Linux Format的June 2022目录

Jonni Bidwell I’ll be keeping my Jammy Jellyfish installed. It’s not yet stung me. But will it become my new daily driver? I’ll reserve judgement till the next Pop!_OS LTS comes out, I suppose. Plus there will surely be a plethora of other great Jellyfish-spawn distros with which to burden my bootloader. Nick Peers I’ll be installing Ubuntu 22.04 on all my machines, but not all at once. My desktop will be upgraded first, and I’ll hold off updating my server until some of the early bugs get ironed out. The thought of being unable to access my NickFlix media server sends shivers down my spine… Les Pounder I’ll upgrade my laptop to Kubuntu 22.04. When I first started with Linux I enjoyed KDE, then I spent some time with…

Keith Edmunds is MD of Tiger Computing Ltd, which provides support for businesses using Linux. We were once asked to look at a Linux firewall that was in place at a Premier League football club. The firewall wouldn’t boot, so no one had any internet access, and that’s why they called us. As is often the way, the firewall has been put in place by “somebody who has left.” That somebody had set up the firewall to PXE boot – that is, to download its bootable image from somewhere else, which in this case was a file server. My first thought was, “Why on earth would you set up a firewall to PXE boot?” And hot on the heels of this question was the answer: because it’s clever. Never mind…

Jon Masters has been involved with Linux for more than 22 years. The end may finally be nearing for the venerable “a.out” file format. With the removal of support from the last two architectures that still implemented it, it’s just a matter of time (perhaps next release). There aren’t many users of “a.out” left out there and readers would be forgiven for wondering what this is. Several decades ago, before there was ELF (Executable and Linkable Format), there was “a.out” and it was the original way Linux handled binaries. The year was 1995. I was 13 years old and had just been accepted into a local university part-time while still in secondary school. At the same time, the great Linux migration from “a.out” to ELF was underway. And it was…

tweaks your troublesome Tux to make it tick smoothly Q Secrecy without conflict I use KeePass on my phone, laptop and desktop. I also use Syncthing to sync the database among the three devices. Syncthing creates “conflict backup files” of the KeePass database when data is updated on more than one device. I’m looking for a solution, either a way for Syncthing to not generate these files or an alternative method of keeping the same password database on all devices. Is there a tool that will enable me to verify and combine both KeePass database files (since it’s encrypted)? Jordan Welch A We went through the same ourselves and tried several solutions. The problem with Syncthing is that it is, by its nature, non-interactive. When faced with a conflict it…

The Seagate EXOS 20TB is targeted at those with cloud data centres, massive scale-out data centre applications, bulk storage and enterprise NAS systems. Whereas the IronWolf Pro was meant for commercial and Enterprise NAS to support the needs of Creative Pro and Medium-to-Large businesses. They look practically identical from the outside, so is the EXOS 20TB just wearing a different hat from its IronWolf Pro brother? The Seagate EXOS 20TB sells for an eye-watering £480. We found the 18TB model for £295. That’s a 70 per cent price increase for a 2TB, or 11 per cent increase in capacity. To the casual observer, this is the same 670g block of metal that houses a CMR (conventional magnetic recording) 7,200RPM hard drive with 10 2TB platters and 20 heads, functioning within…

Most software stores performed reasonably well in this test because they rely on the mature and feature-rich PackageKit subsystem. We tested Gnome Software under Fedora, Discover under Kubuntu, and AppCenter – guess where – under EOS. We wanted to provide the best possible conditions for each store by running them in their native OS environments. All three stores can handle system-wide upgrades and save you from running any CLI commands in the terminal. However, Gnome Software pushes its upgrade capabilities even further and knows how to handle full OS upgrades. That means it can perform an offline upgrade for switching to a newer major OS version once it’s available – that is, of course, if you don’t run a rolling release Linux OS. Discover can’t manage full OS upgrades, and…

Armbian is a Debian-based distro designed as a framework for many models of single board computers (SBCs). Armbian is available for 64 different SBC, some of which we’ve never heard of. No matter which SBC we chose, they all claimed to be lightweight, fast and secure. So with these bold claims in mind, we fired up our trusty Raspberry Pi 4 for a test. We chose the latest Armbian desktop release, Armbian 22.02 Jammy XFCE, which is based on Ubuntu 22.04 “Jammy Jellyfish” and uses the XFCE desktop environment. There’s another CLI release that provides the bare minimum for a build. We tested Armbian on a 2GB Raspberry Pi 4 running at stock speed, which is 1.8GHz on our Pi because we have a later revision of the BCM2711 System…

