Linux FormatDecember 2015的目錄

Jonni Bidwell Fallout 4 on Linux would be nice, likewise a new-fangled Steam Machine. But those are lacking in open-sauciness, so I’ll settle instead for more projects adopting arcane naming and numbering conventions so that people get confused and I get to tell them that they are wrong. That’s the festive spirit, right? Matt Hanson I’ve been reminiscing a lot about my good old Amiga A500+, which I got on Christmas Day 1991, so I would love to find a new Amiga 1200 case that I can put a Raspberry Pi into under the tree this year, along with a distro based on AmigaOS (AEROS, an open source implementation of AmigaOS would certainly do). Nick Peers I’d really like to see an Embymedia server implementation that provides a suitable scraper…

Android, Google’s Linux-based operating system for mobile devices, is the most widely used operating system in the world. However, Google also has Chrome OS, another Linux-based OS that’s mainly geared towards laptop devices, which is just a tad less popular, being installed on less than 3% of computers according to IDC. It make sense that Google would concentrate on its more popular OS. After all, Android is now on smartwatches, TVs and even used for in-car systems, and rumours reported by The Wall Street Journal (http://bit.ly/ChromeOSIntoAndroid) had suggested that Google is looking to replace Chrome OS with Android and that new Chromebooks running this new operating system will be renamed (although the web browser will still be called Chrome). Those rumours were strengthened by Google’s Chief Executive Sundar Pichai’s comments…

"One of the traditional problems that free and open source development (FLOSS) brings is one of channelling resources to improve and maintain the software. Proprietary software has an incredibly simple mechanism for this: pay to use. FLOSS has a more nuanced problem: capturing even a fraction of these savings to then invest them is tough. LibreOffice, as a user-facing project is blessed with an annual stream of tens of thousands of small donations from generous individuals. Other low-level, less glamorous projects such as OpenSSL are much less fortunate. In general, packages hidden behind a distro facade can receive little to no investment to fund basic maintenance. The Linux Foundation’s Core Linux Infrastructure project has brought several corporate donors together to redress this by funding long-term fellowships in several key projects.…

Over the years I have added a couple of laptops for my wife and I and a PC on the TV which are all using Linux too. I have been a subscriber to LXF since 2006 and have been using Linux exclusively on my office PC since then. Even though I’ve been using Linux for years I am just a user, not a programmer. I rarely use the Terminal and I have no interest in writing scripts or learning to program. I just prefer using Linux to Windows as it gives me choice, and it’s 100 times (approximately) easier to install and get up to date, and for the most part it just works. As I am not interested in programming many of the pages towards the back of the…

Blackpool Makerspace Meet every Saturday, 10am to 2pm. At 64 Tyldesley Road, Blackpool. FY1 5DF www.makerspacefy1.co.uk 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 Hull LUG Meet at 8pm in Hartleys Bar, Newland Ave, first Tuesday every month. http://hulllug.org 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 Manchester Hackspace Open night every Wednesday at 42 Edge St, in the Northern Quarter. http://hacman.org.uk Northern Ireland Raspberry Jam Farset Labs, Belfast. Second Saturday of every month from 1pm-5pm. www.farsetlabs.org.uk/events/raspberry_jam.html The Software Society Dundee MakerSpace HQ, Unit 5, Vision Building, 20 Greenmarket Dundee, Angus DD1 4QB United Kingdom. Meeting and Talk every second Thursday.…

Using a video player shouldn’t mean that you have to adapt yourself to its default interface. Instead, you should be able to alter some settings to get a better look and feel or disable unneeded elements. Bomihas a very attractive UI design and we tend to think it doesn’t require many changes. However, you can choose: a different skin from a list of 15 variations; change the font; the player’s behaviour on playback stop; set custom menu font; change system tray integration mode; keyboard shortcuts and mouse actions etc. The VLCinterface has two modes: native and skinnable. Plus, you have a dedicated Toolbars Editor, which lets you rearrange buttons for the native style that you want and even change buttons to sliders or vice a versa. QMPlay2 salvages its less…

User guides, manuals, articles, FAQs and wiki pages make a huge a difference. You may want to learn more about a player that you’ve been using for some time, or you just learn how to use a particular feature. Regardless, documentation is a useful tool to solve problems and highlight important features of a player. Bomihas an attractive website with the support section, but it’s quite small and only has brief instructions on things such as how to make debug logs or feature requests and email them to project maintainers. We assume that as as Bomiis a young project, the situation will improve in future. VLC, as an established player, boasts the best documentation, including detailed user guides for different platforms, active forums (https://forum.videolan.org) and lots of third-party materials (such…

