Índice para December 2021 em Linux Format

Jonni Bidwell I use Arch, and also Arch32, Pop!_OS and Debian. And, albeit briefly, whatever’s on our artisanally crafted DVD. LTS distros, through Snaps and Flatpaks, can now obtain the latest applications too, so adding hacky PPAs on the ilk of Mint and elementary OS is no longer de rigueur. Les Pounder My work machine runs Ubuntu 20.04 LTS. It gives me the stability to get my work done. For my other machines, my X220 is always distro hopping (currently Kubuntu 21.10) and my X390 is on Ubuntu 21.04. My Raspberry Pis are mainly using Raspberry Pi OS and Diet Pi. David Rutland I use Ubuntu 20.04 LTS which, among Linux distros, is the worn and comfy pair of solid old boots. Sure, I’ll slip into Arch for an occasional…

The Software Freedom Conservancy (SFC) organisation (https://sfconservancy.org) is suing TV manufacturer Vizio over what it claims are “repeated failures to fulfil even the basic requirements of the General Public License (GPL).” Vizio, a popular TV brand in the US, uses a smart TV platform called SmartCast, which the SFC alleges “contain software that Vizio unfairly appropriated from a community of developers who intended consumers to have very specific rights to modify, improve, share, and reinstall modified versions of the software.” While the SFC’s lawsuit isn’t looking for monetary damages, it “seeks access to the technical information that the copyleft licenses require Vizio to provide to all customers who purchase its TVs.” You can see the full lawsuit complaint at https://bit.ly/lxf283sfccomplaint. According to the SFC, the non-profit organisation – which includes…

Keith Edmunds is MD of Tiger Computing Ltd, which provides support for businesses using Linux. The CMS acronym, confusingly, can refer to either Content Management Systems, such as WordPress, or Configuration Management Systems such as Puppet, Ansible or Chef. For this issue’s column I’m using CMS to refer to the latter. There are a lot of them – indeed, Wikipedia lists 24 Open Source CMSs. If you have more than one Linux system then you should use a CMS, and they have a place even if you only have one Linux system. There are many reasons to use a CMS, but here are just three to get you going. First, it provides a change control mechanism and, when coupled with an SCM (Software Configuration Management), an audit log. Second, it…

Firefox 93 was recently launched by Mozilla, but even though it was positively received by critics, the launch was overshadowed by the discovery that there were now adverts included in the address bar, a drastic and invasive change that Mozilla had failed to properly disclose. The feature, known as Firefox Suggest, started to appear for some users in Firefox 92, despite there being no official communication about the feature until a blog post on September 15 (https://bit.ly/lxf283ffsuggest), where it describes the feature as “a new discovery feature that is built directly into the browser.” Its inclusion in Firefox 93 is hidden in the release notes, and it led to users complaining online. The relative silence over the feature led to people worrying if data from their address bar was being…

Jon Masters has been involved with Linux for more than 22 years. There was recently the first (but likely far from the last) Rust for Linux conference, known as “Kangrejos”. The purpose of the conference was to further work toward supporting Rust inside the kernel, specifically in driver code. Much interest in Rust exists within various communities because it simultaneously targets system programmers, but also aims to eliminate various memory safety issues inherent to C code. These issues arise from “UB” or Undefined Behaviour, and there’s a lot of it in the C programming language. Rust aims to be both fast (and thus suitable for low-level programming) but also safe, since it provides careful tracking of the ownership of memory (pointer safety). For example allowing only one owner of an…

Neil Bothwick takes two Tuxes into the bathroom, as they’re penguins. Q Where is the program? I read about PDF Mix Tool in LXF281. This is something that I have always wanted to have, so I downloaded the file pdfmixtool-master.tar.gz and then extracted it as pdfmixtool-master. This is a directory containing some files. My problem now is, how do I start the program? I am baffled. Bryan Mitchell A The file you downloaded is the source code from the project’s GitLab repository. All open source software is distributed in this way, although much of it is also built into packages by the distro maintainers. The steps for installing from source can vary, although there are standard ways of doing it. There is normally a README or INSTALL file within the files…

You might think a separate test for NVMe drives would be superfluous, but it’s not (otherwise we wouldn’t have bothered with it). Our five filesystems displayed quite different performance on the blazingly fast Samsung EVO 970 drive with non-volatile memory, so let’s see exactly how it differed from the legacy SSD drive performance. First of all, Ext4 and XFS yielded the best results, while Btrfs dropped by one-third and looked more like Reiser5 in terms of speed in the Postmark test. We checked that deviation using dd, which enabled us to observe the reading speed of a large file, but it only confirmed our initial findings. Notice that this time all three tests indicated that Btrfs did not perform as well on an NVMe drive as it did on SSD.…

Besides the flagship desktop offerings, there are a number of other official editions of Fedora and Ubuntu that you might be interested in. For fun and games (although it actually wasn’t fun at all) we tried installing both OSes on an old machine that, with its 2GB RAM and ancient (but still 64-bit) Celeron processor, fell well below the recommended specifications. Once the installs were complete (which took ages because cheap laptop hard drives of the early 2010s are not fast), both OSes were surprisingly useable. But what turned out to be much more useable was working with the LXQt-powered flavour of each. Gnome had a fairly large, but not surprising given its reputation as the fattest desktop environment, 700MB memory footprint. LXQt had a much more slimline 450MB. Even…

Michael Horne is the co-organiser of Pi Wars (see piwars.org). Follow the competition on Twitter: @PiWarsRobotics. Eben Upton took to the interblogs to explain a couple of awkward changes to the usually cheap-as-chips Raspberry Pi range. The key points are that the Pi 4 2GB model is temporally increasing in price from $35 to $45, and the reintroduction of the discontinued Pi 4 1GB model at the $35 price point. This gives buyers the option of hitting a price point, albeit with less memory. Upton explains this is down to supply chain problems post Covid-19 in the semiconductor industry, which are likely to run through the whole of 2022. Interestingly, these are hitting older 40nm-based products the hardest, which means anything that isn’t a Pi 4, Pi 400 or Compute Module…

OUR EXPERT Mike Bedford With a degree in computer science, but a long standing interest in electronics, Mike likes to straddle the great divide with a foot in both camps - hardware and software. For many users, a major benefit of single board computers like the Raspberry Pi and Arduino products is the ease by which they can be interfaced to real-world hardware, and not just computer peripherals. As such, they’re commonly used at the heart of all sorts of innovative projects. Many devices can be attached to SBCs via standard interfaces like USB or I2C, and simple components like LEDs and pushbuttons can be connected to GPIO ports with an absolute minimum of additional electronics. So you might think there’s no need to use any external electronics beyond the familiar…

OUR EXPERT Shashank Sharma is a trial lawyer in Delhi and an avid Arch user. He’s always on the hunt for pocket-friendly geeky memorabilia. Over the past 15 years, podcasts have become an inalienable part of most modern web users’ daily lives. Whether it’s news or commentary on relevant topics of the day, or informed discussions on niche subjects such as open source software, art of creative writing or comic books, you’ll find a range of podcasts on all such subjects and more. Many modern music players now support playing podcasts, but if you’re looking for a dedicated podcast client for the terminal, Castero just might fit your needs. The old Unix philosophy of having programs that do one thing well is all but forgotten, with behemoth graphical applications that…

OUR EXPERT David Rutland is a tinkerer and a dilettante. He buys domains on a whim and runs them from a Raspberry Pi behind the couch.. The internet is a bleak place in the third decade of the 21st century. Away from the walled-garden shouting matches and ego-stroking of the social media sites, you’d be forgiven for thinking that the bulk of the web is an endless desert of SEO optimised buying guides, VPN affiliate sites and filth. Well, that’s our experience of it anyway. Gone are the days of stumbling around from site to site, following links from personal blogs to whatever whimsical sites the authors care to link to. But it doesn’t need to be that way. Break away from the usual routine and well-trodden paths, and you’ll find…

OUR EXPERT Andrew Smith is a software developer for NHS Digital, has a bachelors degree in software engineering and a master’s degree in computer networks. This month we’re going to look at the multiplayer version of Star-Fighter that was covered in LXF282 and played as a single player game (created by Francis Michael Tayag). We’ll cover the network programming techniques that make it possible to play this game across a LAN (local area network) and where in the source code the changes have been made. Both instances of the game (server and client) will be executed on the same machine, even though it’s possible to run them on separate machines on the same LAN. Network programming in Python is an advanced topic so if any readers are new to Python,…

Ubuntu and Fedora are two of the big names in the Linux distribution world and their stewardships are set up quite differently. While they both have their funding foundations in large commercial segments of the Linux world, Ubuntu is specifically developed to be the commercial offering for all of Canonical’s businesses: desktop (that happens to be used by home consumers); and its server, edge and cloud deployments. Fedora, on the other hand, is the technological bleeding-edge development distro that’s used to forge and test systems that will eventually find their way into Red Hat Enterprise Linux – the big serious distro that’s created a multi-billion dollar business. Let’s not forget, of course, that Fedora is blue and Ubuntu is Orange! Luckily it’s Jonni and Mayank rather than myself comparing the…

PINE64 has revealed the PinePhone Pro, a high-end premium smartphone that runs Linux. According to the pre-order page (www.pine64.org/pinephonepro), the PinePhone Pro comes with a hexa-core Rockchip SoC running at 1.5GHz, along with 4GB dual-channel RAM, 128GB storage, a 13MP main camera and 5MP selfie camera. Pine64 has worked closely with Rockchip when designing the PinePhone Pro to ensure that battery life is as long as possible, while also making sure the phone runs cool. For example, a bespoke suspend state has been developed that enables the PinePhone Pro to go into a low-powered mode to preserve battery, while still being able to receive calls and text messages. There’s also the same privacy switches found in the original PinePhone, making it possible to easily turn off the webcam, microphone and…

Linus Torvalds has released what will likely be the final RC (Release Candidate) kernel prior to 5.15 final. The new kernel will contain a number of features that we’ve covered previously, including a new NTFS filesystem driver, and a new in-kernel “KSMBD” Windows SMB3 network filesystem server intended to compliment the well-known Samba userspace based server. However, there are those who question why the kernel needs a new in-kernel driver vs using Samba instead. More importantly, a number of security issues have already been found in the KSMBD driver, leading to questions of quality. With the imminent release of 5.15 will soon come the merge window for what will become 5.16 in the early new year. We’ll have a complete summary of the features that are merged in the next…

Alexander Tolstoy is excited to discover which filesystem is the most robust and reliable of all. This is not the first time we’ve taken a close look at filesystems here in Linux Format, and you may recall our previous Roundup in LXF203. That was over six years ago now, a lot has changed since then. Btrfs, in particular, was markedly less mature over half a decade ago, especially when you consider the fact that it has now been adopted as a default filesystem for root partitions in mainstream Linux distributions, such as Fedora and openSUSE. We wanted to see if it’s as fast as Ext4 (our previous winner) and also check whether Btrfs has any downsides that could be detrimental to its usage on Linux workstations. There’s some unexpected news in…

The picture for filesystem performance on mechanical/rotational hard drives is different once again. These are the slowest type of consumer storage devices, and we expected our tests here to highlight any potential design weaknesses of our filesystems. And we were right. During both the Postmark test and the dataset unpacking test, we had Ext4, Btrfs and XFS performing equally well. In Postmark, we saw Reiser5 lagging behind by around 30%, while NTFS looked downright ugly. But when it came to dataset unpacking performance, there was a different result: Reiser5 dropped to its worst figures and performed just as poorly as NTFS. It looks as though the next-gen design crafted by Mr Shishkin is having trouble handling small I/O on mechanical hard drives. Although it looked much better on the SSD…

SPECS Ubuntu 21.10 CPU: 2GHz Memory: 2GB HDD: 25GB Build: x86-64, arm64, armhf, ppc64le, s390x SPECS Fedora 35 CPU: 2GHz Memory: 2GB HDD: 20GB Build: amd64 and aarch64 Truth be told, Ubuntu and Fedora, arguably the two leading distros, have very little in common. We apply the fact that both use the Gnome desktop to pit the projects against each other, which only helps accentuate the differences between the two projects and their wares. In terms of similarities, besides their headline Gnome-based editions, both distros have spins based on various popular desktop environments. Furthermore, both projects support multiple architectures and produce a lot more editions than the ones for the desktop users. Even though they go about it differently – and we’ve just spent the last eight pages going over…

OUR EXPERT Sean Conway uses Raspberry Pi projects to fulfil his desire to explore electronics while having fun. SPI is a synchronous serial communication interface specification that was developed by Motorola in the mid-1980s to provide full-duplex (transmit/receive data in both directions) synchronous serial communication between controller and peripheral devices. Synchronous in protocols means that the communication is controlled by a controller (the Raspberry Pi) that talks to the peripheral – in this case an LCD device. The SPI protocol defines no special bits to manage data. Limiting this overhead allows for high-speed data streaming. To provide some flexibility in communication, the serial clock has two options – Clock Polarity (CPOL) and Clock Phase (CPHA) – which, when configured, establish one of four modes. In mode 0, data input/output occurs…

OUR EXPERT Nick Peers loves the PDF format. How else do you explain the thousands of PDF documents scattered across his hard drives? The humble Portable Document Format file (PDF to its mates) is one of the most versatile formats you could ask for. It solves a very simple problem: how do you ensure that a file you share with other people looks identical on their computers even if they don’t have access to the application in which it was created? After starting off as a simple way of sharing and displaying documents in a consistent way, PDFs have evolved to become ever more useful. Armed with the right tools you can search them for specific text (then extract that text), annotate them, add comments and even use them like…

OUR EXPERT Mike Bedford Like most of us, Mike tended to think of the likes of Alan Turing and John von Neumann as the pioneers of computing, so delving further into Charles Babbage’s creations was truly inspiring. Discussion about the first ever computer often results in heated debate fuelled, no doubt, by a degree of patriotism, but also by the vagaries of what’s meant by ‘the first computer’. More precise terms help us get closer to the facts. There’s widespread agreement, for example, that the first programmable, digital electronic computer was Colossus, as designed by British codebreakers in 1943 at the Government Code and Cypher School at Bletchley Park. But it differed from today’s computers in being programmed by flipping switches and plugging patch leads and, most importantly, because it was…

Alexander Tolstoy has some crazy video conferencing ideas after setting up his fake webcam background… FONT EDITOR Glyphtracer Version: GIT Web: https://github.com/jpakkane/glyphtracer Most people don’t ever bother making their own fonts because of the many complexities that are usually involved in the process. Not only do you need to be able to draw professional-looking letters, but you also need to craft spaces between them, think about every last little detail and finally assemble the whole lot into a font file using dedicated font-editing tool. However, thanks to Glyphtracer there’s now a shorter path and a genuine opportunity to create your very own font in minutes. That is perhaps why this tiny piece of software is one of the most inspiring Hotpicks we’ve ever discovered. Glyphtracer is a Python application that…

OUR EXPERT Mihalis Tsoukalos is a systems engineer and technical writer. He’s the author of Go Systems Programming and Mastering Go. You can reach him at @mactsouk. The subject of this month’s tutorial is RESTful services. In particular, you’re going to learn how to develop a client for an existing RESTful server using the Go programming language. The client is going to be able to communicate with the RESTful server that we developed in part one (see LXF282), which means that the command line utility must support all server endpoints. Let’s get started. The supported REST API First, let’s recap what our REST API client needs to support. The REST API is defined on the server side, but remember that you don’t have to support all endpoints. What is important…

At the recent Open Source Summit North America 2021 (https://bit.ly/lxf283opensourcesummit), Google engineers Andrew Delgadillo and Dylan Hatch announced Project Icebreaker, a new kernel project from Google that will be as close to the upstream kernel as possible. According to Hatch, for every major upstream kernel release, Google will release a new Icebreaker kernel “on time, we want to stay caught up with upstream Linux.” This will enable developers to introduce features that are close enough to the mainline that they can be included for the upstream. This is one of the main problems with Google’s current Prodkernel, which runs on data centres, because it’s based on an older upstream kernel with a number of patches on top of it. The patches are rebased on to a newer kernel every two…

Matt Yonkovit is Percona’s Head of Open Source Strategy and a member of SHA (Silly Hats Anonymous). The Linux Foundation published its report on open source jobs last month. It revealed that 97 per cent of hiring managers said people with open source skills were a priority and 50 per cent said they would increase their open source hiring in the next year. Alongside Linux and cloud, demand for Kubernetes qualifications has skyrocketed by 455 per cent over the past two years. Many companies are encouraging their IT teams to use open source because it enables them to be flexible when dealing with problems, and on how they deploy and run their systems. Clearly, the volume of roles requiring open source skills is growing. Two-thirds of developers say they need more…

Epic Games has announced (https://bit. ly/lxf283anticheat) that it’s bringing its Easy Anti-Cheat software to Linux, and it will be free for all game developers to implement. This will help to reduce cheating in competitive online games. It should also enable a large number of games to be made available in Linux. Valve’s Proton tool, which is based on Wine and enables Windows games to run in Linux, would often not work with some of the most popular games due to anti-cheat software not being available in Linux. However, as Epic explains, “Starting with the latest SDK release, developers can activate anti-cheat support for Linux via Wine or Proton with just a few clicks in the Epic Online Services Developer Portal.”…

Alyssa Rosenzweig is a software engineer at Collabora, a global open source consultancy firm.. The open source Panfrost driver for Mali GPUs has now achieved official conformance on Mali-G52 for OpenGL ES 3.1. This is a big step forward for the open source driver, because it now certifies Panfrost for use in commercial products containing Mali G52 and paves the way for further conformance submissions on other Mali GPUs. Conformance requires passing tens of thousands of OpenGL integration tests in a single run, and over the summer, we wrote hundreds of patches to fix failing tests. While no amount of testing can guarantee the absence of bugs, passing conformance gets us close. To ensure we remain conformant, we’ve upgraded our continuous integration infrastructure to run more tests before every merge.…

plus FREE! STM MYTH LAPTOP BAG WORTH £90! The STM Myth Laptop Bag is an extraordinarily spacious carrier with cutting-edge contemporary features and a handsome collection of sophisticated tailoring. The remarkable CableReady system is an incredible tech innovation that sets STM apart from other bags. It enables you to charge on-the-go with lengths of cables out of sight. The air channel back-pane-land-yoke system is cleverly designed to wrap around you and provide improved weight distribution. In other words: maximum comfort. Your special Christmas offer Upgrade to include digital for only £10 Order the gift that keeps on delivering WWW.MAGAZINESDIRECT.COM/LIN/XM21 or call 0330 333 1113 and quote XM21 Terms and conditions: Offer closes 31 January 2022. Offer open to new UK subscribers only. All…

We gave extra attention to performance in this Roundup and conducted a series of tests to measure the filesystems’ capabilities. The hardware setup was built to handle four types of storage under a single Linux workstation. We went with the USB 3.1 Transcend Jetflash stick, Seagate Exos 7E2 hard drive (7,200rpm/128MB cache), Intel 530 Series SSD and Samsung SSD 970 EVO Plus NVMe drive. We decided to conduct a synthetic test for measuring read speed using Postmark, which does a good job in stress-testing I/O using a large number of transactions, giving us figures for sequential reads. As for writing speed, we engaged Sysbench with its fileio mode to measure synchronous write rate on a series of 2GB files. Lastly, we tested the unpacking of the Linux kernel tarball, which…

Fedora and Ubuntu are both highly regarded distros, but have different approaches in a number of areas. If you were to believe the first few Google results comparing them, you’d conclude that Ubuntu is more suited to beginners, that Fedora features new technology first, and that both have large companies backing them. But these listicle summaries rarely tell the full story, so to celebrate the release of new versions of each we thought it’d be a fine time to really put these OSes to the test. We’ll look at software availability, gaming prowess as well as some technical points about how each is put together. The flagship releases of both distros run Gnome and both use the Wayland desktop protocol, so there’s not much to compare there. The interim Ubuntu…

Since browsing the web constitutes a great deal of most people’s computing time, we thought we’d see if we could find any subtle differences between each distro’s out-of-the-box Firefox configuration. We’ve said before that Firefox can be made smoother by enabling the WebRender backend and activating VA-API for hardware-accelerated video decoding. But getting this to work in the real world takes a bit of trial and error. Both distros ship Firefox 93, and if you do a fresh install of Ubuntu this uses Mozilla’s Snap. Users upgrading from previous Ubuntus will get the DEB version from the repos. The first step is getting VA-API working, which on Ubuntu was pretty easy. A simple sudo apt install vainfo pulled in all the required video drivers. Then running vainfo and not getting…

Even though the car industry has been, and still is, quite slow on innovation, cars are now packed with electronics. The systems range from entertainment to keeping track of components and helping you drive safely – or not at all. Ever since Tesla included a tablet instead of instruments, the major manufacturers have been trying to keep up. The Linux Foundation has joined this race by building the Automotive Grade Linux (AGL) distribution that was established in 2014. Designed to be run in a car (obviously) and available at all times, this means a small, embedded system for which there are plenty of options. AGL chose Yocto as an underlying build system as it’s already aimed at embedded systems and commonly used in IoT and other systems. Choosing Yocto means…

OUR EXPERT Les Pounder is associate editor at Tom’s Hardware. Over the past few issues we’ve learnt how to create games, control electronics and create shapes by calculating angles, all with Scratch 3. As good as Scratch 3 is there’s only so much that we can do with the GPIO, and the GPIO is the best feature of the Raspberry Pi. So how can we take our Scratch GPIO projects further? Well, for that we need S3GPIO. S3GPIO is short for Scratch 3 GPIO and it was created by Simon Walters, a Raspberry Pi community member who’s campaigned for children to learn coding and electronics with Scratch. Walters first foray into the GPIO for Scratch was ScratchGPIO, based upon Scratch 1.4. This version is still active – in fact we can…

ISSUE 282 November 2021 Product code: LXFDB0282 In the magazine Linux and Windows can work in perfect harmony – find out how in our eight-page guide. We share files across a network without the need for protocols, emulate the Tandy TRS-80, control the Pi’s GPIO with Scratch, and create our own server. DVD highlights Zorin OS 16 Core, Finnix 123, Lakka 3.4 and LibreELEC 10 (sadly all 64-bit). ISSUE 281 October 2021 Product code: LXFDB0281 In the magazine Discover how to customise the Mint 20 desktop with our in-depth feature. We explore virtual private servers, assess five open source art programs, build a Pi-powered pinhole camera, recreate pseudo-3D racing games and emulate the Atari 800. DVD highlights Mint 20.2 “Uma” and Elementary OS 6.0 “Odin” (both 64-bit). ISSUE 280 September…

OUR EXPERT Matt Holder has been a fan of the open source methodology for over two decades and uses Linux and other tools where possible. In his spare time Matt enjoys listening to music and reading. Chrome OS is based on the open source Chromium OS and over the years there have been various attempts to make Chrome OS builds available to any users who wish to install it on their personal devices. Around five years ago this author was attempting to use builds by ‘ArnoldTheBat’ on old eeePCs. While FydeOS is another Chromium OS build, which is targeted at the Chinese market. This leads us nicely onto Neverware, which has been producing its own OS, called CloudReady, for around five years now. Neverware has a series of supported devices, which…

Version: GIT Web: https://github.com/fangfufu/Linux-Fake-Background-Webcam There are mixed views about the effects of homeworking on employee productivity during this challenging period (clearly not at LXF Towers–ED), but one undisputed result is an increase in the use of video calls and group video conferencing. This HotPick adds some extra functionality to your webcam. Its full name is Linux Fake Background Webcam (LFBW), which is fairly self-explanatory. The idea is to replace your real background with a fake one, using a bunch of open source tools. You need a V4L2-compatible video device (which could be an Android phone), a relatively fresh software stack, including recent versions of Python3 and OpenCV, and enough resolve to set up the v4l2loopback kernel module. The latter is the main obstacle, as some distros don’t include it by default, forcing…

USING THE LXFDVD Using Linux for the first time can be very confusing. It’ll most likely be unlike anything that you’ve operated before, especially if you’re used to Microsoft Windows or Apple macOS. Generally our DVDs are designed to be run directly, which is to say that when you first power on your PC (or Mac, see below) it should ‘boot’ from the DVD – so before Windows or macOS even starts to load – with Linux running directly from the DVD. This trick is known as a Live Disc. It enables you to try out the various versions of Linux without having to install or change anything on your PC. Just remove the DVD, restart your PC and it’ll be exactly as you left it. While many systems will…