Linux Format的February 2019目录

Jonni Bidwell I recently dug up my old Sansa Clip MP3 player (the greatest budget MP3 player of the mid-2000s) which is, or was, not a Linux tool. But then I installed Rockbox on it and it became such. Now it can play not only MP3s (and OGGs and FLACs) but also Doom, in glorious monochrome. John Knight My brother swears by PDFsam, which splits and merges PDF files. I don’t know about “unknown”, but Qtractor is very underrated as an audio editor. Definitely not underground, but if you’ve been pulling your hair out with GIMP, Krita might be the alternative you’ve been looking for. Nick Peers I recently stumbled across the perfect open-source password manager tool: BitWarden. It’s cross-platform, boasts strong encryption and has a host of user-friendly features…

“Years ago, I started an experiment that became the Linux Kernel Podcast (kernelpodcast.org). For over a year I produced a free daily show that had over a thousand regular listeners on all of the major platforms. Then, life intervened, and the daily show became weekly, and finally I couldn’t keep up with it by myself any more. The problem with the podcast wasn’t so much the content (although it takes a vast effort to keep up with the Linux Kernel Mailing List or LKML), but in the creation of narrative, recording, editing and other production involved in maintaining even a modest show on a regular basis. With this in mind, I have recently decided to solve the problem of tracking and summarising community mailing lists through the creation of better…

“I write to you from long in the past. No, I haven’t created a time warp by messing with my system’s locale variables, I speak of the time warp created by print media. That which enables me to write you from 2018, unaware of whatever political brownstorms marred the early part of the 2019. Political angst aside, working around these delays is sometimes tricky. But that’s not all which is tricky in the weird, anachronistic world of magazine publishing. Let me elucidate. Every month people write in criticising the ‘gobbledegook’ that peppers our pages. By the same token people, will also write in accusing us of pandering to newbies with our more accessible features. I like to think we strike a good balance, and as long as we keep getting…

Valve has discontinued its Stream Link device, which enabled you to stream games running on a PC to a TV in another room. Valve stated that it “intends to continue supporting the existing Steam Link hardware as well as distribution of the software versions of Steam Link, available for many leading smartphones, tablets and televisions.” The good news is that Valve has released the Steam Link app for the Raspberry Pi 3 and Raspberry Pi 3 B+ models running the Raspbian Stretch operating system, albeit only in beta at this point. Instructions on how to install and launch the app on your Pi in detailed in Valve’s announcement: http://bit.ly/LXFSteamLinkApp.…

“Horovod, originated by Uber, is an open source distributed training framework for TensorFlow, Keras and PyTorch, which improves speed, scale and resource allocation in machine-learning training activities. It’s also the newest project to come under the LF Deep Learning Foundation. Horovod makes it easy to take single-GPU TensorFlow programs and successfully train them on many GPUs faster. It uses advanced algorithms and leverages features of high-performance networks to provide data scientists, researchers and AI developers with tooling to scale deep learning models with ease and high performance. In benchmarking Horovod against standard distributed TensorFlow, Horovod has come in roughly twice as fast. Uber has used Horovod to support self-driving vehicles, fraud detection and trip forecasting. It’s also used by Alibaba, Amazon and Nvidia. Horovod joins existing LF Deep Learning projects:…

PYCON 2019 PyCon is awesome! We took part in 2018 and spent five days in workshops, talks, lightning pitches and speaking to vendors. For 2019 the event returns to Cleveland, Ohio, US from 1 to 10 May. Around 4,000 visitors from across the world will be attending the leading Python event for every Pythonista. Tickets and more information can be found on the PyCon website: https://us.pycon.org/2019. FOSDEM 2019 Once again the beautiful city of Brussels plays host to FOSDEM on 2 and 3 February 2019. This event is where open source projects big and small rub shoulders and share ideas, including a retro-computing workshop. At FOSDEM you can become accredited, take part in workshops and talks, and take part in a series of fringe events. This event is awesome and…

The converted Decades ago, I was a complete beginner when it came to Windows, I remember calling the Microsoft helpline and not realising initially where the Start button (we’re still looking for the Any key–Ed) was! And so with Linux I’ve been intrigued yet still very much a novice. Thankfully, Linux Format has showed me the way. I was working in a school’s science department and the English department had put 100 Eee PC notepads into storage, no doubt because their operating system didn’t have Word and also they were cumbersome with Wi-Fi. You had to configure it each time! We acquired these notebooks and with the help of Linux Format and its cover disk, I was able to find a suitable light version of Linux – Lubuntu – with…

Shortly after Jolla rolled out Sailfish 3, the third major release of this alternative mobile OS (see LXF236 news), there was more good news. The Finns rolled out the updated version of Sailfish X for Sony Xperia XA2 devices. Let’s find out what’s new. First, some clarification is required to tell X and 3 apart. Sailfish 3 is the current version of the OS for Jolla’s own two phones (Jolla and Jolla C), together with some other phones with limited availability as well as the basement of community builds and adaptations for a few more devices. Sailfish X is just a re-branded version of Sailfish OS for Sony Xperia X mobile devices. The initiative was made possible thanks to Sony Mobile’s attitude towards the open source community. The vendor launched…

All the distros enable you to use excellent Arch’s Pacman tool, but this is probably not ideal for people who want to do things graphically. The Pamac GUI is included in Antergos and the Xfce and Gnome flavours of Manjaro. This is a little bit slicker than the Synaptic-like Octopi used by Netrunner and KaOS (and Manjaro KDE). KaOS includes a GUI cache cleaner and package log, but command-line tools can do these tasks just as well. Netrunner also offers the appstore-style KDE Discover. ArchLabs enables Pamac to be installed from its welcome menu, but doing things CLI-stylee seems more fitting here and, speaking to that, it includes the text-based Pacli front-end. Pacli can help with downgrading packages, something not supported in Arch Linux but something that is on occasion…

