Table of contents for May 2016 in Linux Format

Jonni Bidwell The greatest thing I’ve ever built was my first home – called Red House – with my wife in Kent. I think producing a series of English-language translations of Icelandic Sagas is a close second or possibly my decorative arts firm. Of course, this was in my past life as William Morris. Neil Bothwick Apart from building a 13 desktop distro, including a fair bit of initrd jiggery-pokery to get it all working together? I built my own house, from initial design right through all the various stages of construction. I did almost everything myself… What do you mean, ‘Minecraftdoesn’t count’? Matthew Hanson The greatest thing I’ve ever built is probably the gaming PC I’m using right now, which is packed with obscene amounts of power including two…

Microsoft hasn’t been much of a friend to open source in the past (many of us will find it hard to forget former CEO Steve Ballmer describing Linux as “a cancer that attaches itself in an intellectual property sense to everything it touches ”), but recently the Redmond company has been seen to embrace open source projects. Just last month Microsoft attended the EclipseCon event and joined the Eclipse Foundation as a Solutions Member, allowing a greater sharing of tools (such as the Azure Toolkit for Eclipse and Java SDK for Azure). Perhaps most remarkably, Microsoft is open-sourcing the Team Explorer Everywhere Plugin for Eclipse on GitHub (http://bit.ly/TeamExplorerEverywhere), with the express hope that the Eclipse community will help them develop it. Microsoft also announced that SQL Server will soon be…

“It’s Google Summer of Code time again, which brings wonderful opportunities for students to apply for real-world experience in large and interesting free software code-bases. Curiously, the most valuable thing I’ve taught the many students – and employees – I’ve mentored at Collabora – particularly the most capable students – is nothing about software but an understanding of their own limits. The reality of all giantic code-bases from LibreOfficeto Chromeor the Linux Kernel, is that you cannot hold much of the complexity associated with your problem in your head. That is a huge challenge to those students who have previously designed, written and fully understood only small, new programs. Inevitably they come up against a brick wall with a mental loop trying to code-read and model more things than will…

With reference to Nathan Hawthorne’s letter [Mailserver, p11, LXF207] about lack of Slackware info in the magazine. I suppose part of the problem is Slackware’s seeming ‘don’t release until it’s finished’ policy. The last release you included was Slackware 14.0. Since then they have gone to 14.1, but this is two years old now. However, the slackware-current at slackware.org.uk is ‘alive and kicking. I’ve just downloaded the latest offerings which seem to be dated up to 17 Jan 2016. Malcolm Lang, via email There was a bit of discussion on the validity of using Distrowatch.com to represent usage on Slackware’s wikipedia talk page. Unfortunately, Distrowatch best represents how popular distros are for newer users. Many seasoned users never visit that site. However, to point out that Slackware is still very…

Raspberry Jam Berlin We recently spoke to James Mitchell at the Raspberry Pi birthday party (see p43). James has been running the only Raspberry Jam in Germany since September 2014 and has enjoyed great success with a series of workshops and talks based around the Raspberry Pi. Children are welcome too, so grab the kids and settle down for an afternoon of making and fun! You can read more about Raspberry Jam Berlin at http://raspberryjamberlin.de Linux Presentation Day 2016 This day is your LUGs chance to show off the best of Linux to the general public. The event is set for April 30 and it would be awesome to see and hear from LUGs that are taking part in this worldwide event. Take Linux to the library/community centre and show…

While documentation and avenues of support are important for all kinds of software, they’re crucial for network-deployable software like collaborative editors. Gobby, the easiest to install software of the lot, has a skeletal wiki on GitHub, which is just enough information to get started. Its saving grace are the tons of tutorials and howtos available on the wider internet. Then there’s Etherpadwhich has loads of documentation on the website, including a wiki and a blog. There’s also an online demo and a list of public instances where you can play around with the software before deploying it yourself. Firepadalso has enough documentation to help users integrate it into their existing infrastructure. The documentation also covers the app’s API to help users create their own Firepad instance, and there’s also plenty…

