows no signs of disappearing. The format has become a business standard and the preferred format for sending files to a print shop. Closely related to PostScript (PS), PDF has the advantages of ensuring that files are seen exactly as the user intended and of eliminating concerns about the supported formats or available fonts on the recipient’s word processor. Yet for all these advantages, the PDF format comes from an era less concerned with privacy and security. It does include privacy and security permissions, but these are primitive by modern standards. In fact, these tools are literally a joke. As I have heard several times, PDFs exist in one of two states: compromised and about to be compromised. Fortunately, the means…

GPS lets you determine the position of an object down to single-centimeter accuracy – as long as the object is outside. If the object is inside, the task is a bit more complicated. Satellite navigation doesn’t work well through doors and rooftops, and even if you could replace the satellite signal with equivalent transmissions from locally placed beacons or WLAN access points, the presence of interior walls and furniture muddles up the results of classical analytical techniques such as those used with GPS. What is more, when someone is inside a building, the question is not so much about “What are his coordinates.” What you really want to know is “What room is he in?” Such a problem is better addressed through the tools of machine learning. Of course, creating…

Ubuntu is one of the most popular Linux distros, but it is still missing some benefits that other Linux communities enjoy. For instance, the Ubuntu repositories might not have the package (or the latest version) you need, which means you’ll need to hunt around GitHub for source code to compile that package yourself. The two official alternative methods for getting new versions of packages (snaps and PPAs) are also lacking in many areas (see the “Issues with Snaps and PPAs” box). When it comes to finding and installing new software from a broad and diverse user base, many Ubuntu users look longingly to Arch Linux and its popular Arch User Repository (AUR). The AUR is a large community-driven repository. The goal of AUR is to provide users with easy access…

If you own an Amiga, you can use the original ROM; otherwise, you have to get it some other way. One good option is to buy the Amiga Forever Plus Edition [7] for just under $30 (EUR30). Manufacturer Cloanto is the current rights holder of all Kickstart versions and sells them, among other things, as part of this package. After you confirm payment, you can download directly from the store page, which gives you either an MSI installer (for Windows) or a ZIP archive (Figure 3). Unpack the AmigaForever9Plus.zip archive after completing the download and mount the ISO image af-dvd.iso. Mount the image with a variant of the command: mount -o loop af-dvd.iso /mnt/ The Kickstart ROMs are now in the Amiga Files/Shared/rom/folder. You need two files for PiMiga: the…

Granted, at first glance, it seems like total overkill to create a slideshow with a video editing program. But if you take a closer look, there are good reasons to do so. It is true that even simple programs such as Imagination [1] let you create slideshows relatively quickly from a series of images. Many transitions are available, and zooming is pretty easy. But when it comes to fine-tuning the zoom speed or holding zoom points and then moving the section further, this kind of software quickly reaches its limits. his is where video editing programs come into their own. Although the transitions they offer are only suitable for slideshows to a limited extent, they can be used to control zooms and pans in all variations and in all details.…

There are many PDF viewers for Linux and several of them are good if not exceptional. Okular, in particular, is one of the best we’ve used, because it’s one of the few that will open most PDFs, offers sensible scaling, multiple page views, and the ability to annotate PDFs in a way that can be shared with other people. If you need to manage a library of PDFs, then the ebook editor and manager, Calibre, is another excellent and more ambitious choice. It’s particularly good when you’re researching a subject and need to search across several publications, although Calibre’s PDF-viewing capabilities are little more than perfunctory – which is where Sioyek can help. Sioyek is a new PDF reader developed specifically to help better manage and access academic papers, but…

If KDE Plasma’s System Monitor is the most beautiful monitoring tool we’ve looked at, then Guider is a good candidate for the most comprehensive. It doesn’t even consider itself a monitoring tool, preferring the term “integrated performance analyzer,” which is a fair description. Its list of features includes monitoring, profiling, tracing, visualization, control, logging, networking, and testing, all of which can be conjured from the command line. Guider is written in Python and is easily installed with pip. At its simplest, you can run guider top -a to launch the tool as a simple top process viewer, although simple isn’t really the right word. Every monitoring mode contains a huge amount of data, and it can easily overwhelm your terminal. The top implementation, for example, is wide, listing statistics for…

