Содержание выпуска: March 2020 — Linux Format

“Most of us who use Linux in a professional capacity will be either system administrators or developers. Both jobs need talented, smart people, but it’s a rare person who is skilled and talented at both. It’s made worse by the fact that many developers know a bit about setting up Linux systems, and many sysadmins know a bit about writing code. But don’t conflate the roles. If you’re a sysadmin and you need a quick script to automate or simplify some process, go ahead and write it. Similarly, if you’re a developer and you need to create a test VM, there’s no reason why you shouldn’t create it. But when it comes to building a production Linux infrastructure that’s fit for purpose, the developer should step back. Designing and supporting…

Evernote (https://evernote.com) is a popular application for creating notes, as well as organising them and also building to-do lists, but its lack of availability on Linux has long been a source of frustration for many users. However, it looks like that could soon change, with Ian Small, CEO of Evernote, promising in a 2020 Update (which you can read at http://bit.ly/LXF260Evernote2020) that there will be “new clients for Windows, Mac, and (yes!) Linux, along with the ongoing re-architecture and data migration we’ve been doing in the cloud.” The brief mention of Linux will be welcome news for people who’d been waiting for the app, even though Small doesn’t give any hint of when we can expect it. Evernote’s slowness to finally come over to Linux could mean this move is…

Linus Torvalds announced the release of Linux 5.5-rc7, and implied that it could be the last before 5.5 (although he wasn’t sure if he would need an rc8). In any case, it is certain that Linux 5.5 will be out imminently. The release of 5.5 will bring the opening of the “merge window” during which features intended for 5.6 will be merged. One of the features we already anticipate landing in 5.6 will be support for the WireGuard VPN. WireGuard “aims to be much simpler and easier to audit than IPsec” and is made specifically for inclusion into the Linux kernel. It is only a few thousand lines of code and is well-supported by distributions. It is also (apparently) quite easy to use. Thermal pressure Modern microprocessors perform (as many…

Q Early swap usage I’m using Kubuntu 19.10 and noticed that swap was used very early after starting the desktop, even if there’s still RAM available (4GB RAM, KDE Plasma desktop). How can I troubleshoot what’s causing this early use of swap? isn’t swap supposed to be used only if RAM is full? Can I do something about it? Leon Butcher A This is not a problem to be solved, it is the system working as it should. Memory management in Linux is both advanced and mature – years have gone into optimising it. Data is moved from memory to swap because it is unlikely to be needed but has to remain available in memory in some form. For example, code used when starting up system services may not…

All the distributions were tested on the same dual-core machine with 4GB RAM, and we’ve selected the latest stable release for each distribution. Documentation is one of the most important deciding factors when choosing a distribution if you’re a new user. And just as important is the installation process. Since our focus is on users who’ve probably never installed a Linux distribution before, this is a key criteria. Another important factor is software management and the kind of apps that are shipped with the distribution. Apart from these, the distribution also needs to be easy to use for day-to-day activities. As you spend time with Linux distributions, you’ll learn that adaptability is one of their best qualities. An ideal distribution for newbies is one that does all of the above…

The choice of your first Linux distro depends on a variety of additional factors outside of a its capability. Your past computing experience and willingness to troubleshoot problems are just as important. For those who are willing to embark on a journey through trial and error, it’s an open field. You may well pick any distribution from the top 10 list on Distrowatch.com (careful now–Ed) and begin a new adventure. Debian, Mint, Fedora and Ubuntu all have pros and cons and boast large user communities. They have all been around long enough to have been recommended at one time or another as ideal for new users. However, they aren’t always designed with novices in mind. Regardless of the distribution you settle on, we would advise you to persist with it…

Presuming that you’ve chosen Raspbian, let’s get you up and running with a system that boots from microSD and immediately jumps to an external SSD for storing and running the bulk of the OS. Note that for older models (anything but the Pi 4), USB booting is easier to set up (just add the line program_usb_bootmode=1 to /boot/config.txt on a Raspbian SD card, then reboot with said microSD card and your external drive attached to write the change to firmware). See http://bit.ly/LXF260boot for info. IMPROVING HARDWARE“The USB and Ethernet ports no longer share the same bus” One day, booting the Pi 4 from external storage will be simple, but for now we’ll have to settle for pivoting to the root filesystem. Start by downloading the latest fully loaded version of…

The Arduino and Raspberry Pi are two very different products, but they both cater for eager hackers and makers. What if we could connect an Arduino to our Pi and use it as a slave device? One that reacts to input and sends the output to our Raspberry Pi via Python. To do this we are going to need some special software, and that is where this tutorial starts. Software setup Before we can write any Python code we need to download and install Arduino IDE for Linux ARM 32-bit from the Arduino website: find it at www.arduino.cc/en/Main/Software. Once installed we need to add the user Pi to the correct group to send data to the Arduino. So to add Pi to the group, open a terminal and type the…

Apart from the command-line music player, the project also produces an Android app called Musikdroid. This can be used as a remote control to manage the Musikcube player, or to stream music. First, head over to the Settings view on Musikcube and select Server Setup. The default ports should suffice for most users. Select the Audio Streaming Enabled option using the arrow keys and then press Spacebar. You should now see an [X] adjacent to this option. You can optionally set up a password for remote access. This is all the configuration that is needed to stream music to your Android devices. Next, download the Musikdroid app from the project’s releases page and install it on your Android phone. Once installed, you still need to configure the app. Open its…

Switching to Bitwarden from another password manager? Bitwarden can import your passwords from most managers – first log into your old account and export the data in JSON, XML or CSV format. Then log into your Bitwarden vault through your browser and choose Tools > Import data to import the file, which you should securely delete once done. If you go down the self-hosted server route, make sure you back up the /bw-data folder somewhere safe and secure. It won’t be large – no more than 10MB in most cases – so it can be stored anywhere. If you do back it up to cloud storage, be sure to encrypt the backup itself for an additional layer of security. Length is more important than randomness when creating your master password,…

Visit Tools > Options to set up more Joplin features. Note History: did you ever create a note and see something change in it? When Note History is activated, Joplin will note any change and enable you to view changes to that note. Click the Info icon to review earlier versions. Down the road, you should be able to use Joplin to prepare and update social media posts. External Text Editor: would you rather use your favourite editor (text or Markdown) in Joplin? Point to the location of the editor in the General settings. Geo-Location: if you want to know where you were when you made your note, check Save Geo-location with notes in the Application panel. Don’t check the box if you’d prefer to keep those details private. Plugins:…

If you followed the tutorial in LXF241, you may want to include your project plan and the text of your writing project in the same file. If so, change the #+COLUMNS line to a :COLUMNS: property for the headline holding your plan. If you find commands like Column View not producing the results you want, make sure your cursor is somewhere that creates the right scope. To affect the entire file, place the cursor above the first headline. Don’t forget, you can still place text-based content after the headline and associated data (e.g. properties and LOGBOOK). This is a great place to stash detailed instructions, links to other resources, or anything that will help your team get their tasks done.…

When you want to keep track of your dotfiles, the hidden ones are usually in your home directory. You can use several systems. Most of them require many copy commands integrated into a bunch of scripts. Some of these are also built with a scripting language you may or may not use already. If you have tried some of them, you will find Stow simpler to use than most; it’s made to handle software packages efficiently, not the same way your regular package manager does but independently. It is intended for users who want to try out a new or beta program without messing up the current installation. Simply put, Stow will create symlinks to the appropriate place in your directory tree from the directory you are in. For the…

Virtualisation is another way to separate applications or services – such as enabling you to easily run separate instances of applications on one physical PC. A virtual PC (whether you use VirtualBox, VMware or any other version) emulates a full hardware stack, so every virtual instance needs a full OS installation. While you can simplify this process by copying an existing virtual machine, you cannot avoid the inevitable duplication of system files. Enterprise versions often provide tools to streamline this process, but they come at a cost. The biggest difference is that most container platforms (including Docker as used in this tutorial) provide tools to bring your container into a known state, be that versions of libraries, configuration files or exposed network ports. In contrast, with a virtual machine you…