Irrespective of how you want to use your system, there’s one task that’s performed universally by everyone and that’s managing files. To assist you with the process, you can choose a file manager from one of the excellent available standalone choices. While you are probably familiar with Gnome’s Nautilus (now known simply as Files), KDE’s Dolphin and Xfce’s Thunar, there are several others worth viewing including PCManFM, Xfe and EmelFM2. PCManFM has a clean and uncluttered interface and is used as the default file manager for the LXDE desktop. The file manager enables you to open directories in new tabs or new windows and can also be used in the two-pane mode much like traditional file managers. PCManFM features a side pane and status bar, both of which can optionally…

‘Extremely severe’ DNS bug found in glibc There’s no catchy codename yet but the bug in glibc leaves many applications and devices vulnerable. Linux administrators were – once again – sent scrambling for patches when a flaw in glibc (described by the BBC as a “Mega bug”) was revealed by Google in February. The problem (assigned reference CVE-2015-7547) which it transpired had been introduced way back in 2008, affects all releases of glibc from 2.9 upwards. The Google team discovered the issue only to find that the glibc team had been made aware of it in 2015 and that a team from Red Hat had quietly been assessing the impact in parallel to its own efforts. The buffer overflow at the heart of the problem is created thanks to a…

Prometheusgreatly encourages the addition of instrumentation to services by using the many client libraries available. In the brave new world of DevOps, operational and development staff work closely together of course (Hopefully—if they’re not there are problems to overcome). These generally work by adding an HTTP endpoint which Prometheuscan scrape as per the example we have this month with the node-exporter container. There are examples for several of the ‘main’ languages available: Go, Java, Python, Ruby… and even Bash! In my experience, these are reasonably easy to work with. However for third-party services, such as HAProxy, using these is unlikely to be possible. Never fear—third-party exporters are here. Node-exporter is one such program, but there are many others (with more being added each month). These handy programs bring HTTP endpoints…

Our expert Les Pounder works with the Raspberry Pi Foundation to deliver training for teachers across the UK. Les blogs at http://bigl.es about robots, hacking and all things makery. The latest Raspberry Pi now comes with it’s own built-in Wi-Fi and Bluetooth 4.1/Low Energy (LE) support, thanks entirely to the Broadcom BCM43438 chip. In order to use these features you must ensure that your version of Raspbian is up to date and with it apply a little bit of terminal magic. Ensuring that your Raspberry Pi is connected to the internet via an Ethernet cable, open a new terminal and type the following: This step may take some time depending on the amount of updates required and the speed of your internet connection. Once completed stay in the terminal, we…

All the code that you need to run this project is available online (https://github.com/lesp/R2P10), but we’re going to quickly look at how the key parts of the tutorial work together. To start with we import the functions we need. The first import covers the library that’s required for Explorer pHAT as this will enable our project to interface and use the board. The next two imports are used to import one aspect of each library. To test our code we use a loop that will run forever, while True . This loop will run the code to set output as 1 for our Explorer pHAT so it blinks every half a second. We now create a variable; a container that can store any type of data—in this case we’re using…

Now you’re starting to flex your muscles in Terminal, how about expanding your knowledge by instructing it to display information about a random command each time you open it? To do this, you need to edit a file, so open the Terminal and type the following: This opens the file in the nanotext editor. Use the cursor keys to scroll down to the bottom of the file, then add the following line to it: Press Ctrl+o to save the file (just hit Enter to overwrite it), then Ctrl+x to exit nano. Now close the Terminal window and open a new one to get a brief description of a command. Just type the following, with the actual command listed for a longer description: <command> --help .…

Our expert Neil Bothwick has a great deal of experience with booting up, as he has a computer in every room, but not as much with rebooting since he made the switch to Linux. User management Learn how to control all the users on your Linux distribution Linux is a multi-user operating system. If you are the only user of your computer you may not think that applies to you, but, as you’re about to discover, it does. In this tutorial we will explain why this is important, how it all works and how you can use it to your advantage. Every Linux desktop system has at least two users: there‘s the user you created during installation, the one you log in as and the superuser, which is often called…

