Linux FormatJanuary 2017的目錄

Jonni Bidwell Whenever they sigh because Windows Update decides that now is the best time to instigate an unfortunate series of updating and rebooting events, casually mention that not all operating systems behave this way. Also show them how to do simple terminal stuff so they can pretend to be like the hackers on Mr. Robot. Neil Bothwick By telling them to forget about how Windows does things. The biggest cause of problems for new Linux users is trying to apply Windows methods. Linux is not “like Windows but better and free”, it’s just better (and freed). Failing that you can always break into their house and change all their systems to Linux while they sleep. Nate Drake I first tell people who own an Android smartphone that they have…

We’ve reported previously on Microsoft’s embrace of [death?–Ed] open source, and while we’re cynical old hacks at heart, we were pleased to see such a big corporation, who used to be so hostile to open source, apparently changing its ways. Now, Microsoft has taken a big step by joining the Linux Foundation, the non-profit organisation for advancing open source projects, as a Platinum member, while John Gossman, an architect on the Microsoft Azure team, will join the Linux Foundation board of directors. Microsoft already contributes to a number of Linux Foundation projects, such as Node.js Roundation, Open API Initiative and the Open Container Initiative, so this move has not been completely surprising, though it would have been practically unthinkable a few years ago. Scott Guthrie, Executive Vice President, Microsoft Cloud…

SPARKYLINUX 4.5 The Debian-based SparkyLinux has been updated to version 4.5, which brings LibreOffice 5, Linux kernel 4.8.7 and system 232. It also drops the Pantheon desktop environment, with both the Deepin desktop and Common Desktop Environment (CDE) offered as replacements, alongside existing desktop environments LXDE, LXQt, KDE, Mate and Xfce. Support for the exfat file system has also been added. The Sparky MinimalGUI and Minimal CLI allow you to install SparkyLinux with a minimal set of applications to suite your needs. For more information check out the release notes at http://bit.ly/SparkyLinux4_5. ZENTYAL SERVER 5.0 A major new release of the Ubuntu-based Zentyal distro has been released. Aimed at small business servers, Zentyal Server 5.0 is the first build to be based on Ubuntu 16.04 LTS and includes Samba 4.5.1,…

Determining what group an article is aimed at without having to read at least half-way through, and your insistence on pushing Ubuntu is irritating. I realise that Ubuntu is currently the most popular distro, but that just makes it worse; the most popular distro needs no drumbeating. As you say, ‘apt get...’ could be replaced by any installer, so I would suggest that the large amount of column-space wasted with installation instructions for each featured software should be reclaimed by putting at the end of the article a box containing the components needed, making more space available to discuss the software’s features etc. Leslie T, via email. Neil says: This isn’t about promoting any one distro, it’s about providing reader support and I’d consider it bizarre not to provide tutorials…

Specs... Minimum: OS: Ubuntu 16.04, Steam OS 2.0 (64-bit only) CPU: Intel Core i5 3.4GHz, AMD FX 8350 RAM: 8GB RAM GPU: Nvidia GeForce GTX 660 Ti with 2GB (driver: 367.35) HDD: 35GB NB: AMD and Intel graphics not supported Max finds himself left for dead in the desert – and worse, his iconic Interceptor stolen – after a run-in with a hulking warlord, Max joins forces with a fawning, mechanic named Chumbucket who agrees to help Max build a new car so he may seek revenge and get his original wheels back. Welcome to the open-world wasteland, you’ll randomly encounter lone vehicles or multi-car war parties bristling with spikes, loaded with explosives, or carrying crews of hooting War Boys. Luckily, you’ve got something they don’t: a kickass car-mounted harpoon.…

Specs... OS: Sailfish OS 2.x Display: 720x1280 IPS LCD CPU: Snapdragon 212, Quad-core 1.3 GHz Cortex-A7 GPU: Adreno 304 RAM: 2GB Storage: 16GB Camera: 8 MP rear, 2MP front Comms: Wi-Fi 802.11 b/g/n, Buetooth v4.0, A2DP, EDR, A-GPS, GLONASS Radio: Dual SIM GSM,HSPA,LTE Ports: micro USB Battery: Li-Ion 2500 mAh Size: 142x72x9.6 mm, 150g Jolla C is the second much-anticipated smartphone from Jolla, the Finnish software company, which was launched in May 2016 running Sailfish OS. The first Jolla smartphone came out in 2013 and had low hardware specs and felt more like a continuation of the innovative Nokia N9 of 2011 which was powered by the Linux-based Meego. Back then Jolla had big ambitions, such as the concept of changeable ‘other half’ covers that could be turned into a…

Some distros actively share and help their users get unstuck. For instance, WattOS posts release details on its blog and support can be sought through release-specific forum boards that are fairly active and you can chat with the developers using a help desk on the website. However, the distro ships with no documentation. There’s also no documentation inside Cub Linux but it has fairly active forums with a useful cross-section of boards including several for dispensing help and another for collating documentation. There’s a section on LXLE’s website with links to video and reviews created externally. The support section points to the forums, wikis, mailing lists and IRC channels of the LXLE distro as well as the LXDE desktop. The LXLE forums are a better source of documentation with a…

