Linux FormatFebruary 2016的目錄

This issue we asked our experts: This issue we’re helping people escape Windows, what’s the best reason for fleeing the lands of Microsoft to the fishy embrace of Tux? Jonni Bidwell Suppose I were to show you a place where there are no mandatory multiple-reboot-involving updates. Suppose I told you that in this place we didn’t have to use bloated, configuration-mashing antivirus software. And all settings can be modified by manipulating humble text files. Friends, this place is real: embrace the penguin. Neil Bothwick The best thing about Linux is the community. A large and disparate group of people – usually with no commercial axe to grind – just a desire to make things better in the world of Linux. The openness of Linux means that the movement is usually…

“ This month a huge step forward was announced for Open Source graphics. AMD announced the open-sourcing next January of a really big chunk of cutting-edge driver and game development code. As a customer of ours at Collabora, we’ve always been eager to highlight the futility of proprietary boiler-plate legalese around the company’s SDKs. It is fantastic then to see them go far further than just fixing this – and setting a wonderful example of leadership for other proprietary focussed companies to follow in the process. Open source effects With TressFX, ShadowFX, LiquidVR, FireRender and more SDKs becoming available under an open-source licence it will be easier to write and distribute games that excel for AMD against a single code platform and that will work well for other vendors too.…

Just a quick note, I have not seen anything on Slackware in LXF and it’s one of the oldest Linux distribution and nowhere to be seen. Sure, Debianrelated distros and Red Hat-related distros are good for the new folks to Linux, but Slackware can also be just as good and just as easy to install. I’d love to see something with Slackware, especially for exposure to the distro since it used to be one of the most downloaded, but has now been overtaken by easier distros with more eye candy. I don’t know, just a rambling from a Slackware fan. Keep up the good work at the magazine. I love reading it all on a monthly basis. Nathan Hawthorne, via email. Neil says: The idea of covering Slackware has been…

PHP UK Conference PHP is one of the most popular choices for web development thanks to its large and enthusiastic user base, and is also the power behind the popular Wordpress blogging platform. On 18-19 February 2016, The Brewery London will play host to a two-day PHP conference featuring 30 handpicked speakers across three tracks of talks, including Lorna Mitchel a well-known web development consultant and long-time PHP expert. The event also offers you the opportunity to network and job search, so If you are looking to learn more about server-side scripting language, expand your skills and socialise then this is an ideal opportunity. http://phpconference.co.uk Play Expo Blackpool 2016 Every year there’s a resurgence of retro gaming in Blackpool thanks to Play Expo. This two-day event (April 30-1 May) offers…

A backup is considered a part of system administration, which means it needs to have good documentation. Surprisingly, many of the tools fare poorly in this regard. Back in Time just has bare bones information that’s limited to a short introduction, an illustrated guide and a Github wiki that has a FAQ with a handful of questions. Similarly, Gadmin-Rsync has a simple guide to backing up and restoring data, and besides a run-through of its features and a brief installation guide, the project’s website doesn’t host any other information. However, there are plenty of third-party tutorials for Gadmin-Rsync. Déjà Dup too just has details on how it works on the Gnome wiki as well as some other documentation in the form of questions and answers on its Launchpad page. There’s…

The launch of Windows 10 is a great opportunity for those frustrated with the Microsoft ecosystem to find a better way. And what better way than Linux? If you’ve just bought a PC with Windows 10 pre-installed or upgraded from an earlier version and decided enough’s enough, or have a family member or friend who’s finally seen the light, this feature is for you. The easiest way to migrate from Windows is through Mint, a user-friendly Linux distribution (distro) that’s packed with all the features you need, wrapped up in an accessible user interface particularly suited to first-time switchers. You’ll find the latest version – Linux Mint 17.3 32- & 64-bit – on the LXFDVD. We’ll be using that version to step you through the process, but most of the…

With your fail-safe backup in place, you’re now ready to take the plunge and install Linux Mint. The following procedure assumes you want to install it alongside your existing Windows installation – it’s a good route to follow for first-time switchers, as well as for those helping others to make the migration to Linux. You’ll find the latest version – Mint 17.3 – on the cover disc. Like all versions of Mint, it’s a Long Term Support (LTS) release, with support guaranteed until April 2019. If you’d rather try Ubuntu, go to www.ubuntu.com and select ‘Download. Click ‘Ubuntu Desktop’ and download the correct version for your processor (64-bit in most cases) of either Ubuntu 14.04.3 LTS or for the latest release, 15.10. Creating your Mint or Ubuntu install disc or…