From here you may be wondering what other distros are available from Fedora. As we mentioned at the beginning of the tutorial, there are many other labs provided by Fedora for specific uses, eg for educational purposes, there’s the ‘Sugar On A Stick’ (SOAS) version of the Fedora distro, which provides a child-friendly graphical environment designed to be portable and live-bootable. There are also labs aimed at Linux gaming, design, and scientific applications. The Fedora Games Lab comes bundled with a host of free Linux games form many different genres, while the Fedora Design Suite comes with various multimedia design tools to make your art forms come to life. Fedora Scientific Lab provides different tools for calculations, plotting and analysing data, such as GNU Octave and gnuplot (see Tutorials, p80).…

The source code for gnuplotincludes a large number of demos. The code for these examples is present in a directory called demo. We’d strongly suggest using the example as learning tools as this will help you understand available options and then you can modify the code for your specific purpose. The demo directory includes files covering the following major areas: Basic 2D and 3D plots including lines, bars, circles, stacked graphs, text manipulation. 3D surface plots, polar, cylindrical and spherical plots. Examples that use math and statistical functions and curve fitting. Manipulating binary data and image data. Formatting graphs using text options, page layout options, different styles for lines, arrows, fills, transparency, and animation. You’ll find a sample in many areas, which should help you save time when you start…

Here’s how to read and process the command line arguments in Rust. The full Rust code can be found in argV.rs, where you’ll see that you need to use the std::env package and the env::args() method to read the arguments. Note: argV.rs performs no error checking (we’ll be covering error checking in Rust in the next part). Should you wish to use the command line arguments as numbers, you can use the following Rust code which shows how to properly convert a string to an integer: You’ll learn more about the .unwrap() method in the next issue, but you can see (above) a handy use of the skip() method to skip the first command line argument, which is the name of the executable. If you enter a non-numerical value as…

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You often talk about installing software from a repository (repos), what is that? A repos is a collection of software packages created by the distro and available through a standard interface, either a graphical application or a command line program, but usually both. Why go to all that work for each distro when the writers of the software could do it? Most Linux software is available as source code and needs to be compiled before it can be used. A repos contains compiled (or binary) packages, ready to install. So it saves me time, but does it have other advantages? Because all the packages are built by the distro, they can make sure everything is compatible with everything else that has been included, and that you have a harmonious collection…

In this issue – cue music – Linux users are doing it for themselves. We’re not happy with how our desktops are being built, so we’re going to make one ourselves. It seems a long-standing open source tradition that if you don’t like what you’re given, you can just fork it and do the job yourself. While we’re not going to develop a desktop environment from scratch, we are going to take out our digital digger and look at building our ideal desktop ourselves. No matter if you love Gnome or KDE, we take a look at how you can use these as the basis of your ideal Linux desktop. But perhaps that’s not going far enough for you? For those real minimalists we’re also going to go one step…

e nterpriseLibre packages open-source software into a powerful virtual organisation. The virtual package comes with 28 of the leading open-source applications pre-installed, and it can be launched from almost any internet-connected computer, regardless of its host operating system. Through the online interface you can easily add other users who can then log on to their very own virtual desktop. Impressively, a user’s email account will already be configured to the email application, and they will only need one password to securely access all of the services in EnterpriseLibre, so users won’t need to remember a huge list of different passwords. All apps come ready installed and configured, so configuration – and technical support – is kept to a minimum. By hosting your entire enterprise on the cloud it also means…

Kaos 2016.03 The latest version of the Plasma desktop-toting distro is now available to download. The desktop includes Frameworks 5.20.0, Plasma 5.5.5 and KDE Applications 15.12.2, along with a number of improvements to make the Plasma desktop more enjoyable to use. A working GUI for user management is now here – and long overdue – and a rewritten partitioning feature, based on KPMcore, is included that makes partitioning even easier. For the full release notes head to https://kaosx.us/kaos-2016-03. CLearos 7.2.0 ClearOS 7.2.0 has just been released, and the latest stable version of the CentOS-based distro which is designed for servers. This second release in the ClearOS 7 series is mainly maintenance one and fixes a number of bugs. However, it also brings support for LVM caching and improved virtual machine…

