Linux FormatJanuary 2016的目錄

Jonni Bidwell Douglas Adams once said that he was “rarely happier than when spending an entire day programming my computer to perform automatically a task that would otherwise take me a good ten seconds to do by hand.” It’s a sentiment I share entirely and it’s my general excuse whenever my copy is late for Linux Format. Neil Bothwick Most of my life is driven by shell and Python scripts. My ultimate goal in home automation is to reach the level achieved by Wallace in The Wrong Trousers. Although I may have to use Windows to control it as one lesson from that film is that letting anything penguin-powered near such a setup can have disastrous consequences. Matthew Hanson I love tinkering and building PCs at home, which inevitably involves…

l ibreOfficehas enjoyed a healthy growth in its contributors since its creation – with a monthly average of 16 people contributing code. This has helped LibreOfficehit the milestone of 1,000 developers at the end of 2015, with a global mentoring effort by some of the project’s founders helping to achieve that number. However, as the open source office suite has matured, its complexity has grown, requiring a new influx of developers. The fact that LibreOfficeis available on Linux, Mac OS and Windows, as well as mobile platforms, means there’s a huge need for a large team with a breadth of experience, which is why the LibreOfficeproject is starting up another new drive to attract 1,000 more code contributors to the project The news of LibreOffice’s search for another 1,000 developers…

“This month Collabora has launched a number of easy to access Virtual Machines and packages for LibreOfficeOnline with a sample integration with OwnCloudon OpenSUSE 13.2. This launch provides a great way of getting access to an unstable development version of a key part of what will become Collabora CloudSuite, please do give it a try. This announcement primarily benefits developers, so we even came up with a completely cheesy name for it: Collabora Online Development Edition (CODE). The hope is that CODE will enable everyone to play with, improve and contribute to the LibreOfficeOnline project with ease; even those who are pure web/Javascript developers can customise and play with CODE to their hearts content as it develops. And there’s lots still remaining to be done in the area of feature…

I can’t believe I’m typing this (I have not used windows since Ubuntu 05) but I bought a cheap laptop which had Windows 7 installed, with the intention of installing Linux. As an experiment I downloaded the 10 upgrade and to my amazement have found it rather good (even taking into consideration the pain in finding and downloading new software and inevitable slowing down of the system). Battery life is exceptional and it is a good looking OS and very well integrated. As Microsoft has no doubt spent £millions on it (and Linux distros are often maintained by a person working from home – I think) it is not a fair comparison. I was so unnerved by this that I have taken out a Linux Format subscription and hope that…

FLOSS UK Spring Conference FLOSS UK is the new name for UKUUG (which stands for UK Unix User Group and sounds like a UKIP voter falling off a cliff). This is the longest running system/network administrator conference in the UK. The conference has a long tradition for insightful workshops and talks and excellent lightning talks. The event takes place at Mary Ward House in London on March 15 -17. More details here: http://bit.ly/FLOSSUK2016 Internet of Things Conference Not a day goes by without some new piece of IoT (Internet of Things) hardware claiming to solve all of our problems and it’s a constant struggle to understand which platform will deliver the most benefit. But where can you learn more about the subject and its impact on our future? The answer…

Specs OS: Android 6.0 Display: IPS LCD 5.2-inch, 1,080x1,920, Corning Gorilla Glass 3 CPU: Qualcomm Snapdragon 808, dual-core 1.82GHz A57, quad-core 1.44GHz A53 GPU: Adreno 418 RAM: 2GB Storage: 16GB (32GB option) Camera: 12.3 MP2; 1.55 ›m; f/2.0, front 5MP Battery: 2,700mAh Comms: Wi-Fi 802.11a/b/g/n/ac dual-band, Bluetooth 4.2, A-GPS, NFC, USB Type-C Sensors: Fingerprint, accelerometer, gyro, proximity, compass, barometer Size: 147x72.6x 7.9mm Weight: 136g What’s the sound of one hand clapping? It’s a Nexus 5X owner giving praise to Google and LG for remaking a palm-friendly Android phone while effortlessly holding it in the other hand. The Nexus 5X looks and feels like the Nexus 5 adapted for modern times. It’s lightweight and, with a 5.2-inch display, my fingers can just reach all the way across the screen. Little else…

These days, most Linux distributions (distros) ship with a basic image viewer that can be used to read and edit metadata and tags, and will likely offer some basic image-editing options. If not, then take a look at your distro’s standard repository (repos), which will be full of helpful tools that can help you sort through all your Stallman snaps. Even basic image viewers, such as Geeqie and gThumbhave organisational and editing capabilities. If you shoot a lot of RAW images you should perhaps look at RawTherapeeand GTKRawGallerythat are designed as per the workflow of a professional RAW developer. Finally, if you’re used to Google’s Picasa, which used to have a native Linux version, you can use the Windows freeware on top of Linux via the wonderful Wine.…