When Mint installs itself, it changes the bootloader at the beginning of your hard drive to a program called GNU GRand Unified Bootloader (Grub). Put simply, Grub scans your hard drive for visible operating systems and then presents you with a boot menu, allowing you to switch between them. In most cases – specifically those where your Windows install is detected by the Mint installer – this should be set up to work perfectly from the off. You start your PC, Grub displays the boot menu, and if you don’t make a choice within five seconds, it’ll start to load Linux Mint. In this event, the only thing you’ll want to know is how to make changes to the boot menu – you may prefer to make Windows the default…

ON THE MERITS OF PYLADIES“You don’t feel like you’re representing your entire gender by asking a question.” Amy Boyle used to work at Washington State University in Vancouver developing code that talked to mice. Recently she moved jobs to New Relic – a company that provides tools for realtime monitoring of web applications – where she’s a software engineer. She describes herself as a coder with a love of science and cookies. We had the pleasure of catching up with her right after she gave a great talk on digital signal processing with Python. Linux Format: So I guess we’re both ex-academics, but I’m sure your work in the ivory towers was more interesting than mine. Why don’t you start by telling us what you did at WSU? Amy Boyle:…

1 Blender ( www.blender.org ) It may be a 3D application, but Blender’s Grease Pencil paint tools and its Freestyle renderer – which converts a 3D scene to a flat, cartoon-like image – mean it’s often used to create 2D images. 2 CinePaint ( www.cinepaint.org ) CinePaintis an old fork of Gimp designed for retouching frames of films, and formed part of Oscar-winning visual effects studio Rhythm & Hues’ in-house toolset. 3 FontForge ( https://fontforge.github.io ) A powerful font-design tool with support for all common font formats. FontForge is cross-platform, localised into a range of languages and Python-scriptable. It was used to create the Cantarell font family used in Gnome 3. 4 MyPaint ( http://mypaint.org ) Another staple of open-source concept art…

Of all the applications featured in this article, Gimp (www.gimp.org) is arguably the least tightly focused. Whereas Kritaand Inkscapehave well-defined niches, Gimpis a jack of all trades used by artists on tasks ranging from illustration to image retouching to editing textures for use on 3D models. One such versatile creative is Cameron Bohnstedt (www.cameronbohnstedt.com), currently a contract designer for Daybreak Game Company – better known under its former name, Sony Online Entertainment – and freelance artist working on gig posters, game assets, logos and promotional materials. Having previously used a more conventional designer’s set-up of Adobe software running on an iMac, Bohnstedt had an “on-and-off relationship with open-source” until 2012, when his Mac died. “I figured it was a good time to leave the walled garden and buy a Linux…

One client I’m working with at the moment has made it a policy in the last year to have semi-regular hack days. I’m sure that readers of Linux Format will have at least come across the term, but just in case: hack days are events where a group get together and try to create something in a day (or whatever period of time they’re given). In this particular setting they’re (sort of) expected to be work-related, but the goalposts are very wide: any ideas can be put forward and attempted – and quite often people merge ideas together and work on the result. People can work on their own or in teams. Anyone can join in – it’s not merely a developer event. At the end of the allotted period…

There are two separate reasons to talk about Gimp, the greatest image editor for Linux and an Open Source rival of Adobe Photoshop. The first is that it’s just turned 20 years old – a major milestone that hit the news at the end of November and was celebrated with version 2.8.16. This is a minor release with mostly fixes and small enhancements, such as better handling of layer groups in PSD files and OpenRaster formats. A few days after this came another reason for looking at Gimp: the project released Gimp 2.9.2, a development version that soon will form the ground for the forthcoming version 2.10. This is the first time since May 2012 that the Gimp developers have rolled out a major big release with lots of hot…

For the past nine years, I’ve been living in Berlin working as a Software Quality Assurance Engineer and I’m also the organiser of the Raspberry Jam Berlin. It’s been about one and a half years since I started the Jam. I was inspired by the numerous Jams that were popping up in the UK, and was hungering for something similar over the pond. It’s been great organising the Raspberry Jam. I’ve helped countless people, listened and, hopefully, answered some batty questions, reviewed ideas for art projects and simply introduced people to the Raspberry Pi. When I heard about the Maker Faire coming to Berlin, I jumped at the chance to represent the Raspberry Pi Foundation and show the Berlin public what the Pi is and, more importantly, what it can…