SDR originates from a discovery made about an inexpensive mass-produced DVB-T TV tuner dongle by Antti Palosaari, Eric Fry and Osmocom (in particular Steve Markgraf). DVB-T is an abbreviation for Digital Video Broadcasting-Terrestrial, one standard for digital television broadcasting first published in 1997. The standard defines frequency in the VHF and UHF RF frequency bands and how data is carried on the RF signal. The pioneers of SDR discovered something unique about the Realtek RT2823U coded orthogonal frequency division multiplexing chipset. The raw I/Q data on the RTL2832U chipset could be accessed directly, making the DVB-T tuner a wideband software-defined radio. The custom driver software developed by Steve Markgraf was the keystone to SDR development. Osmocom is an open source mobile communication project that develops software and tools for mobile…

DESKTOP ENVIRONMENT Trinity Version: Trinity Web: http://trinitydesktop.org These days there are very few Linux distributions that support the legacy KDE 4 desktop. Despite that, there is a vibrant community that looks even further into the depth of time and supports development of the yet older KDE 3 branch under the name of Trinity, or TDE for short. This is a stunning example of a project that’s managed to successfully resurrect the historic software and breathe new life into it. Lately there was the new Trinity 14.0.7 release with lots of goodness, plus a generous selection of ready-to-use packages for many mainstream Linux distros, so it is easy to give it a try. Essentially, TDE is KDE 3 updated to work with modern Linux apps and services. It retains all the…

Running pydoc ./gitStatus.py provides a list of the methods and data in gitStatus.py and allows you to browse it using less. Running pydoc ./gitStatus.py > gitStatus.txt will produce gitStatus.txt you can browse in your editor. You can run , which will create gitStatus.html. If you have LAMP server on your system, copy gitStatus.html to /srv/www/ htdocs and serve it up using apache2. Open a browser and select localhost/gitStatus.html in the address bar. /srv/www/htdocs is the location apache2 uses to serve files in our distro. Search for htdocs to find where it is on your system. Your package manager probably has PyQt5 available. It may show up as the installation pattern Qt5. To build a PyQt5 application you need to install python3-qt5 and python3-qt5-devel. Naturally, you’ll need Python 3 as well.…

Although R is a very capable programming language, it can be enhanced using code from other sources. R uses the term Packages to describe R code that gives you extra functionality. There are two ways of installing an R package. If the package is available on CRAN (The Comprehensive R Archive Network), then you can install it using the install.packages() function. Otherwise, you should download it on your Linux machine before installing it using the same install.packages() function, but with different parameters. If you execute the library() function without any arguments, you will get a list of all installed packages. To get a more detailed output of all the installed R packages, you can also use the installed.packages() command. The update.packages() command will try to update all installed CRAN packages…

THE LXF LIBRARY 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…

Projects, projects, projects! From the Raspberry Pi to Linux to Arduino, we’re going to keep you busy in 2020 with only the best maker projects to try in Linux Format! We’re running a maker special with our favourite builds to try, from running an NAS to a fully functional robot build. I’m currently renovating a house – largely by myself – which is fun. I get to play with lots of different tools, work with wood, plaster a wall, do a bit of soldering, break a few things, fix a few things and get a sense of achievement when a room finally doesn’t look like it’s come straight out of Fallout 3. Now, I’m quite often wrong (just ask Jonni) but I get a strong feeling that open source and…

Linus Torvalds, the somewhat outspoken (we hadn’t noticed – Ed) creator of Linux, has taken to a mailing list (http://bit.ly/LXF260LinusZFS) to moan about the ZFS filesystem, saying, “Don’t use ZFS. It’s that simple. It was always more of a buzzword than anything else, I feel, and the licensing issues just make it a nonstarter for me.” The licencing issues Torvalds is referring to is the fact that ZFS uses Common Development and Distribution License (CDDL) 1.0, while the Linux kernel is licensed under the GNU General Public License (GPL) 2.0 – and these are not fully compatible with each other. If ZFS is included with the Linux kernel, this would mean that it is a derivative work of the original Linux kernel. What seems to be particularly troubling for Torvalds…