Working with external data sources and services is an exciting area to explore with your Raspberry Pi. There are many different sources, such as weather, astronomical and mobile communications data. Data sources can be used as a method of input to trigger an event in the physical world, eg such as turning on a fan based on the current temperature or a data source can be used as an output, eg such as an air pressure changes log. In this project we used the Twilio service to access SMS functionality through a Python API. Twilio is a cheap and robust service for projects and after the free trial ends it’s pretty cheap to use at $1 charge per month and around $0.04 per SMS. Using Twilio we can go further…

Are you always backing kickstarters but never at home to receive your rewards when the postman comes? Well, this project can alert you to a parcel via email. With your Raspberry Pi turned off, attach the camera by the camera slot located near the Ethernet port. Next, connect your Passive Infra-Red (PIR) sensor to the following GPIO pins of your Pi. Please note: we are using the Broadcom pin mapping. Boot your Pi and use the configuration tool located in the Preferences menu. Enable your camera and ensure that SSH login is enabled. Reboot and then open Python 3 from the Programming menu. Create a new file, save and call it emailer. py. We start our code by importing a series of libraries. (You can view the full list via…

In this project we sent temperature data to the cloud using a service called Initial State. This service enables users to graph and manipulate data from multiple sources at once. We used the free tier in this tutorial, which retains our data for 24 hours before deleting it. There are other tiers which can retain data indefinitely for an unlimited number of sensors. For our project we used one sensor input, a DS18B20, but thanks to the Raspberry Pi and its GPIO we can use many more sensors to gather data about our home, eg in another tutorial we used a reed switch. This too can be used with Initial State so that we can show data when doors are opened. So using this service we can interpret data about…

We admit that we’ve become quite the fans of Google Chromebooks, [see Roundup, p24 LXF202] but we also perfectly understand if you don’t feel the same way. We’re also a little confused as to why we love them so much, but largely it’s that they just work, are generally low-cost and run Linux. It does also help that you can use Crouton to add real GNU/Linux via a chroot in the form of Ubuntu, but is it as good as a native installation? So Chromebooks run Linux at their heart and Google honours the open source licences, so it maintains the ChromiumOS project. This means if you feel the need you’re able to ‘make’ your own Chromebook with your custom hardware [see Tutorials, p70, LXF199]. Chromebooks have come a long…

The container bandwagon rolls on with a production ready Swarm and multi-host networking. Docker 1.9 and Swarm 1.0 released Ahead of DockerCon EU, which is held in Barcelona in November, Docker released some crowd-pleasing updates to its product, which continues to be the focus of much interest in the Infrastructure/DevOps arena. Version 1.9 of the container technology included a production release of its multi-host networking, which was previewed in the previous release, and allows for virtual networks to be created that span multiple hosts. This allows a much easier way for a user to have complete control over a network topology and which containers are allowed to speak to each other. This is billed as ‘software-defined networking’ for containers and also allows for the underpinning VXLAN driver to be swapped…

I’ve probably mentioned it before, but one of the things I really like about open source is that there’s often an alternative choice available when it comes to choosing software. It allows ideas to evolve and things to improve over time (hopefully, anyway). Parts of the ELK stack can be replaced for example. Fluentd is an alternative to Logstash, written in Ruby (and handily has drivers available for Docker) which has a large installed user base (I work with some clients who call this arrangement a ‘FEK’ stack). Graylog is an open source based company which uses Elasticsearch(and MongoDB) as part of its setup as well as its own alternatives for the ‘LK’ portions of the stack. Grafanacan act as an alternative to Kibana(apparently – I haven’t tried it yet),…

Among the many criticisms levelled at Gnome 3 and Unity, the most uttered is that these desktop environments force upon their users an interface that looks like it belongs on a touchscreen. Certainly both of these desktops have at least reasonable touchscreen support (both support multitouch gestures), but users actually making regular use of it are very much in the minority. Plasma 5 also has reasonable touchscreen support, but it’s immediately apparent that, at least it’s default state, it has been designed to serve under traditional mouse and keyboard rule. Both Windows and Ubuntu have much to say on convergence – the idea that you can take your phone running the respective OS, plug in a display and some peripherals, and then will occur a strange prestidigitation wherein the OS…

