Indholdsfortegnelse for Summer 2016 i Linux Format

Jonni Bidwell Mint has been great for ‘fixing’ various old XP machines. Auntie Ethel loves it – she’s currently learning ROP exploits in order to exact revenge following some poor adjudication at the bridge club. As well as being accessible, it has the most wonderful squelchy effect on the context menu. It’s reason enough to get a new video card. Neil Bothwick It has to be the colour. While many people switched to Mint because of the old-school desktop environments, for me it was the chance to have a desktop that was anything but a murky brown or purple. Please don’t tell me defaults can be changed when all it takes is a switch of distro. Matt Hanson My favourite feature of Mint is actually the Cinnamon desktop environment. It’s…

“The first-boot Linux experience is one of the best things about the modern Linux desktop distro. First of all, many Linux desktop distros come pre-installed with the likes of Firefox and LibreOffice, but you still need to get the other things. Doing this usually takes just one or two entries on the command line. You then relax as the system does its magic. It’s awesome, but there’s a problem with the Linux package manager ecosystem, and it’s the fact that there’s an ecosystem of package managers at all. Packed field There’s a slew of package systems to choose from: Debian, Ubuntu and its derivatives (such as Linux Mint, see our Feature, p32) use APT; Fedora and Red Hat use Yum; OpenSUSE uses ZYpp, which is compatible with Yum; Slackware has…

Since you started doing them, I’ve been closely following the Raspberry Pi articles, but I never really had the time and/or X incentive to actually get one and do something with it, although I did make note of potential projects I may get around to at some point. Now I do have the time and incentive. The more I read up on it the less sure I am on what to use at the heart of the project. I had originally thought it would be a toss-up between Pi or Arduino, but now I’m reading about the Beaglebone, the ODROID-C2, and the Banana Pi. Unless it was in one of the rare issues I don’t get due to being out of the country, I don’t think you have done a…

Specs CPU: 1.7GHz Intel Celeron 3215U (dual-core, 2MB cache) Graphics: Intel HD Graphics GT1 RAM: 4GB DDR3L Screen: 13.3-inch 1920 x 1080 Matte FHD LCD Storage: 16GB M2.NGFF Solid State Drive, MicroSD slot Optical drive: None Ports: 1x USB 3.0, 1x USB 2.0, HDMI, headphone and microphone combo jack Connectivity: Intel Dual Band Wireless-AC 7260 802.11AC, Bluetooth 4.0 Camera: Built-in 720p HD video camera Weight: 2.17kg (4.8lb) Size: 382 x 252.5 x 20mm (15.04 x 9.94 x 0.78 in) W x D x H Perhaps high-end Chromebooks were inevitable, but it looks like the Chromebook Pixel has started a trend. This new Dell model features an FHD screen, more memory, and more processing power than one might expect – or arguably need – from an average Chromebook. Perhaps it is…

Kazam, VokoScreen and ScreenStudio offer no in-application documentation. Kazam also doesn’t offer any documentation on its website but there’s a forum for support. VokoScreen’s website lists a handful of tips and hints and a solitary demo video in German. While there are no forums, the application enables you to contact the developer via email to resolve any issues. ScreenStudio also only has basic install instructions on its website that gives an overview of the application’s features and basic usage. The developer is an avid YouTuber and the official channel is full of screencasts of various Linux application and games that show off the app’s capabilities. All the options in DemoRecorder’s interface include a Help button, which opens the man page for the CLI utility that powers that feature. On its…

Kazam includes a simple three-tab Preferences window that offers very little flexibility. It enables you to select the speaker and microphone capture devices and adjust their volume levels. You can also toggle the countdown splash that appears before the app begins recording. From under the Screencast tab you can change the framerate for the capture which defaults to 15FPS. There’s also a pull-down menu that allows you to choose between the default H264 (MP4) and the VP8 (WebM) containers. You can also ask the application to save recordings automatically by just selecting a directory and specifying a filename prefix. Similarly, all settings in VokoScreen are housed within the Settings tabs. Here you can choose the default location for storing videos. You can also choose the default video player which is…

“Mint has risen through the rankings to become one of the most popular Linux distros.” Mint’s motto, ‘From freedom came elegance’, speaks to an entirely different class of distribution (distro): one that isn’t shackled by commercial interest and one that actually wants to be pleasurable for desktop users. Linux Mint was born 10 years ago out of lead developer Clement Lefebvre’s desire to build a distro that was both powerful and easy to use. Now it has risen through the rankings to become one of the most popular Linux distros out there. Linux Mint has definitely become something much bigger than its first nickname ‘Ubuntu with codecs’. It now features its own desktop, core applications and support channels. Along the way there have been hiccups and detours, but the project…