“Recently I set up an OpenStack cluster at home containing a mix of x86 and Arm nodes. I used ‘Kolla’ – containerised OpenStack – and deployed it using kolla-ansible. This latter part is supposed to provide a turnkey solution: edit a few config files, sit back and automate the hundreds of steps involved. The reality was a little different. While (eventually) the scripts more or less worked, there was a problem. Guest (‘instance’) VMs could not reach the outside world. I traced various tap, bridge and other networking interfaces that connect a guest through a virtual router and on to a host network. It led me to conclude that netfilter NAT wasn’t working within the network namespaces used for the ‘vrouter’ virtual routers in OpenStack. Many hours later I realised…

Build Brighton Thursday evening is open night. http://buildbrighton.com Cornwall Tech Jam Second Saturday of the month, alternating between Bodmin and Camborne. www.cornwalltechjam.uk Thingqbator An IoT-focused makerspace, meeting weekly at The Shed MMU. mcr.thingqbator.org Leeds Hackspace Open night every Tuesday 7pm-late. Open day second Saturday of the month, 11am-4pm. http://leedshackspace.org.uk Huddersfield Raspberry Jam Meet every month at Huddersfield Library, typically the fourth Saturday of each month. http://huddersfieldraspberryjam.co.uk rLab Reading Hackspace Unit C1, Weldale St, Reading, open sessions Wednesday from 7pm. http://rlab.org.uk Horsham Raspberry Jam Park Side, Chart Way, Horsham. www.facebook.com/hackhorsham Medway Makers Meet every 3-4 weeks on a Sunday. Full details at: http://meetup.com/Medway-Makers Maidstone Hackspace We hold open evenings every Wednesday from 5.30pm-8pm. https://maidstone-hackspace.org.uk Glasgow Makers and Hardware Hackers Mitchell Library, Glasgow. www.facebook.com/groups/115303729096198…

Nothing’s more infuriating than random computer crashes. If it is reproducible, you have somewhere to start looking, but if it happens at any time and using any software, where do you begin? If it happens regardless of the software you are using, it may be a hardware problem. If you have a spare PSU, try swapping that. Desktop PSUs can vary greatly in quality, and the cheaper ones can cause the sort of power glitches that will crash a computer. They can also damage components that cost several times more than a new PSU. If it’s a laptop, the battery may be on the way out. If the computer doesn’t run reliably on battery power alone, look for a replacement battery. The other common culprit is faulty memory – not…

Easy streaming I really enjoyed the Media Streamers article in LXF257, but I do think that MiniDLNA is worth a mention as a lightweight alternative. Personally I got fed up with the Kodi interface and network reliability problems. I’ve installed MiniDLNA on a Raspberry Pi 4 running Raspbian Lite connected by Ethernet to my router. For the client side I use VLC on Android and Linux, while my PS4 is very happy with its default media player. I’m not a heavy user, and this has been rock solid for both music and video streaming. I know that it requires a little command-line configuration, but it’s fairly straightforward to set up with as many disks as you want – well worth a try if you have a spare Pi in a…

Novice users must learn to navigate not just the new appearance of the desktop, but also the different way of doing routine things, such as configuring graphics cards, connecting to internet radio stations, installing new software, etc. In this Roundup the projects must provide extensive and easy-to-grasp documentation to help acclimatise new users. Additional resources, such as forum boards, mailing lists, wikis, etc. to tap the collective experience of the community is also appreciated. The First Steps section on the Manjaro website is a primer for new users. A comprehensive user guide is also available as a downloadable PDF, and the wiki is full of information on every topic, including installation, customisation, software management. Solus has a neatly arranged help center with documentation on different topics, such as gaming, hardware…

Last year the fourth incarnation of Raspberry Pi launched, and barring some teething issues with firmware and non-compliant USB-C ports, it didn’t disappoint. But once you’ve invested your £35, what are you going to do with that cut-price, cut-sized hardware? How do you exploit its abilities? We have a few ideas that use those new features – the gigabit Ethernet, upgraded CPU and GPU, 4K-capable dual HDMI ports –and make the Pi 4 shine. The Pi 4 is a feasible compact desktop computer at last. Its architecture, including USB 3 ports that no longer share a bus, lends itself to running as a custom NAS controller, a network appliance, or a TV media box. And as software support improves, that firmware firms up and key distros bring their full functionality…

You don’t have to use your Pi to learn Python, Linux, electronics, or anything at all really (although remember, knowledge is power – Ed). It has also got the potential to be a cheap and cheerful source of entertainment for you. So here are a few top project ideas to keep you happy. Media box Unusually in the company, LibreELEC – which dubs itself “just enough OS for Kodi”— has kept pace with the Pi 4 and appears to be providing regular updates. That makes setting up a Pi 4 as a Kodi box absolutely trivial. Head to http://libreelec.tv, grab the Raspberry Pi 4 image from the downloads section, and write it to a card with Etcher. There’s a whole seedy streaming subculture of Kodi that we won’t go into…

PyFirmata is not the only way to communicate between Arduino and Pi, but it is the easiest! Another way is to read data that is printed to a serial console – the serial monitor in Arduino parlance. Here is a quick line to print a sentence to the Arduino serial monitor: Then, using a Python library called pySerial, we can read the data coming into an open port, such as ttyUSB0. We need to connect at the correct speed and then listen out for the data, which is then printed to the Python shell. So using this method we could use a sensor to take a reading and then send that reading to the serial monitor, which is then read by our Python code. We can also send data to…

If you want to sync your password file via your own cloud storage, try Buttercup (https://buttercup.pw). This has native apps for all platforms, plus browser add-ons for Firefox and Chrome. Installable DEB and RPM packages are available via the main homepage, with a portable AppImage available too (http://bit.ly/lfxbuttercup). Launch the app, click the Add Archive button to connect your choice of cloud service. Once connected, click New Archive, give it a name and click Open In Buttercup to set up your master password. You can create new logins and organise passwords in groups. But most of the time you’ll use Buttercup to store online passwords. Click the Buttercup icon followed by + to link your cloud provider and access your archive. Whenever you log into a website, look for the…

There have been a lot of note-taking apps for Linux over the years, most notably BasKet for KDE and Tomboy for Gnome. Perhaps you’ve used a personal wiki to collect thoughts and webpages to clear your mind and be more productive. Chances are that you’ve also used the Evernote app to “Remember everything”. This proprietary app runs on Windows, Mac, and has mobile apps for iOS and Android. Until recently, it also ran on Linux via Wine, but corporate priorities changed. That left the field open for a new open source contender. Enter Joplin. Named after the 20th-century composer Scott Joplin, the king of ragtime music, this JavaScript app from Laurent Cozic runs on every platform you can think of (if you count Linux on mainframe). Joplin is a very…

You can attach files and images up to 10MB to any note. Click the paperclip on the toolbar, or drag the file or image to a note. You can also copy an image to the clipboard and paste it into a note. Joplin creates a link to non-graphic files in the HTML version of the note, and Markdown creates a unique ID. Images always display in the HTML viewer. Attachments can be tricky when you’re synchronising with mobile apps. This is especially true if you’ve got data caps from your carrier or limited space on your phone. By default, Joplin will always download everything to the mobile app on each sync. To change this on the mobile apps, go to Configuration, and scroll to Synchronization. Go to Attachment Download Behavior,…

Headlines are handled differently to /checklists/ in Org-Mode. While both enable you to specify items that need to be done, checklists have a couple of shortcomings when compared to headlines. Firstly, they cannot have custom states; they’re either completed or incomplete. Secondly, they don’t constitute the structure of the Org-Mode document. Checklists are contained entirely within one headline. Thirdly, they can’t have properties associated with themwe’ll cover why this is important. However, they are still useful if you just need to create a quick list of items that need to be completed. They can also be nested, and rolled-up to boot.…

If you want to share your dotfiles, go to GitHub and look for automatic systems. A good one is autodot (https:// github.com/ajmalsiddiqui/ autodot). It requires npm though, so if you do not use that look elsewhere. If you just want a backup of your configuration data and want it secure, you can get a Keybase (https:// keybase.io ) account. It has a fully end-to-end encrypted git service. There, you can even store your new masterpiece without worrying that someone will find it. With every dotfile collection, you are bound to need new fonts. GitHub is your saviour again. Nerd-fonts is a great collection of fonts, the problem is how addictive it is to keep looking for fonts. (https:// github.com/ryanoasis/ nerd-fonts#patched-fonts).…

We’re going to demystify and make Docker easy to use, explaining how to run it and expose services to the internet. For our case study we will use Nextcloud and a fresh installation of Ubuntu Server 18.04. The goal here is not to demonstrate a ‘better’ way of running Nextcloud, but rather how to use the Docker platform. Docker is probably the best-known container system for Linux, although it is far from the only one. Containers allow developers to build all the necessary libraries, services and configuration files into a predefined package that can be recreated on-demand. They solve an age-old problem where applications work fine in development but not when they’re moved into production due to various dependencies, such as OS version, libraries, etc. This may sound similar to…

While Docker is not the only container solution out there, it’s definitely one of the better-known ones. Anyone can create a Docker image from scratch, but the learning curve is quite steep, so being able to start with an existing container can make a big difference as we start to work with it. Docker provides a central repository of images called Docker Hub, and this is accessible to everyone immediately after Docker is installed – we don’t need to register or create API keys, we can pull an image just by referencing its name. Docker Hub contains both official images created by the team at Docker Inc. as well as a vast array of images created by the community. One such community team are the guys at www.linuxserver.io who maintain…

Methods to be added to gitStatus.py: hasGitDir(self, dir): returns True if dir has a subdirectory .git. appendSlash(self, str): appends / to str if str doesn’t end with /. quickCheckPriority(self, dir): uses git status --porcelain. It returns COLOR_RED for modified files, COLOR_ORANGE for deleted, added, copied or untracked files, else COLOR_GREEN. refresh(self): This is the SLOT for the pushButtonRefresh clicked signal. It clears and repopulates the dialog. statusSelectionChanged(self): when listWidgetStatus selection has changed. Sets a stylesheet for the selected item in listWidgetStatus. repoSelectionChanged(self): when listWidgetRepo selection has changed. Sets a stylesheet for the selected item in listWidgetRepo. Also invokes git status --porcelain to populate listWidgetStatus. populateDialog(self): fills in all the fields of the dialog. Searches disk(s) for directories containing git repositories and populates listWidgetRepo accordingly. parseConfigFile(self): reads or creates gitStatus.ini and…

You can learn more about R at www. r-project.org and about RStudio at https:// rstudio.com. Additionally, search for R packages by visiting CRAN at http://cran. r-project.org. If you are looking for something simpler but programmable for creating your own calendars, you can give GraphViz (http:// graphviz.org) a try. However, as calendar creation is not directly supported by Graphviz, you will need to write code. You can learn more about heat maps at https:// en.wikipedia. org/wiki/Heat_map. Additionally, you can find another way of creating calendars in R by visiting http://bit.ly/ lxf260calendar.…

What’s a BSD? Linux isn’t the only open source kernel, so we offer a Linux-user’s guide to running BSD and suggest why you’d want to. Get your life in order! We explore Lifeograph and how it can help you organise everything in your life, from notes to journals and diaries. Manage your logs Linux loves logs, they’re everywhere. We explain how you can get to grips and manage your many logs the easy way. LibreOffice Calc masterclass Think you’re good with spreadsheets? You ain’t seen nothing until you start coding LibreOffice Calc for full control. Contents of future issues subject to change – we might be mere shadows dancing on a cave wall. LXF261 will be on sale Tuesday 10 March 2020…

“Recently we had a lovely email, which hopefully you’ll have the pleasure of reading next issue, from a computing veteran. He talked about the revolutionary innovations he had seen over the course of his career, from punchcards to personal computers, and wondered why we don’t see such revolutions anymore. CPU clock speeds and misrepresentations of Moore’s law are commonly used to support this argument (our dear reader did not use these and that is why we like him). This got me to thinking, are all improvements really incremental now, or do they just seem that way? Let’s take Linux as a sort of microcosm here. Linux journalists would dearly love if every new release of a distro was packed with revolutionary and shiny features, but these days we often have…

“If you have a device with Mali T720 or T820, then you are in luck – your device is now supported via Panfrost in upstream Mesa at feature parity with other Mali GPUs. So get out your Allwinner H6 or Amlogic S912 board, grab the latest Mesa and enjoy a match of SuperTuxKart all with fully free and open source mainline drivers! These Mali GPUs, found in devices like television boxes, prioritise simplicity. But that’s simplicity for the hardware. For us, on the other hand, new changes often mean new complexity – but we’re up to the challenge. Over the past few months, fellow Collaboran Tomeu Vizoso and I reverse-engineered the Mali T720 and adapted Panfrost for the new devices. With improvements relating to Mali’s tiler, framebuffer descriptors, and our…

Anup Patel posted v.10 of a patch series implementing RISC-V support in KVM (the built-in Linux hypervisor layer). The patches have been booted successfully under QEMU and the implementation is pretty complete, modulo a few pieces of in-kernel emulation for platform management (SBI v0.2, PLIC, etc.) that are punted to KVM userspace (in the host). The patches even try to handle non-homogeneous RISC-V platforms with mixed cores, where it might be necessary to trap and emulate basic features. Greg Kroah-Hartman published a ‘Linux Kernel Code of Conduct Committee: August 2019 to November 2019 report’, and then another for December. He summarised the number of complaints received under the Linux Kernel Code of Conduct (www.kernel. org/code-of-conduct.html). The idea is to publish anonymised reports to promote civil discourse upstream. Complaints are handled…

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…

The end of support for Windows 7 in January 2020 is just one of the many reasons that might compel new users to switch to Linux in the new year. If you’ve never used Linux before, or have limited experience, choosing a Linux distribution out of an ever-growing list can be a very daunting task. Linux distributions can be categorised on the basis of many different criteria, such as the default desktop environment, their package management system and even the resource requirements. Conventional wisdom suggests that rolling-release distributions are best suited for advanced users. While this might have been true in the early to mid-2000s, it’s no longer the case, with the myriad sources of information, vast amounts of documentation and informational video tutorials scattered across the internet. This is…

The desktop environment (DE) is the collection of all the graphical elements that you can see on the desktop, such as windows, toolbars and icons – as well as a Window Manager, which is responsible for the appearance of the windows in the GUI. You’re unlikely to persist with a distribution if you detest the look and behaviour of its DE. Zorin OS produces two free editions. The core edition, which is the subject of this Roundup, ships with the Gnome 3 desktop environment. It’s one of the oldest DE available and the default on dozens of Linux distributions. The Zorin Lite edition, intended for older machines, favours the lightweight Xfce environment. Manjaro ships three official editions. We’ve featured the KDE edition in this Roundup, but the project also offers…

There are a number of other Pi distros that aren’t yet supported/ don’t work on Pi 4, but are nonetheless noteworthy. Fedora currently provides ARMv7 and AArch64 builds, but until Pi 4 kernel fixes are upstreamed there’s no official Pi 4 support. Similarly, FreeBSD should get a Pi 4 version in time. The Raspberry Pi has long been the home of the resurrected RISC OS, which comes from Arm roots on the Acorn Archimedes, but a 64-bit version specifically for the Pi 4 would be a huge surprise – there has not, thus far, been any 64-bit release of RISC OS for any platform, and it would mean a major rewrite of the code. However, there’s nothing stopping you trying a 32-bit version. It’s not as though the ARMv8 processor…

The Pi can’t run the official Steam client, but it can be used as a Steam Link, streaming games from your main PC to your living room TV. This function has been disappointing on previous models, but it works tremendously well on the newest Raspberry Pi 4. A Pi running the Steam Link app is functionally equivalent to Valve’s outdated Steam Link hardware, only dialed up to 10: the Pi is a much more powerful device. The app has been updated for the fourth-generation Pi – just run sudo apt install steamlink to install it – but we’d say it still has a little way to go. The old techniques for running it automatically don’t yet work, so you need to keep a keyboard and mouse connected to your Pi…