Do you feel you ought to be in control of most things? Then put your organisation skills to the test and try managing a whole virtual city? In Lincity-ng you’re committed to building, developing and maintaining a city and your end goal is to achieve a sustainable economy. The game is an improved and polished version of the older Lincity, which in turn is a clone of the famous classic SimCity. In the latest game you can build a city from scratch or start with a scenario where there is already a city with some issue or other, such as a lack of food, depopulation, insufficient power supply and so on. Your job is to fix it and manage the budgets, because city funds can be easily frittered away. The…

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. RAID Xxxx How to set up, troubleshoot and monitor different types of RAID Last month we looked at using LVM [see Tutorials, p72, LXF205] to manage partitioning and multiple disk drives. There is another technology used when multiple drives are involved called RAID. To give it it’s full name, Redundant Array of Inexpensive Disks combines multiple disks into a single block device to give extra capacity or redundancy in case of failure. The simplest form of RAID is two disks in what is called a RAID 1 array. In this case the two disks are mirrors…

If you have set up your Linux install using Logical Volume Management then you’ll find yourself frustrated should you attempt to repartition it using GParted– it simply won’t work. That’s not a problem though, because all you need is the right tool. You can, of course, configure your partitions from the command line, but a better bet is to employ the user-friendly LVM utility. To do so, boot from your Live CD, then open Software Center and search for ‘LVM. Select ‘Logical Volume Management’ and click More Info > Use This Source > Install. Once installed, launch LVM and you’ll find a more pleasant environment to work in. Start by resizing your root partition to free up available space: expand Logical View, select ‘root’ and click ‘Edit Properties. Use the…

Our expert Mayank Sharma is a very private person. He encrypts his cafe latte order every morning to his local barista. He may live in New Delhi – who knows. Encryption Xxxx Create and place an encrypted storage container on a drive While you can control access to the data on your computer using user accounts and file permissions, they aren’t enough to prevent a determined intruder from gaining access to your private files. The only reliable way to keep your personal data to yourself is to use encryption. Sure, working with encrypted data is an involved process, but it’ll go a long way in reinforcing your security and insulating your data. ZuluCryptis a graphical encryption application that has an intuitive and easy-to-follow interface. Using the application you can create…

Lazy lists are a unique characteristic of Perl 6 that might look strange the first time you see it. But before explaining more about lazy infinite lists, let’s see some code that defines one that also does some calculations: Lazy lists are like arrays with a few major differences. First, they don’t necessarily have a predefined size; they can even be infinite. Second, they don’t calculate their values in advance but on a need-to-calculate basis. Finally, once they calculate a value, the value can be stored for fast lookup. It should be made clear that infinite lists are supported because of their laziness property. The opposite of infinite lists are eager lists which are like C arrays. Perl 6 supports both eager and infinite lists. However, as lazy lists are…

There are a number of good chess graphical user interfaces for Linux, we’re using Xboard as it’s fairly ubiquitous amongst common distro repos, but be sure to check out PyChess as well. Installation will just be a matter of: $ sudo apt-get install xboard Now fire up Xboard and select Engine >Load New 1st Engine. Enter Sunfish in the Nickname field, for the Engine Directory use /home/user/ Chess (replacing user with your username – Xboard doesn’t seem to understand the ~ shorthand) and for the Engine Command use python /home/user/Chess/xboard.py . Leave all the other settings as they are and select ‘OK’. The default XBoard setup gives the human player white pieces and if all has gone well the window title should now read ‘Sunfish. Now you have your formidable…

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…

We often recommend using the shell to run commands on a Linux system. While many distros provide graphical configuration tools for some tasks, they often work differently, while the underlying shell commands are consistent across all distros. By showing you the shell commands to use to perform a task, the information we give applies to all distros and can even be used on a remote computer using SSH. However, we understand that not everyone is particularly comfortable with using the shell, even though it is a valuable skill to learn, but there is a more universal graphical alternative. It’s called Webmin (www.webmin.com) and is almost certainly in your distro’s software repos. As the name implies, this is a web-based administration tool. It runs on your computer, there is no cloud…

Smart homes, smart TVs, smart watches, smart phones, smart fridges: is there anything that isn’t smart these days? Smart humans, might be a useful start. The startling thing is that behind that huge list of smart things is Linux (and perhaps a bit of BSD). The open source nature of Linux; its lightweight footprint and robust security (though nothing is foolproof) makes it perfect for use in tiny, deployable, internet-connected smart things. Linux has enabled an entire generation of new gadgets, but alongside the software you do need hardware. That’s where the Raspberry Pi plays its part. We now all have access to the software smarts and handy hardware to build our own tiny internet-connected devices that can transform a home, school or office into an automated paradise. This issue…