There are a large number of projects that are working to make good use of an outdated computer. If you are ready to go out of your comfort zone, there are esoteric options such as SliTaz, Tiny Core Linux and Puppy Linux. There’s also VectorLinux, which is available in several variants including a Light Edition that uses IceWM. Also, don’t overlook the Lubuntu and Xubuntu spins of the Ubuntu project. There’s also Emmabuntüs which is designed to ship with reconditioned computers assembled by humanitarian organisations from donated pieces of hardware. Alternatives to the cloud-centric Cub Linux, include Peppermint OS which has a lot more online apps than Cub. Besides the usual Google apps, there are several online tools such as Editor by pixlr.com and a bunch of games. There’s also…

It’s a strange concept, but Linux really does treat everything as a file. Storage devices, e.g. hard drives, can be found at /dev/sda, /dev/sdb etc and their partitions are referred to as sda1, sda2. Partition information can be displayed with the lsblk command. We can garner technical information on the system’s processor using cat /proc/cpuinfo , or cat /proc/meminfo for memory stats. The partition where Linux is installed is mounted as the root directory /. This is about the closest thing to the C: drive in Windows, but the two abstractions have some key differences. For one thing, other partitions are mounted as directories inside the / hierarchy, e.g. a hard drive might be mounted at /mnt/backup or an auto-mounted USB stick at /run/media/user/thumb. Furthermore, there are pseudo-filesystems, e.g. /dev,…

Many people are put off Linux by large software companies who don’t make Linux versions of their popular commercial wares. Most commonly, Microsoft Office, Adobe’s Creative Cloud suite and many AAA games (although that is changing). Yet many people don’t really need these: LibreOffice can handle most Office files, while GIMP, Inkscape, darktable and Krita can certainly give Photoshop, Lightroom and Illustrator a run for their money. Cloud storage services such as Dropbox can be integrated into the Linux desktop, but we could also go one better and set up our own Nextcloud instance. If you really must talk to your coworkers, a Slack client is available and Microsoft are even working on a new Linux Skype client. In the meantime, the old one more or less works. Most distros…

The four cores held within Intel’s Core i5-6500 provide plenty of computational power when it comes to modern workloads, but if you’re looking to game, you’re going to need to invest in a new graphics card. In short, there’s never been a better time to buy a contemporary graphics card than right now. With both AMD and Nvidia making the jump from a 28nm processing node down to 14 and 16nm respectively, the power gains in graphical horsepower has been an exponential jump, with both AMD’s RX 480 and Nvidia’s GeForce GTX 1060 providing phenomenal value for money [I can only afford a GTX 1050–Ed]. In our testing the GTX 1060 3GB is by far the best value card you can buy right now. If you’re looking to game at…

The old mantra goes, if you want a cheap and cheerful core, go AMD. If you want a powerful core, go Intel. At least, that’s how it used to be around seven to eight years ago. Alas, the game has changed and AMD’s ageing architecture just cannot keep up with the powerhouse that is Intel. Skylake dominates the field when it comes to performance per watt and AMD just can’t keep up because of it. With an ageing architecture and chipsets that just don’t provide any of the modern features natively, AMD is sorely in need of an update. That’s where Zen comes in. Due to be released early 2017, the new line of processors will fit into the AM4+ socket, consolidating all the previous motherboard choices down into a…

SSDs first launched just over six years ago in 2010. They were volatile, not particularly fast and ridiculously expensive. Since then, we’ve seen capacity grow, prices drop and speed and stability increase to the point where you can now buy a 120GB SSD capable of sequential read and writes speeds of up to 550MB/s for little more than £50. However, soon after we saturated that bus, M.2 was launched. A continuation on mSATA, the idea of M.2 was simple: bypass SATA entirely by transferring sensitive data across the PCIe bus instead. This way you could circumvent the 565MB/s maximum and have far faster drives in a far smaller form factor. At first these PCIe drives came as big bulky add-in cards, laden with heatsinks and memory chips. They still used…

Many years ago now, I recall a colleague emailing me the output of a command showing details of a newly built filesystem. Not just any filesystem mind you— this was the first one we’d ever created which broke the magical 1TB ceiling. Even more impressive than that (you had to be there, I guess), it was mirrored between data centres using the proprietary software we used at the time, via a dedicated cross-site link which could handle a (then) huge amount of bandwidth and a SAN which connected our ridiculously expensive servers to equally expensive disk arrays. Happy days indeed. For hardware vendor sales people anyway. It’s a different ball game nowadays with hardware costs at a fraction of what they were (if you actually need your own hardware), our…

The goals in Raspberry Pi’s early days were earthbound, but then Dave Honess joined the team and everything went to infinity and beyond! Dave is the lead for the Astro Pi project, which sees two Raspberry Pi computers complete with Sense HAT boards being housed on the International Space Station until 2020. The project asked children across the UK to write their own code-based projects using these devices. If their project was chosen, then it would be uploaded to the ISS and ESA Astronaut Tim Peake would run the code in space! Well, it’s no secret that this project was insanely popular and it has ignited a new interest in space and the sciences. A subject as rich and challenging as space is an awesome cross-curricular fountain of inspiration and…