Want to learn more about packaging and the Open Build Service? The OBS Documentation space (https://openbuildservice.org/help) has manuals, videos and slide shows to help you use the system. OpenSUSE’s Build Service portal (https://en.opensuse.org) Portal:Build_Service offers information for new packagers and developers. Do check out the Build Service Tutorial at https://en.opensuse.org/openSUSE:Build_Service_Tutorial, too. The RPM Packaging Guide at Github https://rpm-packaging-guide.github.io walks you through a standard process, minus OBS. Red Hat offers a chapter of its manual on packaging and distributing software. See https://red.ht/3vl0R3d. Debian provides help at https://wiki.debian.org/packaging/intro for packaging newcomers. Seven ways to set up Debian Unstable (aka sid): https://wiki.debian.org/Packaging/Pre-Requisites. Finally, Ubuntu will also help you with its Packaging Guide at https://packaging.ubuntu.com/html/index.html.…

We’re lucky enough to own a small Z80-powered machine, in this case an RC2014 Micro kit. The kit itself is £54 and you need to solder it yourself, but that was part of the charm. We’re building a computer from scratch, not just plugging in components. The kit took around an hour to solder and we then connected it to our computer using a USB to Serial converter and the tio serial console tool. We were then presented with a classic BASIC interpreter and spent a fun few hours writing code. If you want to take the project a step further, the RC2014 Mini is a slightly more powerful unit, which has an optional CP/M module that we can use to build our own CP/M computer. When connecting other modules…

3 GREAT WAYS TO SUBSCRIBE Print, digital-only, and print+digital bundles! USA From $132 For 13 issues REST OF THE WORLD From $132 For 13 issues EUROPE From €100 For 13 issues IT’S EASY TO SUBSCRIBE! Visit www.magazinesdirect.com/linux-format Call +44 0330 333 1113 Lines open Monday-Friday, 9am-5pm, UK time…

MQTT stands for Message Queuing Telemetry Transport and is a messaging service that can be accessed by a wide range of hardware. Libraries exist for devices all the way from x86 to microcontroller boards. The messaging protocol requires very little processing power and a tiny amount of bandwidth. MQTT operates as a publish-subscribe system. An MQTT broker runs somewhere on the network, which devices can publish to. Other devices then subscribe to the broker and are able to act when certain messages are received. The recommended broker to use for Home Assistant is called Mosquito and can be installed from the Add-On store (Configuration>Add-Ons, Backups and Supervisor). Once installed, navigate to the users section of the configuration and add a new user for MQTT. This can be a limited user…

The Wine Project hosts a database where users can report their experiences running applications and games under Wine (https://appdb.winehq.org). In particular, it’s important to check the database if you’re considering investing money in a Windows program. Even if a program appears to launch properly when run under Wine, it’s worth checking to see if there are any gotchas in store when you try to access certain features. Some reports feature tips and tricks to get the program going, depending on the specific version too, and it’s well worth expanding the Comments and How To/Notes sections at the bottom of the page for extra information about getting programs working. If you’re having difficulties running a particular program, particularly one of an older vintage, it’s sometimes worth causing Wine to simulate an…

Official sources state that as of March 2022, spam emails constitute around 3,000 per cent of all internet traffic – encouraging users to purchase industrial-strength Indian Cialis and a range of other drugs, presumably to use while cavorting with all of the sexy singles in our neighbourhood. Large email providers take measures to limit accounts on their servers from being used as spam palaces by ne’er-dowells. Gmail, for instance, will prevent you from adding more than 500 recipients for a single email and sending more than 500 emails in a single day. If you violate these limits then your Gmail account will be temporarily blocked, and if you repeatedly break the rules, you may lose your Google account entirely. ProtonMail limits are even tighter, with both hourly sending limits and…

believes that we should build better open source applications instead of a new iron curtain. Version: 2022.2.5 Web: https://github.com/firedm/firedm FireDM aims to be the ultimate all-in-one suite for downloading items to your hard drive. This application takes Libcurl, Ffmpeg and of course Youtube-dl, and wraps them up with a collection of Python scripts and a custom-made GUI. The result is a responsive and compact application that can download anything, be it an online video, an ISO image of a Linux distro you want to try, or just some random files. As you might know, Youtube-dl supports dozens of popular video-hosting platforms, not just YouTube, FireDM works with Youtube-dl’s advanced features and enables you to download playlists, select video quality, download just subtitles or just the audio track, perform batch downloads…