Over 20 years ago Peter Mattis and Spencer Kimball developed the General Image Manipulation Program, with the first public release in January 1996. Abbreviated to the always-fun-to-Google-at-work Gimp, the first release was compatible with Unix systems like Linux, however since then it has been ported to Windows, Mac OS X and other operating systems. It has also had its name changed (with the blessing of Richard Stallman) to GNU Image Manipulation Program. To celebrate the 20th anniversary of when Peter Mattis announced the availability of General Image Manipulation Program on Usenet (which can be read at http://bit.ly/Gimphistory), a new version of Gimp (2.8.16 – which can be downloaded from http://www.gimp.org/downloads) has been released. This new version includes support for layer groups in OpenRaster files, fixes for layer groups in PSD,…

MAKULULINUX 10 MakuluLinux 10 has just been released. This distro is built from Debian and Ubuntu packages and comes with the Cinnamon desktop environment. The idea is to create a familiar feel for Windows users who have recently entered the brave new world of Linux. A culmination of over 3,300 hours’ work, MakuluLinux 10 “Aero” has been extensively tested to make sure it’s as stable as it is powerful, making it a great choice for convincing people to ditch Microsoft’s OS. Find out more and download it from: http://makululinux.com/aero. ORACLE LINUX 7.2 Oracle has announced the 7.2 release of its distro built from Red Hat Enterprise Linux source code. As well as being binary compatible with Red Hat Enterprise, it comes with two kernels – a ‘Red Hat Compatible Kernel’…

Linux is people We reflect on a good year for open source. With the new year soon upon us we naturally look back over the year and celebrate the events that entertained, informed and expanded the community. Events are the lifeblood that keep all of the many communities active. Speaking face to face with your peers and working together enables projects to improve and innovate; the old adage of ‘many hands makes light work’ is especially true for many projects. At the start of 2015 we had the Raspberry Pi’s third birthday celebration in Cambridge. Taking place over two days this event celebrated the success story that is the Raspberry Pi and its impact on many communities. The Raspberry Pi has now sold 7 million units, and this exposes Linux…

Specs... Display: 42mm: 1.37-inch (35mm), 263ppi (360x325) 46mm: 1.56-inch (40mm), 233ppi (360x330) Case: 46x11.4mm, 42x11.4mm CPU: Qualcomm Snapdragon 400, 1.2 GHz quad-core GPU: Adreno 305 450MHz Sensors: Accelerometer, Ambient Light Sensor, Gyroscope, Vibration/Haptics engine Battery: 42mm: 300mAh, 46mm: 400mAh RAM: 512MB Storage: 4GB Comms: Bluetooth 4.0, Wi-Fi 802.11 b/g, microphone The first Moto 360 has been one of the most popular – if not the most popular – smartwatches on the market. It’s the top Android Wear watch that can go head to head with the Apple Watch, and then some. It definitely has annoyances – like its flat tire-looking display and middling battery life – but in terms of design, comfort and overall functionality, the watch has done well. The new Moto 360 screen has a higher pixel density…

Who doesn’t like more bang for their buck? While these managers pack in a lot of features, some can take on more work thanks to optional plugins. The two managers that make the most of plugins are DigiKamand KPhotoAlbum. Both can be extended with plugins from the KIPI (KDE Image Plugins Interface) framework. The KIPI package ships with 40 plugins that add all kinds of abilities to the app, eg you can export images to flash, stitch them into a panorama, blend bracketed images and stream them to a DLNA device etc. When you are done sorting and touching up your images, you can even publish them on the web or post them to friends straight from within the application. Thanks to the KIPI plugins, both DigiKamand KPhotoAlbumcan export images…

Our homes are being changed by technology and changing how we live. Many homes now have smart televisions, central heating systems that know when you arrive home and how warm you like each room in your house and even fridges that tweet reminders to buy more milk. But how easy is it to create your own piece of 21st century technology? Home automation is becoming a mainstream project for many hobby hackers, largely thanks to the rise of the Raspberry Pi, and in particular the release of the Pi 2, which is a powerful and cost-effective platform. The Pi’s GPIO (General Purpose Input Output) can interface with many common electronic components, such as sensors, relays and transistors. All of which can be programmed using Python and other languages. The Pi…

Sensors are an exciting method of automatically generating input which can be used to trigger events based on movement, sound and light etc. The Raspberry Pi can be connected to many different types of sensor. In this project we use a simple, passive infra-red sensor to detect movement. It operates by sending a current to the Pi when triggered. Another type of sensor that could be used is an ultrasonic sensor, which sends a pulse of ultrasonic sound to determine the distance of an object from the sensor. This is a great sensor but it requires a little mathematics in order for it to work. Both the PIR and ultrasonic sensor can be picked up for less than £3 on eBay. The Pi can only directly use digital sensors as…