LEDs (Light Emitting Diodes) are the most basic of components; they permit current to flow in one direction and the output of that current is the light that we see. But the humble LED can only go so far before we need something more powerful and flexible and this is where the WS2812 LED comes into play. The WS2812 standard, commonly referred to as NeoPixels, is a brand name created by Adafruit and is used to identify a string of LEDs that can have their brightness and colour individually controlled. WS2812 LEDs come in many forms, from single ‘pixels’ up to many metres of pixels chained together. Each pixel has a data in and a data out pin. This data is communicated via pin 18 of our Raspberry Pi using…

In order to make sure your setup is secure you’ll need your own Mumble Server. You can set this up yourself on a separate Raspberry Pi if you only plan on communicating over your home wireless network e.g for an intercom. Alternatively, you can rent a Mumble server online. If you want to play around with a mumble server of your own you can get a free one month trial at http://www.mumble.com/free-mumble-server.php. Once your server is setup note down the domain name and its port. You should also think of a username you’d like to register and set up a channel specifically for you and your friends. (The default is Root). Next connect to your Pi via SSH or open the Terminal and run the command to edit TalkiePi’s configuration.…

There are numerous environment variables out there —sadly there’s no documentation within Ubuntu to provide you with a neat set of definitions for each one, but visit http://bit.ly/EnvironmentalVariables for a comprehensive list. In the meantime, get a head start with these commonly used variables: PWD This contains the path to your current working directory and so changes as you move between directories. OLDPWD contains the previously accessed directory. TERM The type of running Terminal being used, which is addressed by programs wishing to use specific Terminal capabilities. COLUMNS/LINES Sets the default number of columns (80) and lines (25) for the console. Try adjusting these if lines don’t wrap. PWXDG_CURRENT_DESKTOP The current desktop environment being used. USER/LOGNAME The name of the currently logged on user is recorded in both of these…

When you want to update your local copy to the latest version, move into the directory and ‘pull’ the difference. Git handles both files and directories under the directory that we’ve just cloned. Note that any files we want to add must be added both to the directory and then added into git. Git has a lot of features that we haven’t used in this tutorial, but we may need to use the version control system’s pull command: When this command is run, git starts by checking that it is in the correct directory tree by checking the contents of the .git directory. The next step is to determine what changes has been made since last time it was synced and merge these changes into your local copy. The command…

1 Basic scanning The most common use of Nmap is to find all online hosts within a given IP range. The default command used for this takes some time to scan the complete network, the total time depends on the number of hosts present on the network. However, we can optimise the process in order to scan the range faster. The time taken to complete the scan here was 6.67 seconds when scanning 100 hosts. If the whole IP range for a particular network is to be scanned, it would take a lot more time. 2 Faster scanning Now, let’s try to speed up the process. The n switch tells Nmap not to perform the DNS resolution of the IP addresses, hence making the process faster. The T switch tells…

Each subvolume is a part of a filesystem with its own directory hierarchy that mimics the structure of any other Linux filesystem. This means that like partitions, subvolumes can be mounted and they are also similar to directories, in that each subvolume can further hold files, directories and other subvolumes. There’s also no limit to the number of nested subvolumes you can create. The contents of a subvolume can be accessed the same as you would a directory. But you can also mount a subvolume as a separate filesystem, using the mount command and providing a mount point. On a SUSE installation, the freshly created / filesystem is also a subvolume. Snapperwill only create snapshots of specified subvolumes and not just any directory of your choosing. For instance, you can’t…

LaTeX is a great tool for typesetting documents and books, which is used by many students, researchers and professionals. So, being able to bring your Graphviz output to LaTeX is very handy because Unix tools aren’t isolated entities. The dot2tex utility does exactly this! On a Debian system you can install it as follows: The following command shows how to use dot2tex in order to convert our example file, simple.dot to LaTeX format: The previous command has two parts. The first part is the execution of the dot command; what dot does here is generate a file that’s suitable for the dot2tex utility that becomes the input of the dot2tex utility using a Unix pipe (second part). The output of dot2tex is saved in a new file named simple.tex…

1 Mini media player Q I have an old versions of the WD TV Live Media Player Wi-Fi 1080p. Unlike my Roku 3, which is unable to connect to any computer, the WD TV easily enables me to connect to my computers. I read that Western Digital will no longer sell these devices. I would like to know if there’s anything in Linux that we can use to create our own device. I like the WD TV media player because I can connect to my CentOS computer which has Samba set up to share my movies. The WD TV connects to as a ‘windows server’ and I can play back my videos on my TV. Is it possible to make a similar device out of a Pi? tpgbz4z A I…

Star Question ★ Ergonomic mousing Q I am a relative newbie using Linux Mint 17.1 Rebecca Mate 64-bit. I have an Evoluent vertical ergonomic mouse with a third (middle) clicker button, plus two-thumb clickers. Is there any software available for configuring the nonstandard mouse buttons so that they have functionality within Mint? I’ve looked in the Software Manager but don’t see anything. HM A The tool for altering input device settings, including mouse button mapping, is xinput . This is a shell command, there doesn’t appear to be a decent GUI configuration tool for it (there are plenty for trackpads, but not generic pointing devices). However, xinput isn’t hard to use and makes experimenting with different settings easy. First, you need to identify the ID of your device with $…