Due to the small size of the drone it’s quite difficult to keep things neat as you tuck in wires, wrap insulation tape and zip ties around the frame in order to hold everything together. Whilst it might seem fiddly and time-consuming to make sure that the PXFMini, Raspberry Pi Zero combo are absolutely level, it’s one of the most important aspects of the build! From the outset of building the frame you need to continually check that everything about your build is as accurate as possible. The frame kit that we’ve used in this project does the job well despite it being cheap, but there are some of the parts, including the frame legs, that take a bit to fit correctly and have a habit of dropping out. The…

At Google’s IO conference in May, the search giant unveiled a new component that has quietly been introduced into its data centres and which powered AlphaGo, the system that defeated Go champion Lee Sedol in the highly publicised set of matches earlier this year. TPU (or Tensor Processing Unit) is a custom ASIC (Application-Specific Integrated Circuit) for running machine learning applications, specifically tailored for TensorFlow (www.tensorflow.org, an open source library for ‘machine intelligence’). Google has been using these chips to improve the relevancy of search results (‘RankBrain’) and to increase the accuracy and quality of maps in its Street View application. Google claims that it has found TPUs have delivered an order of magnitude better optimised performance per watt for machine learning, giving a three- generation leap of Moore’s law.…

So how is this in any way different to Platform as a Service (PaaS) then? The comparison can be confusing—after all, I would simply deploy my application to a PaaS provider and not worry about servers there either. Serverless architectures though, differ in that they are expected to bring the whole application up and take it back down for every request if necessary. A PaaS infrastructure would never do this and sits as a halfway house between serverless and Infrastructure as a Service architectural patterns. Scaling is seamless in the serverless world too (at least, in the utopia it hints at) whereas a PaaS provider will charge for adding additional scale (which is usually very costly). How can I avoid the overhead of starting up a JVM instance when I…

In brief... A flexible UPS (Uninterruptible Power Supply) that provides multiple power sources, such as batteries and solar power, for critical Raspberry Pi projects. The board attaches to the GPIO and comes with an extensive suite of software tools that enable configuration and management of even the most minute details of the board and the attached sources of power. The Raspberry Pi has been used to power many different projects, including some where it is a mission-critical component. For these dedicated projects it is prudent to have a secondary means of powering the Pi, should the mains supply suffer a sudden interruption or shutdown. An Uninterruptible Power Supply (UPS) provides a temporary solution to powering your Pi. The S.USV HAT is compatible with all versions of Raspberry Pi that come…

Our expert Nate Drake enjoys writing about security and retro tech, when not fixing machines for Apple. [What!? – Ed] His girlfriend has strictly forbidden him to put her Pi up a tree. Back when the Information Superhighway was the nosy old lady who owned the corner shop, Secret Agents would often exchange messages by placing them at a prearranged location under a rock to be collected later by another shadowy figure in trench coat and dark glasses. With the revelations about mass surveillance in recent years, privacy has never been more important and as conventional wisdom seems to be that the only way to secure data is to keep it offline (and under a rock), it was only a matter of time before technology provided us with a way…

You can grant different levels of access to the server to different users if you wish, too. If necessary, you can create a limited user on the server – the simplest way to this is through the User Accounts system settings tool where you then enable the account and set a password – and then log into that account once to set it up. Once done, log off and back into your main account, then add the following line to the end of your sshd_config file: Beneath this line, add any specific rules you wish to employ for that user: eg you could grant a limited user access using a password rather than via an SSH key, eg If your server has multiple users set up, but you wish to…

In addition to using it as a MAAS provisioning server, you can setup an Ubuntu Server install as a traditional server as well. However, deploying and configuring a server is an involved process. The Ubuntu Server-based Zentyal enables you to build complex server installations using a point-and-click interface. You can use a Zentyal installation as a file sharing server as well as a Domain Controller. It can also filter email, scan for viruses, manage printers, deploy VPNs and other core infrastructure services, such as DNS and DHCP. Additionally, you can issue and manage your secure certificates. The distro is available on an installation disc of its own. But you can also install it on top of an existing Ubuntu Server installation. First, add the Zentyal repository with: Next, import its…

Our expert Nick Peers has been playing around with computers for over 30 years, and has been dabbling with Linux for the best part of a decade. Turtl Set up a Turtl server and use an open source alternative to Evernote Note-taking tools such as Evernote can be incredibly useful, but if you’re looking for an open-source alternative then Turtl is shaping up to be a good rival. Turtl (http://turtl.it) is a little tricker to set up, but has all the core functionality you need—it can take notes, bookmark websites and store photos and other documents. You can share notes with others, organise notes into boards (and make them easier to find with tagging and filtering) and access it on a range of devices, from computers (Windows and Mac as…