Back in LXF247 we interviewed the Zephyr Project’s Thea Aldritch, where we learned Zephyr is a tiny real-time operating system (RTOS) that is destined for great things. Zephyr is not Linux, but that didn’t stop kernel don Greg Kroah-Hartman, in our last issue, describing it as one of his favourite Linux Foundation projects. Kate has had over 30 years’ experience in the software world as a developer and a manager. She’s also a key player in the SPDX project, which aims to sort out code licensing once and for all. She gives us an update on what’s new with the Zephyr project, and how it’s learning from Linux. Linux Format: Can you tell me about your role at the Linux Foundation? Kate Stewart: Well I’m the director of the project…

If you’re running an Arch-based distro like Manjaro or KaOS, use yay or a similar utility to grab the Joplin package from the Arch User Repository. Make a catchall notebook to put random web clippings in, as you cannot create a new notebook from the web clipper. You can always move the clipping to a new notebook when you return to the desktop app. You can import any Markdown (.md) file you have created into Joplin with the same import utility you used for Evernote: Just go to File > Import > MD.…

Properties are similar to the Tags we introduced in LXF241, in that they’re metadata about a headline (or task, in our case). However, they’re different in the following ways: you can only enter a single value for a particular property in a given headline, and there are special properties with built-in functionality. You designate a property by enclosing it in colons. All properties are placed in the /Properties Drawer/, which comes immediately after the headline, starts with :PROPERTIES: and finishes with :END:. You can toggle it open and closed with the Tab key, just like a headline. For example, the following shows this structure for a custom property called /URL/: Alternatively, you can specify properties that apply to the entire document by putting them in the header. Header properties are…

To keep your home directory clean, you may consider autotrash. This is a handy utility that checks the age and/or filename and erases according to your settings. You can run the utility by hand, but more likely you will want to make a crontab entry that clears the Trash on a regular basis. The simplest way to use it is to add autotrash -d 30 in your crontab at regular intervals. This will remove all files that are older than 30 days from the Trash. You can also choose more carefully how autotrash does its job. One example is to make autotrash empty the Trash when there is less than a certain amount of space left on the volume. The parameter is --max-free to start removing files when you have…

If you want to shortcut the installation process for Docker, cheat. sh is available in the project archive at https://github. com/prel-im/lxf260. If you place the file in your home directory and execute via ‘bash cheat. sh $USER’, it will run all the commands to install Docker Server on Ubuntu 18.04. Docker allows you to map TCP or UDP ports in your containers through to your host. You cannot map a container to a port on your host that is already listening (e.g. if you run a SSH server on the host, you cannot map TCP/22 to a container).…

Two SDR dongles were used in the project. One was a plastic-cased dongle with a fixed-length antenna, purchased from www.banggood.com. The other was a metal-case device with two adjustable antennas purchased from www.rtl-sdr.com. Both units were used successfully. The former was CA$15, while the latter was CA$40. Both units can plug directly into a Pi USB port. The physical size of the SDR-RTL unit restricted access to the remaining USB ports. The banggood unit restricted access to the USB port directly below, but not the others. In order to plug into the unused ports the USB connector must be very thin or it won’t get by the dongle. The performance of the RTL_SDR unit exceeded the banggood unit. The signal strength unit was higher and had greater stability in not…

In order to determine the status of the files in a git working directory, we interrogate the repository using the git status --porcelain command. The --porcelain option makes it a bit easier for a computer to read the output. It simply proceeds the file path with an M for modified, D for deleted, R for renamed, A for added and ?? for untracked. A modified file has a different version in the repository from the version in the working directory, so your repository is not up to date: you haven’t committed your latest changes. An untracked file is present in the working directory but doesn’t exist in your repository. Perhaps it’s a file that you meant to add to the repository, but you haven’t gotten around to it yet. A…

List – a generic vector containing other objects, and a vector is a sequence of data elements of the same basic type. Data frame – a list of vectors of equal length that is primarily used for storing data tables. It is used a lot in R and is equivalent to the concept of a table. Array – a multi-dimensional object. Factor – a mode numeric and class factor. Matrix – a two-dimensional array that contains numeric data and has rows and columns. The mode() function returns the mode of an object, whereas the class() function returns the class of an object – they can both be very useful when you do not know the kind of R object you are dealing with. The data types that you are going…

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…