Are Linux users becoming more conservative or is it just me? It used to be that we wanted the latest software, and we wanted it now! Nowadays, it seems like new ideas are to be avoided. KDE’s semantic desktop, Gnome 3, Unity and, most of all, at least so far, systemd. The vociferous minority seem to shout and stamp their feet every time something comes along that is not ‘the Unix way’, whatever that really is. The funny thing is that things carry on working and the vast majority of users are still happy. Ubuntu is still the most popular home distro out there, despite all the furore over the switch to Unity. It has now started using systemd, but most users probably won’t even notice any difference. What has…

When was the last time you tried to get someone to use Linux? A family member, a friend, your workplace, heck, how about your entire government? It all starts with a simple install, but unless there’s someone there to give them a disc or the right download, it’s only the lucky few that are ever going to discover Linux for themselves. Considering it’s nearly impossible to buy a new PC preinstalled with Linux it really is down to people to get into Linux themselves or with a little help from their friends… So if you’re new to Linux we have a complete guide to get you started, it’ll hold your hand, explain how to use live discs and try Linux in a virtual machine, so you don’t even need to…

At the end of 016, Lenovo faced a consumer backlash after it announced that the Yoga 900 and Yoga 900S hybrid laptops (which can be folded into a tablet mode), along with the IdeaPad 710 device could only support Windows. After a furious response, Lenovo has now taken the step of releasing a BIOS update that adds an AHCI SATA mode so that users can now install Linux. Lenovo had claimed that the unique designs of the Yoga laptops meant that only Windows 10 was supported, and created further confusion for a time over whether future hardware would support Linux after it emerged that new Kaby Lake chips from Intel and AMDs upcoming Zen chips, would only support Windows 10. Lenovo’s climbdown over Linux support is welcome, but it still…

“Everyone is talking about DevOps. The integration of software developers and operations personnel is one of the hottest topics in IT right now. The idea is simple: let’s break down the barriers between those who know exactly why they are building a particular piece of software and those who are maintaining the IT infrastructure, and professionals will be able to make much better judgements about how to deploy and integrate software continuously. What started as a cultural movement has grown into a central element of the modern IT landscape—and a rapidly growing career field. This overwhelming success wouldn’t have been possible without a little help from open source. It was a very organic process: the moment the DevOps community noticed a tool was missing, it set out to create it.…

Find and join a LUG Alpinux, le LUG de Savoie, France Meet on the first and third Thursday of the month at the Maison des Associations de Chambéry. www.alpinux.org Bristol Hackspace Studio G11, 37 Philip Street, Bedminster, Bristol, UK, BS3 4EA http://bristol.hackspace.org.uk Cheltenham Hackspace The Runnings trading estate, Cheltenham. Thursday night is open evening from 7pm. www.cheltenhamhackspace.org LAMM (Lancaster and Morecambe Makers) Unit 5, Sharpes Mill, White Cross, Lancaster, Open Night on Wednesday from 6:30pm til late. www.lamm.space Huddersfield Raspberry Jam Meet every month at Huddersfield Library, typically the fourth Saturday of each month. huddersfieldraspberryjam.co.uk Hull Raspberry Jam Malet Lambert School, Hull. Every other month. https://twitter.com/hullraspjam North Kent Raspberry Pi User Group Every 2 weeks at Medway Makers, 12 Dunlin Drive, St Mary’s Island, Chatham ME4 3JE. https://nkrpug.wordpress.com Preston Hackspace…

Many people are put off dabbling with Linux by the fear of damaging their current install. In theory installing side-by-side with an existing operating system will work just fine, but there’s plenty of stories online detailing situations where this hasn’t happened. This is usually due to user error, or the Windows bootloader acting like a spoilt child that it has to share its candy, but that’s moot because there are a few ways one can happily explore Linux without actually installing it: We can use the live environment from the installation media, or we can install it in a virtual machine (see below). Neither of these gives as smooth and polished an experience as an actual install, but both methods are delightfully risk-free. There are advantages and disadvantages to both—using…

One of the most daunting things a new Linux user will encounter is the jargon. There is so much terminology, nomenclature and more three letter acronyms (TLAs) than you could shake the detached appendage of a shrub at. This can be frustrating so here’s our jargon busting guide: Boot loader A small program that loads as soon as the PC’s BIOS or UEFI has finished initialising the system. Provides a menu from which multiple OSes may be booted. Its main job is to get the system into a state where the kernel can be loaded. The most common one is called Grub(GRand Unified Bootloader). Shell An application which allows commands to be typed and run on the system. Linux desktops and servers mainly use Bashas the default shell. Terminal Strictly…

An oft’ cursed bugbear is the labyrinthine complexity of video drivers in Linux. More precisely, the arrangements and rituals for installing the proprietary drivers from AMD and Nvidia, which for ideological (as in the case of Debian or Fedora) reasons may not be redistributed by a distro’s normal update channels. Many distros do provide packages for these, but since they require extensive and rigorous testing before inclusion, they often lag behind the GPU vendors’ releases. The open-source Nouveau driver for Nvidia graphics has been a tremendously successful project, while FOSS support for AMD cards via the Radeon (older cards) and AMDGPU (newer) drivers has greatly benefitted from AMD’s contributions. Intel too provide an open source driver for its integrated GPUs. So, excepting peculiar or Jurassic hardware, most Linux installs have…

Unless you’re some kind of god, then sooner or later you’ll encounter Linux not behaving as it should, or as you would expect it to. The first thing to do is to search the web for a solution, error messages and hardware model numbers are useful for this. It might be a frustrating situation, and unfortunately a lot of misinformation is out there. In general, it’s a bad idea to blindly copy and paste random code you find on forums when you don’t know what it does. You’ll rapidly discover there is a lot of outdated and just plain wrong information on the internet. Spend some time trying to figure out the problem (or proposed solution) first, stepping away from the screen or thinking about it overnight is seriously underrated.…

Paranoid, moi? A bit of me wonders whether a bottle or three of Boërl & Kroff Brut champagne (a mere £1,957 a bottle) was opened in certain quarters in November to celebrate the passing of the Investigatory Powers Act into law. This bill, variants of which have been previously failed to make it through Parliament (hence the celebration at it finally getting through), has been called “one of the most extreme surveillance laws ever passed in a democracy” by the Open Rights Group (www.openrightsgroup.org). I’m sure that some of the intentions behind the bill are well meant. However, given post-Snowden revelations and the recent ruling by the investigatory power tribunal that the security services operated illegally for years collecting vast amounts of communications data, I think I can be forgiven…

As with all the best tools, Gluster is very CLI driven (at least the open source version is—I’ve never used the Red Hat supported product). There are a few key commands worth knowing right from the start, especially for when things go wrong (which they can, despite Gluster being resilient). The $ gluster volume info command does exactly as you’d expect and gives a quick overview and status of volumes in the trusted pool. Use $ gluster peer status for a quick confirmation that nodes can see each other. The start|info|stop commands are handy for providing performance metrics, especially if there are suspicions that a particular node is lagging behind its peers in one way or another. Another really useful command to know is which gives some insights into the…

If you use an assignment expression to create a variable that doesn’t exist, then a new shell variable will be created. This type of variable only applies to the current shell, and unlike environment variables, it can’t influence how other applications behave. That said, it’s possible to convert an existing shell variable to an environment variable using the command, which will enable it to be used with programs and processes as well as the shell: . Alternatively, you can save time by using the command to create a shell variable and export it all in one go: . If you later wish to reverse this move without having to completely erase the variable in question, then use the flag to un-export it back to a shell variable, e.g.…

The sections available in the confuguration file are as follows: core This is used for choosing compositor options and load modules. In Ubuntu 16.10, we found the modules referenced in the manual page weren’t the same as the ones on our system. You can also choose your back-end here, this is not usually needed since the correct is chosen for your system. libinput The Input device configuration. At the time of writing, only enable_tap is available. shell Desktop customisation. Here you set the background and behaviours of your windows, such as fading at open and close and how many workspaces you want. This can also override the default weston-desktop-shell option, to use it, design your own or find a nice one on the web. launcher Add launcher to the…

As Linux’s popularity continues to grow, administrators are increasingly moving to the system to create networks and servers for a whole host of tasks. However, this means that Linux is also the first choice for many attackers. Practical Linux Security Cookbook is full of step-by-step recipes, screenshots and walkthroughs to take you through everything you’ll need to help you create more secure Linux systems, starting by introducing the various threats and taking you all the way to managing user authenticity both locally and remotely, mitigating network attacks, and learning to patch bash vulnerabilities and monitor system logs for security. Linux Format readers can get 50% off Practical Linux Security Cookbook by Tajinder Kalsi on www.packtpub.com by using the code CTPLSC50 at the checkout. Offer ends midnight on 31 January 2017.…

Our expert Mihalis Tsoukalos (@mactsouk) has an M.Sc. in IT from UCL and a B.Sc. in Mathematics, which makes him a DB-admining, software-coding, Unix-using, mathematical machine. You can reach him at www.mtsoukalos.eu. Graphviz Graphviz Learn how to create programs with GraphViz and the DOT language Graphviz is a collection of tools for generating directed or undirected graph layouts. According to The Design and Analysis of Computer Algorithms book by Alfred V. Aho et al: “a graph G(V,E) is a finite, nonempty set of vertices V (or nodes) and a set of edges E. If the edges E, that have the form of (a,b), are ordered pairs of vertices then we have a directed graph. If the edges E are unordered pairs of vertices then we have an undirected graph.” Yes,…

Our expert Mihalis Tsoukalos (@mactsouk) has an MSc in IT from UCL and a BSc in Mathematics, which makes him a DB-admining, software-coding, Unix-using, mathematical machine. You can reach him at www.mtsoukalos.eu. The subject of this tutorial is something very beautiful and impressive: fractals. After learning the required theory, you’ll learn how to plot extremely beautiful images using various programming languages. We’ll cover scripts in R, Perl, Python and LaTeX that you can easily port to the programming language of your choice. Although fractals and chaos theory are areas of advanced mathematics, they can also be fun from time to time, and generate impressive images—even if you don’t understand all the presented theory you should enjoy the produced images! A fractal is natural phenomenon and a mathematical set. Fractals present a…