Our expert Mihalis Tsoukalos (@mactsouk) has an M.Sc. in IT from UCL and a B.Sc. in Mathematics. He’s a DB-admining, software-coding, Unix-using, mathematical machine. You can reach him at www.mtsoukalos.eu. ggplot2 Create stunning graphics using R’s powerful plot creation package We’ll cover ggplot2 in this tutorial, a powerful R package written by Hadley Wickham, that works, thinks and plots in layers and allows you to generate impressive plots. You will learn how to create histograms, bar charts, box plots, density plots, draw points and lines—but most importantly you’ll learn how to customise the output. All presented examples will be developed as R scripts, which means that they can be executed without the need for a graphical environment. This also allows you to run them as cron jobs. Warning: plotting data…

Our expert Neil Mohr has booted more systems than he cares to recall, though there was that one time he booted a PC out of the window, well, he had given it plenty of warning… Libreboot Free your system of binary blobs by using open boot firmware You don’t want to install Libreboot on your perfectly working system, you really don’t. But you’re now thinking “why wouldn’t I want to install Libreboot?” which is akin to someone that’s walked up a slight incline getting to work thinking “why wouldn’t I want to climb K2?” It’s not that climbing K2 is a bad idea – it’s actually a terrible idea – it’s just that for most people it’s entirely unnecessary. Hopefully that’s put off most people but we’ll persevere putting the…

SOAP (Simple Object Access Protocol) A messaging protocol, usually over HTTP, that can expose your services and data with XML. The interface uses a WSDL (Web Services Description Language) to define request and response information, and this interface, again, being XML and is the interface contact, and it’s a mature protocol with lots of tool support to help provide or control an interface. REST (Representational State Transfer) A style of interface that’s usually over HTTP and follows the same verbs to define operations, GET, PUT, POST and DELETE. In a nutshell, REST interfaces should be simple, stateless for scalability (ideal for Play framework). It’s not mandatory to use JSON for representing data but it’s common due to the links with web applications and REST API usage. JSON (JavaScript Object Notation)…

If you use a mutable static global variable then you will need to put it in an unsafe block of code. You mainly use unsafe blocks of code for low level operations that you don’t want to be handled by the strict type system of Rust. The following code, saved as unsafe.rs, illustrates the concept of the unsafe block: Here, the static global mutable variable is MONEY . Being mutable means than its value can change. If you’re using multiple threads, then one thread can read this variable while another one is changing its value which may result in unsafe memory—for this reason you have to use an unsafe block. The good thing is that very little code needs to be unsafe.…

Among the other services that Systemd provides is an alternative to the old syslog daemon, called journald. In may ways this works just the same, any program uses the standard system calls to write entries to the system log, and those are handled by journald. What is different is the way in which journald stores the information, using an indexed binary format rather than plain text files. Apart from using far less disk space (log entries are highly compressible) this makes extracting information from the logs so much easier, eg $ journalctl -d -p err will show all entries since the last reboot ( -b ) with a priority of error or more serious. You can run this after installing new hardware, or a kernel upgrade, to make sure everything…

2016 is turning out to be an exciting year for GNU/Linux distro releases. First we had the release of the class-leading Ubuntu 16.04 LTS, and from that a host of spin-off distros have been slowly appearing. The next most popular release is Linux Mint 18. Based on that LTS Ubuntu release, this next big Mint release brings with it a host of huge changes to the popular distro. To celebrate Linux Mint 18 being released, we’re running a comprehensive feature on what’s new and exciting in this release of Mint, from its all-new X-Apps to the new improved Cinnamon desktop that so many know and love. We run you through the install process, look at how Mint is built, examine where it went wrong with its security in the past,…

Another month and another round of great news for Linux gamers. At this year’s E3 gaming convention Dell announced new Steam Machines in its gaming enthusiast Alienware range. These console-like PCs can be plugged into TVs in the front room and run the Debian-based SteamOS operating system. With the latest Intel Skylake CPUs and Nvidia GTX 960 graphics cards, these Steam Machines will play the latest blockbuster games with ease, and an increasing number of these games are being ported over to Linux thanks to Valve. AMD also took to the stage to announce that its new Radeon RX 470 and Radeon RX 460 graphics cards, which are based on its eagerly anticipated Polaris architecture, will ship with both open and closed source Linux drivers. Nvidia has also offered Linux…

kDe neon 5.7 Fresh off the heels of the newly-released KDE Plasma Desktop 5.7 comes KDE neon 5.7, a Kubuntubased distro that specialises in fast development that allows it to take advantage of a cutting-edge desktop stack, which includes the latest version of Plasma. As well as KDE Plasma 5.7,itfeatures Qt 5.7,aswellas improved Wayland integration,a new system tray and a new task manager. To find out more visit the release announcement at http://bit.ly/KDEPlasma5_7. ZenwALk LinuX 8.0 The latest major version of the Slackware-based distro, Zenwalk Linux 8.0, has been released after what it calls a “long development blackout”. It comes with updates to essential programs (such as LibreOffice 5.1.3, Chromium 51, MPlayer 1.3 and FFmpeg 3.0.1), as well as the Linux kernel 4.4.14 and the Xfce 4.12.1 desktop environment. The…

North West Makefest buzzing Liverpool Makefest 2016 doubles attendance. Liverpool Makefest was the surprise hit of 2015 and generated quite a buzz around the North West of England. In 2015 they saw 1,800 people in attendance, so could they beat that in 2016? The answer was a resounding “Yes”, with attendance doubling to about 4,000 people attending the free one-day event in Liverpool’s Central Library. For 2016 the number of stalls doubled, offering plenty of interesting project ideas for makers of all ages. At this year’s event we saw makers large and small. Local astronomy groups demonstrated how they are using Raspberry Pi and 3D printers to augment their hobby. Children demonstrated their Raspberry Pi and Arduino projects and offered hands-on sessions for interested parties. We also saw the low-cost…

While the primary task of the applications is to create screencasts, many of them offer additional features and functionality. The visible functions are also assisted by back-end functionality that kicks in only under special circumstances, eg, the lightweight Kazam works wonderfully if it’s installed on older computers or inside virtual machines. In addition to screencasts, Kazam can also capture screenshots as well. You can also use SSR on older machines as the application can automatically reduce the framerate depending on the available processing power. You can also use the app to preview the recording area which can be a great time saver for certain people. ScreenStudio’s biggest add-on is its ability to stream to other websites and create a customised interface for the screencast. VokoScreen includes the ability to playback…

1. Boot the LXFDVD Ideally, starting your computer with the DVD in the drive should bring up the stylish menu pictured below. Unfortunately there’s a lot that can go wrong here, you’ll need to make sure Secure Boot is switched off and also that your machine will boot from the optical drive before other devices that have operating systems on them. There are some pointers at https://help.ubuntu.com/community/BootFromCD. 2. Choose your poison We’ve provided the two most popular versions, Cinnamon and Mate on the disc. Mate is more suited to older hardware (it’s also your only choice if you have a 32-bit CPU), but it will work just fine on newer machines. It’s ideal if you yearn for the simpler days of Gnome 2. Choose your version and press ‘Enter’. Start…

Before you start double check your drone and make sure that everything is in place and all wires are secure and taped to the frame. As this will be your first attempt at flying the drone remove the propellers so if anything does go wrong the drone will at least stay exactly where it is rather than bouncing round the room poking eyes out and smashing ornaments. Start by switching on the controller making sure that all switches are in the up position and the throttle is in the lower position. Now connect the battery to the power module and you should hear a beep as the board starts loading which can take up to a minute to complete. Another beep will highlight the end of the boot sequence and…

“Those who are keen on home recording will appreciate the guitar overdrive pedal effect.” Ekois a sound wave editor that recently hit version 5.20, yet there are very few people that have ever heard of this small but very useful application. We think that Eko has received very little attention considering what it manages to achieve as a one-man project, but it’s worth taking a closer look at it. Eko may look minimalistic and sometimes resemble simple wave editors, such as KWave, but there are many features with some extras that you will not find even in Audacity. It’s best to start exploring Eko from its Functions menu, which includes silence and noise generators, fade in/fade out feature, wave normaliser and offset editor etc. By default, Eko opens the extra…

Since the Raspberry Pi was released in 2012 it has opened up a whole new world of opportunities for children to learn about computer science. At last computing is affordable for people of all ages, and children stand a much better chance of learning computer science and programming. However the mention of computer science for some teachers can be daunting – they don’t feel confident enough with their own coding skills, never mind having to teach it. Some children also feel it’s too hard, but in my opinion we are all on this journey together, and that got me thinking about how to try and make it less of a barrier. So I have developed a new Python module that can aid this problem. EduPython is a companion for the…

Our expert Les Pounder works with the Raspberry Pi Foundation as one of its Picademy trainers. He hacks all manner of projects to life and blogs about them http://bigl.es. The new Raspberry Pi camera and the latest version of the Pi Zero with camera interface offer a compact HD recording platform and with it we can easily build our own ‘lifecam’ that can be worn slug about our person while out and about—and that’s precisely what we’re going to build in this month’s tutorial! For this project you will need a Raspberry Pi Zero 1.3, a Pi Camera, the latest release of Raspbian, one LED, one 220 ohm resistor (RED-RED-BROWN-GOLD) and one momentary switch/pushbutton. All of the code for this project can be downloaded from https://github.com/lesp/LXF214-PiZero-Lifecam/archive/master.zip. With the Raspberry Pi…

The PirateBox set up is ridiculously simple but there may be a few tweaks you wish to make. Chief among these is that you may wish to change the name of your access point from ‘Pirate Box : Share Freely’ to something less conspicuous. You can do this fairly easily by accessing the box via ssh then entering the command vi /etc/config/wireless which will allow you to change both the wireless channel and the network name. Be sure to type wq when you are done to quit and save any changes. By default the PirateBox’s network name also has no encryption, which is a must if you’re going to be accessing sensitive data without any snooping on your connection. Enter the command vi /opt/piratebox/conf/hostapd.conf and change the following options as…

Our expert Nick Peers has been using SSH to maintain his Pi-powered Plex media server. Now the thought of installing a few X Window apps for remote access purposes takes on a whole new appeal. Terminal Xxxx Learn how to access X Window apps remotely using SSH One of the great things about the Terminal is that it allows you to access and control another PC remotely using SSH. This is particularly useful if you have a PC set up as a dedicated server, one that’s running headless (so no attached monitor or input devices), as it enables you to tuck it away somewhere while retaining easy access to it from another computer. Systems running Ubuntu typically use OpenSSH to manage command-line connections—this basically gives you access from the Terminal…

Our expert Mayank Sharma has configured so many of his devices for anonymous use lately that he’s confused about who is anymore. It’s all gone a bit A Scanner Darkly. Ubuntu Ubuntu Server Server Create a MAAS setup and add Juju for deploying software Distributing software and infrastructure as services has established itself in the mainstream with solutions such as Google Docs and Amazon Web Services. There’s also Canonical’s Metal as a Service (MAAS) that’s designed to simplify the provisioning of individual server nodes in a cluster. In many ways, MAAS is similar to Infrastructure as a Service (IaaS) in that it’s a mechanism for provisioning a new machine. However, the key difference between the two is that while IaaS usually deals with virtual machines, MAAS is designed to provision…

It’s fair to say Turtl is still in relatively early stages of its development, particularly as far as the server is concerned. It’s annoying having to start everything up manually, leaving a Terminal window open to run the Turtl API—you then need to manually hit Ctrl+C to stop Turtl. There are also various bugs to contend with – the TIME-FORMATTER error was worked around by removing the offending line from the start.lisp file under common-lisp. We also ran into problems logging into our accounts on different platforms—the server threw up a CL-HASH-UTIL:HGET error, which has been reported at Bounty Source. It’s worth persevering with though— we were able to access Turtl remotely over the internet and store file attachments on the server, which means it’s doing the basics right, even…

The main difference between ggplot2 and other R packages with similar functionality is that ggplot2 is based on the principles of grammar. The underlying grammar of ggplot2 is based on the book The Grammar of Graphics written by Leland Wilkinson along with statisticians, computer scientists, geographers, researchers and others interested in visualising data in mind. According to the book, a graphic is a physical representation of a graph that has various aesthetic attributes, such as colour and size. What the grammar does is tell you that a plot is a mapping from data to aesthetic properties of geometric objects. Therefore, it contains two main kinds of rules: mathematical and aesthetic. The mathematical rules are used for generating graphs and the aesthetic rules are used when drawing the graphs. Although it’s…

Our expert Bernard Jason has been developing applications on Unix since the early ‘90s in C, Java and Scala. There is often a need to expose functionality in a company for consumers whether internal or external. This kind of thing had been achieved, this century at least, using SOAP but now there’s REST, too. There are pros and cons to both methods. SOAP is very specific and is well defined and tends to cause fewer surprises due to its maturity. However, it’s also heavy to define and even to implement, but the end product, if done well, leaves less room for mistakes or discussion. REST is newer, and more suited to the web, and tends to be based around JSON request and responses, but can be XML or other data…