FOG The constant barrage of repetitive tasks such as running checks, troubleshooting errors, swapping out dead hard disks, doing fresh installations over and over again can sap the energy out of any system admin, irrespective of the size of their network. Using FOG you can image and clone machines from the comforts of the admin HQ. FOG is a complex piece of software and offers plenty of options, with various fields to describe the host images. It can also arrange them into groups for easier management. There are also several options to schedule the imaging process. FOG can also be used to debug imaged computers, remotely wipe hosts and more. The server also handles regular admin tasks such as installing software and can even manage printers on the network. The…

OSMO A personal information manager (PIM) helps you keep track and organise all the information coming in from various sources. Osmo is a lightweight PIM that helps manage appointments, tasks, contacts and notes. The application has a straightforward and integrated interface with four tabs on the top for Calendar, Tasks, Contact and Notes. The program lacks any menus, but the action-linked buttons at the top change as you switch between the four components. The Calendar pane provides a simple functional calendar along with some related information such as the week number and the number of days to the end of the year. You can double-click a date to add notes or right-click a date to add a task. The options for defining a task in Osmo are housed within a…

ZULUCRYPT While you can control access to the data on your computer using user accounts and file permissions, they aren’t enough to prevent a determined intruder from gaining access to your private files. The only reliable mechanism to keep your personal data to yourself is to encrypt it. Sure, working with encrypted data is an involved process, but it’ll go a long way in reinforcing your security and insulating your data. zuluCrypt is a graphical encryption tool that has an intuitive, easy-to-follow interface. Using the program you can create an encrypted disk within a file, a partition and even USB disks. It can also encrypt individual files with GPG. zuluCrypt can perform block device encryption, which means that it can encrypt everything written to a certain block device. The block…

The Internet offers a vast amount of astronomical related resources but if you want to be inspired by the variety and beauty of all those distant words, visiting the NASA Image Galleries at www.nasa.gov/multimedia/imagegallery is a must. Although NASA’s images are static, the amount of detail you can see is staggering. Many of the images were obtained from the various space probes that have been launched towards every corner of the Solar System for decades. So, for example, returning our attention to Jupiter’s moon Io, you can even see the plume of one of its volcanoes firing sulphur 300km into space. And in addition to seeing how planets and moons looked from fly-bys or from orbit, in the case of Mars you can look at images from the planet’s surface…

In the traditional system, for each file you must define read, write and execute permissions, and you must do so for the owner of the file, as well as the group which the user belongs to, and ‘others’. The chmod command is used to set permissions, and accepts numerical or symbolic values as argument. Any file can be set to be read, written to, or for scripts, executed. The acceptable values are: Setting the permission to 664, with chmod 664 filename for instance, means that the owner and the group can both read and write to the file, while others can only read it. We can’t set different access permissions for different users. For instance, there’s no means of allowing user ‘linuxlala’ to read, write, and execute files, while at…

1 Click Set basic the + button criteria and choose New Automatic Playlist. Choose which field (from Title or Artist to Composer or song duration). Choose your matching criteria. Available options depend on the criteria that you choose. 2 Enter Choose your multiple first value. To criteria match (or not match) using multiple criteria, click Add as many times as you like and repeat. By default, all criteria must be reached, but you can tick Add If Any Criteria Are Matched to turn it into an OR search. 3 You Final might options end up with a playlist that contain hundreds of songs. Tick the Limit To button to restrict the number by songs, minutes or file size. Next, set a sort order. Finally, click New to review – choose…

Export your document to a blog using the org-export-to blog feature. You can write to wordpress, using the org2blog feature in Emacs, and with this feature you can log into wordpress and your own blog. You can also read Twitter with twittering mode, the code is available on MELPA and as a GitHub repository. You can read and send tweets, there is even an icon mode so you can see those. There are many parts that are set and ready in SpacEmacs, but if you feel lost without having set it yourself, make sure you figure out Configuration Layers if you’re going to use it.…

The USB stick has transformed our concept of disposable media. Gone are the piles of floppy disks, CDs and DVDs. Wherever there’s a need for ad-hoc storage we now reach for the essential tool that USB storage has become. We use them to “netwalk” files when we find ourselves without a network connection. They’re invaluable as boot, recovery and install media and are a portable home for personal files. In this tutorial we’ll create a versatile USB stick you can use as an emergency boot device, to boot live or installation ISO images, and as a data store – with and without encryption. It’ll work with either BIOS or UEFI while also making data accessible to macOS, Windows or even a smart TV or camera. We’ll show how to boot…

A final example is Tails Linux – we previously set an encrypted data partition that we can use as a persistent volume. If you aren’t familiar with Tails then you should read more about this privacy distro at tails.boum.org. A menu entry for Tails Linux looks like this: A few additional steps are required if you want to use the encrypted data partition for Tails persistence. Unlock it like we did when formatting it and do the following: These steps configure the encrypted volume so that Tails recognises it as a persistent volume, otherwise it will be ignored. Finish by unmounting and locking. Booting your Tails image should now recognise the persistence partition.…

Network configuration in Linux was never straightforward. It wasn’t overly complicated either, but every distro seems to do it in a different way. Red Hat has /etc/network and stores configuration as key-value value, Slackware relies on two shell scripts under /etc/rc.d. Debian and (until recently) Ubuntu employs ifupdown, which reads /etc/network/interfaces and its contents. Does this world need yet another network configuration system? The quick answer would be ‘no’, but it depends on the motivation. Neither of the existing implementations show great support for Wi-Fi and mobile broadband, which are typically managed through NetworkManager. The all-encompassing systemd has networkd, and sometimes these two run side-by-side. Wouldn’t it be nice to have a single configuration file, one could almost say one file to rule them all? Meet Netplan This is exactly…

HotPicks is one of, if not the most popular section of Linux Format and while the reader survey tells me that, I don’t actually understand why! My gut feeling is that people love the choice, variety and freedom HotPicks delivers every issue. I guess the truth is the sheer variety of open source means it can be hard to discover the best tools for the job and HotPicks offers a way to discover the best each issue… so say hello to our HotPicks Special! It’s a guide to this vast open source world and isn’t that what this magazine is here for? So we’re running a best open source software list for 2019. We’ve not done anything like this for over two years, so it’s more than time we help…

Over on CrowdSupply (http://bit.ly/LXFCrowdSupply ) the Libre RISC-V M-Class project is looking for funding. Described as a “100 per cent libre RISC-V + 3D GPU chip for mobile devices”, it promises to be a low-power 64-bit quad-core SoC running at 800MHz and suitable for tablets, netbooks and embedded systems. Its full source code and files are available, including operating systems, processor and 3D GPU and VPU. This system-on-chip features a RISC-V CPU, along with the Kazan GPU (http://bit.ly/LXFKazan) which was previously known as Vulkan-CPU back when it was a Google Summer of Code 2017 project. It’s a libre-licenced software-rendered Vulkan driver written in Rust, and uses optimised 3D instructions. According to the Libre RISC-V M-Class SoC project, it’s targeting graphics performance of 25fps at 1,280x720 resolution, an 5-6 GFLOPs. The…

Linus Torvalds announced Linux 4.20 Release Candidate (RC) 6, saying that he was happy with the general trend toward smaller RCs typically expected at the tail end of a kernel development cycle. His main concern was that with holidays upon us he didn’t want to see the Linux 5.0 (formerly 4.21) merge window opening on Christmas Day. Beyond that, the performance troubles with some recent security patches (STIBP, covered in LXF245) had calmed down and a fix had been incorporated for a filesystem issue (see the box, right). THE IDEA OF AN X32 ABI SOUNDS REASONABLE, BUT THE PROBLEM COMES IN THE IMPLEMENTATION. In a typical kernel development cycle, there are up to eight release candidates following an initial couple of weeks of (potentially) disruptive changes as new features are…

“Security is a compromise between keeping the bad guys out and providing easy access for the good guys. At least with open source software we can examine the code for security vulnerabilities, intended or otherwise. The corollary is that open source also opens the door for some to insert malicious code. One such example came to light late November when the popular NPM Node.js library was found to be shipping with embedded malware. That’s been fixed now, but the truth is it will happen again. For all the plus points of open source software, this is a potential negative. Far worse, though, is what’s happened in Australia. The recently-passed Assistance and Access Act gives the Australian government the right to mandate “back door” access to software. Couldn’t happen here, could…

A er you looking for an open source smartphone? Then it looks like you’ll soon have even more choice, with Necuno Solutions and WebOS Ports collaborating on a “truly open source and secure mobile hardware platform” called Necuno Mobile. Using LuneOS, which is an open source operating system based on Palm and HP’s long-dead WebOS, this collaboration aims to offer Necuno Mobile as a platform for open source smartphone handsets. In an announcement posted at http://bit.ly/LXFNecuno, Tanja Drca, Chief Communications Officer at Necuno Solutions, says that, “We believe users should be able to choose an operating system for their mobile device and LuneOS can be one of the choices. LuneOS is a good effort of bringing open-source alternative to the mobile operating system world.” While “a good effort” isn’t the…

Where is Windows? Q I’ve used Linux Mint for 12 months and find it okay. But then I bought your latest issue and it featured dual-booting with the latest Mint. I’m now on my fourth attempt but I can’t get Mint to dual boot when I install it. It detects my Windows installation, and asks if I want to delete it. I click no then it just loads Mint and I never see my XP again. Alan Crofts, via email A First, identify if your Windows installation is still there but not showing up or whether it’s actually gone. Load up the partition editor in Mint and look to see whether you have a Windows partition. Then you can mount this partition to see whether it contains Windows. You may…

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 Neil 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…

Send your thoughts to the Linux Format dungeon server at linuxformat@futurenet.com be picked as Letter Of The Month and win* an amazing 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.…

Few would disagree that Arch is a fine distribution: cutting-edge, customisable and possessed of an enthusiastic community and excellent documentation. But it’s not for everyone. Many people are put off by the lack of an installer: having to manually partition disks and chroot into a bootstrapped install to get things going doesn’t really score any user-friendliness points. Those that surmount that obstacle are met with a new challenge: namely, building the minimal install into something useable. If you’re installing it for desktop use, you’ll find getting that desktop to look and play nice is decidedly non-trivial. In short, it really makes you appreciate the efforts that other distros go to, to have all this set up out of the box. But the goodness of Arch can be married with the…

The Archwiki is a truly great learning resource. It’s well-written (and consistently formatted), covers pretty much everything you can imagine, and is kept up to date. A lot of what you’ll find there is applicable to other distros, all the more so if Arch is their progenitor. The Arch forums are likewise a veritable fount of knowledge, but beware – fools are not suffered lightly there. In terms of bespoke support Manjaro shines ahead here. It has its own mailing lists, bugtracker, IRC channel, a comprehensive wiki and friendly (relatively speaking) forums. There are also subforums for discussion in about 30 other languages, because Manjaro users are a diverse bunch. Netrunner benefits from this by osmosis, but they too have their own (rather more modest) forum. The Antergos wiki appears…

PENCIL 2D You can use Pencil 2D to create both static and animated drawings. It’s a comprehensive program that will help digital designers create professional-grade cartoons and animations in multiple layers. The intuitive tool is well complemented by the video tutorials on its website. www.pencil2d.org DARKTABLE If you work with RAW images, darktable will help you create a professional digital darkroom to process them. The tool’s interface gives you access to a full gamut of image manipulation and editing tools on par with commercial heavyweights from the likes of Adobe and Apple. www.darktable.org FOTOXX A comprehensive image-manipulation program with a rich set of retouch and edit functions that go beyond changing brightness, contrast and colour. Like most dedicated image editors, Fotoxx enables you to select an object or area within…