SQLite 3 supports the INTEGER, REAL, TEXT, BLOB data types and the NULL value: INTEGER This holds integer values of up to 8 bytes depending on the value. REAL This will hold floating point numbers using 8 bytes. TEXT The TEXT data type holds text strings which are stored using the database encoding. Most of the time, this encoding will be UTF-8. Binary Large Object (BLOB) This data type is used for storing binary data like images and compressed files. NULL The NULL value is used for representing missing values or empty cells. As there’s no Boolean data type, you can use the INTEGER data type instead. Additionally, SQLite 3 uses the INTEGER, REAL or TEXT data types to store dates and times, e.g. the Unix time is stored using…

Linux Format is proud to produce the biggest and best magazine that we can. A rough word count of LXF217 showed it had 65,010 words. That’s a few thousand more than Animal Farm and Kafka’s The Metamorphosis combined, but with way more Linux, coding and free software (but hopefully less bugs). That’s as much as the competition, and as for the best, well… that’s a subjective claim, but we do sell way more copies than any other Linux mag in the UK. As we like giving things to our readers, each issue the Star Question will win a copy or two of our amazing Guru Guides or Made Simple books – discover the full range at: http://bit.ly/LXFspecials. For a chance to win, email a question to lxf.answers@futurenet.com, or post it…

What is DNS? DNS stands for Domain Name Service, which is effectively the internet’s phone book. How does that work? Every connected device is identified by a unique IP address, a numeric address, usually expressed as a sequence of four numbers separated by dots, like 80.244.178.150. These are not particularly easy to remember so we have domain names such as www.linuxformat.com. So the DNS system connects the names to the numbers? Exactly. When you type the web address, such as our website’s URL – www.linuxformat.com, into your browser of choice your web browser asks the system resolver to translate that into an IP address. The system what? The system resolver is the mechanism that the operating system uses to resolve domain names into IP addresses. It usually does this by…

“One troubling prediction is the rising sophistication of APTs that are tailor-made for individuals.” After a year that many people would characterise as ‘eventful’, it’s time to look back and learn from the security issues that cropped up in a bid to make the new year as safe as possible. A definite theme emerged in 2016, with ransomware becoming a troublingly effective method of making money out of cybercrime. In August, research from Malwarebytes showed that nearly 40% of all businesses have experienced a ransomware attack—with the figure even higher in the UK, where 54% of businesses surveyed had been victims of an attack. One-fifth of British companies claimed they had been charged over $10,000 to unlock their files and Malwarebytes’ research suggested that over half of businesses in the…

We’ve often said that storing all of your important files on a single large capacity drive is folly, and the recently-released Backblaze Hard Drive Failure rate for Q3 2016 report (which can be read at https://www.backblaze.com/blog/hard-drive-failure-rates-q3-2016/) backs up our advice by showing that the Seagate 8TB hard drive has a failure rate of 1.46%, with the Western Digital 6TB drive suffering from an unacceptable 11.31% failure rate. Meanwhile more sensible capacities, such as the HGST 2TB and HGST 3TB drives suffered from just 0.69% and 0.35% failure rates, respectively. Basically, use smaller hard drives to store your files, and avoid 3TB Seagate if possible! There’s not been much good news coming out of the US government recently, but there is a glimmer of hope with the ‘People’s Code’ project (https://code.gov/#/)…

Linux love I’ve been thinking about moving to Linux for months, but I have a two-year-old Lenovo PC with Windows 10 and don’t know if I want to partition off a bit of its hard drive to set up a dual-boot scenario or go and buy a cheap PC and go from there. My thought is that I’d make a home server, but I might set up a file, web, mail or database server. Bryce Samuelson, via email. Neil says: Does the laptop have a DVD drive? You can boot the Linux Formatdisc and run most of the distros ‘live’ off the disc without needing to install anything. That should give you a good flavour of Linux. The next step is you could write one of the distro ISO files…

Specs OS: Android 6.0.1 CPU: Snapdragon 820 quad-core 2x 2.15GHz Kryo, 2x 1.6GHz Kryo RAM: 6GB SSD: 64GB Display: 5.5-inch, 1080 x 1920 AMOLED Power: 3000mAh Camera: 16MP main, 8MP rear Comms: Wi-Fi 802.11 ac, Bluetooth 4.2 LE, NFC, USB-C Sensors: Fingerprint, accelerometer, gyro, proximity, compass Size: 152.7x74.7 x7.4mm Weight: 158g Third time’s a charm, right? Well, that’s what OnePlus will be hoping with its third-generation flagship smartphone, the OnePlus 3. True to its ‘Never Settle’ mantra, OnePlus is pushing forward with its ‘flagship specs for half the price’ game plan and with the new OnePlus 3 the signs are positive. There’s no QHD resolution, nor is there a microSD slot, and users have just one internal storage option: 64GB. But if you can look past those minor shortcomings, and…