There was a time when Ubuntu releases, especially the non-LTS ones, brought about more change than in a slot machine. However, the last few releases have broken away from that tradition and have shipped with only incremental changes. Ubuntu 15.10 follows this script as the developers have concentrated their efforts on polishing the next iteration of the core components. The release comes at a time when the desktop is shunning its traditional definition and is trying to find its feet in the battle of the form factors. Developers everywhere are trying to consolidate many devices with a standardised user experience: from computers that you strap onto your wrist to the one that sits beneath your office table. The changes in Ubuntu 15.10 are mostly at the invisible end of the…

Digital Ocean (DO) is a New York-based cloud hosting provider. Since its inauguration in 2011, the company has witnessed phenomenal growth and is now second only to Amazon Web Services (as far as web-facing IP addresses are concerned). Tammy Butow, a former cybercrime investigator at the National Australian Bank and founder of Ladies Who Linux is their Platform Support Manager. We caught up with her to talk about life at the edge of the cloud. Linux Format: What does your job at Digital Ocean involve? Tammy Butow: I’m the Platform Support Manager and I work with a team of Linux system administrators and trust and safety analysts. We support developers who want to use the Digital Ocean cloud, so if they have any questions or come across any issues they…

Valve, the company behind the Steam platform, has been promising to disrupt the way we play games in our living rooms with Steam Machines. These are compact gaming PCs designed to replace gaming consoles, such as Xbox One and PlayStation 4. Running SteamOS, Valve’s Debian-based distro, the first commercially available boxes should go on sale in November – hopefully by the time you read this magazine. Steam Machines are being made by a variety of manufacturers, such as Asus and Alienware, and come in all different shapes and sizes. This means that if you don’t want to build a gaming machine yourself, you should be able to find one that suits your needs – and budget. Prices start from $449 (around £292 – roughly the cost of a PlayStation 4…

In the main tutorial I mention that Open vSwitch is set up by the Vagrant-based installer. But what does this actually do? Open vSwitch (more commonly known simply as OVS) is an open source, production-ready multilayer virtual switch. It’s fairly ubiquitous in public clouds and is designed to support standard management protocols while at the same time being extendible. It’s pretty much a case of doing what its name suggests: it acts as a virtual switch. In our Vagrant-based setup detailed here, each node has a bridge ‘kbr0’ which is used in favour of the more usual ‘docker0’ interface. OVS sits in front of that and creates GRE (which stands for ‘Generic Routing Encapsulation’) tunnels between the nodes – basically point to point connections – with each node having an…

Since 2012 seven million Pis have been sold and more than 3,800 coding clubs have been established with more than 44,000 children regularly attending Code Clubs across the UK with around 40% being girls. But it’s not enough. Both the Foundation and Code Club want to do more and to facilitate that Code Club will become a wholly owned subsidiary of the Raspberry Pi Foundation. The Pi Foundation told us explicitly the brand and approach will continue unchanged, as it’s a proven model that works incredibly well. For the people that run clubs nothing will change, Code Club HQ will continue to create awesome projects running on whatever hardware they like to use. The Pi Foundation sees this as an opportunity to diversify its education programme, reaching out to an…

Our expert Les Pounder travels the UK working with the Raspberry Pi Foundation to deliver its popular Picademy training to teachers. He also writes a blog at http://bigl.es. Last issue, we introduced the Sense Hat which will power the Astro Pi mission aboard the International Space Station. For this tutorial we’ll use it to control a Raspberry Pi camera, and use a joystick to control settings, such as the timer and flash and to trigger taking a picture. For the whole project you will need a Raspberry Pi 2, A+ or B+, the latest release of Raspbian, as well as the HAT and camera. All of the code is at http://bit.ly/LXF205AstroCam. Installation of the camera and Sense Hat is a little tricky, and requires threading the ribbon cable of the…

Our expert Mayank Sharma was a contributing editor for www.linux.com and has written for Linux Today, Digg and PC Plus. Video games in the 1980s were quite different from the latest crop of frag-’em- till- you’re- dead point-and-shoot games. They were tastefully crafted 8- bit graphical masterpieces, with an intense storylines and gameplay that kept you engrossed for hours. If reading this makes you feel nostalgic, you can emulate the golden era of gaming consoles on your modern hardware and escape back to that golden era. The new quad-core Raspberry Pi 2 has enough number-crunching power to recreate the video game consoles of yesteryear virtually. Most of the software that creates the defunct platforms is available as open source software, which you can install on top of a Raspbian distribution…