EICIEL (45) Everything in Linux is a file and the access control list (ACL) helps determine the access rights for each file. You can modify the permissions from the command line or use the graphical Eiciel utility that’s in the official repositories of most distros. https://rofi.roger-ferrer.org/eiciel FSLINT You can use the graphical FSLint tool for a comprehensive cleanup of your file system. It can remove duplicate files, temporary files as well as files that are otherwise difficult to locate and remove, such as files with invalid names, empty directories and bad IDs. www.pixelbeat.org/fslint NEXTCLOUD Online storage services are a convenient option for accessing and sharing your data anywhere on the planet. With Nextcloud you can roll out a hosted storage server that gets you the convenience of an omnipresent storage…

GLANCES Glances is a Python script that smartly displays a lot of information about your current session inside a standard terminal window. You can use the tool to monitor remote machines and use the built-in web interface to monitor machines using a web browser. https://nicolargo.github.io/glances FIREJAIL Firejail enhances security by isolating programs and processes inside limited sandboxed environments. By locking away the web browser or any tool that can be compromised, firejail prevents a compromised program from accessing critical areas of the filesystem. https://firejail.wordpress.com PORTAINER Using Docker via the terminal isn’t all that cumbersome and the tool is well documented. To make your life easier however, you can use Portrainer, which is an open source, web-based graphical front-end that supports all the features exposed by the Docker API. You can…

ATOM Atom describes itself as a hackable text editor. Developed by GitHub, the tool has a built-in package manager that enables users to search and install plugins from within it. About 80 plugins ship with the utility by default. One of its more interesting features is the find and replace function that can also modify text across multiple files as you type. Atom can also be used as an IDE and one of its highlights is the smart autocomplete feature. There’s also a bracket matcher feature that highlights the line-number of the closing bracket corresponding to the one under your cursor. You can also define custom key bindings and add more functionality with packages for items such as minimaps and syntax-specific snippet libraries. https://atom.io. BPYTHON A Python shell that provides…

If you’re confused by light years, it’s a measure of distance, not time. It’s the distance light travels in a year which is 9,500,000, 000,000km. Even so, a light year is a short distance in astronomical terms – the nearest star other than the sun is 4.3 light years away,. Fancy looking for evidence of aliens? The SETI@ Home project ( setiathome.berkeley.edu ) uses spare processing time on volunteers’ PCs to analyse radio telescope data in the search for extra terrestrial intelligence. Did you know that a telescope is a time machine? Because the light we see from distant stars and galaxies will have been travelling for many years to reach us – often millions of years in the case of other galaxies – we’re seeing those objects…

The awarding-winning Palace Games, which is behind a string of award winning escape rooms across the US – has utilised the Raspberry Pi to power the ticks and puzzles it uses in its escape rooms. What’s an escape room, we imagine you just asked? Escape rooms are real-world puzzles contained in the form of a room, which you need to escape. Rooms are usually themed and can be scary, historic and just silly, but all will require you to solve a number of puzzles within a set time to escape. They’re group events and are often used for team-building exercises. Behind the scenes of the Edison Escape Room is a network of Raspberry Pis running the Banyan Framework, which is designed to orchestrate event-driven, physical computing devices in an asynchronous…

The Raspberry Pi is ideally suited to working in remote locations and in this tutorial we shall use a remote Raspberry Pi to gather temperature data using a DHT11 temperature sensor and then share that data with our data centre team via Dropbox. Then the data centre team can use their awesome Linux supercomputers to crunch the data and save the world! All of the code, further screenshots and a detailed high-resolution circuit diagram can be downloaded from https://github.com/lesp/LXF246-Sharing-data-from-remote-sensors/archive/master.zip. Sensor sweep Connecting the DHT11 to the Raspberry Pi is simple: we used the three-pin version of the DHT11. Connections, looking at the blue plastic cage, are from left to right: Pin 1 to 3V3 GPIO Pin 2 to GPIO17 Pin 3 to GND Use the female-to-female jumper wires to connect…

As versatile as the Raspberry Pi is, it’s a good idea to be certain that it’s the right device for the project you have in mind. You might just be using the Raspberry Pi for retro gaming or Kodi. It might be acting as a desktop replacement, or as the main component of an IoT project. If your Raspberry Pi is up to the task, then it should work fine. The problem is when you choose a task that the Pi just can’t do, even when the hardware appears to be a good fit. Conversely, the Raspberry Pi might be far too advanced for the task you have in mind, such as flashing an LED over the web, or something equally low-spec. Perhaps there isn’t quite enough RAM; or maybe…

This tutorial will show you how to install and configure Silverjuke for use on a touchscreen monitor. By the end of the tutorial you’ll have a standalone jukebox that will boot automatically into Silverjuke’s kiosk mode that doesn’t require a keyboard or mouse to be connected. We settled on Ubuntu 18.04 which supports the Intel NUC and Acer T232HL monitor we were using. Silverjuke is available in many different distros, and the source code is available on github. We used a network cable to connect, but if your device has Wi-Fi you can configure this when you install Ubuntu. You’ll need a bootable Ubuntu USB key which you can download from http://releases.ubuntu.com/18.04. We opted for a minimal install with no additional drivers, and used the entire disk. Enter user and…