Our expert Mihalis Tsoukalos (@mactsouk) has an M.Sc. in IT from UCL and a B.Sc. in Mathematics. He’s a DB-admining, software-coding, Unix-using, mathematical machine. You can reach him at www.mtsoukalos.eu. This month we’ll cover concurrent programming in Rust. Concurrency and threads are first class citizens in Rust and you should use concurrent techniques as a first resort when solving a problem. Bear in mind, however, that usually there’s more than one way to solve a problem concurrently! So, when developing concurrent applications think about their design and consider that the most important property of a concurrent application is making functions as autonomous and independent as possible so that they can be executed in parallel. This tutorial uses the current stable release of Rust which is 1.9. The next stable release…

1 Much troubled protocol Q I’m a complete newbie to Linux. After my laptop that was running Windows 10 (upgraded from Windows 7) completely failed on me, I decided to try out Linux, so downloaded Linux Mint 17.2 on my desktop PC and installed this on my laptop. Installation was very simple and within half an hour my laptop had been given a new lease of life. I’m enjoying it so far but have hit a couple of stumbling blocks. One being I just cannot get Linux Mint to recognise my Android phone (it’s an HTC One M8). I’ve enabled USB debugging on the phone and also installed mtptools, but I get the same error every time: A big part of what I use the laptop for is managing my…

Where is it stored? Q I have created a symbolic link (symlink) from /usr/share/<dir> to /home/<user>/. The /usr/share tree is on sda and /home is on sdb. If I store a file in /usr/share/<dir>—is that file physically stored on sda or sdb? And if it’s on sda, how do I get it to sdb? I want it to survive a re-install. Yes, I can copy it over by hand, but there’s a lot of files/packages/ directories to copy, so why not be lazy? Dutch_Master A A symbolic link is simply a pointer to a different location, so when you write to /home/user/dir you are redirected to /usr/share/dir. You can test this for yourself by using $ df -h /usr /home to see how much space is available on each filesystem,…

You may have noticed fewer 32-bit distros on our DVDs. Many of the smaller distro projects have dropped support for it. Testing on two separate architectures has become more than many of them can manage given the dwindling 32-bit user base. Now the larger distros are following suit. The current Ubuntu 16.04 desktop edition is the last that will be available with both 32-bit and 64-bit installers—16.10 will be 64-bit only. Other distros, such as OpenSUSE and even Debian are going down the same road. All is not lost for 32-bit users, you’ll still be able to install Ubuntu 32-bit from a netinstall disc and add the desktop packages, but there will be no more 32-bit live disc and easy installer. Ubuntu 16.04 is an LTS release, so packages will…

“Building i386 images is not ‘free’, it costs build, QA and validation time.” t he European Union, David Cameron, almost all of the Labour Shadow cabinet… all are going out of fashion or disappearing completely, but will 32-bit distributions (distros) follow suit? Painfully forced UK politics comparisons aside, the fate of Linux distros that support 32-bit hardware is once more up for debate, with Ubuntu’s Dimitri John Ledkov suggesting in a mailing list in June (http://bit.ly/32BitDebate) that Canonical should consider dropping support for 32-bit distros in the near future. He did so pointing out that 32-bit hardware is becoming ever more uncommon, with third parties dropping support, and that “Building i386 images is not ‘for free’, it comes at the cost of utilizing our build farm, QA and validation time……

After six years it looks like Sony is finally going to pay PlayStation 3 owners, after it removed the ability to install Linux in March 2010, which annoyed many people who’d already bought the console only to find a much trumpeted feature had been taken away from them. While the deal is still being thrashed out, it looks like Sony will pay $55 to any PS3 owner who had a console manufactured between November 2006 and September 2009 and can prove they lost the use of Linux. If you don’t have proof you may still be able to claim $9. You should get an email from Sony (if you signed up for the PlayStation network) detailing how to claim. Security researcher Dymtro “Cr4sh” Oleksiuk has found another critical vulnerability in…

RAID it You know, you’ve been posting some darned useful articles recently. Back in LXF206 there was one on RAID [Tutorials, p76]. I remember messing with that back with Ubuntu 10.04, with the objective of building a high-reliability PC. I even got to scripting the RAID build, to make it easier and faster. Then in LXF207 you had a review of Fedora Security Lab [p20], and put it on the cover-disk of LXF208. So far, so brilliant. Next step? How about an article on how to install Linux on a RAID set? Back with Ubuntu 10.04, Canonical produced the ‘Alternate-build’ CD, with a simple text-based installer to make room for the RAID additions, but not any more. An article on how to augment and process a standard-release would be ooh-so-helpful.…