LXF290 will be on sale Tuesday 31 May 2022 Discover Portainer Forget the mess that is Docker – we sip from the Portainer cup and take Red Hat’s container system for a spin. CAD for beginners Before Blender and 3D printers, people used CAD to design 3D spaces and objects. We get to grips with FreeCAD. Run a website Content Management Systems rule the web and, outside of WordPress, what’s the right open source solution for you? Linux, the final frontier For a long time space was the one place Linux was barred from, but now it’s even on Mars! What happened there? Contents of future issues subject to change – we might not be able to afford to put the lights on!…

It’s LTS time again! If you’re down with the Linux lingo then you’ll already know what this means, but to the rest of the world it’s a Long Term Support release and for Ubuntu this comes around every two years, with 20.04 being the last such release. Why is any of this important? An LTS freezes development and provides a stable and secure install that Canonical – the company behind Ubuntu – guarantees will receive five years of security and kernel updates, with potentially a further three years (and perhaps as long as five) of Extended Support Maintenance, although you need to register for this. It offers peace of mind for those wanting a quiet time of it or more likely admins who prefer stable, secure and predictable systems to…

Apple’s M1 processor is one of the most interesting products the company has made in recent times, and the Asahi Linux project (https://asahilinux.org) brings a customised remix of Arch Linux ARM with the Plasma desktop to M1-powered Macs and MacBooks. As the release notes reveal (https://bit.ly/lxf289asahi), Mac and MacBooks that use the M1 chip, or the more powerful M1 Pro and M1 Max chips are supported. However there’s no mention of the brand-new M1 Ultra chip (which is essentially two M1 Max chips connected via a low-latency connection), and the announcement says that the new Mac Studio, which is currently the only product to use the M1 Ultra, is not currently supported. The ability to run Linux on these new Mac devices is exciting because the ARM-based M1 chips offer…

Q4OS 4.8 This Debian-based distro has a new version out, and is now based on Debian 11.3. This includes the latest stable kernel, along with security and bug fixes. The installation process has also been upgraded to offer a more polished experience when you’re setting up the distro. As the release announcement states (see https://bit.ly/lxf289q4os), language and localisation support has been improved in the API library for various tools as well. DEEPIN 20.5 Another Debian-based distro has a new release out, with Deepin 20.5 bringing in a number of new features that were suggested by user feedback. Perhaps the most notable addition is face recognition, which enables you to securely log into Deepin by glancing at your webcam. The kernel has also been updated to version 5.15.24, and numerous vulnerabilities…

Linus Torvalds announced the release of Linux 5.17, saying “we had an extra week at the end of this release cycle, and I’m happy to report that it was very calm indeed.” The latest kernel includes many new features, such as support for “Compile Once, Run Everywhere” or “CO-RE” BPF programs that enable developers to ship BPF (Berkeley Packet Filter, a kind of JITable small program that’s loaded directly into the kernel on behalf of a user) portably without recompiling for each target machine’s kernel. Another new feature is support for a new AMD P-State driver, replacing the legacy ACPI P-State driver with an ACPI CPPC-enabled one instead. The upshot of this is that those with recent Zen CPUs should see improved power and performance management, with the kernel able…

Linux has more filesystems than you can shake a stick at. There are the traditional disk-based filesystems such as ext2/3/4 and XFS. Then we have the all-in-one filesystems and volume managers like ZFS and btrfs, not to mention the virtual filesystems using in/proc,/sys and/dev. So here’s one more: tmpfs. This is a filesystem that exists only in memory. When the computer is switched off, its contents are gone – forever. This makes it useful for data that you don’t want hanging around. It’s most commonly used to mount the/tmp directory because that’s supposed to be wiped when you reboot anyway. Because the files are stored in memory only, tmpfs is fast – much faster than a spinning disk and also faster then an SSD. You create a tmpfs from the…