Because Emacs has so many options, enthusiasts have created so-called distributions that set everything up the way they like it. SpacEmacs is such a distribution but with added flexibility. One of the features of SpacEmacs is configuration layers. Each layer is used for a specific specialisation, usually a programming language. An example is HTML and JavaScript: they’re the first entries in the default configuration file .spacEmacs, where the layers are defined. That definition is done in the variable dotspacEmacs-configurationlayers. If you want to tweak your setup, you have two options. One is to add variables in this file and the other is to create your own layer. Experienced users of Emacs might wonder why SpacEmacs users don’t install packages using MELPA? The reason is that SpacEmacs will consider your packages…

Mebibyte partition alignment is recommended to optimise filesystem performance. The latest Ext4 includes features that break backward compatibility. Consider disabling 64bit and metadata_ csum. Labelled partitions are easily identified using /dev/disk/bypartlabel and sgdisk -L lists the available partition type codes. Using sgdisk makes scripting easy. You can use a GPT-aware interactive tool such as gdisk or gparted if you prefer. You can loop mount an ISO and look at its boot configuration files to discover the parameters required to boot it. You can specify the imgdevpath using a partition label, UUID or any valid device path. You can prepare a used stick by wiping it with random data: cat /dev/ urandom > /dev/sdX.…

Wi-Fi isn’t the same as Ethernet with no patch cords. Given the media is accessible to anyone, care needs to be taken to stop eavesdropping. The first take on that, Wired Equivalent Privacy (WEP) was simple to configure. You only needed a static key, basically a sequence of hexadecimal digits which could be as short as ten of them. You supplied these to iwconfig and the kernel happily handled the rest. However, it was discovered that WEP is neither wired-equivalent or private. Stronger encryption schemes required more sophisticated authenticators, often called supplicants as they supply credentials. Those were typically implemented as userspace daemons. Until recently, there was essentially one such daemon in Linux: wpa_supplicant. It is a time-proven technology you are likely to find everywhere: from your home router through…

Systemd is often criticised for trying to be everything, which is a clear departure from the Unix way. Like it or not, systemd can manage network connections, and a service to do this is systemd-networkd (or networkd, for short). Like Netplan (and other daemons), networkd can read files from three locations, of which Netplan stores its generated configs in /run/systemd/network. But instead of a single config spanning multiple conf.d snippets, networkd provides three config types. The first one is .network, which contains [Match] sections to select physical devices based on their name, driver or MAC address. Then it applies network-level settings, such as whether to enable DHCP or IP forwarding or which DNS server to use. The second is .netdev, which serves roughly the same purpose but creates virtual devices.…

The first difference between Middleman and Hugo is that the former in written in Ruby and requires a Ruby installation in order to be executed, whereas the latter is written in Go and is a statically linked binary, which means that it has no other dependencies. The point here is that, if you are familiar with Ruby, choosing Middleman is the rational choice. The second difference is that Hugo has a larger development community than Middleman, which means that you might be able to choose from a bigger variety of themes. Additionally, the documentation site of Hugo is friendlier than the documentation site of Middleman, although this is a matter of personal taste. Middleman can handle larger blog sites than Hugo, which means that if you want to create the…

Early in 2012 a project emerged from the depths of MIT’s computer science laboratories. It was a new computer language with the disarming name of Julia. Over the next six years, as the language, now developed in the open on GitHub, matured and accreted a large and widely varied constellation of libraries, it gained a devoted following of scientists, engineers and others who were involved with high-performance numerical computing. This year the language reached version 1.0, and with that milestone comes a promise of long-term stability. Its new release saw a renewed surge of interest by research groups and the press, even including an interview on the US National Public Radio network. But do we need yet another programming language? The hundreds of research groups and computational science teams that…

Although Microsoft bundles its Edge web browser with Windows 10, the software continues to go unloved. A recent Netmarketshare report indicated that Edge’s user base has been shrinking (http://bit.ly/LXFNetMarketShare). Microsoft has now confirmed that Edge will be rebuilt on the Chromium rendering engine. While Microsoft isn’t ditching Edge, it’s embarrassing for the company to admit that its Edge browser, and the EdgeHTML browser engine have failed. In a blog post (http://bit.ly/LXFEdgeBlog),Joe Belfiore, corporate vice president of Windows, stated that “we intend to adopt the Chromium open source project in the development of Microsoft Edge on the desktop to create better web compatibility for our customers and less fragmentation of the web for all web developers”. Edge has its own browser engine, EdgeHTML, which had been praised for its performance in…

“Recently, a group of Linux multimedia and desktop experts, including myself, gathered in Edinburgh to take part in a hackfest with a common goal: improving the state of multimedia handling under Linux by exploring a new paradigm: PipeWire. PipeWire is a new daemon that aims to improve the way applications share multimedia content and access devices under Linux. Originally designed to provide access to webcams, it now also supports audio. By enabling existing JACK applications to run unmodified alongside normal desktop programs, PipeWire is bringing Linux to parity with macOS and meeting one of its key design goals: supporting JACK-like low latency while having PulseAudio-level automation and ease of use. PipeWire also introduces an enhanced security model for interacting with audio and video devices. It allows both sandboxed and normal…

In early December, Jens Axboe posted a patch entitled “blk-mq: fix corruption with direct issue”. This addressed a bug in Linux 4.19 that had been seen with (for example) Ext4 filesystems running on certain SCSI devices. Those bitten by this bug would typically not know much about it until they started seeing error messages of the form “EXT4-fs error (device sda1): ext4_ iget:4831: inode #7142: comm dpkg-query: bad extra_isize 24937 (inode size 256)”. This message was the (Ext4) filesystem code complaining that it was reading “garbage” from the disk block layer underneath, which it was, because silent data corruption had already occurred by the time the message was displayed. By then, it was too late to save the filesystem from corruption, and a fairly significant number of user bug reports…