Don’t sweat if you don’t have a gaming controller – you can create and use a virtual one from within your phone or tablet instead. To create the virtual gamepad, head to the XTerminaland enter the following commands to install the required components: Once you have the components, switch to the root user with the su command. You’re prompted for the root user’s password (raspberry). Once authenticated, enter The above steps take a little time to complete. Once they’ve finished, you can launch the controller and enable it to start up automatically at boot: Now grab your phone or tablet, open the web browser (the developers recommend Google Chromefor best results) and enter the IP address of the Pi in the address bar. You should now see a virtual controller…

If you’d like to set aside a maximum amount of space for your shared folder, and you’ve enabled Logical Volume Manager on your Ubuntu install [see Tutorials, p72, LXF202], then you can use LVM to set up a dedicated partition as a shared volume. If you want to avoid using the Terminal, boot from your Ubuntu install disc, then search the Software Center for ‘lvm. Select ‘Logical Volume Management’ and click More info > Use This Source > Install. Once done, launch Logical Volume Management from Launcher, expand Logical View, select root and click ‘Edit Properties. Reduce the size of your main partition by the amount you wish to allocate to the shared volume – say 2GB. Now reboot into your main Ubuntu installation. Open Terminal and type sudo mkdir…

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. LVM How to set up and use Logical Volume Manager with ext4 Back when hard drives were small and expensive, partition management was not much of an issue. Once you had your root, swap and home partitions in place, there wasn’t much space left for anything else, and multiple drives were a luxury. Now that hard drives are so large, fast and cheap, we need a better way to organise things. Yes, you could just have root and swap and dump everything on the root partition but there are many advantages to separate filesystems. So called…

Our expert Mihalis Tsoukalos is a Unix administrator, programmer, DBA and mathematician who enjoys writing articles and learning new things. This article is about Lua, the lightweight, fast and embeddable scripting language and how its scripts can be used in the lightweight Conkysystem monitor. Lua was created back in 1993 by Roberto Ierusalimschy – it means ‘moon’ in Portuguese – and it’s currently the leading scripting language for games. Lua’s biggest advantage is that it enables you to build everything yourself, which is also its biggest disadvantage as sometimes you end up having to build everything yourself! On a Ubuntu system you can install Lua by executing apt-get install lua5.2 as root. You can find the precise version of Lua you’re using by running luac -v , which will show…

Our expert Jonni Bidwell knows that winter is coming. His old PC is the only thing keeping drafty Future Towers warm. The Unity game engine has featured a Linux runtime since version 4, which was released in 2012. Allowing developers to export to Linux without any extra effort has enabled a raft of great titles find their way to our penguin-powered desktops: Cities: Skylines, Kerbal Space Program and Pillars of Eternity and the list goes on. Until recently, those wanting to actually make Unity games on – as opposed to for – Linux were forced to run the editor through Wine. We’ve showed how to do this in past issues [see Code Academy, p88 LXF199] and unlike many of our other Wine experiences found it to work pretty well. However,…

This month we answer questions on: 1 Over sensitive touchpads 2 Talking to older SSH servers 3 Mounting Android devices 4 Wireless connection issues 5 Securely destroying data 6 Slow desktop startup issue 1 Touchy touchpad Q I find the touchpad on my laptop too sensitive; when I’m typing, I sometimes accidentally move the mouse pointer so that the text I type goes somewhere completely different. I don’t want to get rid of the tap to click feature as I find it very useful, but can I either reduce the sensitivity or even turn it off temporarily when I am typing? I’m using Kubuntu 15.04. Chris Collins A If your trackpad uses the synaptics driver, and the majority do, you can use the Touchpad tab in the Input Devices section…

Mount Points Drive locations and mount points can be confusing, particularly those coming from Windows and expecting something akin to the C:, D:, E: notation. In Linux, everything is available in the root filesystem at /. When a device is mounted, you specify both the device to mount and the place to mount it, called the mount point. The contents of the device are then visible inside that mount point. A mount point is nothing magic, it is simply a directory. The most common example is of using a separate partition for the home directory. In this case, home on the root partition is an empty directory, as you can see if you boot from a live CD and mount the root partition. Once the other partition is mounted at…

We receive several questions each month that we are unable to answer, because they give insufficient detail about the problem. In order to give the best answers to your questions, we need to know as much as possible. If you get an error message, please tell us the exact message and precisely what you did to invoke it. If you have a hardware problem, let us know about the hardware. If Linux is already running, you can use the Hardinfo program (http://hardinfo.berlios.de) that gives a full report on your hardware and system as an HTML file you can send us. Alternatively, the output from lshw is just as useful (http://ezix.org/project/wiki/HardwareLiSter). One or both of these should be in your distro’s repositories. If you are unwilling, or unable, to install these,…