Using a software store occasionally to install just one application is perfectly fine. However, some people prefer more intense shopping and would like to install many software titles at once. A good store would put all such requests in line and process them sequentially. It quickly turned out that Gnome Software looked very uncomfortable during this particular test. It didn’t fail, since all programs in the queue were finally installed correctly, but the store didn’t provide any feedback about what programs were scheduled to installed, what their progress was and what was the result. Gnome Software definitely doesn’t want you to leave the product card before it’s installed. KDE’s Discover preformed much better in that regard. After we pushed many Install buttons here and there, we saw the ‘Tasks’ section,…

Matt Holder has worked in IT for 15 years, with 13 years’ experience in supporting IT in schools. Ever since my teenage years I’ve had an interest in programming and electronics. Many hours were spent sat next to my dad, learning how to program in QBasic. I then happened upon a book, which showed how to use a parallel port to interface with the outside world. Dad and I spent many more hours devising a timing system that could be used to time cars as they hurtled around my Scalextric track. Following this, I carried on developing various electronic circuits. I was bitten by the Linux bug two decades ago now. I can still remember being sat in a fast food restaurant, with the yellow logo with a friend of…

Arducam’s latest crowdfunded camera features the familiar official Raspberry Pi camera form factor, but with an autofocus lens and a sensor: Sony’s IMX519. This is even more powerful than the one used in the official Raspberry Pi HQ camera. The case for the camera is sold separately, but if you can spare the extra £4.50 you’ll discover that it features a 1/4-inch thread for tripods. The included CSI flat flex cable is the same as the one used with the official Pi cameras, and it can be changed for either longer or shorter cables, or used with converters if the Raspberry Pi Zero is your device of choice. As you would expect from a Raspberry Pi camera, the unit connects to the Camera (CSI) port alongside the HDMI port. In…

At high school we had a business studies room, next door to our IT department (Goldstar 286 PCs and the RM Nimbus!), which doubled as a form room. Everyday we sat there for registration and important messages, but sometimes we were let loose on the computers. However, these weren’t x86 machines. Rather, they were Amstrad PCW8256 and 8512 powered by the mighty Zilog Z80 processor. Amstrad, founded by Alan Michael Sugar (AMS-Trading) in 1968 was a well-known manufacturer of low-cost computers and consumer technology. Sometimes its consumer tech was maligned, but in the realm of computing Amstrad had success and gained a strong following. The company would later purchase the Sinclair brand from Sinclair Research (which saw new models of the ZX Spectrum being released). Amstrad had a history of…

The founder of Amstrad, Lord Alan Sugar, reportedly sketched out the original Amstrad PCW as a low-cost replacement for a typewriter. It was a single-box design with integrated portrait display and printer – largely because the biggest use for computers at the time was for word processing. PCW stood for Personal Computer Word-processor, while the printer was spun out as a standalone unit and a traditional (due to cost) landscape display ended up being used. The original PCW 8256 shipped in 1985 with a separate keyboard, printer and a main unit with a 12-inch green monochrome CRT display with an unusual 32 lines of 90 characters. This diverged from the normal 25x80 character displays of the time. The PCW 9512 was launched two years later. This device moved to a…

Wine enables the Linux user to run software that was designed to run under Windows directly on the Linux desktop. Wine stands for Wine Is Not An Emulator, and that gives some clue as to how it works. Rather than emulating a PC, as is the case with a virtual machine, Wine remaps the calls made by Windows software to equivalent Linux calls. This means that the Windows application is, effectively, running natively on Linux. The advantages of this approach, as opposed to virtualisation, are that fewer resources are consumed, performance is improved and Windows applications run seamlessly on the Linux desktop. Installing the latest Wine The standard Wine package in the repository of most Linux distributions is Wine Stable, and this is the branch that most users are looking…

Developers like to be able to launch virtual machines quickly for testing, but when developers write code on different platforms it can become a bit more complex to test if they have to use different virtualisation stacks. Fortunately, Ubuntu provides a solution for quick, disposable Ubuntu-based virtual machines on Intelbased machines, and it’s even supported on the new Mac M1 based devices (with a few limitations, naturally). This virtualisation software is called Multipass. Multipass is basically a front-end tool to start virtual machines, but it can support many varied back ends including VirtualBox, LXD, KVM and others. Multipass is essentially an abstracted automation tool to create a VM on the underlying hypervisor, which is why it can work on most platforms because the underlying hypervisor works on those platforms. To…