The Free Software Foundation (www.fsf.org ) has received a number of charitable donations worth $1 million from Handshake (https://handshake.org), an organisation that has created a decentralised, permissionless peer-to-peer naming protocol compatible with DNS. According to the FSF (see http://bit.ly/LXFFSFFund), these contributions will “support the FSF’s organisational capacity, including its advocacy, education, and licensing initiatives, as well as projects fiscally sponsored by the FSF.” This follows a similar gift of $1 million from the Pineapple Fund, and helps the FSF to continue to protect people’s rights to use, study, copy, modify and redistribute computer programs, particularly GNU/Linux software. Handshake’s donations will also be invested in Replicant (https://replicant.us/), an Android distro for mobile devices, the GNU Project, GNU Guix and GuixSD, GNU Octave and GNU Toolchain. John W Eaton, original author and…

FREEBSD 12.0 The first entry in FreeBSD’s 12 series is now available to download, and brings a range of updates including penSSL 1.1.1, OpenSSH 7.8 and Clang 6.0.1. KDE has been updated to 5.12.5, there’s been some driver updates and various Lua loader improvements as well. According to the release announcement, TRIM support has been improved as well for the UFS filesystem. Find out more and download at http://bit.ly/LXFFreeBSD12. 4MLINUX 27.0 A new version of this desktop Linux project has been released with a number of new features and improvements, mainly relating to media playback. There’s support for AV1 video codec, a quick way to disable PulseAudio (which the release notes state is important to play classic video games like Doom), and better support for people using KVM. More classic…

Build Brighton Thursday evenings is open night. www.buildbrighton.com Cornwall Tech Jam Second Saturday of the month alternating between Bodmin and Camborne. www.cornwalltechjam.uk Huddersfield Raspberry Jam Meet every month at Huddersfield Library, typically on the fourth Saturday of each month. https://huddersfieldraspberryjam.co.uk Horsham Raspberry Jam Park side, 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 rLab Reading Hackspace Unit C1, Weldale ST, Reading, Open Sessions Wednesday from 7pm. http://rlab.org.uk Glasgow Makers and Hardware Hackers Mitchell Library, Glasgow. https://m.facebook.com/groups/115303729096198 Teesside Hackspace Tuesday Evenings at Teesside Hackspace. www.teessidehackspace.org.uk…

Gone are the days when every Linux user needed command line skills, although many of us still find it a more effective way of getting some things done. However, the need may still arise, either directly or via SSH. Once that happens you may find the need to work with files and miss your graphical file manager. Enter Midnight Commander. This program, invoked by running mc , is an old style, twin-pane file manager. It’s not a graphical program, instead it uses ncurses to produce a pseudo-graphical appearance in a text terminal. To control it, use a list of numbered commands at the bottom of the display, which correspond to your keyboard’s function keys. Midnight Commander can do more than move files around. It can descend into archives, edit text…

Octomonster Because of your 9/10 review I went and bought an OCTOCAM kit. I will never trust you again (!) The hardware assembles easily enough, but the software has been a week-long horror show with no end in sight. Because the Pi Zero W has only two USB ports and one of those must be used for Power, it can handle a keyboard but no mouse. The MotionEYE software, which should be used with this kit, crashes regularly after one or two minutes. Its install process is almost impossible without major searches and a bit of extra hardware, such as a LAN-to-USB ethernet dongle. You need to do a much better job in future of actually getting the kit up and running before you give it a 9/10. Greg Morse,…

Conventional wisdom says that AMD is the budget darling, while Intel has you covered at the high end. Conventional wisdom is out of step with reality. Because, right now, if you want serious performance, AMD’s Threadripper should be at the top of your list, while anyone on a super-tight budget is better served by Intel’s Pentium chips and the likes of the Core i3-8100. AMD doesn’t want to leave any market segment to Intel, though, so it has revived the Athlon brand for this release, its most affordable Zen chip to date. Before we delve into the details, it’s worth mentioning the price. In theory, this is a £50 CPU, but in truth, you’ll do well to actually find it for that, because it’s one of those chips that tends…

We installed each distro on a Dell XPS13, which enabled us to test HiDPI and touchscreen support. We checked that the distros happily installed alongside other operating systems without breaking them. Further testing was done in virtual machines (limited to 3GB of RAM), which gave us some idea of how the distros would run on older hardware. We looked at what came with an out-of-the-box install, and whether this struck the right balance between usefulness and bloat. Since we’ve focused on distros providing a desktop, we looked at how stylish and effective those desktops were. Bear in mind that it’s possible to install and configure alternative desktops to your liking. We compared repositories to Arch Linux’s, renowned for offering the very latest software and making minimal changes to upstream releases.…

Comparing different desktops is a tricky business, especially when we have species from all over the spectrum. We’re not going to mark Archlabs down because it uses a lightweight window manager, and we’re not giving extra points to Antergos because it uses a readily available (though undeniably cool) icon theme. Instead, we’ll focus on how each desktop is styled relative to the components installed. We’re interested in icons and colour schemes working together, considered layouts, and freedom from clutter. Since we’re au fait with setting up various desktop environments from scratch in Arch, we’ll give credit for sorting out common quirks or deviations from the defaults (as long as they’re useful deviations). Whatever desktop you end up using, since Arch always ships the latest releases, you’ll probably end up with…

Several Arch-based distros have come and gone over the years, but some have stood the test of time and new ones spring up regularly. It’s common for distros to add non-free software to improve the user experience, but Parabola and more recently Hyperbola go to the other extreme. These two, as well as being named after curves, are both FSF-approved and use the Linux-libre kernel. Hyperbola takes inspiration from Debian, using an older, tried ‘n’ tested kernel. Arch may have stopped supporting 32-bit, but the Arch Linux 32 distro is alive and well. Arch-XFerience and Anarchy Linux, both Xfce affairs, are worth a look. Chakra Linux, a KDE offering, impressed us last year, but hasn’t been updated since then. Those wanting something even more lightweight than ArchLabs should check out…