In this project we used a 12V power supply to power a pump, but you may be asking why we had to use a relay? The Pi can’t tolerate voltages over 5V and to use anything above that would risk damaging the GPIO or the Pi itself. A relay is a magnetic switch triggered by a circuit connected to the Raspberry Pi. This circuit is 5V tolerant and when activated it enables a magnet which pulls a switch inside the relay closed. There’s no connection between the Pi and high voltage circuit, which means we can safely control high voltages. We used the Piface Relay Plus board which comes with four relays attached. Alternatively, you could use a relay on a breadboard, but for safety reasons we would suggest only…

Another Linux option is to go down the Android route. A few brave companies have attempted to push Android laptops and Android hybrid devices, such as the Dell Venue 10 7000 [see Reviews, p17, LXF202]. An alternative to this is to get an Android tablet and pick up one of the many Bluetooth keyboard case options or alternatively just buy a Bluetooth keyboard and mouse, as Android via the handy Linux kernel does support pointing devices and full keyboards. The limitation as with Chromebooks is that many won’t see Android as a full GNU/Linux distro and people do have a reasonable point. We’ve used a Nexus 5 to write on with a separate Bluetooth keyboard. It works but multitasking is highly limited, as you might expect, in terms of when…

How times change. Previously I might have been found impatiently refreshing web pages for the launch of festival or gig tickets, but recently I was hitting the reload button waiting for the release of a government draft policy paper. I was eager to read the Draft Investigatory Powers Bill (which can be found at http://bit.ly/DraftIPBill). This was published with quite a lot of publicity (and, it has to be said, an unusual amount of pre-briefing to the press). The early twenties version of me would be horrified! This is a large document as it turns out. Its 299 pages in total, accompanied by another 26 separate documents, which are impossible to summarise in the 300 words allowed for the column! There’s a lot of ongoing analysis available on the internet,…

KDE 4’s January 2008 release was met, as is traditional, with a barrage of criticism. Initial concerns focussed on instability and a lack of polish, and moved on to the over-configurability of the manifold ‘plasmoids’ and finally settled on the burden that it placed on system resources. The end product was radically different to KDE 3.5, which jarred long-time users. But this is the price of getting contemporary and KDE 4 has undoubtedly brought the desktop environment out of the Windows XP era. Transitioning to the Qt4 toolkit made for slicker-looking applications, and the switch to the Plasma framework allowed for a consistent desktop informed by modern design elements. Yet for all the changes, KDE 4 largely stuck with the traditional desktop metaphor, with menus and application pagers and system…

Modern Gnome is a desktop environment where the traditional desktop computing metaphor meets best practices from the mobile world of easy-to-use touchscreen devices. But, if we cast an eye back to the past, it wasn’t always this way, we remember when the previous generation of Gnome (2.x series) was dominating on Linux desktops, which helped bring it to an enterprise-level quality. Gnome 2 inspired Red Hat engineers to roll out their beautiful Bluecurve theme that was the first attempt to unify the look and feel of GTK-base and Qt-basedapplications. This was a couple of years after, Novell triumphed with its innovative XGL desktop, which was also based on Gnome 2. There are also many other reasons why Gnome 2 matters and why many people miss the desktop despite the Gnome…

Our expert Matt Hanson loves playing games on any platform – as long as it’s fun and lets him put off real work, he’ll play it. Gaming Install and set up Games for organising your Linux games collection Gaming on Linux is getting easier than ever before with services, such as Steam, offering you easy access to hundreds of new and classic computer games. While the growing number of services and websites that offer Linux compatible games is certainly welcome – allowing an increasing number of gamers to move from Windows – it can mean your games collection can become unruly with no consistent way to find and launch them. Not only are games saved in different folders and hard drives, but some require you to launch them through another…

Our expert Mayank Sharma hasn’t worked as a sysadmin as he’s too busy writing about how to set up and manage Linux for all kinds of tasks on many systems for LXF’s loyal readers. Imaging Xxxx Use Fog to create a base image and upload it ready for deployment Managing a network of computers is an involved process. Before you can tackle the problem of actively monitoring the machines, you have to install an operating system on each one of them. This is a time-consuming task even for a small network with about 10 computers. Computer cloning involves setting up the operating system, drivers, software and data on one computer, then automatically replicating the same setup on other computers. This technique, known as ghosting or imaging, is used by system…

There are several ways of combining disks to form a RAID array, each of which have their own advantages and drawbacks. In these descriptions, N refers to the number of devices in the array and S is the size of each. The commonly seen levels are: RAID 0 Not really RAID, as it just joins several disks together. You are better off using LVM for this. No resistance to failure. The total size N * S. RAID 1 This is two or more disk with all data mirrored across all disks. It tolerates failure of N - 1 disks, total size is S. RAID 5 A RAID of three or more disks with data and parity information distributed so that any single drive can fail with no loss of data.…