Valve has put a huge number of human hours into getting as many games as possible stamped with Playable or Verified status. But even Verified titles may have glitches or aberrations. And if you’d like to see them fixed then your best bet (as long as it’s a title that plays through Proton) is to report the issue at https://github.com/ValveSoftware/Proton/issues. Conversely many games currently don’t work with Proton because of various anti-cheat technologies. On Windows these often work by installing a kernel module that monitors either the game’s process or its communication with game servers. This prevents thirdparty cheats or hacks meddling with the game and granting players high scores, enchanted boots or whatever. Unless these mechanisms are adapted for Linux (more precisely Proton) then titles that rely on them…

Part Two Missed part one? Turn to page 62 to get hold of it! The subject of this second Rust tutorial is working with files and directories as filesystem entities. This means that we’re going to learn how to move, delete and copy files, explore directories, search directory trees and learn information about file permissions and file metadata. But first, we’re going to learn about the Result data type. To get started we’re going to look deeper into the Result data type (std::result::Result) that we first saw in last month’s Rust tutorial. Result is a Rust enum. An enum is a type with a list of different predefined values. An enum variable can only have one of these predefined values at any given time. The definition of Result is as…

Gabriel Krisman Bertazix is a senior software engineer at Collabora. While filesystems developers do their best to avoid corruption, it’s impossible to completely protect a system from accidental issues. Whether they’re caused by random bit flips, disk crashes or software bugs, users don’t enjoy losing their data for no reason. This is why filesystem developers put a huge effort in not only testing their code, but also in developing recovery tools. In fact, all persistent filesystems deployed in production are accompanied by some support infrastructure. When an error happens, administrators and recovery daemons must be notified ASAP so they can begin emergency recovery procedures, like recover from backups, rebuild RAIDs, replace disks or run fsck. When one needs to watch over a large quantity of machines, like in a cloud…

While support of 32-bit hardware has been abandoned by many major distros, none have stopped supporting 32-bit applications, until now. While Fedora stopped supporting 32-bit PCs in 2019, developers are now being asked to stop building i686 versions of packages that don’t have any dependencies – also known as “leaf packages”. As a wiki entry (https://bit.ly/lxf289fedora) explains, as long as the packages aren’t depended on by other i686 packages, developers are asked not to put in “significant investment of time or resources” to support i686 architecture, and this will no longer be considered a breaking change. This could cause issues for proprietary software such as Steam, which still features 32-bit games. We’ll be keeping an eye on the community response to this.…

Matt Yonkovit is the head of open source strategy at Percona By the time you read this, I’ll have finished my first in-person conference since the pandemic. Themed around the PostgreSQL open source database and taking place in San Jose, the Postgres Conference brought together people who wanted to know the latest happenings around data and how to manage it. So what did we learn from this event? Well, there was a range of attitudes. For some, this was their first event out in two years, and they were apprehensive. For others, this was the latest chance to get out and meet up with people, chat through problems, and learn more. Wherever people were in this range, the event was a great opportunity to share in the world of open…

Catalin Marinas posted a patch updating some Arm contacts since Grant Likely has taken a new role as CTO of Linaro. This author has personally known Grant for many years and is very excited for his new opportunity. Anup Patel posted some patches to clean up IPI (Inter-Processor-Interrupt) support for RISC-V machines. IPIs are commonly used for code running on one processor core (“hart” in RISC-V) to signal another that it needs to perform an action. An example of this is tearing down an address space that’s been used by multiple other cores which may still contain cached data in their local TLB (Translation Lookaside Buffer – a kind of cache structure). Traditionally, RISC-V had a less-performant mechanism for IPIs, but a new interrupt controller architecture (AIA with IMSIC) aims…

We’d love to try and answer any questions you send to lxf.answers@futurenet.com, no matter what the level. We’ve all been stuck before, so don’t be shy. However, we’re only human (although many suspect Jonni is a robot), so it’s important that you include as much information as you can. If something works on one distro but not another, then tell us. If you get an error message, please tell us the exact message and precisely what you did to invoke it. If you have, or suspect, a hardware problem, let us know about the hardware. Consider installing hardinfo or lshw. These programs list the hardware on your machine, so send us their output. If you’re unwilling, or unable, to install these, run the following commands in a root terminal and…