As inevitable as the changing seasons, Ubuntu releases another version. But unlike the ever shorter days and colder nights, Ubuntu 15.10 brings with it something far more exciting: ever improving desktop stability and ever improving kernel reliability. As Canonical gears up for the big introduction of Mir (its X replacement) and Unity 8, other essential pieces are falling into place. We’ve had the happy shift to Systemd (which is clearly ten times better than Sysv) and now we have the introduction of the Linux Kernel 4.2 and the new improved package manager Snappy. All of these pieces make Ubuntu 15.10 the strongest and most stable release in its history. It often feels like overkill but it’s hard to understate just how big a thing an Ubuntu release is to the…

Things are certainly looking up for Docker, the open platform for distributed applications, with a recent global survey of 138 organisation (Source: O’Reilly Media) finding that 93% of businesses are using, or planning to use, containerisation technologies for development, testing or production. These statistics alone show how much potential Docker has, but further findings from the survey should also prove to be an enjoyable read for Docker staff. Of the respondents who said they are using or considering using a container technology, 78% said that Dockerwould be their technology of choice, while 53% said they are planning to adopt containers in the next 12 months. Since its launch in 2013 more than 800 million containers have been used from the public Docker Hub (https://docs.docker.com/docker-hub), and the containerisation technology has been…

OPENELEC 6.0 While the makers of Plex are celebrating the launch of their new media server software, another media-centric distro has released a major update. OpenELEC 6.0 has just been released and comes with the new Kodi 15.2 media centre software that doesn’t just stream media, but allows you to turn your PC into a PVR device to record videos. Linux kernel 4.1 is also included and a host of software included with the distro has been updated. Check out the release announcement at http://bit.ly/OpenELEC6 for more information. 4MLINUX 14.0 4MLinux, the compact Linux distro that focuses on the four Ms (maintenance, multimedia, minisever and mystery) has hit version 14.0, bringing the GCC 5.2.0 update and downloadable extensions for Audacious, Opera and SMTube. The multimedia part of 4MLinux’s vision gets…

To celebrate the release of Star Wars: The Force Awakens, we are giving readers the chance to win one of five BB-8 droids by Sphero. With this gadget you can design a route for BB-8 and control from your smart device. You can also create and send holographic videos. BB-8 will learn to recognise your voice, and adapt personality as you interact. Who wouldn’t want one? All you have to do to be in with a chance of owning one of these remarkable gadgets is answer the following question: By taking part you agree to be bound by the Competition Rules. Open to UK and Republic of Ireland residents aged 18 and over. The closing date is 11:59pm on 31 December 2015 (GMT). Five winners drawn at random from the…

Cambridge Raspberry Jam Cambridge is the home of the Raspberry Pi and every three months it hosts the Cambridge Raspberry Jam, which is a mix of conference, workshops and vendor stands all rolled together into a celebration of the Pi. Organised by Michael Horne and Tim Richardson – the same team who organise the annual Pi Wars robotics event – the jam started with around 30 visitors but now regularly attracts around 200. The jam takes place at the Institute of Astronomy and you can find out more at the website. http://camjam.me FOSDEM 2016 FOSDEM is the annual free event for software developers to meet and share ideas. This year it takes place between January 30-31 at the Universite Libre De Bruxelles Solbosch Campus Brussels, Belgium. This is a massive…

This topic is sometimes confusing, because there are two considerations: one is hardware-accelerated video decoding (which depends on the video codec used) and the other is the hardware-accelerated output device (if it’s supported by a kernel video driver and provided with a proper API). To offload a CPU well, both need to be covered. Bomihas good support for video codec acceleration, but it doesn’t provide a setting for choosing the video output. Even though MPV– on which Bomiis based – supports both VAAPI and VDPAU, Bomidoesn’t enable you to set it explicitly, so in many configs (mostly Radeon ones) accelerated decoding is useless. VLCalso relies on system-wide hardware acceleration and only has a general checkbox for ‘Accelerated video output’ in its Video setting, which will do nothing in many cases.…

Set up online accounts Not everyone will be keen to use proprietary services, but for those who don’t mind sullying their open source credentials can use some of the popular online ones, such as Gmail, Google Docs, Flickr, Picasa, Facebook, Google+ and more in Ubuntu 15.10 by configuring the distro to grant access data housed inside these services. To get started, bring up the System Settings by clicking on the gears icon in the top-right corner of the screen and head to the Online Accounts option. Once you’ve added an account, you can search for content on these online services from the Dash. Just as you would search for local content, the Search lens will also display documents on Google Docs and the Photos lens will show pictures from Facebook,…

1 Bye Software Center Although it’s designed to be very user friendly, the Ubuntu Software Center isn’t very intuitive when it comes to installing components apart from applications, such as individual libraries. Synaptic is a graphical front-end for the command-line for the powerful APT utility and is one of the most popular package managers. It’s available in the official Ubuntu repositories, and you can install it with a simple sudo apt-get install synaptic command. 2 Customise Quicklists Quicklists are a set of commonly used tasks that you can access directly by right-clicking on an app’s icon in the launcher. To add and customise quicklists, grab the Quicklist Editor from http://bit.ly/QuicklistEditor. The application scans the launcher and displays all the items currently on it along with their quicklist entries. You can…

There are several similarities between the Ubuntu and the Fedora project. For instance, both projects are backed by for-profit companies and employ the top software developers that are critical to the respective projects. One difference between the two is their package management systems. Fedora uses RPM packages in contrast to Ubuntu that uses Debs. Another difference between the two is the default desktop, with Fedora defaulting to Gnome 3. That said both Ubuntu and Fedora projects support other desktops as well via a number of distro variants. In addition to the desktop flavour, both projects also produce server releases. However, while Fedora has long been used as a test bed for Red Hat’s subscription-based RHEL distro, Ubuntu has always focused on the desktop user. This is also why Ubuntu is…

Red Hat buys Ansible Open source giant beefs up configuration management offering with multi-million dollar purchase of company behind popular project. Red Hat this month signed a significant deal to acquire Ansible, the company behind the eponymous devops/ configuration management tool. This oft rumoured deal gives Red Hat a strong additional component in its hybrid management portfolio. The company states that Ansible will be used to help customers: deploy and manage applications across the public and private cloud; speed up service delivery; streamline OpenStack installations and accelerate container adoption. The price for the deal is at the moment undisclosed, but some estimates put it as high as $100m. According to a Red Hat FAQ on the acquisition, there may be plans to open source all of Ansible’s software, including the…

Did you at some point during the main article think that using kubectl to look at logs from service running in the pods was a waste of time and came with a large overhead? If so, 10 Linux guru points to you and go to the top of the class; it absolutely is and does. It’s common during any Dockerpilot to have to address how things are logged. Clearly keeping logs locally on the hosts with the containers barely reduces the issue. Even more so with Kubernetes where the whole aim is to not even care where pods actually run. The best way to tackle this is to set up a central logging server and have logs shipped to it. This matches the more traditional Linux ‘syslog’ server which would…

The official Raspberry Pi camera is one of the oldest add-ons that has been made for the Raspberry Pi. It uses a 5MP sensor to create 1080p video and high quality still images at 2,592x1,944 pixels. It works with a robust and well written Python library that is very capable. High speed photography at 90fps is possible by reducing the resolution to 640x480 pixels, and this enables the camera to be used in scientific experiments and sports photography. The camera can also be used as a novel form of input using colour detection built into the Picamera Python library. Another form of input is OpenCV which enables a computer to ‘see, requiring the user to program the computer to look for and interpret objects/faces and act accordingly. This form of…

The RetroPie script is a wonderful tool that you can use to convert a stock Raspbian distro into the ultimate arcade machine. Or, if you are already running a version of RetroPie, you can use the script to update to a newer version without downloading and reinstalling the whole thing all over again. To upgrade your installation, exit Emulation Station and enter the following in the CLI: The above commands refresh the distro’s repos and brings it up to date by re-installing any outdated packages. With the base distro updated, it’s time to update the various gaming emulators. Again on the CLI, type: As you are in the script, the first task is to update the RetroPie-Setup script itself. The script lists two different upgrade options at the top. The…

If you want to experiment with LVM, you could use an external hard disk drive, but you will find that the drive would be slowed down by the USB bus. However, for quick testing, using disk image files are an easy solution, assuming, of course, you have the spare space: This creates two files then creates block devices that access those files. Now you can use /dev/loop0 and /dev/loop1 in place of /dev/sdb1 and /dev/sdc1 in the examples. You will lose the loop devices if you reboot, but not the files, so just run the losetup commands again in that case.…

1 Create basic query You’ll need to create separate queries for each group of contacts you have in Base. Switch to Queries view in the left-hand pane, then double-click ‘Use Wizard to Create Query’. Click ‘>>’ to add all available fields to the query. Click ‘Next’, then use the dropdown menus to ensure results are sorted in the desired order (typically surname and then first name). Click ‘Next’. 2 Finish setting up query Leave ‘Match all of the following selected’, then click the Fields drop-down menu to select your group or category field from the list. Leave Condition set to ‘is equal to’ and enter the desired group value (such as ‘home’ or ‘work’) into the Value box. Click ‘Next’, leave ‘Detailed query’ selected and click ‘Next’ again. Leave the…

Our expert Sean Conway finds his day job, where he recently racked and networked eight servers, from bare metal to production launches, made an excellent backdrop for this tutorial. Package managers Using Yum, RPM and DNF for software shenanigans You don’t have to be mad to manage software but it helps. That’s MAD as in being aware of the three main functions involved in managing software: Modification ('M’ or updates) of software, adding ('A') software and deleting ('D') software. In this tutorial, we’ll cover the tools used for managing software on a Red Hat system, including Red Hat Package Manager (RPM) and Yellowdog Updater Modifier (Yum). An easy way for a novice to understand the differences between the two package managers is to use an analogy: the difference between a…

Although Lua is not a systems programming language, it can interact with the operating system using the Operating System library. However, the Operating System library only provides two functions for file manipulation: os.rename and os.remove which are for renaming and deleting a file respectively. The following Lua code shows you how to read environment variables: As you can see, if the variable you are trying to read isn’t defined, the call returns nil. The os.clock() function returns an approximation of the amount of CPU time in seconds. You call it as follows: The os.difftime(t2, t1) function returns the difference in seconds between two times whereas the os.date() returns the date as a string using the MM/DD/YY HH:MM:SS format. The os.execute([command]) function allows you to run external commands and is analogous…

Before you do anything at all with Unity, it’s worth noting that the Unity editor requires around 4GB of hard disk space. This means that you’ll want to have at least 6GB free before you fetch the package. If you use Arch Linux and the unity-editor package in the AUR, and are using a helper application such as Yaourt, then you’ll need even more space since the package is first built in /tmp and then copied over to its final resting place in /opt/Unity/. Space on /tmp is set up by Systemdby default on Arch, but usually only around 600MB are set up. You’ll want to override this by adding a line like the following into /etc/ fstab and then issuing mount /tmp -o remount as root, and the…

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 of one 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…

Slow startup Q I have a dual disk setup on my Ubuntu 14.04 system: an SSD for / and a 1TB hard drive for /home. Booting is fast but initial operation of the computer, for the first few minutes, is really slow. The first time I launch the Unity dash and search for an application, it can take a minute before the results appear. The next time it will be more or less instant. Loading Nautilus and displaying all my files is also slow on the first run. Arthur Hale A It sounds like the problem is with your hard drive rather than your solid state drive – if it’s nearly full it could be fragmented. The system boots from the SSD quickly and loads the desktop from the SSD…

A while back someone came up with a fascinating experiment, which asked: could a community of thousands work together to play Pokémonusing commands typed into a public chatroom on Twtich, the video streaming service? It was a frustrating, enlightening, occasionally boring and frequently hilarious experiment and it worked. Now a new experiment is being run: can Twitch install Arch Linux? Every five seconds the most popular keystroke in the chat will be entered into an Arch Linux virtual machine. A recent twist saw a botnet take over and partially install Gentoo before the community wrestled back control. You can watch it live and join in at www.twitch.tv/twitchinstallsarchlinux. A new version of the popular Plex Media Player has been released, with the creators promising that it refines the home streaming experience.…

Coasters I couldn’t help it but to write and let you know that I do actually use a LXFDVD as a coaster at work (I keep all the material backed up)! It’s really great, because when they notice it, people ask about Linux and I try to give them a bit of an idea what it is! Last but not least I would like to thank you all for keeping the magazine full of insightful and no-nonsense information. Thanks to you I’ve been able to further my knowledge in Linux and revive some old workstations that would have never been possible with Windows in this case. Felix Attard, via email Neil says: Using the discs as covert propaganda, we like it! The alternative is whittling them into deadly throwing stars…

Are hackspaces the new Linux user groups? We look at the changing face of user groups. Things are changing. In the past five years of writing this page, I’ve noticed that the number of hack and maker spaces is increasing but does this spell the end of the LUG? My own LUG has now become Blackpool Makerspace and our projects span much more than hacking a Linux distro, eg we do things like prototype projects with 3D printers and laser cutters now, too. The rise of maker culture is driving such activities and gatherings into the mainstream. Maker culture is typically a hacker-centric activity, which goes beyond electronics enthusiasts to crafters, potters and musicians, and creates an exciting crossover with art-based groups. This mix of people comes together in a…

It’s hard to keep track of the total number of video players for Linux as its a popular area of open source software development. You shouldn’t limit yourself with only five players from this Roundup. For instance, Ragevideo player (www.enlightenment.org/about-rage), which is a part of the Enlightenment desktop, offers some cool things like live preview during seeking (just like online players), Gnome Videos (or Totemas it was called) can look too primitive, but it’s very good at playing files over the network shares. Or maybe you’d prefer Miro, (www.getmiro.com/download) a complete iTunes-like replacement where you can do everything including purchasing videos from Amazon etc. Despite this being the age of cloud services and Internet of things, one thing remains the same in any time: your files. The philosophy of Unix,…