The best time to partition is when you’re setting up a fresh install. In Ubuntu, when prompted to erase the disk, select ‘Something else’ and click ‘Continue. You’ll see a single device – /dev/sda – is set up. Click the ‘New Partition Table…’ button, read the warning and click ‘Continue. Now select the free space and click the ‘+’ button next to Change to create a partition. Let’s begin with the main system partition. This can be as little as 15-20GB space, but make it larger if necessary. Once you’ve calculated how much you need in gigabytes, multiply it by 1,024 and enter the figure in the Size box. Leave ‘Primary, ‘Beginning of this space’ and ‘Ext4 journaling file system’ selected, choose / under Mount point and click ‘OK’. Select…

Our expert Mihalis Tsoukalos is a Unix admin, a programmer, a DBA and a mathematician who enjoys writing articles and learning new things. Perl 6 is the latest version and it supports object-oriented programming, including generics, roles and multiple dispatch, as well as functional programming primitives, including list evaluation, junctions, autothreading and hyperoperators. One major new feature is support for multi-cores, and it also supports definable grammars which increases the pattern matching capabilities of Perl, and enables developers to perform generalised string processing. We’ll be using Rakudo, a compiler for Perl 6 code. You can install Perl 6 on an Ubuntu distro with sudo apt-get install rakudo . (The full install process is pictured, above.) Despite the name of the package, the compiler‘s executable is called perl6. Use $ perl6…

Our expert Jonni Bidwell is rumoured to be a mechanical Turk, it would explain the rat-a-tat of gears as he produces words in exchange for bread and beer. Legend tells of one Sissa ibn Dahir who invented the game of Chess for an Indian king. So impressed was that king that he offered Sissa anything he desired as a reward. Being of a calculating bent, Sissa replied “Then I wish that one grain of wheat shall be put on the first square of the chessboard, two on the second, and that the number of grains shall be doubled until the last square is reached: whatever the quantity this might be, I desire to receive it”. The king soon realised that there was not enough wheat in the world to fulfil…

This month we answer questions on: 1 Blank boot screen issues 2 Installing to RAID 3 OpenVPN 4 Multiple monitors 5 Sending to root files 6 Virus risks using Linux * How to boot Windows 10 from Grub 1 Blank screen of nothing I’m having trouble with Ubuntu 15.04 on LXF198. It boots to a blank screen on my Dell Dimension E521 with Nvidia adaptor. I don’t see a safe boot option. Is there a work around? If I can get the DVD to boot, how can I make sure the same doesn’t happen after I install Ubuntu? Wandersman57 A blank screen during boot is often caused by kernel modesetting not getting on with certain combinations of Nvidia (and Radeon) graphics cards and driver combinations. Kernel modesetting is where the…

RAMming speed Processors these days are fast, really fast. Unless you are gaming, rendering video or compiling large programs, you are unlikely to use more than a fraction of your available horsepower. More time is lost on I/O these days, transferring large amounts of data to and from storage devices. One way of greatly speeding up this process is to switch from spinning disks to SSDs, which are much faster. However, they are also far more expensive, especially if you have a lot of data. There is often a cheaper, although not as effective, method of improving the situation - by adding more memory. If you have looked at a system monitor, or the output from free, you may have wondered why Linux uses so much of your memory and…

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,…

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…

There’s bad news for people running Google’s Chromeweb browser on 32-bit Linux distributions (distros), as Google will end official support for those platforms in March 2016. While the browser will still work on distros like Ubuntu Precise (12.04), and Debian 7 (wheezy), they will no longer receive essential updates and security fixes. Google does intend to continue to support 32-bit build configurations for Chromium. Managing your Docker containers is an important part of many people’s jobs, but does it have to be a boring one? The rather impressive Dockercraftproject lets you visualise and manage Docker containers in Minecraft. Sure you can only use it on your local machine for now as it doesn’t support authentication, but it shows you what a bit of imagination and inventive coding can achieve. You…

Blackpool Makerspace Blackpool Makerspace, 64 Tyldesley Road, 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 Coding Evening Help teachers learn computing and have have a beer. Various locations across the UK. www.codingevening.org Egham Raspberry Jam Gartner UK HQ, Quarterly. Next one January 2016. Date to be finalised http://winkleink.blogspot.com 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. 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…