Oggcamp 2016 Sadly, time has beaten the new organising team for Oggcamp, which will return in 2017. This will be the first “break” in the popular Oggcamp event since it was started in 2009. The team are working to find suitable locations across the UK, with a number of venues on offer. Stay tuned! http://oggcamp.org PHP North West 2016 PHP has been powering the web for many years and is the backbone to the Wordpress platform. But in an ever changing world, with the PHP framework ever evolving, developers need to keep their skills sharp, and there is no better place than PHPNW. Taking place in Manchester from September 30 until October 2, this event offers talks, workshops and a hackathon. Plenty of opportunities to keep your PHP skills sharp…

There aren’t many Linux screencasting apps that are still actively developed besides the ones that are covered in this Roundup. RecordItNow and RecordMyDesktopare good examples of apps that haven’t been updated in over half a decade but still work well. If you don’t want the fancy features and conveniences that come with the dedicated screencasters we’ve covered, you can also use VLC and the console-based FFmpeg to make screencasts. In VLC, head to Media > Open Capture Device and select Desktop from the pull-down menu. To use FFmpeg to record your screen, fire up the terminal and enter: You can also use the Open Broadcaster Software which is designed for live streaming the desktop. However, you can also save the screencast to a local file instead of streaming it over…

A standard install will create two partitions (three on UEFI machines): one for the OS and a swap partition. This is a perfectly reasonable set up, but some people prefer to tweak things a little, eg it’s common to have a separate /home partition so that in the event that something terrible happens the OS partition can be wiped and reinstalled, without touching any user files or settings. Be aware that if you install a different distro with this trick, then the settings saved in the /home partition may not be valid and could cause problems. A separate home partition is straightforward to do from the installer, just choose the ‘Something else’ option. The current disk layout will be displayed. Assuming we are nixing everything on the drive, we can…

“The latest open source drones are challenging more expensive rivals with advanced features.” WHAT YOU NEED Raspberry Pi Zero Erle Robotics PXF Mini Erle Robotics PXF Mini Power Module HobbyKing Spec FPV250 100mm male to male servo cable FlySky-i6 controller Edimax AC EW-7811UAC RC XT-60 connectors Quadcopters (drones) used to take hours of practice to master as even the simplest manoeuvres, such as takeoff and landing, could prove difficult. Learning to fly one took time and ultimately determination and before you even took to the skies there was the small matter of building one. Now that there’s a good selection of pre-built and programmed drones on the market, you can go into major High Street retailers and buy one directly off the shelf. Drones such as the 3DR SOLO, Parrot…

This week I was reading an article that mentioned the Cathedral and the Bazaar, the essay (and later, book that’s often included on the Linux Format cover disk) is now 19 years olditfamously influenced Netscape into releasing the code for its web browser. I’m sadly all too aware of my own ageing, especially after a visit to the gym, but it was a solid reminder that a significant period of time has passed outside my internal monologue gave me pause for thought… Or what might possibly be termed a ‘mid career crisis’. Put simply, I don’t feel as though I’ve done enough when it comes to open source, in both terms of producing projects of my own or contributing to others. I mean, not everyone can be a Torvalds or…

The ‘Baader-Meinhof Phenomenon’ is the name given to situation where a person comes across a piece of information for the first time and they suddenly begin to see it again elsewhere repeatedly. This is certainly the case for me and the ‘twelve-factor app’, which has cropped up for me all over the place since hearing about it just this month (while doing the research for this article). Its the name of a methodology for building software as a service applications which meet a certain set of criteria. This isn’t new (I’m just late to the party), it was developed by one of the co-founders of the popular platform as a service company, Heroku, and the influence of the companies offering will be clear to anyone who’s used it. Despite this,…

For this project we wanted to create a portable device that could be easily worn with little discomfort. So we elected to use the Raspberry Pi Zero with the new Pi camera. We enclosed the project in a project box, which can be bought from various electronics retailers. But our biggest issue was powering the project. Yes, we could use a standard USB powerbank, but that would be too large. Luckily, we found a credit-card sized battery pack from eBay. This Lithium Polymer (LiPo) battery provides plenty of power and is relatively light, but we had to be careful as LiPo batteries are sensitive and can be dangerous is punctured or damaged We carefully removed the battery and its protection driver board from the case. We soldered wires from the…

To use SSH for accessing your Piratebox, open your terminal on your computer and type the following command: ssh alarm@alarmpi . The system will ask you for the password. The default password is alarm. You will certainly want to change this via the passwd command to keep your Piratebox safe. If the ssh command times out, the most likely reason is that you need to give your Pi a few more minutes to boot up. If time fails to heal this particular wound, then your Wi-Fi adaptor may not be supported. Feel free to visit the Piratebox website for a list of mods or to ask for further help on the forum. Assuming all went to plan, if you are planning on hosting a large amount of images etc, this…