Announced as “the world’s first crowd-sourced tablet” in late 2014, the Jolla Tablet looked the part. It promised a pin-sharp 2,048x1,536, 7-inch screen, a quad-core 64-bit Intel chipset, and a whole lot more—and people were enticed. The tablet was a huge crowdfunding success, raising a staggering $2,571,262—479% of the original target. Understandably, Jolla was overjoyed by the result. What followed, however, was a litany of unfulfilled promises. Initial delays led to months of waiting with reports of manufacturer disputes among other issues. In the end, only a few hundred tablets were shipped, far fewer than the thousands expected. Jolla admitted defeat, and a large-scale refund program was initiated—and the official take on the affair seems to be that it served as a valuable learning opportunity for the company, at least…

All the distros in the Roundup are either based on one of the branches of either the Ubuntu or the Debian projects. To start with, antiX uses the Debian Stable repositories (repos) by default, but you can make it use the Debian Testing and Unstable repos easily. The distro takes good advantage of the large repos of Debian software but unlike the other derivative distros in this Roundup, antiX doesn’t borrow the installer from Debian and instead uses its own. Bunsen Labs is also based on Debian Stable but unlike antiX it uses Debian’s installer as well. While Bunsen offers live installable media for 32-bit and 64-bit systems, you can grab packages for the Armhf (ARM) architecture from its repos. The other three distros are all based on Ubuntu and…

“You can try Linux risk-free straight from our coverdiscs or in a virtual machine.” Anyone can be a Linux user, in fact anyone fortunate enough to own any kind of consumer technology or has used the Internet is very likely already a Linux user. It’s at the heart of Android phones, home routers, smart TVs, pwned IoT devices and most of the web servers in the world. Its also running on 99% of the world’s fastest supercomputers. But you can use it as a desktop operating system too—it’s easier than it has ever been. You can try Linux risk-free straight from our coverdiscs or in a virtual machine. There are desktops to suit fans of Windows and macOS, and there are desktops for people with taste [straight in with the…

1 Install VirtualBox VirtualBox is free (and open source). Windows and Mac versions can be downloaded from www.virtualbox.org. Follow the appropriate download links and fetch and run the binary. It installs like any other application would. 2 Choose your distro Distros are shipped as ISO files (images of install discs), which will behave just like discs in our virtual machine, so you’ll want to grab one of these. ISO files can be large, so you may want to use one from the LXFDVD’s instead and copy it to a hard drive first. 3 Set up a new VM Open VirtualBox, select ‘New’, give the VM a name and set its type to ‘Linux’. If your distro is in the Version box select it, otherwise choose ‘Other Linux’. You should give…

Some readers will have memories of doing things in MS-DOS and they probably aren’t good. Other readers will be baffled as to why, in this age of shiny graphics and plentiful RAM, someone would want to control their machine with cryptic text input. It turns out that pretty much anything can be done from the command-line, once you know the relevant incantations. So let’s take a terminal crash course. It will be easy to find the terminal application from your desktop’s menu (or Dash or Activities panel). On Ubuntu and Gnome-based distros, it’s called Terminal, while KDE Plasma calls it Konsole. Starting it up will open a rather intimidating window with a prompt, such as user@host:~$ , where user and host are the names chosen for the user and computer…

Despite AMD contributing hardware specs and developer time to Linux, the present situation is a little awkward, depending on your hardware. Their older proprietary driver, fglrx, is being phased out and is no longer supported by the X.org server, so users of older ATI cards should just use the open source radeon driver. More modern (‘Volcanic Islands’ and newer) chipsets are supported by the shiny new AMDGPU framework (and this support actually extends back further, but this requires kernel tinkering), which features a common open-source kernel module, and an optional proprietary userland driver, enticingly entitled AMDGPU-Pro. This should make for a much more robust driver, since having the module’s source enables much more straightforward integration with each distro. However, AMDGPU-Pro is still in beta and only officially supports Ubuntu and…

Your next key component to install is your RAM. To do this, unlock the latches on the memory slots located to the right of your processor. Make sure you line up each stick with the notches on the board and firmly slot each stick into place, pushing down on both ends until you hear a satisfying click sound. Then it’s onto cabling. You’ll want to plug in the largest 24-pin ATX cable into the motherboard. Install the 8-pin CPU power at the top of the board. (These look similar to those used with add-in cards and GPUs, however, each pin is shaped differently to ensure you don’t plug it into the wrong place). Next, you’ll want to plug SATA power into your hard drive. Find the one that looks like…

Krusader Digikam Neural Enhance Tuxguitar Devilspie2 Kup Homebank Featherpad Spek Mouse Boat Freeciv “For those who need a manager for doing everything without switching between windows.” File manager Krusader Version: 2.5 Web: https://krusader.org Twin-panel style of file manager doesn’t appear to be disappear anytime soon, and this is certainly true for Krusader, a file manager with a long history. Krusader 2.5 is a shiny new release of the manager after more than four years of development, which has included implementing many new features and porting the application to Qt5 and KF5 libraries. Krusader reveals the depth of its built-in features when you start using it on in everyday life. The most notable are built-in archive support, remote connectivity options (such as SFTP and Samba), a disk usage statistic pie chart,…