After the excitement over the interesting, if expensive, Pi-top laptop, we now have the inevitable follow-up which is called the Pi-topCEED. This is a desktop version of the laptop model (see the full review opposite). After finishing a successful Indiegogo fundraising campaign in mid-December – gaining over 380% of the required funds – the Pi-topCEED aims to deliver a combined 13.3-inch high definition desktop display and chassis with the custom Pi-topOS for $99. http://bit.ly/Pi-topCEED.…

Our game is good, but what will make it great is scoring and a time limit. Firstly our score is a variable. Select the Rocket sprite, click on the Variable palette and choose ‘Make a new variable. Call it score and set it for all sprites. We’ll use a ‘When I receive start’ Broadcast to trigger the scoring system to life. Every time the game starts, we set the score to 0, found in the Variables palette. Now add a Forever loop from the Control palette and then use three If statements stacked on top of each other in the loop. The first If conditional uses the ‘touching sprite’ block in Sensing to advance our score by 10 points if we touch the Space Dragon, before waiting for 1 second.…

If you’ve stored music on the NAS, wouldn’t it be really cool if you could stream it across the network straight from the NAS itself? Using the forked-daapdplugin, you can do just that. To use the plugin, just install it like any other; this adds a new entry under the Services section, labelled iTunes/DAAP. Before you can stream music, you need to configure the plugin by pointing it to the shared folder on the NAS that contains the music files. Head to the plugin’s page and use the Shared Folder drop-down menu to select the folder that houses the music. Once you’ve saved the changes, use a player such as Rhythmbox, Amarok, Banshee and so on, which will automatically pick up the DAAP server running on your NAS and enable…

Our expert Mayank Sharma is not working as a sysadmin – 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. Security testing Identify the holes in your network and beef up your security Kali Linux is the Swiss Army knife for ethical hackers. The distro is loaded with tools for penetration testing that you can use to compromise your own network in order to identify the weak points of entry that can be exploited by crackers. The Kali Linux menu is arranged in the order in which a network is usually infiltrated. It begins with tools for infiltration testing and moves on to vulnerability analysis, wireless attacks and exploitation. Kali Linux is available in multiple…

Our expert Neil Bothwick has a computer in every room and a compelling desire to control them all at one time, remotely from the terminal on one computer. Hence this tutorial… Tmux Xxxx Run multiple terminal sessions simultaneously within a single terminal Tmux is a terminal multiplexer. That term may sound familiar if you have ever used screen[Tutorials, p74, LXF192]. A terminal multiplexer enables you to run one or more detachable terminal sessions inside a single terminal or virtual console. Some of the graphical terminals provide tabs, allowing you to run several terminals in the same window, but a multiplexer goes much further. It also doesn’t require an X terminal, although it is very happy running inside of one. Tmuxis probably not installed on your distro by default, but should…

Our expert Nick Peers has embraced virtualisation for the best part of ten years after discovering how experimenting in a virtual environment was better for his PC’s health. Virtualisation Virtualisation Set up and easily run virtual machines on your PC Today’s multi-core PCs are built to run multiple tasks simultaneously, and what better way to tap into all that power than through virtualisation? Virtualisation, and in particular hardware virtualisation, is the process of splitting a single physical PC (known as the ‘host’) into multiple virtual PCs (referred to as ‘guests'), each capable of working and acting independently of the other. Virtualisation software allows the host to carve up its memory, processor, storage and other hardware resources in order to share individual parcels with one or more guests. If your PC…

1 Consolidate snapshots If your VM contains snapshots, the resizing process will affect only the original base image. To resolve this, right-click the VM and choose Settings, then append -old on to the end of its name. Click ‘OK’, right-click the VM again, but this time choose Clone. Click ‘Expert Mode’’, then rename it and verify that ‘Full Clone’ and ‘Current machine state’ are selected before clicking ‘Clone’. 2 Resize virtual drive Close VirtualBox, open Terminal and navigate to the folder containing your VDI file. Now type the following command, replacing drivename.vdi with the filename of your particular VDI file: The resize figure is in MB, so 10000 equals 10,000MB or 10GB. 3 Extend partition The drive concerned has been resized, but you’ll now need to repartition it. Boot your…

There are two ways that video may be displayed on-screen: progressive scan and interlacing. Progressive scan is the newer standard, favoured by modern technologies and displays, while interlaced video harks back to the days of older analogue TV sets but remains a standard in certain areas, including DVB television broadcasts. