Indholdsfortegnelse for June 2019 i Linux Format

Jonni Bidwell After 28 years of greybeards telling newbies to RTFM, it’s time for an AI to determine what the user is struggling with, but rather than helping them, direct them to a tersely worded man page that they may be enlightened. Nick Peers I’ve been struggling how to develop a strategy for the hundreds of audiobook CDs my family possesses. Some kind of simple rip and management backend – perhaps with Cozy Audiobook Player as its frontend? Les Pounder I’d love to hack flashing lights and neopixels into Linux. Type in an incorrect command and all the lights shine bright! This would be great in an office if we included sirens and annoying ringtones to alert your colleagues to your status, helping them congratulate you accordingly! Mayank Sharma I…

Firefox, Mozilla’s open source web browser, has been on a bit of a winning streak recently, with a number of recent releases bringing new features to make browsing the web a more secure – and enjoyable – experience. Mozilla has just released Firefox 66, which after a brief delay due to an issue with using certain web apps such as PowerPoint Online is now rolling out to users (you can read more on this at our sister website’s report: http://bit.ly/LXFFirefox66delay). It comes with a number of features that promise to make browsing websites less annoying, especially if you frequent sites that like to autoplay sounds and bug you to enable notifications. Websites will no longer give you a scare by blasting out audio – though you can add individual sites…

“There’s a wealth of technical information about Linux available both online and in print. There’s much less information available about how to build secure, resilient and scalable Linux business solutions. In March, my book, The Linux Solution, was published. It was written for CTOs and technical department heads that rely on Linux for their businesses, and builds on 20+ years of designing, building and supporting. Linux in a commercial environment. It’s available both in paperback and Kindle versions, but until 31st May, you can download a PDF copy of the book from http://bit.ly/2IjPT6T1 for free! If you leave a review on Amazon, screenshot it and mail it to me at keith@tiger-computing.co.uk, on 1st June I’ll pick one review at random and send a paperback copy of the book. Good luck!”…

When Canonical ditched its plans for Ubuntu Touch, its mobile operating system that was supposed to be an alternative to Android and iOS, a community of volunteers banded together to continue the development of the software under the name UBports, which has now become official. The UBports Foundation states that “forming an official Foundation has been a long-time goal for UBports,” but that “to make our dream come true, we had to cross some hurdles.” This involved preparing and submitting documents for the Foundation structure. You can find out more about the creation of the UBports Foundation at http://bit.ly/LXFUBports.…

Linus Torvalds announced Linux 5.1-rc4, following the closure of the 5.1 merge window as we went to press last month. Overall, Linus notes that “nothing really odd stands out”, with the bulk of changes continuing to be for “All kinds of drivers”. That being said, he did highlight the inclusion of a new driver from Habanalabs for its AI accelerator chip – Torvalds suspects “we’ll be starting to see more of that kind of stuff”. General fixes include an optimisation that enables applications to control the “Pressure Stall Indicators track the amount of time apps are blocked waiting for memory.” Speculative Store Buffer Bypass speculative execution vulnerability mitigation in a more fine-grained way, such that, for example, Java sandboxes can be made safer without impacting other apps. Use a computer…

Memory loss Q I have forgotten my root password. Is there a way to reset it or will I have to reinstall everything? Alex Wade A All is not lost, and there’s no need to reinstall. There are at least three ways to reset the root password that I can think of: sudo, single-user boot or a Live distro. All of them provide ways of becoming root without the root password, so that you can then reset it. The simplest idea, if your distro is set up to use sudo with suitable permissions, is to run $ sudo -i This runs an interactive shell as root, from which you can run $ passwd to set a new password. A similar approach is to run $ sudo /bin/bash If sudo is…

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…

Plastic wrap I wondered whether you have any plans to stop using the plastic wrap Linux Format comes in when posted? The wrapping is one of the few remaining items of plastic that enters our household! Replacement with something compostable or with paper would be great. Andy Beverley Mark, head of production, says We are investigating this – it’s on the agenda at the PPA Postal Committee, which I sit on, for further exploration. However, as an industry we face a number of challenges in this field. Alternative substrates to standard poly, such as potato/corn starch material, which we have seen used by the National Trust, are hugely expensive and to my knowledge are only available from a very limited number of suppliers – principally in Italy that require stringent…

The Jetson AGX Xavier, in both module and developer kit forms, sits at the very top of what is becoming an increasingly crowded family. The Jetson TX1, Nvidia’s first real attempt at moving the Jetson range from high-end hobbyist toy to the professional world, is still actively developed and sold, as is last year’s Jetson TX2. In all cases, software developed for any Jetson model is, theoretically at least, directly compatible with any other Jetson model – as long as it doesn’t rely on specific hardware, such as the Tensor Cores or DLAs of the Jetson AGX Xavier. It’s the company’s latest launch, announced shortly before this issue went to press, that is its most novel: the Jetson Nano, a sub-£100 entry into the range which is aimed at bringing…

Linux has no shortage of healing utilities and tools that are designed to put broken computers back into active duty. Sure, the Linux kernel by design (and Linux distros by extension) has a higher threshold for breaking down, but a hardware failure or a clumsy operator can still wreak considerable havoc. The plethora of repair tools help users get out of all kinds of sticky situations. However, due to the sheer number of options on offer, the average Linux desktop user might not always choose the best tool for the job. Also, while you can find the tools in the official repositories of virtually all mainstream distros, since many of them are CLI-based they do not show up in application menus – so many greenhorns are actually oblivious of their…