The best drawing tools seem to have the word “paint” in their title. There’s the famous Deluxe Paint that helped sell a million Commodore Amigas in the 1980s, and regular PCs in the 1990s, to such an extent that its pixelated Tutankhamen and Venus images are now synonymous with the dawn of high-quality graphics composition on home hardware. Deluxe Paint also helped many of us adapt to what might have been our first touch of a mouse, left-clicking to draw and drag those pixels across our flickering CRT televisions. Later came Photon Paint with 3D modeling and texture mapping and then even CinePaint, which was an early fork of Gimp with real movie-making credits to its name. And now we have VPaint. The V in VPaint is for vector, which…

When I want to keep up with what’s happening in the world, I can check my favorite online newspapers or, if I’m in a hurry, use a news ticker. But what if I don’t want to leave the command line to do that? I use getnews.tech to fill this gap. You can easily query getnews.tech via the web using curl. If you want to host it yourself to save data, you can find the code and installation instructions on GitHub [1]. You also need an API key from News API [2], which is free for private users, but you do need to register. News API serves as the actual data source, while getnews.tech acts as the CLI wrapper to operate and sort and takes care of the human-readable output. If…

Satellite-based systems such as GPS or Galileo determine the position via multilateration, deriving the distance in a linear way from the signal propagation time. If you know the position of a satellite (right black dot in Figure 8) and its distance (the gray sphere surrounding the black dot), you can guess your approximate location. The intersection of the gray sphere with the blue sphere (which represents the surface of the Earth) restricts your location to the green circle. A second satellite reduces the possible positions to the intersections between the green and red circles. If a third satellite is added, you are no longer limited to the surface of the blue sphere. You can measure altitude as an intersection with the cap of a third satellite (not shown in Figure…

Creating distributed and concurrent applications doesn’t have to be difficult. Elixir [1] allows hobbyists and new programmers to create projects that can work across multiple nodes. A general-purpose programming language, Elixer runs on top of the Erlang virtual machine (VM) [2], which is known for running low-latency, distributed, and fault-tolerant systems. In this article, I look at three projects (Figure 1) that use basic Elixir functions, with no custom project setup or imported libraries. The first project employs remote functions between a PC and a Raspberry Pi, the second project uses multinode requests to get Pi statistics, and the final project looks at dynamic sharing of data between three nodes. These projects require only 10 to 25 lines of Elixir code, showing that distributed projects don’t have to be complicated.…

Transferring files from one computer to another usually requires the installation of some kind of server. Samba (or a network share, in Windows speak) is the classic approach to doing this. You can also use SSH to move files from one computer to another quite easily. But if you don’t want to install and set up a server, the only option is to use a USB stick since very few desktop environments integrate tools for easy data transfer. As an alternative to this, there are a number of simply designed programs that transfer files and folders over the local network at the push of a button without requiring an Internet connection. And the system does not rely on background services or cloud servers such as commercial services like Dropbox or…

There are few time-wasting utilities as satisfying as a music and audio visualizer. And while they can turn what should be a purely listening experience into a gluttonous audio/ visual feast of migraine-inducing proportions, they can equally enhance the listening experience, especially at a party or at a live performance. But even on the humble desktop, they’re a lot of fun, and projectM is the best visualizer we’ve come across in years. A music visualizer is really any kind of visual effect that attempts to graphically sympathize with the sound that is pushed through it. They usually involve lots of bouncing lines syncopated to a beat; or psychedelic, pulsing wheels of color turning against one another, or everything combined. They can be an old-school Amiga demo, part tech demo, and…

When Tim Berners-Lee invented the URL back in 1994, he could never have anticipated that the humble uniform resource locator would become so easily subverted. Back then, a URL was nothing more than a static web address for an actual HTML page that either existed or didn’t. There were assumptions, such as the root of a location being served by an index.html file, but most pages were static, written by hand, and didn’t change location. They certainly weren’t dynamic or served via a content delivery network. All of this has changed in the decades since. Most people laugh at hand-written HTML now, and even if you wrote it, you probably couldn’t persuade your browser to load it without carefully wrapping it within HTTPS. Most web pages are now generated programmatically…

Sid Meier’s Civilization games are some of the best games ever made. They combine empire building and resource management with finely balanced strategy – and even some historical and economic contexts that make sense today. It’s no surprise that remakes and other games inspired by them often grace these pages. The original games span the entire modern gaming epoch, from the pixelated Amiga graphics of the early 1990s to the retina displays of iPads, Android phones, and consoles in the current era, which means there’s an aesthetic to suit every remake. UnCiv is one of the best, taking inspiration from the current, penultimate Civilization release, Civilization V, originally released in 2010 but still very much alive. However, the inspiration that UnCiv has taken from Civ V isn’t in the graphics…