An Ubuntu release isn’t just about a solitary Unity-based desktop distro but a whole family of spins. Besides the changes in the core infrastructure of the main release, every spin also adds its own. Kubuntu 15.10, eg uses the latest KDE Plasma 5.4 desktop and KDE Apps 15.08. Plasma 5.4 introduces a slew of improvements and changes, including preliminary support for Wayland and improved support for HiDPI (High Dots Per Inch) screens. The release also removes any remaining wrinkles from Plasma 5’s new flat look. The newest member of the Ubuntu family, Ubuntu Mate 15.10, ships with Mate 1.10. This release of the lightweight desktop comes with several improvements to its core components and applications. The distro also uses an updated Ubuntu Mate Welcome screen, which now enables you to…

Setting up a firewall helps insulate your computer from the crackers and malicious users looking for illegal entry into your system. Linux includes the powerful and comprehensive iptables firewall which can be easily managed with the Gufwapplication. It’s available in Ubuntu’s Universe repos and can be installed with sudo apt-get install gufw . Once the app is installed, bring up the System Settings window and click the ‘Firewall Configuration’ option under the System section. Begin by first enabling the firewall. Once enabled you can set the Incoming and Outgoing policies by selecting one of the three options in the drop-down menus. The Allow option will allow traffic without asking any questions. The Deny option will silently discard all incoming or outgoing packets. The Reject option is different in that it…

Ubuntu has recently introduced a new service manager called Systemdreplacing its own Upstartmanager. Although most desktop users don’t need to interact with the service manager directly, a working knowledge might come in handy to bail you out of sticky situations. The Systemdservice manager uses the systemctl command to control the services. Enter the systemctl command in a terminal window to list the status of everything that is controlled by Systemd. Then use the systemctl list-units -t service command, which will only lists the active services. You can check the status of any individual service with the systemctl status command such as: systemctl status sshd.service. Similarly, you can change the state of the service by replacing status with start , restart and stop – eg sudo systemctl start sshd. service will…

Mageia, which came out on top in our annual best Linux distribution roundup [see Features, p32, LXF203] sits pretty much in contrast to Ubuntu. The distro, which has had a long association with the Linux community in one form or another, is managed by a non-profit and has a very democratic and transparent development process. Mageia is a wonderfully put together distro that looks elegant with its custom theme and customised KDE desktop. The KDE Plasma desktop also adheres to the classic desktop metaphor and unlike Ubuntu will not trip up first-time users. By default, Mageia ships with only open source software, but you can infuse proprietary applications and codecs into your installation without much effort. Unlike Ubuntu, Mageia greets its users with a Welcome app which does a nice…

Wine(which stands for Wine Is Not an Emulator) is a compatibility layer that enables Windows programs to run on Linux. Although it’s usually used for running office suites and other programs that haven’t made it to Linux (or don’t have an open source alternative), it can also be used for running Windows games in Linux as well. Of course, there’s a performance impact to running a game via Winerather than natively, so it’s not really recommended for graphically demanding games – unless you have one hell of a machine. However if you have CDs of some old Windows games lying around, or you want to try an indie that hasn’t made it to Linux just yet – then Wineis a great possible solution. To install, open up the Terminal and…

We’ve had many Linux Format readers write into us about receiving – or having relatives receive – those annoying ‘technical support’ spoof calls. I certainly have had them. A very kind sounding foreign gentleman rang to express concern about my computer’s recent performance issues. Amused and somewhat curious about the scam and how it worked, I kept him on the phone for as long as I could. The well-spoken gentlemen explained that he worked for “Windows” and they had spotted that things were amiss. He then offered to “resolve everything for me” and “was I sat at my computer now?” I strung him along and pretended to struggle to even get the computer switched on in an attempt to glean more information out of him before he either ran out…

For anyone planning furnishings for their house or apartment before going out and buying anything, SweetHome3D is a great open source utility. Similar features exist such as IKEA’s planning tool, but it’s not open source and limited to IKEA-branded accessories only, as you’d expect. SweetHome3D also has a much wider set of features, including an expandable furniture set and textures library, support for multiple levels on a plan and most appealingly editable parameters of each item, including size and proportions. You can also make your own items from scratch if you want or by importing from various supported 3D formats, such as OBJ, DAE, KMZ and 3DS. The visual layout of SweetHome3D has a furniture categories tree on the left, where you can expand and drag the desired items onto…