Specs ... OS: Android 6.0 Display: Amoled 5.7-inch, 1,440x2,560, Corning Gorilla Glass 4 CPU: Qualcomm Snapdragon 810 v2.1, 2.0GHz octacore 64-bit GPU: Adreno 430 RAM: 3GB Storage: 32GB, 64/128GB options Camera: 12.3 MP2; 1.55 ›m; f/2.0, front 8MP Battery: 3,450mAh Comms: Wi-Fi 802.11a/b/g/n/ac dual-band, A-GPS, Bluetooth 4.2 LE, NFC, USB Type-C Sensors: Fingerprint, accelerometer, gyro, proximity, compass, barometer Size: 159.3x77.8 x7.3mm Weight: 178g The Nexus 6P is Google’s flagship Android phablet for 2015/16, but with a 5.7-inch display and cheaper price it won’t stretch your hand or your wallet quite as far as the 2014 Nexus 6. The ‘P’ in the Nexus 6P’s name stands for ‘Premium, thanks to its all-metal unibody design that’s meant to rival the aluminum iPhone 6S Plus and glass-and-metal infused Samsung Galaxy Note 5. It’s…

While a simple image viewer wouldn’t need much documentation, the photo managers in this Roundupare all multifaceted. Some, such as DigiKam and KPhotoAlbum, have detailed documentation that you can read in various formats both online and offline. The DigiKam wiki has several user-contributed tutorials that cover a wide range of topics: from basic features to advanced image editing. The project doesn’t have a forum, but there is a mailing list to get support for problems not covered in the docs or the FAQ. KPhotoAlbumalso hosts a wiki and a mailing list. Besides textual documentation the project has several videos that introduce different features. While the videos are based on an older release, they do cover some essential functionality provided by the manager, such as facial recognition. Shotwell’s website offers brief…

Controlling high voltage devices is a project for those that know their stuff but with Energenie we can significantly reduce the risk. Energenie units at their core are simply 433MHz receivers that control a relay; a component that uses a low voltage to control a magnetic switch in a high voltage circuit. On the Raspberry Pi we have a transmitter which can instruct the receivers to turn on and off. Energenie units are a safe way to control mains electricity. The standard Python library for Energenie is rather cumbersome, requiring the user to control the GPIO pins used by the transmitter in order to connect to each device and issue the correct instruction. This library has been made a lot simpler thanks to Ben Nuttal, a member of the Raspberry…

The Raspberry Pi has made many different types of projects possible and one that’s popular is CCTV. The official Pi Camera, along with the Pi offer a low cost, high quality and low-power project you can build quickly. In this project, we used motionto stream our webcam to a webpage, but motioncan be used to search for motion and stream as well, eg we can record a video stream to a local or cloud device which will be triggered by a burglar, baby or Jack Russell terrier. Add a Passive Infra Red (PIR) sensor to this code, such as the one used in our delivery watch project, and you have a powerful application that can alert you to incidents and record the evidence. Another great application to use with a…

When the business world comes knocking companies pay attention, largely as there’s cash to be had. Because of this if you’re on the lookout for a high-end workstation you’re going to have a much better time of it. There are segments of the business world that do demand Linux-supported devices – eg NASA and the petrochemical industry – and happen to have large pots of cash. This also means those workstations aren’t cheap. We’ve mentioned the Dell Precision range and we’ve reviewed the HP Zbook 15u G2 [see Reviews, p17, LXF196] and plan to review the new Lenovo ThinkPad P70. These are heavyweight laptops and in many ways are more like mobile desktops. But if you’re interested in doing heavy number-crunching on the move, these are more than capable. We…

Elastic are the company behind the Elk stack (previously known as Elasticsearch until March this year). As per a lot of companies founded on open source, they offer a variety of paid support contracts for their software stack, as well as offering other ‘enterprise’ type arrangements for some additional software. The big selling point of a contract is, of course, that they are the people who actually write most of the code for these products. At the highest support level (price on application) they will provide emergency patches for bug fixes. Having taken a fair amount of funding, the company has expanded into offering cloud based hosting for an ELK setup – a ‘managed’ solution in other words. The company’s commercial offerings include Shield (which provides encryption, role-based access control…

Use of the KDE tricronym to refer to the desktop environment began to be phased out after version 4.5, which was released with another two letters, becoming KDE SC (Software Compilation). Nowadays, the KDE monicker tends to refer to the whole community centred around the desktop. While the underlying Qtlibraries have always been separate from the desktop environment that they power, KDE 4 gave rise to a number of auxiliary libraries (collectively lumped together and referred to as kdelibs), some of which were part of the desktop itself, and some of which were only required for certain applications. In the latest incarnation of the desktop, these libraries have been updated and rearranged: some of their functionality is now provided by Qt components, some have been annexed into a collection referred…