As we mentioned earlier, many of the rescue distros that we’ve featured in past issues are no longer maintained. While they might not support the latest hardware, nor have the latest version of the bundled utilities, you can still use them to repair older machines, however. For example there’s Rescatux (Tux with fingers should not be!–Ed) that has an interesting helper app to help you repair different parts of your installation without needing to be aware of the underlying CLI tool. Then there’s Trinity Rescue Kit, which features an elaborate boot menu designed to help you find the right repair tool. Many repair and rescue tools also roll their utilities into Live CDs that you can use if you know the tool you need to use. For example, Boot-Repair has…

Lack of so-called accelerated graphics and indeed the modesty of hardware under consideration mean that installing Linux won’t suddenly turn your Chromebook into a powerhouse. It could make it more useful, and it might also make it less useful. For example, if all you care about is accessing Google’s services then Linux proper isn’t going to help you here. However, there’s a lot to be said for the hybrid approach. We’ve seen that, without even risking our device’s sanctity by engaging Developer Mode, we can have all the benefits (if that’s the way you see it) of being able to run proprietary apps on a better-supported platform, while at the same time having easy access to our favourite Linux ones. Sure, there’s a Spotify client for Linux, but it’s far…

Developer Mode is activated from the recovery screen, usually accessed by powering the device on while holding the Esc and Refresh keys. See http://bit.ly/lxf250chrome if this doesn’t work for you, as not all Chromebooks are created equal. On our Pixel Slate, for example, getting to recovery mode involved holding down both volume buttons and the power button for around five seconds. Once you see the recovery screen, press Ctrl+D (there are no visual cues to do so) to begin the transition to developerville. It takes a few minutes to prepare the device, and when it’s ready it will reboot to a rather scary looking screen telling you that “OS verification has been disabled”. From here you can press Ctrl+D to boot into Developer Mode, or press Space to revert to…

Naturally we wanted to see exactly what was possible with Crostini, so rather than installing standard, Linux apps (GIMP, SSH, Visual Studio Code), we thought we’d try a few more left-field bits of software. First up was Steam, not necessarily to play games – although the Pixel Slate’s UHD 615 graphics should handle simple things like Stardew Valley – or even to stream them, though that should work too. Mostly, we just wanted to see how the VM coped with multi-architecture shenanigans (Steam relies on a lot of 32-bit libraries), and maybe if we were lucky confuse Steam’s survey results by adding another esoteric device. Firstly, though, we need to add another repository to apt. So get thee back to the terminal and add a new repo list with: $…

LXF: Mitigating hearing loss is pretty complicated. How does it work? DJ: On the correction side it can get quite complex. So for example, if you just have a straight amplifier, that’ll amplify everything you hear – including a truck going past, people chatting in the restaurant or whatever. That can all be quite distressing to the wearer, because they’re hearing sounds that they don’t want to hear louder than the ones that they do. This is the main focus of digital hearing aids, rather than the traditional analogue ones – to use algorithms to filter out noise and to focus amplification. That’s where it gets really tricky and we need multiple audio channels. Research earpieces have up to three microphones per ear and they use different techniques, such as…

GMCNgine has so far introduced enhanced API integration so that members can add data easily, created real-time poster generation, added the Facebook AMBER alert program, introduced location-based geotargeting of alerts, enabled facial recognition software and integrated the abductor search criteria. However, as this is an elastic system designed to evolve alongside technology and individuals, it is about to take further steps into enhancing its capabilities. Coming up is the ability to introduce age progression and Microsoft’s PhotoDNA technology to potentially catch older cases.Partnerships with big data organisations will allow for the integration of image data sources from the clear and dark web, alongside multi-jurisdictional arrest and conviction data, sex offender registries and other law enforcement data. Other goals includes a focus on increasing the GMCN membership, and analysing data and…

The chances are that when you flash a new image to your Raspberry Pi’s microSD card, you’re doing it wrong. While the Pi’s default desktop experience in Raspbian has improved, the configuration side of things hasn’t really matured as much as it could have. The result is you booting up with a keyboard, mouse and monitor attached, and setting up wireless networking, SSH and various other options. But while the pre-boot configuration could be better, it isn’t completely absent. A Raspberry Pi running Raspbian Stretch – and some other operating systems, but we’re concentrating on Raspbian – can be configured while the microSD card is still inserted in your PC. Wireless networking and SSH can be preconfigured, as can settings for the display, memory and even overclocking. This is thanks…

The SG92R is an inexpensive, compact, angular rotation servomotor with plastic gears, suitable for use in control applications such as radio-controlled aircraft. It requires a digital pulse signal frequency of 50Hz. The angular control motion and position of the actuator of the servomotor is a function of the pulse width signal applied. By varying the duty cycle (pulse width) of the signal applied, the motion and final position are defined.…

You can use dmidecode to find a wealth of information about your hardware on a host of different operating systems, such as Linux, various BSD, Solaris and more. While there are other hardware detection utilities such as lshw, dmidecode stands out because of its reliance on reading the DMI table. But what is DMI? DMI stands for Desktop Management Interface. The DMI table on a machine contains a host of information that’s not readily available elsewhere, or at all. For instance, you’ll be hard-pressed to find a tool which can identify the serial number or asset number of a particular component. The Linux kernel relies on information such as this to correctly identify the motherboard and other components on your system and thus install the correct drivers. If you’re looking…

If you’re looking for Cheese on steroids, as it were, try Webcamoid (https://webcamoid.github.io). Ubuntu users can try installing it via the Terminal: When we attempted this in Ubuntu 18.04, the program failed to launch. Another option – which worked for us – was to download the ‘Installable’ version directly from the website. Once done, open the ~/Downloads folder, right-click the webcamoid-installer-8.6.0-x86_64.run file and choose Properties > Permissions. Tick ‘Allow executing file as a program’, click OK and finally double-click the installer and follow the prompts to launch Webcamoid. Webcamoid offers a similar set of features to GTK+ UVC Viewer, but offers significantly more effects filters – around 60, most of which can be fine-tuned using sliders. You also have a choice of output formats when taking pictures (PNG, GIF and…

Once upon a time, there was a single primary channel for kernel-touserspace communication, and it was called ioctl() . Using a single system call with three integer arguments for everything quickly became clunky, though. Enter Netlink, designed by Alexey Kuznetsov, who worked on initial Linux networking. Netlink is a socket layer interface between the kernel and the userspace, or even two userspace programs. It’s conceptually similar to UNIX sockets and UDP, as it’s datagram-based. The address family for these sockets is AF_NETLINK, and the protocol selects the kernel module to communicate with. As with many if not all datagram protocols, Netlink is inherently unreliable, so applications should take care to acknowledge messages they receive if needed. In Netlink, endpoints are identified by their port IDs (or pids). For the kernel,…

Suppose you want to create a command that will remove all the symlinks to findit from the /usr/local/bin directory. Let’s first look at the command we used to find all of the symlinks. That was: $ findlink --dir=/usr/local/bin --linkto=findit --extended Add the --query option to see what the command actually does: $ findlink --dir=/usr/local/bin --linkto=findit --extended --query Executing this command gives us: find /usr/local/bin -type l -lname findit -exec ls -lhF --color {} + 2>/dev/null Keeping this search, change the command run from ls to rm : find /usr/local/bin -type l -lname findit -exec rm {} + As we’re trying to remove files from /usr/local/bin, we only have read and execute privileges, so we’ll have to precede this with sudo : $ sudo find /usr/local/bin -type l -lname findit -exec…

You can learn more about InfluxDB by visiting www. influxdata.com, while its documentation can be found at http://bit.ly/ lxf250influxdoc.Last, you can find more about the Enterprise edition of InfluxDB at http://bit.ly/ lxf250influxent. By default, the InfluxDB server process uses TCP port 8086 for client/server communication, with the InfluxDB HTTP API and TCP port 8088 for the RPC service that is used for backup and restore operations. The Line Protocol is the format used by InfluxDB for writing points in a measurement. Each individual line of the Line Protocol represents a single data point in InfluxDB. Find out more about Line Protocol at http://bit.ly/ lxf250line.…

YOUR NEW MAINSTAY DISTRO Solus Linux 4.0 64-bit Solus has always been quite an exciting distro. The keen-eyed among you will have noticed that the latest release, Solus 4.0 ‘Fortitude’, hit the net back in March. And now it’s here – well, over on the front of the mag, or wherever you’ve put the disc. Most notably, it’s not based on Ubuntu, Debian, Fedora or anything for that matter – it’s totally independent. It has its own desktop environment, Budgie – available on other distros and featuring in the official Ubuntu Budgie flavour – that not only is fabulous, but is fast and becoming even more so. We’re particularly fond of its Raven sidebar, which can configure pretty much anything you like. The current version, Budgie 10.5, has a new…

Using Chromebooks is a bittersweet experience; it feels as if we’re so close to using a successful Linux-based ecosystem, and yet it never comes close to feeling like a fully fledged FOSS solution. In spite (or despite?) of our misgivings about Google Chromebooks, the platform has become a hit – not just in educational circles, but businesses are also picking them up for a number of reasons. Not least their ease of maintenance, low cost, lightweight software footprint and the built-in integration with the flourishing Google ecosystem. There are bonuses to running the shared Linux heritage. It has enabled Google to expand the the Chromebook’s basic abilities to running not just Android apps (in a clever containerised system), but now fully fledged desktop Linux software too. It’s this flexibility that…

Microsoft’s embrace of Linux continues with the software maker bringing its free Visual Studio Code application to Linux as a Snap application. While it was made available as a standard Linux application earlier in 2019, offering it as a Snap app is a canny move in our opinion. Snaps are containerised packages that can run natively on a variety of Linux distros, which means Microsoft doesn’t need to fiddle about making sure it’s supported on each distribution – and it can be automatically updated as well. An unofficial community-created version of Visual Studio Code was released in May 2017, but if you were holding out for official support from Microsoft, you’ll want to download the new version from https://snapcraft.io/ code . There are also early ‘Insider’ builds for you to…

OPENSSH 8.0 The latest version of OpenSSH should be ready to be released by the time you read this, with Damien Miller taking to Twitter to announce its imminent arrival. The new version brings better security when copying filenames with scp (though it’s still recommended that you don’t use the scp protocol), as well as experimental quantum-computing-resistant key exchange for more futureproof encryption. Find out more at http://bit.ly/LXFOpenSSH8. NIXOS 19.03 NixOS is an independent distro that uses the Nix package manager to install snapshots of packages and manage software via a configuration file. The latest version includes refactoring of the Kubernetes module to help enhance security. According to the release notes (http://bit.ly/LXFNixOS), “Two-way TLS and RBAC has been enabled by default for all components,” and a UEFI-enabled image for AArch64…

“Linux 5.1 will deprecate support for the venerable ‘a.out’ executable format which has been supported by Linux since its earliest days. An executable format is a container for representing binaries that will be run by a system. This includes the code itself in binary format, as created by an assembler following compilation by a compiler, as well as various linking information required to join different a.out binaries into a single application image. ‘a.out’ literally stands for ‘assembler output’ and this is why when you compile using gcc, the default image file name is a.out. As file formats go, a.out has its fair share of problems, and as a result has long since been replaced by ELF (Executable and Linking Format) on nearly all Linux and UNIX-like systems. Chief among the…

Build Brighton Thursday evening is open night. www.buildbrighton.com Cornwall Tech Jam Second Saturday of the month, alternating between Bodmin and Camborne. www.cornwalltechjam.uk Glasgow Makers and Hardware Hackers Mitchell Library, Glasgow. https://m.facebook.com/groups/115303729096198 Huddersfield Raspberry Jam Meet every month at Huddersfield Library, typically on the fourth Saturday of each month. https://huddersfieldraspberryjam.co.uk Horsham Raspberry Jam Parkside, Chart Way, Horsham. www.facebook.com/hackhorsham Leeds Hackspace Open night every Tuesday 7pm-late, open day second Saturday of the month, 11am-4pm. www.leedshackspace.org.uk Medway Makers 12 Dunlin Drive, St Mary’s Island, Chatham ME2 3JE. www.medwaymakers.com New Jersey Linux User’s Group Last Tuesday of every month, at Panara Bread, 165 Route 4 West, Paramus, NJ. http://njlnux.org PLUG – Perth Linux Users’ Group Once a month, at Spacecubed, 45 Saint Georges Terrace, Perth, Western Australia. www.plug.org.au rLab Reading Hackspace Unit C1, Weldale ST,…

Our parameters for testing haven’t really changed from the previous rescue Roundup in LXF209: we’re still looking for the distros with the widest collection of tools that’ll help us with all kinds of repair and rescue operations. However, that’s not the only parameter we’re interested in and it really isn’t even the most important one. Instead of the number of tools, the effectiveness of the complete distro gets more weighting in our books. Distros that help you wade through the multitude of tools and home in on the right tool for the job are rated higher than distros that only claim to bundle the largest number of rescue utilities. Since many of these utilities interact directly with disks and the crucial data they house, they can do more harm than…

Chromebooks are unfathomably popular. Cheaper ones make for ideal learning aids, or first laptops for kids. According to Wikipedia, 60 per cent of computers purchased by schools in the USA were Chromebooks and almost 5 per cent of the entire PC market. The rise of web apps (and open document formats) means it’s no longer necessary to have MS Office installed on any device you want to work on – even Microsoft would rather you use its web apps nowadays. This means that at last Linux has a chance at being used by the masses. Budget Chromebooks are common, but there are a few high-end devices out there – Google’s Pixelbook and Pixel Slate for example. These premium models offer better touchscreen displays, which make them great for watching movies…

Lucky old us managed to get hold of one of the new generation of Chrome OS tablets: Google’s Pixel Slate, the i5 edition with 128GB storage, which was launched in January 2019. It’s definitely at the high end of the available Chrome OS devices, what with its delicious 3000x2000 display and expensive optional keyboard. But for all intents and purposes, everything we do with it will apply to a regular Chromebook. That being said, there are so many devices on the market, all with their own quirks and all locked down to various degrees, that it’s not always possible to boot another OS without reflashing firmware. Flashing a new BIOS, or indeed patching and repacking the old one, is well documented, but this may require hardware modification and risk bricking…

Crostini is Chrome OS’s tasty mix of technologies that together enable a Linux container to be fired up in ChromeOS. With that Linux applications can be installed, launched and hacked more or less as if the device were actually running Linux (I think you’ll find ChromeOS is already running a Linux kernel: you mean GNU/Linux – Ed). GUI apps should work, albeit slowly, while audio input and output should work, but sadly there’s no USB access available at present. Crostini is only available for some Chromebooks and tablets. Older, 32-bit Arm devices are certainly not supported, but some newer AArch64 devices, like the Rockchip RK3399-based Chromebook Flip 101PA and Samsung Chromebook Plus, are up to the task. Newer x86 devices will almost certainly be fine, but older ones won’t. The…

1 Download Download the Linux version from http://bit.ly/lxf250studio, which will require you to agree with some Ts and Cs. We need to share this with Crostini: open the Files app, right-click the Downloads folder and click ‘Share with Linux’. We can now access it under /mnt/chromeos/MyFiles/Downloads in the Terminal. 2 Unzip We’ll need the unzip utility, and we’ll need to ensure we’re in our home directory so that permissions work: 3 Create Run: $ ./android-studio/bin/studio.sh A friendly wizard will guide you through the setup process and download the required components. It will also tell you about enabling KVM acceleration for the built-in Android emulator, but you can safely ignore this.…

The Raspberry Pi Foundation is run as a charity with an attached trading arm, but on the whole it exists to release to the world those delicious Raspberry Pis we all love to consume, for as little money as possible. So given the meagre asking price for a Pi, it certainly helps if the Foundation can make some extra money to help fund all the software development, educational activities and goodly works that it puts out into the world. Adding to the growing range of Raspberry Pi Foundation peripherals, and things to stock in that lovely new store in Cambridge, is an official keyboard and mouse in Raspberry Pi red and white. As you can see, the mouse is a standard three-button wheel mouse, while the keyboard is a 78-key,…

Another option for pre-configuring your Raspberry Pi’s installation is PiBakery v2, which includes a host of extra features. For example, you’re no longer limited to the PiBakery version of Raspbian. Any Raspbian-based IMG file can be used, potentially enabling easier setup of RetroPie, OSMC, and other distros. Like the original PiBakery, it supports Raspbian Lite and the full version. PiBakery v2 can also handle editing of any Raspbian microSD card, rather than being limited to ones created with PiBakery. Also on offer is improved Linux support (the original is limited to Windows and macOS unless you compile) and the ability to import XML files from previous versions. Multiple block sources can be added, enabling you to maintain your own custom blocks. All of this means that all configuration of a…

If you don’t have much of a background in electronics, you might find it difficult to follow technical descriptions, especially when different terms are used in the same article to represent the same thing. Two examples would be ‘cycles per second’ and ‘Hertz’, and ‘duty cycle’ referring to ‘pulse width’. We’ve experienced the same frustration and we’ve made every effort to use the same term or collocate them with its alternate form. The ideal scenario would be to suggest that the interchange of terms in technical writing shouldn’t be accepted. It confuses the reader and can make a complex subject matter worse. With five technical writing courses to his credit, the author agrees, but has seen little change in the industry over his 37-year career. What is the novice suppose…

Video capture is easy nowadays, thanks to Linux’s wide range of video tools. Whether you want to record video messages, create animated movies, chat with far-flung friends and family or keep an eye on things while you’re away, there’s a multitude of apps to give you exactly what you need. Of course, you also need a camera to record yourself, and because of Linux’s universal UVC driver, you have access to a wide range of cheap – and some not so cheap – webcams. UVC stands for USB Video Class, which doesn’t simply cover external webcams but also includes internal models found in laptops. It’s been a part of all Linux installations since kernel 2.6.26, and works in a similar way to mass-storage drivers in that it provides a generic…

Search eBay for ‘flexible webcam’ to find a cheap model that’s particularly suited for recording stop-motion animations. Use the flexible neck and manual focus to set up the perfect shot each time. The UVC driver has its own web page at http:// bit.ly/lxf250uvc- where you should first scroll down for a list of supported webcams. There’s also an FAQ that may help with troubleshooting. If you find yourself juggling multiple video chat platforms, take a look at Franz (https:// meetfranz.com). It provides a web-based wrapper for accessing them from a single, centralised window. Supported platforms include all the major players, including Skype, Slack, Facebook Messenger and Google Hangouts.…

Recently it has been an exciting time for Linux gaming. What was once a pretty niche hobby involving either Tux Racer/Kart or screaming at Wine has evolved into a perfectly reasonably pastime. Linux titles began appearing in Humble Bundles in 2010, and the Source and Unreal engines came to Linux in 2012. But by far the most dominant force in getting games on Linux has been Steam. Steam Machines and their bespoke distro SteamOS may not have (or ever) enjoyed the success Valve hoped for, but the Steam client coming to Linux in 2013 has slowly but surely brought thousands of titles to our favourite OS. Steam Play, Valve’s latest attempt to get yet more titles on Linux through its Proton layer (a Wine fork) has and will up this…

The most common use of the thin client-server dynamic is running a Windows-based terminal service. Amazingly, this can be done with a Raspberry Pi, introducing the possibility that the thinnest of thin clients could be rolled out across budget-hit organisations and public services who don’t want to part with their existing servers or make the full sensible leap to open source. This is possible thanks to WTware, a long-running thin-client operating system that has released a Raspberry Pi version. Compatible with the Raspberry Pi 2 or later, it requires you to download a Windows configuration tool to create a custom disk image. WTware requires terminal services to be running on the Windows computer, a feature absent from Windows Home editions. It’s in Windows 10 Pro and Windows Server 2016, though.…

If you were around Linux 15 years ago, you’d probably agree the ecosystem was quite different then. There was no systemd (for bad or for good). Microsoft was a strong opponent to Linux and open source in general; it has been only a few years since Microsoft CEO Steve Ballmer called it “cancer”. There was no Google Chrome, and Mozilla Firefox was slowly gaining market share from Internet Explorer. Yet IE6 was still strong, which was making it much harder to develop rich web applications, something that Microsoft supposedly didn’t want to happen. The operating system you ran was a key factor to which applications were available to you, and we were continuously declaring the next year to be the year of Linux on desktops. Fast forward to 2019. What…

In this Administeria, we praise an ip-like interface to network objects. While it’s useful in many scenarios, it’s not the only one possible or even feasible for more advanced use cases. Consider the veth pair configuration we used as an example and note how many steps it takes. What if an interim step fails for whatever reason? You’ll end up having a half-configured veth pair and will need to clean things up before starting over. Wouldn’t it be better to have a transactional interface which either applies all configuration bits together or doesn’t make any changes at all? That’s an IPDB job. DB stands for ‘database’, and changes made to this database aren’t propagated to the system unless you call .commit() , either directly or by leaving the context manager.…

The Go language wasn’t released when we first developed findit. We’ve since added the findgo alias to findit. Let’s look at the hooks we added to make it find Go files (*.go) and to find text within Go files, to see how easy it is. The first step was to add a new script to finditgetScript.sh. In the case statement of the getScript() function, add the following lines: findgo) # find go files ext=’\.go$’ fdesc=’go files’ ;; Then add the new alias, findgo, to the FILES array in makefindit.sh: declare -r FILES=”finda findasm findawk findc findh findch \ findblock findchar findjsp findgo ... Next, we added an entry to the alias() function in findit-usage.sh: findgo: find in go files That’s all we needed to do. If you had actually changed…

Time-series databases store time-stamped data, which means that you will have to work with dates and times. Time-series data include data such as stock trades and quotes, metrics of all kind, analytics and events. Generally speaking, there are two kinds of time-series data: regular time series – this is data that arrive at regular intervals; and irregular time series – these are events that arrive whenever they come in. The main reason for having a time-series database is that they can better serve time-series data which might come in extremely large amounts. They can also more easily and efficiently query time-series data, because their query languages are more aware of times and dates than regular databases. Moreover, everything is indexed by time, which makes searching for data even faster. Lastly,…

USING THE LXFDVD Using Linux for the first time can be very confusing. It’ll be unlike anything that you’ve likely 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) 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 boot from a…

“It’s now possible to run Android applications in the same graphical environment as regular Wayland Linux applications with full 3D acceleration. SPURV, a new experimental containerised Android environment, enables Android application windows to be rendered alongside native Wayland applications in Linux. Running Android has some advantages compared to native Linux applications, for example with regard to the availability of apps and application developers. For current non-Android systems, SPURV enables a path forward to running Android applications in the same graphical environment as traditional non-Android applications are run. One key difference from other existing Android-Linux integrations is that SPURV offers Android applications direct access to the hardware. Having direct access to the GPU in particular enables faster graphics, but does come with security trade-offs. However, on the embedded hardware platforms targeted…

Popular Terminal-based text editor GNU nano 4.0 was released at the end of March. The latest version brought a number of new features that are listed at http://bit.ly/LXFnano4, including smooth scrolling one line at a time becoming the default. However, the release of the latest version has been overshadowed by a very public falling out between David Lawrence Ramsey, a former maintainer of nano, and Benno Schulenberg, the current maintainer. The two exchanged frosty – and at times downright aggressive – messages in a public mailing list (http://bit.ly/LXFnanoDrama) titled ‘On the future of nano’. It appears tensions have been building for a while, and have now been spectacularly aired. The disagreement is over maintenance issues and how the software should be updated. Ramsey has laid down an ultimatum, telling Schulenberg…

“Well it’s that time again—Ubuntu 19.04 Disco Dingo has been released, Fedora 30 is out, Linux Format issue 250 has hit the streets. Actually none of those things are true at present, but they will be by the time you read this, and that is exciting. In this instalment of “it’s deadline day so here’s 180 words of caffeine-fuelled ramblings”, let’s discuss bugs. Actually just one bug, but an expensive one, $370,000 (in 1996) expensive. The Ariane 5 rocket borrowed a lot of its code from its predecessor, the Ariane 4. This code was “carefully” checked and simulations run to see where things would need modification to ensure a successful mission. A lot of the amendments involved changing 16-bit integers to 64-bit floating point variables, to accommodate more precision or…

Yany Weijiang posted an updated patch series implementing guest virtual machine Control-flow Enforcement Technology. The patches, which are still being iterated for the non-virtualised case in parallel, aim to use hardware in future processors that can protect aginst Return Orientated Programming and Jump Orientated Programming stack/control flow subversion attacks. Janakarajan Natarajan posted support for the industry-standard platform level Collaborative Processor Performance Control on newer AMD processors. This will enable systems using ACPI6.1 or later to provide fine-grained control and performance profiles when using AMD Ryzen or EPYC CPUs. Steven Price is working on support for “generic page walk” code in Linux. As we’ve mentioned before, Linux applications have a view of memory known as virtual memory in which every address is translated by underlying special purpose hardware in the Memory…

3DMEETUP.UK Birmingham on 18-19 May is the place to be for the UK’s 3D printing community. With the price of printers dropping on a daily basis, you need a community to help you get the best from your purchase. At 3Dmeetup.uk there will be 3D printing experts from across the UK, more, head over to the website at https://2019.pycon-au.org. OPEN SOURCE SUMMIT NORTH AMERICA 21-23 August at the Hilton San Diego Bayfront is the time and place for sysadmins, devops and open source professionals, with over 2,000 experts on hand and a diverse selection of talks, workshops and tracks for all levels of users. Learn more about AI, the cloud, automation and more from this three-day conference. Tickets range from $800 to $1,200, so be quick! http://bit.ly/lxf250user showing off their favourite…

Editing configuration files directly can be a little risky at times, as a mistake may mean that the program they relate to may fail to start. This becomes more than just a little inconvenient if the program is critical to using your system. One such file is the user specification file at /etc/passwd – a mistake in this may leave you unable to login. While it may be possible to boot from a rescue disk and fix the problem, this is one of those problems that we would prefer not to have in the first place. What we want is a program that will enable us to edit the file, but also check that all is well before actually writing it back to disk. Such a program is vipw. Despite…

Send your thoughts to the Linux Format dungeon server at linuxformat@futurenet.com, be picked as Letter Of The Month and win* a 32GB Nitrokey Storage 2! The Nitrokey is worth a cool €149, has 32GB of hardware-encrypted storage, supports hidden volumes, secures your online accounts with onetime passwords, can encrypt emails, files and hard drives and is an open source, open hardware solution. Protected with AES-256 and RSA keys up to 4,096! Learn more at www.nitrokey.com.…

Chrome OS is incredibly security conscious by default. On modern Chrome OS devices, the Verified Boot process starts with a read-only signed firmware image. This can only be modified by direct flashing with an EEPROM programmer, an act of cardinal defiance that would certainly void your warranty and probably end in tears. This then verifies and fires up another firmware image (the read-write firmware), which in turn will, under normal operation, verify and fire up a signed Chrome OS kernel. This second firmware – actually, there are two so that it can be safely updated – will usually refuse to load any kernel images not signed by Google. However, if you activate Developer mode it will happily boot any signed kernel, even one you signed yourself with a key you…

Well, we’ve seen a variety of ways in which you can make your Chromebook do things it’s not really supposed to. But there’s probably one more thing you’re itching to do – and we’d get lynched if we didn’t include it. Yep: install Linux so that it boots right off the bat. Developer Mode enables you, on some hardware anyway, to boot from USB, but it turns out there’s an easier way in the form of Chrx. You’ll still need to be in Developer Mode in order to proceed with this madness, but you won’t need a USB stick or SD card – which is handy because the Pixel Slate has no such interfaces, and all the USB-C adapters at Future Towers have been horded by some unknown and possibly…

LXF: How did the project evolve with the shift to an Arm SoC? CO: The device consists of a BeagleBone Black small board computer, with a custom circuit board called the Cape4all which sits on top [much like a Raspberry Pi HAT]. This is an open hardware bit of kit that’s got three audio codecs on it, which enables six mono inputs and four mono outputs to connect to the BeagleBone Black. This was developed by the university, but they had a lot of trouble getting the driver running. They managed to get one out of three codecs working, but they had a lot of difficulty with the others. At that point they asked for some external help, and they got in contact with us. Really the rest is just…

The GMCNgine comprises a bevy of open source technologies: Nodejs: an open-source, cross-platform JavaScript run-time environment that executes JavaScript code outside of a browser. All of the back-end work is done in Nodejs. ExpressJS: free and open-source software under the MIT licence. It is designed for building web applications and APIs and is the de facto standard server framework for Node.js. Swagger: an open-source software framework backed by a large ecosystem of tools that helps developers design, build, document, and consume RESTful web services. React: a JavaScript library for building user interfaces under the MIT licence. There are also multiple front-end libraries such as: Bootstrap: a free and open-source CSS framework directed at responsive, mobile-first frontend web development. However, this has been modified a lot to adapt to the GMCNgine…

The high street may not be the place that it used to be. Electronics stores such as Tandy, RadioShack and Maplin have all faded into history, but in early 2019 something happened to buck this trend. The Raspberry Pi has disrupted many things, chiefly providing cheap access to technology and enabling millions to learn new skills and make media centres. But its latest disruption is the opening of its own Raspberry Pi Store in Cambridge’s Grand Arcade – a perfect place to visit for many makers and hackers. But why? Well, we may live in a time where we can order everything from the internet and have same-day delivery, but sometimes we need to get hands-on with tech and learn more about it before we hand over the cash. At…

Your information radiator will most likely be in landscape orientation, just like the monitor on your desk. But what if you want to show off your DAKboard using a portrait display? Well, rotating the screen is quite simple – perhaps not as simple as on Ubuntu/Fedora desktops, but all it requires is a little basic terminal work. In Raspbian, open a terminal and type: $ sudo nano /boot/config.txt Scroll to the bottom of the file and add the following two lines: #ROTATE HDMI display_hdmi_rotate=X Change the X to 1 for 90 degrees, 2 for 180 or 3 for 270 degrees. To save press Ctrl+O, then press Return, then Ctrl+X to exit. Reboot the Raspberry Pi and your display should now be rotated and ready for use. If the effect is…

If you’re looking for a simple surveillance tool to run from your PC, head to www.ivideon.com/ivideon-server-linux and download the installation script to your ~/Downloads folder. Now open the Terminal and issue the following commands: Once complete, launch ivideon Server via the applications menu, then step through the ludicrously easy setup wizard: set up a free account, connect your webcams, enable local recording (which is completely free) and then configure it to start with your PC. You’ll then need to wait briefly while the server marries up with your online account, at which point you should look to install various clients or access your cameras through a web browser. Luckily, free clients are available for Linux, iOS and Android via www.ivideon. com/downloads – again, the Linux client can be installed with…

While perusing the Steam Store you might notice that titles only specify support for Ubuntu 12.04 in their system requirements. This might seem a little odd, in an age where we’re always telling you to get the latest things, and the Steam client itself updates itself on a daily basis. Don’t worry – there’s no need to go hunting out an LXFDVD from seven years ago, as games do work on newer distros. But things are like this for a reason. The Steam runtime – the set of libraries which games (and the Steam client itself) use to interface with the rest of the system – is still based on the library versions that shipped with that ancient version of Ubuntu. It includes a lot of 32-bit libraries, but let’s…

If neither regular Wine nor Proton will suffice, Lutris has an entire management system for picking the best version of Wine – there are even versions optimised for specific games. Of chief interest are the tkg builds of Wine. Put together by Tk-Glitch, wine-tkg aims to be “the Wine to rule them all”, by combining Esync and DXVK with regular Wine, along with D9VK and VKD3D for Direct3D 12 support. DXVK is the compatibility layer upon which Valve’s Proton is famously based, and translates between Direct3D 11 and Vulkan – the much faster replacement API for OpenGL. We could barely understand a word of Esync’s documentation, but there are some deeply impressive optimisations based around executing operations in user-space. Combine Esync with DKVK and you have a potential gaming powerhouse.…

Upon first boot, the Terminal management screen is displayed. This lets you further configure the connection to a Windows Server with WTware, including vital options such as connecting to your wireless network. You’ll find this option in the Wi-Fi settings screen, and you’ll need to add the SSID (network name) as well as the passkey, then select Start Wi-Fi Driver to connect. If this isn’t suitable, you can switch to Ethernet using the Network media option. For further configuration, use the ‘Connect for’ option. Again, this requires the selection of the Wi-Fi network, giving you the option to save the credentials. Following this stage, you can connect to the remote server using the detected IP address. Other servers can also be accessed. Input the credentials to gain access to a…

Being a veteran Linux admin, you likely remember times when you ran ifconfig to set up network addresses and route to manage IP routes. These days, a single all-in-one tool, ip, handles everything, from IP address assignment and route management to creating network namespaces and setting up tunnels between the hosts. Given this versatility, it comes as no surprise that ip is typically the workhorse behind many network-automation scripts. Quite often, these scripts are written in Python, and call ip with subprocess.check_ output() or similar. Then the output is parsed, the exit code is analysed and so forth. There is nothing wrong with this approach, but wouldn’t it be nice to have all of ip in a Python-native format? Sniffing communications That’s what the library pyroute2 (https://pyroute2. org) is all…

APPLICATION FIREWALL OpenSnitch Version: 1.0.0b Web: https://github.com/evilsocket/openSnitch Linux has always been very strong in terms of security, but has always required certain skills in order to configure things correctly. Users of macOS might know the great Little Snitch firewall that works on per-application basis. Once an app wants to send or receive data over the network, a window pops up and lets a user allow or deny the connection. Well, it looks like the missing Little Snitch clone for Linux is finally here, so please meet OpenSnitch. It takes a little more effort to get it running than its inspiration, but this game is worth the candle! OpenSnitch consists of a Systemd daemon that works in the background, and a UI frontend. The project’s GitHub page offers a comprehensive manual…

You can find all the scripts and the Makefile on the LXFDVD and in the LXF web archive at https:// linuxformat. com/archivesunder issue LXF250. Remember to use the -m or --match option to look inside files and display matching text. If you leave out this option, findit will simply list the names of the files in which the content was found. Remember, you can always add the -q or --query option to a findit command to see exactly what the command is doing. Findit commands with the --query option do not execute a search, they simply return the find command with all of its options verbatim. Findit commands are normally case-sensitive. To ignore case in the find, you use the -I or --ignore-case-find option. To ignore case in the grep search…

What is InfluxDB, exactly? Well, it’s an open source time-series, events and metrics database that is optimised to handle high-write and heavy query loads. We’ll kick things off by covering how to correctly install InfluxDB and learn about InfluxQL, which is the query language of InfluxDB, before exploring how to read and write data to InfluxDB, administer it and work with it using Python 3 and Go. Installing InfluxDB InfluxDB has two versions: the open source version, which can be installed on a single machine, and the paid enterprise version that can be installed on a cluster. Most people will be more than happy with the open source version, and that’s the one we’ll be using on Linux. The installation process includes the following two easy steps: You should note…

The first version of InfluxDB was released in 2013. It’s written in Go, and its source code can be found at https://github.com/ influxdata/influxdb. InfluxDB can be used for storing log data, monitoring data, application metrics, Internet of Things sensor data and real-time analytics, and the paid version of InfluxDB adds high availability and scaling to the open source version of InfluxDB. It’s important to remember that the data stored in InfluxDB is structured as a time value together with the other values. This means that you cannot store any data in an InfluxDB database without an accompanying time field – after all, InfluxDB is a time-series database! InfluxDB is schemaless, which means that you do not have to define a table in order to store data in it. Tables, which…

READING MATTER Advanced Bash Scripting Guide Go further with shell scripting. Bash Guide for Beginners Get to grips with the basics of Bash scripting. Bourne Shell Scripting First steps in shell scripting. The Cathedral and the Bazaar Eric S Raymond’s classic text explains the advantages of open development. The Debian Book Essential guide for sysadmins. Dive Into Python Everything you need to know. Introduction to Linux A handy guide full of pointers for new Linux users. Linux Dictionary The A-Z of everything to do with Linux. Linux Kernel in a Nutshell An introduction to the kernel written by master hacker Greg Kroah-Hartman. The Linux System Administrator’s Guide Take control of your system. Tools Summary Overview of GNU tools. GNU Emacs Manual Six hundred pages of essential information! Producing Open Source…