UMS This streaming server will transform your Linux desktop into the ultimate media streaming station to broadcast media to other computers, smartphones, tablets, gaming consoles and even TVs. UMS streams media via the Universal Plug and Play (UPnP) protocols to any DLNA-compliant device. You’ll have to roll-out UMS, although the procedure is fairly simple. The first time you launch it, UMS takes you through a basic three-step configuration wizard. Although you can start streaming without further configuration, UMS does include an admin panel that offers customisable options and tips to guide new users. It also includes a minimal web interface for streaming your content. www.universalmediaserver.com MPV A resource-conscious video player that also looks good on modern machines. Based on mplayer2, MPV continues the tradition of CLI by introducing optimised and…

JITSI An all-in-one instant messaging app, Jitsi has an impressive set of audio and video-conferencing features. As a VoIP client, it enables you to make calls using the Session Initiation Protocol (SIP). It has all the features you’d expected from a softphone in that it can mute, put on hold, transfer and record calls. It can also make registrar-less SIP calls to other Jitsi users on the local network. You can use Jitsi to make video calls to one user or to several on both SIP and XMPP networks, while using Jitsi Videobridge, you can host multi-user video calls. It’s also a capable IM client with several unique features including the ability to stream and share the desktop of users at both ends of the call at the same time.…

UGET By default, the lightweight uGet download manager relies on curl, but if you install the aria2 package, it can take on some more features, such as the ability to download torrents. UGet is an all-round downloader that has all the features you’d expect from a download manager. It features a download queue, can pause and resume downloads and also accelerates downloads by grabbing files from multiple parallel streams. Furthermore, batch downloads are one of its specialities. You can use the tool to prioritise the download queue and even regulate the speed of the downloads individually. UGet can also shut down and hibernate your computer once it’s finished downloading all the files. https://ugetdm.com BRAVE While popular browsers can be equipped to thwart information leaks, Brave ships with privacy-strengthening features. The…

Jorge Salamero Sanz is technical marketing manager for Sysdig where he works on monitoring and security for containers. We caught up with him at the O’Reilly Velocity conference in London to chat about how greybeard-style monitoring doesn’t help in the magickal world of DevOps, microservices and CI/CD – where containers flit in and out of existence like so many quantum particles. Besides computers, he’s and avid hiker and skier, and most recently has gotten into motorsports – maintaining his own vehicle and driving it round the track at terrifying velocity. Ah well, that’s safer than curl | sudo bash we suppose. Linux Format: How did you get into computer science and open source? Jorge Salamero: I guess it was a natural move, my parents bought a laptop and before the…

Our first advice here is not to rush into making a purchase. Spend lots of time observing with your naked eyes and binoculars. Only if you find you’re still fascinated by the vastness of space after several months, and if you’re still braving the cold several nights each week, this might this be the time to consider buying an astronomical telescope. This isn’t the place to give detailed guidance on how to choose a telescope, let alone reviewing a range of models. But if all you take away from this is that you really ought to spend a lot of time reading up on the subject before investing, perhaps, several hundred pounds, we’ll have accomplished our mission. In a nutshell, however, you can pay anything from less than £50 to…

Back in 2011 I felt a compelling need to change the curriculum in the school I taught at. I was the subject leader for ICT, and I wanted to lead the move away from a dependency on proprietary software that our students simply couldn’t afford to use at home unless I encouraged them to break copyright law! My interests in Linux and the FSF were developing, and I wondered if this new device called the Raspberry Pi might be the answer I was searching for. After attending BarCamps, Python meetups and Linux/FSF themed un-conferences in Manchester I was inspired to start something similar in Preston where I taught, but with a focus on the Raspberry Pi computer, digital making and supporting computing education. Although many forums, channels and online video…

At the start of the project we instructed the code to look for the Python interpreter, and now we need to take two steps to make our app run. First, we need to make the code run from the terminal rather than open the Python editor. In a terminal we shall make the file executable by changing its permissions: Now give it a quick test by typing this into the terminal: If the code works, great! If not, double-check before moving on. The last step is to tell our Raspberry Pi to run the code on every fifth minute in the hour (5, 10, 15, 20 and so on), for that we need to use cron. In a terminal type the following: It will ask which editor to use, choose…

You can use the permissions system on Linux distributions to define access rights for the owner/group/others for each file or directory. But this traditional system of permissions-driven access suffers from a critical flaw: namely, you can’t define different permissions for different users for the same file. This is where Access Control Lists (ACLs) come in to save the day. Using the setfacl command, you can define the ACL permissions for a file or directory. The getfacl command can similarly be used to retrieve the ACL information for any given file or directory. But before we dive into understanding how ACLs work, and putting them to use, a quick primer on the permissions system is in order. Refer to Primer On Permissions (below). An ACL comprises a set of rules which…

Thanks to its support for plugins, you can add extra features to Rhythmbox easily. To do so, click Rhythmbox on the desktop’s top menu and select Plugins from the drop-down menu. Plugins include Grilo Media Browser, which adds support for a wide range of local and internet streaming services, including the ubiquitous DLNA standard. Fed up of constantly adjusting volume between albums? Enable ReplayGain to keep the level consistent. Song Lyrics will enable you to display lyrics when listening to music by pressing Ctrl+L, while SoundCloud lets you browse and play sounds from the website. These plugins scratch the surface of what’s available – for more head to wiki.gnome.org/Apps/Rhythmbox/Plugins/ThirdParty.…

Cover art is an essential part of any jukebox experience and your jukebox will look more authentic and be easier to navigate if your albums all have the correct covers. Silverjuke will recognise cover art if it’s in the same folders as the music files and although it does have the capability to search and update covers from the internet it’s not great for updating covers automatically or in bulk. Searching for an album in Silverjuke will start a Google (or similar) search and you need to download any resulting images to the right folder. Not something you would want to do several hundred times. So if Silverjuke can’t find a cover it will generate an Avatarish (think social media, not James Cameron) cover using the album title and artist…