SSH servers are particularly vulnerable to password brute-force attack. Even if you have what you consider a reasonably strong password in place, it’s worth considering disabling password authentication in favour of SSH keys. Start by generating the required public and private SSH keys on your client: Hit Enter to accept the default location for the file. When prompted, a passphrase gives you greater security, but you can skip this by simply hitting Enter. Once created, you need to transfer this key to your host: (Note, if you’ve changed the port number for TCP communications you’ll need to specify this,eg ssh-copy-id nick@ubuntuvm -p 100 ) Once done, type the following to log in: Specify your passphrase if you set it for a more secure connection. You can then disable insecure connections…

Switch to the Nodes tab in the administration interface and use the ‘Add Hardware’ button to add a new machine. The form for defining a new machine is fairly straightforward. You’ll be asked to choose a name for the machine as well as the domain, architecture and its MAC address. The most important information on this page is selecting the right power type. A set up where you’d want to use MAAS will typically have a IP-controlled power distribution unit (PDU) which you can remotely power on the connected machines. The MAAS server supports a large number of PDUs that you can select using the Power type pull-down menu. Depending on the PDU, you’ll be asked for more information to enable the MAAS Server to communicate with it. Once you’ve…

The most important part of the visualisation process is the data that’s used! For our examples the format of the data set is the following table: The data file contains data for 55 server machines. The first column is the machine name, the second column is the amount of RAM in GigaBytes, the third column says whether a machine has gone to service or not, the fourth column is the total number of physical disks a machine has, the fifth column holds the size of the SSD disk of the machine in GigaBytes and the last column is the uptime of the machine in days, that’s right, total days uptime! Loading the data file into R can be easily done with the help of the following command that is used…

The Libreboot process requires that all binary blobs and proprietary software be removed or disabled from the processor and chipset. The upshot of this is that they have to be flashed by an external device, in our case a Raspberry Pi, but Libreboot offers a Beagle Board Black guide, too. Most devices use a Small Outline Integrated Circuit or SOIC. The X200, eg, has a SOIC-16 as it has 16 pins. A dedicated tool, the Pomona 5252 provides a secure clip with jumper pins, making it easy to connect to your flashing device. Other models will vary, eg, the X200S or Table version uses a surface mount chip and requires soldering, not recommend.…

Swagger is a specification for documentation of REST APIs. It takes out some of the guess work, as it can define the request, response information as well as provide some useful text description along with the ability to try it out. There is a HTML user interface for Swagger that when pointed at the appropriate data can display the information about your APIs. This appropriate data is a JSON payload that provides all the information about your application. The JSON document is swagger.json. The interface also provides the ability to experiment with the APIs with ‘Try it out!’ buttons. This can help developers experiment with the APIs or test sample requests. How you provide the functionality behind this button is the trick. You can do any of the following: Provide…

It is a common misconception that concurrency and parallelism are the same thing. As you will see, concurrency is actually better! Parallelism is the simultaneous execution of multiple things whereas concurrency is a composition of independently executing things. In other words, concurrency is about structuring a thing in a way that it can be executed in parallel. So, the goal of concurrency is not parallelism but creating things with an independent and good structure. It is only when you manage to make two or more things that you build in a concurrent way to execute simultaneously that you have parallelism. What is being executed is usually a function— this isn’t compulsory but is very helpful because functions, when implemented correctly, allow for a somehow autonomous execution. In concurrency, adding more…

Linux Format is proud to produce the biggest and best magazine that we can. A rough word count of LXF193 showed it had 55,242 words. That’s a few thousand more than Animal Farm and Kafka’s The Metamorphosis combined, but with way more Linux, coding and free software (but hopefully less bugs). That’s as much as the competition, and as for the best, well… that’s a subjective claim, but we do sell way more copies than any other Linux mag in the UK. As we like giving things to our readers, each issue the Star Question will win a copy or two of our amazing Guru Guides or Made Simple books – discover the full range at: http://bit.ly/LXFspecials. For a chance to win, email a question to lxf.answers@futurenet.com, or post it…

GPG What is GPG? GPG, or GnuPG, is Gnu Privacy Guard, which is an open source implementation of the PGP (Pretty Good Privacy) encryption system. So it’s an encryption program. There are plenty of those, what’s so special about this one? It uses public-key cryptography. What’s that then and why does it matter? Traditional cryptography uses a key to encrypt and decrypt data, it’s often called symmetric cryptography because of that. The problem is that once you encrypt a message with the key, you have to get the key to the recipient, securely, in order for them to decrypt the message. Anyone who gets hold of that key can also read the message. Yet if you had a secure means of sending the key without fear of interception, you could…