OggCamp cancelled Seeks new blood to help organise the event. Since 2009 OggCamp has brought together Linux users, podcasters, musicians, hackers, makers, crafters and many more subcultures of the maker movement. The event started life as a collaboration between the Ubuntu UK Podcast and Linux Outlaws. Over the years OggCamp has had its fair share of successes, including being the only place to try and buy Raspberry Pi computers in mid-2012, when demand was outstripping supply. For five years, our very own Les Pounder was part of the organising team, but in 2015 he had to call time on his involvement. Unfortunately, Dan Lynch, of Linux Outlaws, has been ruled out as an organiser for the 2016 event due to hospital treatment. Other members of the original team are also…

One open source application that we didn’t have space to include in the Roundup is OnlyOffice. The enterprise edition of this, which is meant to be deployed on your servers, is free for up to five active users. There’s also a subscription-based online version. If you aren’t averse to hosted service, there’s Meetingwords which is powered by Etherpadand shares its interface. The service is free to use for up to 32 participants although they do host a tip jar for accepting donations. Meetingwords will delete pads that have not been used for more than a week. CollabEdit is another online service which is free to use but is proprietary and is primarily meant for code collaboration. The service allows members to chat with each other and keeps documents for 60…

“A feature of the desktop is its ability to enable remote access and file sharing with a click.” Gnome 3 has come a long way since the early releases that riled long-term users and helped boost desktops newcomers Cinnamon and Mate. Over the years and subsequent releases, Gnome’s our-way-or-the-highway attitude has given way to a new level of desktop malleability and offers interesting tweakable options for users who’d like to adapt their desktop. Gnome’s System Settings is still pretty basic in comparison to the control panels of some of its peers like KDE, but it still packs quite a punch. One of the good things about Gnome 3 is its unified search in the Activities Overview that looks to match the search string to relevant apps, settings as well as…

Our expert Alastair Jennings started working with Lingo and Actionscript back in the mid ‘90s and has thankfully left both behind. Today he works with software and hardware for various projects including photographic rigs, 3D printers and robot dogs. BBC micro:bit Discover the basics of coding to create a simple memory game The BBC micro:bit has finally dropped into the hands of many Year 7 students across the country and there’s already a wealth of tutorials and resources out there to help both students and teachers get started. Those projects are great at the basics, introducing you to what the micro:bit is, the coding languages that you can use, and how to connect physical inputs and outputs such as LEDs and motors to it. Once coded and wired up there’s…

My first taste of computing was with the 8-bit based British home computing revolution of the early eighties. Requesting books like The Commodore 64 Programmer’s Reference Guide for Christmas, I ended up delving into assembly language and trying out the various tricks to shave a CPU cycle or a byte of memory here and there for demos. I believe my love of Unix/Linux can be traced directly back to those days (as can my failure to ever get a dance at the school disco). I was sold on the idea of small programs that could be made to work together to perform powerful tasks and finding out the various tricks that would make programs more efficient and the system run more smoothly. Small is cool It’s a stretch to say…

Time for a confession. Up until recently, I hadn’t heard of or noticed Alpine Linux (http://alpinelinux.org). It had completely slipped me by. However, colleagues began raving to me about it for use in Dockerimages due to its simplistic nature and accordingly small size. Then came an announcement from Docker itself that the creator of Alpine, Natanael Copa, had been hired by them, and that it was in the process of moving away from Ubuntu and adopting Alpine for use in its official images. So what gives? Alpine is built around musl libc (http://musl-libc.org) and Busybox. (Do all small distros use Busybox? An amazing bit of software.) Musl (pronounced ‘mussel’) also looks like an impressive achievement. This is an implementation of libc that strives to be correct in terms of standards-conformance…

1 Pairing a mobile device To pair a mobile device, such as a smartphone, to our Raspberry Pi, we first need to make the Pi discoverable. To do this we right-click on the Bluetooth icon and select ‘Make Discoverable’. This will only give us 60 seconds to find the Raspberry Pi, so on your smartphone open the Bluetooth settings and search for the Raspberry Pi. Once found, you should opt to ‘pair’ your device to the Pi. This will trigger a new dialog box to pop up on the Pi. Click on ‘Confirm’ to activate the pairing and then confirm the same action on your mobile device. 2 FIle transfer We can now use this Bluetooth connection to send files from our Pi 3 to a Bluetooth device and to…