Picraft started with a hack someone made for rendering an image captured with picamera in Minecraft. I wanted to make a video-rendering variant but discovered that the Minecraft Pi Edition (MCPI) wasn’t fast enough. I gave up on the idea until I ran across a hack using Sonic Pi: a real-time spectrum analyser in Minecraft. This was updating much faster, and I discovered the answer was to concatenate requests together in a single network transaction. I went back to see if I could implement something similar in MCPI. Unfortunately, the more I dug into it, the more I discovered things I didn’t like (camelCase, getters, setters etc). So, I set out to replace it. I started with the basics: a decent Vector class, supporting every operation I could think of,…

In the latest version of Scratch, released with the new Jessie image, the Raspberry Pi camera can be used to generate sprites which are controllable using the Scratch palette of commands. The new version of Scratch also supports add-on boards, such as Sense Hat, to enable younger children to recreate projects like AstroCam. Work is still ongoing for this project but the Raspberry Pi Foundation have invested a significant resources to create a version of Scratch which will meet the needs of many different users.…

Our expert Nick Peers has been playing around with computers for over 30 years, and dabbling with Linux for the best part of a decade. Sharing Explore different sharing systems and set up file and folder shares Sharing files between computers is one of the most fundamental reasons for setting up a local network. It’s something that’s designed to work seamlessly with your day-to-day file browsing, so everything’s handled using shared folders, which are made accessible to other computers connected to the same local network. Users can control exactly who has access to each folder and determine what rights they have over the files within that folder. These rights can usually be boiled down to two basic settings: full read/write access and read-only. The latter makes it possible to share…

Our expert Nick Peers has been playing around with computers for over 30 years, and dabbling with Linux for the best part of a decade. LibreOffice Using the power of mail merge with Base, Calc and Writer Anyone who’s had to write the same letter to many different people, dutifully substituting names and addresses for each one, will appreciate what mail merge can offer. (So will those too lazy to write names and addresses on envelopes at Christmas time). Thankfully, LibreOffice Writer possesses a tool that can simplify the process in the form of its Mail Merge Wizard. A mail merge works by taking a list of contacts and automatically inserting key information from that list into specific parts of a document – eg the address block in a letter,…

Before you import your spreadsheet list of contacts into Base, open it in Calcand first verify you have column headers (such as first_name, last_name, address and so on) in row 1 – Base will create the relevant fields from these headers. If you’ve not done this, select the first row by clicking the ‘1’ to the left of it, then right-click and choose ‘Insert Rows Above. Enter your field names into the new blank row. When entering or editing field names, make sure there are no spaces between words by using an underscore character (‘_’) as a substitute – for example, ‘first_name. Finally, you need to add one or two extra fields to your list: name the first field ‘category’ or ‘group, which allows you to filter contacts accordingly into…

Dependency is the requirement that some software packages need a specific version of a share package to be installed in order to run. Share software packages are designed so that multiple programs can take advantage of their code. Two or more packages that use specific shared packages/libraries may not run if the share package version level isn’t correct and a specific version may break one package, yet permit another to work. An example of a software dependency would be a package that contains Perl scripts. If the version of Perl installed on the computer doesn’t support all the functions used in the scripts, the dependency for the package installation may fail as an earlier version of shared Perl libraries may not contain the necessary components that are needed to support…

The bad news is that tables are the only ‘container’ type in Lua. The good thing is that Lua tables are very flexible and powerful as they are associative arrays, which means that they can store any kind of key and value pairs. The following Lua code shows how to create and use a table: It’s required that you first declare an empty array before adding elements to it. As you can see from the last line of the previous output, if there is not a value associated to a key, the return value will be “nil” – assigning “nil” to an existing key erases the key and value pair from the table. The aforementioned example shows how to use a Lua table as a traditional array but you can…

We often give a solution as commands to type in a terminal. While it is usually possible to do the same with a distro’s graphical tools, the differences between these mean that such solutions are very specific. The terminal commands are more flexible and, most importantly, can be used with all distributions. System configuration commands often have to be run as the superuser, often called root. There are two main ways of doing this, depending on your distro. Many, especially Ubuntu and its derivatives, prefix the command with sudo , which asks for the user password and sets up root privileges for the duration of the command only. Other distros use su , which requires the root password and gives full root access until you type logout. If your distro…

Disk space usage No matter how large your hard disk, it will still gradually fill up. While larger disks make this less of a priority than it used to be, media files sizes are much larger now. There’s also the matter of space wasted by files that are no longer needed, temporary and cache files dropped into your home directory by various programs, as well as things like package files left over from software updates. Whether you want to spend time reclaiming this wasted space depends on which you have more of, free space or free time, but the first step is to locate the space hogs. There are several programs that will show you how much space each directory uses. KDE users can install Filelight while Gnome users probably…