If you look in the Shape field at the top of the Shape tab and click the white box, you can choose from a number of preset shapes for your image frames, including our old friend Tux! If you have the Guide Manager window off to the side, any changes you make in the Guide Manager will immediately take place on the page in the main window below, saving you a lot of time in the long run. Scribus enables you to place page margins and images wherever you like, but average home printers won’t go all the way to the edge. Full-page printing may be fine for professional machines, but check your printer’s manual before you commit.…

Emacs has so many settings and functions that it can get a little overwhelming. Sometimes all you want is a limited range of functions that are suitable for the task in hand. To work with an Emacs client that does very little, you need to launch it with only what you need. But then you have an Emacs session you’ll need to start all over again. A better solution is to have flexible setups and be able to quickly switch between them. CHEmacs is a script that you can download from GitHub and install in your home directory. It replaces your .Emacs file and is run before you start Emacs. Because it’s run before Emacs itself, you can’t download it from MELPA or any other repository. The setup is fairly…

You can use VirtualBox to test your USB stick. Ensure you have write access to the device (chown $USER /dev/sdX if necessary) and then create a raw virtual hard drive mapping like this: Create a virtual machine and opt to use an existing hard disk when prompted, selecting the virtual disk created previously. Boot the virtual machine to test your USB stick. VirtualBox machines usually boot using a BIOS but you can also test your USB stick’s UEFI capability. Bring up the machine’s settings and select the Enable EFI option on the System tab.…

All problems in computer science can be solved by another layer of indirection. Except it introduces yet another level of indirection. The aphorism coined to David Wheeler isn’t news but, surprisingly, it stays up to date. In Linux, it is further amplified because the system is open, and all of the abstraction layers it implements can be clearly seen. This isn’t to say abstraction layers are not doing any good. Many primitives we take for granted – sockets, processes or files, say – are actually abstractions on top of memory buffers, CPU contexts and device blocks. And, yes, these are abstractions as well. Without this high-level view, you’d be forced to connect logic gates, which makes the road to your database backup script way too long. The tricky part is…

Many of us recognise NetworkManager as signal strength indicator in the system’s dock. This is an applet backed by the NetworkManager daemon. The applet and the daemon communicate via D-Bus, and NetworkManager has its own config file and management CLI. NetworkManager considers three locations: /usr/lib, /run, and /etc. The priority is different, though: a config in /etc shadows the one in /run. Users don’t edit the main config file, NetworkManager. conf, but add their own snippets under conf.d. Netplan does exactly this as generated snippets go in /run/NetworkManager/conf.d. NetworkManager uses a keyfile format A typical config lists plugins to be loaded and a few settings. There is one plugin that’s always present, called keyfile, which manages system-wide connection storage (/etc/NetworkManager/system-connections) for NetworkManager. Most of the time, you manage NetworkManager through…

You can get more info about Middleman at https://middlemanapp.  com. The documentation, can be found at https://middlemanapp. com/basics/install and the Community site at https://middlemanapp. com/community/. However, nothing can replace the experience you are going to get from actually using Middleman. If you think Middleman is too complex for your tastes, take a took at Hugo ( https://gohugo.io  ), which is also a framework for building static websites. Hugo is simpler than Middleman whereas Middleman can support more complex sites than Hugo. You can also have a look at the Jekyll static website generator (https://jekyllrb.com). In order to create your content you will need to learn a language; Markdown is a very good candidate as it is easy to learn and easy to use. Additionally, Middleman itself is responsible for converting…

The Markdown language is a way of writing formatted text that can be easily converted into HTML or other formats. Markdown saves you from having to write HTML code, which is pretty ugly, and therefore can help you write posts and articles easily and quickly. Beginning a new line with a single hash character will create an H1 HTML header. If you use two hash characters (##) at the beginning of a line, you will get an H2 HTML header, and so on. In order to present a word or a phrase in italics you should write it as _Italics_ . For bold, you should use **Bold** . You can include small code exempts using backquotes like `middleman build` , multiple lines of code using ``` at the beginning and…

Julia headquarters http://julialang.org Installation https://julialang.org/downloads Julia benchmarks https://julialang.org/benchmarks Libraries https://juliaobserver.com Documentation https://docs.julialang.org/en/stable About the language design: Julia: A Fresh Approach to Numerical Computing by Bezanson J, et al., SIAM Review 2015. doi:10.1137/14100067. Julia 1.0 announcement https://julialang.org/blog/2018/08/one-point-zero Syntax cheat-sheet http://bogumilkaminski.pl/files/julia_express.pdf Plots metapackage http://docs.juliaplots.org/latest Learning links https://julialang.org/learning Official package registry https://pkg.julialang.org…

AN EASY DEAL DISTRO Bodhi 5.0 32-bit This isn’t the first time we’ve featured Bodhi 5 on the disc, but it is the first time it’s appeared in 32-bit form. The future of 32-bit Ubuntu isn’t clear. All the official flavours elected to continue producing 32-bit media for 18.04, and well-known Ubuntu derivatives (most notably Linux Mint) continue to cater to the 32-bit crowd. With the release of Ubuntu 18.10 the 32-bit tide ebbed a little further away, with the Kubuntu, Mate and Budgie flavours no longer catering to these older CPUs, but let’s focus on Bodhi. With its stylish Moksha desktop, Bodhi has long been a popular choice for older hardware, and continues to be available in 32-bit form and will be supported until 2023. The legacy release of…

USING THE LXFDVD Using Linux for the first time can be very confusing. It’ll be unlike anything that you’ve likely used before, especially if you’re used to Microsoft Windows or Apple Mac OS. 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 Mac OS 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…

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…