Our expert Nick Peers now finds the Terminal a safe, familiar haven, after years of shying away from it, having been exposed to dozens of distros in the past few months. Terminal Xxxx Accessing information and navigating your files and folders Last issue we introduced you to the basics of using the Terminal. We opened by revealing it works in the same way as your Linux shell; how commands are structured (utility command -option); plus gave you the tools to manage software packages and get further help. This time, we’re going to look at how you can navigate your file system, work with files and folders and learn some more time-saving shortcuts in the bargain. When you open a new Terminal window, the command prompt automatically places you in your…

Our expert Alex Campbell Is the associate editor of our sister magazine in the US, Maximum PC and its resident Linux and hardware guru building more PC rigs than he’s had hot dinners. FreeNAS build a low-cost NAS box with spare hardware components When writing build tutorials, it can be tempting to keep revisiting the same theme in a build. In our case (when writing for Maximum PC), it’s all geared toward games, games and more games (our audience being gamers) and actually very interested to see whether the Debian-based Steam OS can compete with Windows. Currently, our verdict is that it’s a great concept but driver optimisation is letting it down, so we’re recommending dual-boot for now. Most of the money we see in a build goes toward graphics…

Our expert Afnan Rehman loves to tinker with Linux in his free time. Fortunately, he has a lot of free time. Fedora Fedora Securit Security Lab Lab Take the distro for a test drive and uncover its key tools When you want to address your security concerns, whether it be at home or in the office, it can be confusing knowing where to start. There are a myriad of options out which can leave you wondering if there’s a way to get everything you need in one package that you can deploy wherever needed. Enter the Fedora Security Lab, the all-in-one solution to all your problems. First, what’s Fedora Security Lab? Fedora, as we all know, is a wonderful Linux distribution (distro) that was first developed by the community Fedora…

Our expert Rafeeq Rehman is a consultant and author with interests in data science, emerging technologies, IoT and information security. He has helped a host of companies advance their businesses through digital transformation. Gnuplot nuplot Learn how to start plotting your data on good-looking graphs With the explosion of data collection and cheap storage and emergence of Big Data technologies, data visualisation has emerged as a new field in itself. Today, many new technologies for data visualisation are available addressing different needs, including JavaScript and web-based tools, and gnuplotis one of these, especially when it comes to plotting mathematical functions in 2D and 3D surfaces and plotting key-value output from Hadoop MapReduce. It’s also very useful for statistical functions, curve fitting and probability while some other uses of gnuplot include…

Our expert Mihalis Tsoukalos has an M.Sc. in IT from UCL and a B.Sc. in Mathematics. He’s a Unix-using, DB- -admining, software programming, mathematical, writing machine. This tutorial is a gentle introduction to the Rust programming language. In later tutorials, we’ll talk about more specific areas of Rust but for now we will cover the foundations. By the end of it, through calculating Fibonacci numbers and writing a small Rust program that calculates the number of characters in a text file you should have an understanding of the basics and get a good sense of the language. Additionally, you’ll learn about the various data types and how the Cargopackage manager can help you build Rust projects. Installing Rust on a Linux distribution (distro), in our case Debian, is as simple…

Our expert Paul Hudson is an award-winning developer and author who is working on a new Swift book that you should totally buy. *nudge nudge* https://gum.co/proswift. [Hey! Ads will be in contact with an invoice – ED] Last issue we used readLine(), arrays and nil coalescing to track GitHub commits on the command line, which I hope gave you a trial-by-fire introduction to making something useful with Swift. (See the LXFDVD or issue archive for a PDF of the Swift tutorials from the last month and the month before, plus complete source code for this project.) In this tutorial I want to build on that knowledge by reading command-line switches, saving user data back to disk and writing code to catch errors. As I said before, Swift is designed to…

The recent attack on the official Linux Mint website highlighted the importance of using checksums for downloaded files. Most distros provide MD5 checksums for their ISO images. This is a 128-bit cryptographic hash of the contents of a file. The same file will always generate the same checksum, but change just one bit of the original and it will have a completely different checksum. You can generate the checksum of a file with $ md5sum somefile and compare it with the file you downloaded. If it doesn’t match, your downloaded file is either corrupted or been tampered with. Rather than checking each checksum individually, if you’ve downloaded a file containing one or more checksums, you can check them and get a report of which passed with $ md5sum --check somefile.md5…

Choice is good, right? I’ve always subscribed to that view, and the nature of open source means that the number of choices tends to grow. Projects are forked to suit individual needs, or sometimes wheels are re-invented from scratch. When choosing a distro or desktop environment, many of those choices are made for you (unless you use something like Gentoo or Arch), so you get one terminal program, one browser, one office suite by default. There are other options, but you have to install them, and to do that you have to know about them, so many people stick with whatever their distro offers. The variety of choice becomes apparent when you install multiple desktop environments, and this month’s DVD with thirteen to choose from in one distro takes this…

“16.04 will support the impressive ZFs filesystem baked into the os.” Canonical has been working hard on the latest long term support (LTS) version of its Linux distro, Ubuntu “Xenial Xerus” 16.04, and the wealth of headline new features in this release prove that all of that hard work is paying off, as 16.04 looks set to be one of the most interesting, and feature-packed releases in years. This makes a change from usual LTS releases, which tend to value stability and security over innovation. Some of the features of Ubuntu 16.04 deal with making the interface more configurable and easier to use. You can now move the Unity launcher to the bottom of the screen if you’re after a Mac-like dock system, and the Software Center has been dropped…

Qualcomm, the company behind a lot of the world’s mobile and ARM processors, has announced its collaboration with Red Hat to port its Enterprise Linux Server for ARM Development Preview onto Qualcomm’s server platforms, paving the way for ARM servers. This means that the two companies can now work on quickly developing new applications for enterprise servers running on ARM system-on-chips. Arcade fans rejoice—the popular MAMEemulation software has now become free and open source, with over 90% of the core files of the project now available under the 3-Clause BSD licence, with the project as a whole now distributed under the terms of the GNU General Public License, version 2 or later. The emulation software (also known as Multiple Arcade Machine Emulator) is popular with arcade machine fans who build…

Colour corrected Like Mats Werf [Mailserver, p11, LXF206], I originally had problems printing colour with an HP printer (mine is a Deskjet 5940), which consistently gave dark, muddy results compared to the onscreen version. Like Mats, I also explored the world of colour calibration, but with little practical success, not least because I have a monitor with limited adjustment. I did, however, find that direct prints from a digital camera via PictBridge to the same printer were showing the correct colours, so it wasn’t a basic problem with the printer itself. After some trial and error, I discovered that if I opened the printer properties dialogue and changed the ‘Colour’ drop-down on the Device settings tab from the default setting of ‘From driver’ to ‘Colour, the printed colours matched the…

Blackpool Makerspace 64 Tyldesley Road, Blackpool 10am every Saturday. https://blackpoolmakerspace.wordpress.com Bristol and Bath LUG Meet on the fourth Saturday of each month at the Knights Templar (near Temple Meads Station) at 12.30pm until 4pm. www.bristol.lug.org.uk Egham Raspberry Jam Meet at Gartner UK HQ every quarter. http://winkleink.blogspot.co.uk Lincoln LUG Meet on the third Wednesday of the month at 7.00pm, Lincoln Bowl, Washingborough Road, Lincoln, LN4 1EF. www.lincoln.lug.org.uk Liverpool LUG Meet on the first Wednesday of the month from 7pm onwards at DoES Liverpool, Gostins Building, Hanover Street, Liverpool. http://liv.lug.org.uk/wiki Manchester Hackspace Open night every Wednesday at their space at 42 Edge St, in the Northern Quarter of Manchester. http://hacman.org.uk Surrey & Hampshire Hackspace Meet weekly each Thursday from 6.30pm at Games Galaxy in Farnborough. www.sh-hackspace.org.uk Tyneside LUG Meet from 12pm, first…