AUSTRIAN AUDIO Hi-X15 Over-Ear Headphones YOUR GIFT! WORTH £89 Don’t miss out, subscribe now! Product features Low-impedance headphones, ideal for low-power outputs like mobile devices Soft memory foam earpads to keep you comfortable during long listening sessions Foldable all-metal hinges for easy storage – uncommon at this price range Detachable 1.4m cable Designed and engineered in Austria SUBSCRIBE NOW! www.magazinesdirect.com/lin/a33x Call 0330 333 1113 and quote A33X Save money today! SUBSCRIBE DON’T MISS! Includes 5 years of Linux User & Developer issues PLUS: Exclusive access1 to the Linux Format subs area! 1,000s of DRM-free PDF back issues and articles! Get instant access back to issue 66 (May 2005) with tutorials, interviews, features and reviews. At linuxformat.com CHOOSE YOUR PACKAGE! NOT FROM THE UK? Turn to page 63 for more great…

An Ubuntu 22.04 LTS release doesn’t just include the main Gnome-based distro, but also pushes out new releases for the Ubuntu Server, along with updates to downstream distros such as Kubuntu, Lubuntu, Ubuntu Budgie, Ubuntu MATE, Ubuntu Studio, and Xubuntu. One of our favourites is Ubuntu Budgie, which in the 22.04 release features a slightly tweaked default layout, with the icons in the panel now having additional spacing to ensure they don’t appear cramped. The release also yanks the Gnome Control Center from the distro, and replaces it with the Budgie Control Center. In terms of usability, hot corners in Budgie sport an option to delay their activation. Then there’s Ubuntu Studio that uses the same KDE Plasma desktop environment as the official Kubuntu release. Note that due to the…

is going on a shopping spree, but this time it’s to open source software stores! This is the first time that we’ve put software stores up against each other, to identify the most compelling option. This is because stores have started to play a significant role in modern Linux operating systems and have become a factor of their appeal, for those who either want to try Linux, or are thinking of switching their current OS. Historically, Linux distros had package managers, and these still exist. However, a package manager normally lists thousands of packages that are mostly seen as internal technical ‘stuff’ by consumer-level users. That’s why stores, with their curated and visually appealing items are a better showcase of what the modern open source ecosystem has to offer. We’re…

Eighteen years ago Canonical, led by dot-com magnatecum-space tourist Mark Shuttleworth, unleashed the first Ubuntu release. It was nothing short of revolutionary. Suddenly Linux was a thing for human beings. Networking worked out of the box, as did a glorious – albeit brown – Gnome 2 desktop. It was built on Debian and inherited that reputation of stability, but it wasn’t Debian. It was something special. A huge community rallied around Canonical, which promised that it would listen. A bespoke bugtracker named Launchpad was set up, and the first bug filed was “Microsoft has a majority market share”. For many, Linux’s golden age was about to begin, and there was a palpable sense that Bug #1 would soon be fixed. Flash forward to today, and you’ll see that not all…

Wayland by default was tested in Ubuntu 17.10, but that was perhaps a little ambitious. Now the technology has matured and Canonical is confident that it’s – to dredge up an irksome phrase – “ready for prime time”. Extensive testing has taken place and the team are confident that the Wayland experience will be good for all. Yep, even those using Nvidia hardware. If it’s not, well, that’s fine. The old X11 session is still there. Wayland has been fairly misrepresented in the press, (who, me?–Ed) historically. The most egregious falsehoods were that remote desktop sessions, screen sharing and even humble screenshotting are impossible with Wayland. Do not believe such myths. The problem wasn’t Wayland, it was programs that didn’t support it. All the screenshots in this feature would not…

Pibrella is an awesome little board. We first came across it in 2014 while delivering a training course and since then we’ve used it with hundreds of learners. This £10 board may be eight years old, but it’s still a great way to get to grips with electronics on the Raspberry Pi. In this tutorial we’ll learn a little about this board, and create a reaction game to prove who’s the fastest of them all! Because Pibrella was designed for the original 26-pin GPIO Raspberry Pi it has to connect to the first 26 GPIO pins of any Pi. The first 26 pins are from the micro SD card. With the Raspberry Pi powered off, connect Pibrella so that it fits directly on top of the Pi. No part of…

Open Build Service does most of the actual package building on its own after you finish configuring the package. While OBS hides the machinations of package-building behind its web interface, here’s what’s actually happening: In RPM-based distros, the RPM build system takes your program from its compressed archive (organised in the same directory hierarchy as you want to install on the end-user’s system) and places it uncompressed into the/rpmbuild/BUILDROOT directory. This directory is a “chroot jail,” a protected sandbox that can’t interact with the rest of the system. When the build is complete, RPM wraps the contents of BUILDROOT into another archive with the cpio archiving tool. When the user installs the package, RPM copies the files in the directories you specified. For Debian and other DEB-based distros, you usually…

If you read ebooks on various devices such as tablets, desktop or Kindle, then it makes sense to retain ebooks in the format supported by all devices. While most desktop ebook readers support various popular ebook formats such as EPUB, MOBI and PDF, some devices such as Kindle are far more limited. It makes sense to have all your ebooks in the same file format so that they can easily be moved between devices per your convenience. Thankfully, a nifty command-line utility does this trick. If you work with ebooks, you might already be familiar with Calibre, a popular graphical ebook manager. In addition to doubling as an ebook viewer, you can also use Calibre to download news and magazines from the web, share and backup your library, convert between…

One thing that Czkawka (currently) doesn’t do well is rid your hard drive of system and temporary files. Its tool simply targets files based on their file type: #, thumbs.db, .bak, ~, .tmp, .temp, .ds_store,.crdownload, .part, .cache, .dmp, .download and.partial. If you’re looking for a tool that can do a better job of removing such useless flotsam and jetsam, pair Czkawka with (see the grab above) Bleachbit, which can hunt out temp files across your system and a range of programs, including your web browser(s). Avoid the version shipped with your distro, and instead download the latest version as a.deb direct from the author (www.bleachbit.org/download/linux). Once installed, it can be run under your normal username as well as the root user (choose the ‘as admin’ version from the launcher). From…

In the 1980s, the Z80 reigned supreme. It was everywhere, and the processor can still be found in industrial and commercial machinery. But while the Z80 was a beast of a CPU, it couldn’t manage to run a graphical OS. Until now. SYMBOS (SYmbiosis Multitasking Based Operating System) is a multitasking OS for the PCW, CPC, MSX and Enterprise 64/128 computers. Considering that SYMBOS is meant for 4MHz Z80s, this is an awesome programming achievement. Taking the PCW shortcomings into consideration, any type of graphical output is amazing, but SYMBOS is truly multitasking, with games and applications running at once! Created back in 2000, SYMBOS is still being actively developed, with a community of coders tinkering on additions and enhancements to this free download. SYMBOS comes with everything a desktop…

ISSUE 288 May 2022 Product code: LXFDB0288 In the magazine From flashing lights to image recognition and even an aircraft tracking system – we show you how to get more from your Raspberry Pi. Elsewhere, we transform photos and video with the G’MIC plugin, emulate the Acorn Archimedes, process satellite imagery, find out how practical it is to use a Pi as your daily driver, and code memory-secure systems in the programming language Rust. ISSUE 287 April 2022 Product code: LXFDB0287 In the magazine Discover the ins and outs of the Linux kernel. Then turn your hand at open source projects including ebook publishing, home automation and organising your research efforts. We test five alternatives to Ubuntu, preview Valve’s exciting Steam Deck handheld console, and discover how the Emmabuntüs collective…

If you read through, rather than skipped, over the opening paragraphs of this tutorial, you’ll have learned something about this writer’s dislike of instant messaging services. When you use WhatsApp (just as an example), the app on your phone is just a front-end to a massive communications infrastructure, which comes with pitfalls around surveillance, confidentiality and lack of control. Whatsapp, which is really Facebook (aka Meta) in disguise, knows who you contact, when you contact, and can probably make an educated guess as to what you discuss. And then there’s the fact that you’re limited to contacting people within the WhatsApp network. By using an app such as Delta Chat, your email server can take the place of instant messenger services, enabling you to communicate instantly and easily with your…

options, including setting the VM to start automatically, selecting the hypervisor and advanced networking, are performed with the multipass set command. More information on set can be found at https://multipass.run/docs/set-command, but here we’ll cover a few useful shortcuts. One example is that under Linux only the LXD hypervisor permits changing the network interfaces. Install LXD and all its requirements and then it becomes possible to use the different networks available within the virtualised environments. Change the hypervisor using the command sudo multipass set local.driver="lxd". Make sure all the VMs are stopped; this may require a reboot. Once the VMs are running on LXD, to see the available network interfaces the VMs can utilise run multipass networks. To specify the VM to be launched is, use--network switch with the appropriate network…

Atomic updates are all the rage these days. ChromeOS, iOS, Android, Fedora Silverblue and EndlessOS (as well as most modern embedded devices) all feature an OS partition that’s mounted read only. At update time, a new filesystem is downloaded, the partition is unmounted and the downloaded image is written out in a single transaction. This greatly reduces the probability of an update breaking the OS, especially if there are two such partitions that are updated alternately, ensuring a fallback (ChromeOS does exactly this). Having a read-only OS doesn’t mean additional software can’t be added – it can – but it’s added to a different partition (and optionally melded atop the root partition via UnionFS or some other voodoo). SteamOS 3, as you’ve probably figured, uses atomic updates (complete with “A/B”…

In Rust terminology, std is a crate, and everything under it is called a module. It’s helpful to have a look at the following modules: std::string is for working with the String data type. https://doc.rust-lang.org/std/string/struct.String.html. std::vec contains the Vector data type. You can learn about it at https://doc.rust-lang.org/std/vec/struct.Vec.html. std::net contains networking functionality related to TCP/IP. https://doc.rust-lang.org/std/net/index.html. std::fmt contains utilities for printing strings – see https://doc.rust-lang.org/std/fmt/index.html. std::thread module is about native threads. See https://doc.rust-lang.org/std/thread/index.html. std::os provides OS specific functionality. For Linux-related info see https://doc.rust-lang.org/std/os/linux/index.html. std::fs contains filesystem manipulation operations. Its help page is at https://doc.rust-lang.org/std/fs/index.html. std::io, which is going to be used in the next tutorial, is all about File I/O. See https://doc.rust-lang.org/std/io. You can learn even more about the Rust Standard Library at https://doc.rust-lang.org/std/. Finally, visit https://doc.rust-lang.org/core/index.html to find out…

In Linux and Unix, everything is a file, even your printer! As a result, there are many types of Unix and Linux files, including the following. Plain text files: these are used for storing text used for system configuration files, YAML files, source code, etc. Easily processed line by line, character by character or even word by word. Binary files: from an OS perspective, these are just like plain text files. The reason for a separate entry is that usually there’s no point in processing binary files the same way as plain text files. Directories: these filesystem entries contain lists of files and references to other files instead of any kind of user stored data. Links: there exist two kinds of links, which are symbolic links and hard links. Please…

We’re going to take a look at an old Blackjack project and see how we can update and modify it. Blackjack is a card game where the aim is to get a value total of 21 (or closest to 21) across the cards you’re given, to win a round of the game. The original project contains some interactive features that we can experiment with, such as buttons and events, along with some pleasing visual resources that we’ll look at in this tutorial. The original project that this tutorial is based on was created by Allan Lavell, and the original source code can be retrieved from https://github.com/bashkirtsevich-llc/PyBlackJack. During this tutorial we’ll cover how the game program works and what resources are included for the project to work. We’ll then look at…

There have been quite a few object orientated programming techniques used in the project. For example, classes have been used to create all the buttons we interact with in the game program: Hit Button, Deal Button, Stand Button… etc. Each button class contains various properties and functions for the necessary operations to take place. Below we look at the dealButton class as an example. Only the main parts of the class are shown to demonstrate the main concepts and ideas. A class is first declared using the class keyword as demonstrated above, class dealButton in this case. The next step is to write out the class constructor identified by def __init__(self), which is used to initialise properties (or variables) to certain values when an instance of the class is created.…

Even though object orientated programming has been implemented in this project, these individual functions have been used to help with the gameplay of Blackjack: imageLoad for loading an image resource. soundLoad used to load a sound resource. display this displays text on the screen. playClick for playing a sound resource once loaded. gameOver used to display the game-over screen. shuffle use this to shuffle the deck of cards using the Fisher-Yates algorithm, which helps eliminate the element of predictability. createDeck this creates the logical structure of deck of cards. returnFromDead when the main deck of cards has been emptied. deckDeal used to shuffle the deck. hit for taking cards from the deck. checkValue this checks the value of the hand of player and dealer. blackJack for seeing if blackjack has…