Mumble software, like the TalkiePi program, can use certificates to connect to Mumble servers. This avoids the need for typing in passwords and allows you to register accounts easily with new servers. By default, this feature is switched off in TalkiePi as Daniel Choate’s own server, which he set up for his children, doesn’t require certificates. If you wish to use other Mumble servers, however, connect to your Raspberry Pi via SSH then run su mumble to switch to the mumble user and cd ~ to switch to the home directory. You’ll need to generate a container for your certificate with the command: You’ll also be asked to enter a password. Next create the certificate itself with the command: Enter the same password as before and press return when…

Our expert Nick Peers thinks it would be wonderful if you could set (and edit) environment variables for your life. SAVINGS =1,000,000 and that sort of thing. He hasn’t thought it through. Terminal Use environment variables to change the behaviour of your shell Variables play a key role in your day-to-day computing life, even if you don’t realise it. They can be used within individual scripts or programs to provide convenient shortcuts to information or settings, but can also be applied on a wider level through any Terminal shell session too. There are two distinct types of variable that apply to shell sessions: environment variables and shell variables. Both provide useful settings such as locale (LANG), user’s home directory (HOME) and paths to commands (PATH). The most obvious benefit is…

Our expert Mats Tage Axelsson has spent decades making his computers run Linux. His first system with Linux was a laptop from IBM back in a time when the company was still making them. Wayland Compile, install and customise the replacement for X11 When we run our computers, we generally leave the display server alone and tend to focus on fiddling with the GUI above it tweaking this interface’s appearance and moving menus. But with the introduction of other display servers, such as Wayland and Mir, it does beg the question: is it time to ditch X Windows System (or X11 for short) and go for something more contemporary? X11 was first released way back in 1987. The protocol has been implemented for many systems, even on Linux we have…

Our expert Tajinder Kalsi has over 9 years’ experience within the information security industry and has hosted seminars in over 125 colleges across India in his spare time. He currently works as an independent information security consultant. Nmap How the standard Linux tool can help secure your networks Security is one of the biggest issues in software while also being one of the most invisible. We could spend months dissecting exactly why this is, but let’s get straight into some practical security skills. In this tutorial, taken from Tajinder Kalsi’s Practical Linux Security Cookbook, we’ll look at how to use Nmap to scan hosts and then how to gain a root on a vulnerable Linux system. Nmap is a really useful tool for performing network scans. It’s been around for…

Our expert Shashank Sharma Having tested his mettle against dd and looking for other challenges, he now spends his days bustling through courtrooms as a trial lawyer in Delhi. Snapper Snapper Xxxx set up, configure and schedule snapshots for easy system rollbacks Nothing spells turmoil, pain and anguish as a broken system that won’t let you access your precious data. Doesn’t matter if it’s a poorly configured graphics card keeping you from running a GUI or a nefarious software installation that renders your distribution (distro) unbootable. Thankfully, Linux distros offer a range of data backup solutions and there are even tools designed to help you clone entire disks to work around such a scenario. Enter Snapper, self-styled as the ultimate snapshot tool for Linux, which leverages the powers of a…

The Boost Graph Library, which is a collection of portable C++ source libraries, contains an interface to the DOT language. You can see the C++ code of graphViz.cpp for an example, which illustrates how you can create Graphviz code from C++. The previous code tries to be as simple as possible because C++ tends to be difficult to understand sometimes—it just makes two nodes and one edge to connect these two nodes. What you need to remember is that you can even use C++ to generate Graphviz code. Compiling and executing graphViz.cpp creates the following output: The Boost Graph Library can create even more advanced graphs, which will require even more complex C++ commands. If you are more interested in the Boost library, you can start by visiting www.boost.org.…

The Sierpinski triangle is another ingenious way to generate a fractal that is based on geometry and works with equilateral triangles, which are subdivided recursively into smaller equilateral triangles. The algorithm is easy to understand and works as follows: you start with a equilateral triangle that you divide into four smaller equal equilateral triangles. Then, you remove the central one—this triangle remains empty and is always visible because it will never be used in the process. Last, you do the same for the remaining three equilateral triangles for as many times as needed. The final product of the Sierpinski triangle fractal is still composed of multiple equilateral triangles. You can look see this action at the bottom of the page.…

CRUD stands for Create, Read, Update and Delete which are the basic operations that can be performed on a database such as SQLite 3. In order to be able to follow this tutorial, it would be very helpful to have the basic CRUD commands in mind so that you can check what the Python scripts do. The following SQL commands illustrate the four basic operations: The image (pictured on the previous page) shows the output from the previous operations using an example database. To find all tables of a SQLite 3 database, you should execute .tables from the SQLite 3 shell which, all being well, produce output similar to the following:…

Wildcards are used to match multiple files in a shell. The two main wildcards are asterisk * and question mark ?. * matches any number of characters, so *.jpg is expanded by the shell to a list of all files with a .jpg extension. It’s important to understand that this expansion is done by the shell before passing the list of files to whatever command you have called. If you have two files called in.txt and out.txt and you run $ ls *.txt the shell replaces the wildcard expression with the list of matching files and then calls the command, so it runs $ ls in.txt out.txt . The command has no idea that a wildcard has been used. The other wildcard commonly used is ?, which matches any single…

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 Bash scripting. 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…