To facilitate communication between the participants, collaborative editors usually rely on a centralised server and other components and installing all this can be an involved process. This is especially true of Etherpadwhich isn’t available in your distro’s repository (repos). Even while it’s procedure is an involved one, it’s quite straightforward and well-documented. Etherpad requires the Node.js JavaScript runtime and recommends compiling it manually from source instead of relying on the version in your distro’s repos. In contrast, OwnCloud Documents is bundled as an official plugin inside the OwnCloud file-sharing server. But while it doesn’t take more than a few clicks to install, installing the OwnCloud server takes as much time as any other self-hosted server. Then there’s the case of Firepad which is supposed to be integrated into an existing…

You’ll be able to create a fairly decent, functional desktop by collating the components we’ve mentioned, there are other bits you can add to the mix. Some of the lightweight window managers even lack the ability to set wallpapers and you’ll need another tool for that. Two of the most popular ones are Feh and Nitrogen. Feh is a very fast and light command-line image viewer that’s also capable of setting the wallpaper. In contrast, Nitrogenis a graphical utility which enables you to preview the wallpapers before setting them. Popular accessories that adorn many custom desktops are sets of applets and widgets. While many full fledged desktops, especially KDE, include elaborate mechanisms to decorate the desktop with visually appeasing widgets and applets, the standalone window managers listed above lack this…

ON TEACHING CODING“For me programming has to have an aim; programming for its own sake is boring.” LXF: Martin, thanks for taking the time to talk to us. You have enjoyed quite a rapid rise to success thanks to the popularity of Minecraft and are seen as the ‘go-to guy’ when it comes to Pi Minecraft hacking. Martin O’Hanlon: Thanks for having me. Ha! I think that there a lot more people who can take that crown, but I am prepared to accept that if you want to code some weird stuff in Minecraft, then I am pretty good at that. LXF: Minecraft is seen as a ‘kids game’ so was using Minecraft a conscious decision to play and experiment? MO: Actually, it was by pure chance. In 2008 I…

Integrating electronics into your project is where the fun really begins, and a simple push switch to close the circuit is the fastest off board interaction that you can have. To use simply attach one of the push switch connectors to Pin O and the other to the GND, connections can be made using the crocodile clips that come with the micro:bit. Once the code is run with the Pin 0 activated the push switch attached will work in the same way as the two onboard buttons. If you want to expand this further then it’s not too much of a leap to add an LED and 220ohm resistor so that the LED illuminates as the button is pressed! Once you’re familiar with the way that the three main pins…

Time series data, as recorded by Prometheus, is a set of data points collected over time. In the real world – which I rarely venture out into – an example of this type of data would be the value of a company’s stock taken hourly across the whole year. In Prometheus’ world – which I’m much more comfortable with truth be told – these are (millisecond precision) timestamped values (which are always 64-bit floats) along with associated labelled dimensions. A good example for understanding what I mean by dimensions is given by SoundCloud: Consider HTTP requests using the method GET to query the endpoint /api/tracks which resulted in a 200 HTTP status code. Prometheus names the time series like this The query language used by Prometheuscan perform various operations using…

When I joined the Raspberry Pi Creative Technologist programme (RPCT www.raspberrypi.org/creatives), I expected code, code and more code… but I couldn’t have been any more wrong. The programme supports and inspires young people who are interested in creative uses of technology. It’s been great having the experiences that I’ve had on the course as it’s all about a journey of self-progression to making your own art exhibition piece. My project idea was pretty solid all the way through, it had to have LEDs, music and interaction with the viewer; but behold the iterations, so far I’m at six… which is both good and bad. It’s good in terms of having improved the piece that much, but bad as time is running out as the course is only a year long.…

Our expert Les Pounder doesn’t like sleep, which is good as it gives him more time to craft crazy projects and interview endless Raspberry Pi experts for the pages of LXF. What Star Wars fan hasn’t dreamed of owning their own droid? The droids C-3PO and R2-D2 serve as the narrators to an epic story encompassing a galatic battle between good and evil [evil? I thought this was just a trade dispute? – Ed]. R2-D2 was first seen (chronologically) in Episode 1: The Phantom Menace, and saved Queen Amidala and her party as they left the planet of Naboo. R2-D2 is an Astromech droid, a robotic engineer that can fix any problem, and in this tutorial we’ll construct our own R2-D2 robot by hacking a store-bought toy with the smallest…