The cottage industry around the development of new music players for Linux continues, and this time we’ll take a look at a Deadbeef. The name may sound strange, but it’s just a magic hex number that spells a word, in this case 0xDEADBEEF. Visually, the player looks neat and compact, it has playback and volume controls on the top and a playlist area below it, welcoming a user to drag and drop music there. There are some interesting features that make Deadbeef distinctive, which you may want to try. First, it automatically splits CUE files to tracks and enables gapless playback for FLAC, APE, TTA, Ogg Vorbis, Wavpack, WAV, MPAC and ALAC formats. Unlike many other players that cut off silence at the start and end positions to achieve the…

You’ve probably heard us mention Steam in these pages before. It’s a platform created by Valve (perhaps best known for the Half-Life game series) and is a store front for hundreds of games. At its heart, it’s a method of DRM and although we’re not huge fans of that, it does come with loads of cool features such as cloud saves, which enable you to save your progress on one machine and pick up where you left off on another, and in-home streaming. This feature is in its infancy at the moment, but already allows you to stream games from one PC over your home network to another PC. At the moment you can’t stream from one Linux PC to another, though streaming from a Windows PC to a Linux…

Fog is a complex piece of software and while we’ve covered the core feature of the server, it ships with several more. The Fog server is scalable and can manage large networks spread over multiple locations in the same building or around the world. It allows you to arrange hosts into several groups for easier management. One of the most useful features of the Fog server, especially for admins of larger networks, is the multicast ability. Using this feature you can deploy multiple machines in one go. However, to use this feature successfully you’ll need to make sure your Fog host has enough computational and network resources to stream multiple images simultaneously. For such larger networks, you can have multiple Fog installations configured as storage servers. These storage servers share…

Our expert Nick Peers has been hooked on Linux – starting with Ubuntu and now Minibian – for 10 years. His preference for GUI tools is tempered by a growing love of the Terminal. Hard Xxxx drives Divide your drive into partitions to protect your data Partitioning allows you to carve up a single physical hard drive into smaller, virtual drives known as partitions or volumes (although there is a difference, as we’ll explain later). Each volume acts independently of the others, providing a measure of redundancy for data that’s spread across the drive. If one partition develops problems then you can restore it without affecting what’s stored elsewhere. This redundancy provides the first of a number of reasons to partition your drive: it allows you to move your personal…

It’s now easier and simpler to convert a proper string to its numerical value. As both numbers and strings are objects, the conversion is done using a built-in object method. The base() method takes two arguments: the first is the base of the number and the second, which is optional, defines the number of digits that will be used when dealing with fractions. If the second parameter is omitted, then a default value is chosen which is 0 for integers and bigger for other types of numbers. The .chr method turns an integer into a single unicode character. Objects of type Str, a built-in class, are immutable. You can define an immutable string as follows: Please note that the use of the := operator. Perl 6 supports binding with the…

In 1770 Baron Wolfgang von Kempelen wowed the Viennese court with ‘The Turk', a clockwork automaton sat before a chessboard. Kempelen claimed that his invention would best any human chess player. Indeed, the Baron and the Turk travelled around Europe and wowed onlookers with the latter’s prodigious talent. The Turk was a hoax, and its talent actually belonged to the poor person hiding under the table. However, it inspired people to think more about chess playing machines, and in 1950 Shannon and Turing both published papers on the subject. By the 1960s computers were playing reasonable chess: John McCarthy (dubbed the father of AI) and Alan Kotok at MIT developed a program that would best most beginners. This program, running on an IBM 7090, played a correspondence match via telegraph…

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…

* Wrong Windows One of my computers dual-boots Ubuntu and Windows 7 (my wife has been using it and hasn’t noticed), I tried the free upgrade but on reboot it’s still looking for Windows 7 not 10. How can I restore the MBR so it can’t see Linux? I can then upgrade and restore Grub. John Warburton There is no need to restore the MBR, that will make your Linux installation unbootable. You can continue to dual-boot with Windows 10. You are currently using Grubto boot, but it will not know that you have switched to Windows 10, so you need to tell it. Boot into Ubuntu, open a terminal and run $ sudo update-grub . This will scan your system for installed operating systems and pick up on Windows…

Here in the UK, we have yet another piece of surveillance legislation going through Parliament, the Investigatory Powers Bill. This will make mass surveillance legal and even require ISPs to keep records of their customers’ online activities for the past year. The only good thing about this is that at least it’s now out in the open, after the revelations of recent years regarding government mass surveillance, and is being discussed in an open forum. Not everyone lives in a society where basic liberties are acknowledged or even discussed, so we should take care to preserve those rights. It is quite timely that we have the latest release of Tails on this month’s DVD. This uses open source’s ability to take pieces from various projects and combine them in a…