In last part we revealed some handy keyboard shortcuts to help you enter commands more quickly, but the following keys will help you navigate the Terminal itself more efficiently: Home/End Press these to jump to the beginning or end of the current line. Ctrl+left/right cursor Move quickly between arguments. Ctrl+u Clear the entire line to start again. Ctrl+k Delete everything from the cursor’s position onwards. Ctrl+w Delete the word before the cursor. Accidentally omitted sudo from your command? Just type sudo !! and hit Enter to repeat the last command with sudo applied to it. And if you make a typo when entering a command, instead of retyping the entire command again, just use the following syntax to correct the mistyped word (in the following example, dpkg was originally mistyped…

There are so many different programs in Security Lab that it would be difficult to cover them all in one document. Security Lab itself limits its documentation to the OS. If you’d like to learn more about the programs, most of them have their own documentations and tutorials that you can peruse to your heart’s content. Most of the programs covered here, such as Wireshark, Nmap, Ncrack, John, and Nwipe, have their own sites. Wireshark documentation can be found at www.wireshark.org and docs for Nmap, Ncrack, and Nwipecan all be found together on https://nmap.org, where you can find extensive information on how to use and understand the many different functions. You can also get a brief overview of the software itself and its major programs at https://labs.fedoraproject.org/en/security. Information on john…

The graphing utility, gnuplotis almost 30 years-old and was initially created to plot mathematical functions and scientific data. It’s available for many operating systems, including Linux, Windows, various versions of Unix and OSX. Historically, people used gnuplotwhen there were no sophisticated tools available to draw and print graphs, as it enabled users to create text-based input and draw/export the output into different graphical formats. The utility is part of almost all major Linux distros and is a de-facto tool for plotting functions and visualising scientific data in science and engineering circles. The tool is open source software (with copyrights) and can be downloaded and installed free of cost. Many books are also available for learning its many powerful features. There are also manuals and a large number of examples available…

Rust comes with a plethora of modules that can speed up your development process. All modules that belong to the Standard Library are under the std:: tree. Some important and handy modules are: std::env For inspecting a process’s environment and manipulating it. std::fs For cross-platform filesystem manipulation operations; std::net For TCP and UDP communication; std::os For OS specific operations. std::path For cross-platform path manipulation operations. std::process For dealing with Linux processes; std::threads For working with threads std::time For dealing with time. Please note that std::os has three subcategories: std::os::linux, std::os::raw and std::os::unix. Head to https://doc.rust-lang.org/std for more about the Standard Library and the std module is available to all Rust crates by default.…

Faking it Q I tried the latest LXFDVD, both Mint 17.3 – in Cinnamon and Mate flavour – and OpenSUSE. They succeeded in the live disc boot but Mint crashed on the install and OpenSUSE claimed to have installed but on a boot failed to find the hard drive. Perhaps it is because I have a RAID 0 stripe disk. I did give OpenSUSE a little test to see how easy it was to install an alternative browser – Opera being my favourite at the moment – and it was hard. The furthest I got was ‘go away and study the Yast manuals. A deeply dispiriting experience of how easy Linux is to use as a desktop replacement. rez A The problem is indeed caused by your RAID setup. This…

System tools Essentials Checkinstall Install tarballs with your package manager. Coreutils The basic utilities that should exist on every operating system. HardInfo A system benchmarking tool. Kernel Source code for the latest stable kernel release, should you need it. Memtest86+ Check for faulty memory. Plop A simple manager for booting OSes, from CD, DVD and USB. RawWrite Create boot floppy disks under MS-DOS in Windows. Smart Boot Manager An OS-agnostic manager with an easy-to-use interface. WvDial Connect with a dial-up modem. Reading matter Bookshelf Advanced Bash-Scripting Guide Go further with shell scripting. Bash Guide for Beginners Get to grips with Bashscripting. Bourne Shell Scripting Guide Get started with shell scripting. The Cathedral and the Bazaar Eric S Raymond’s classic text explaining the advantages of open development. The Debian Administrator’s Handbook…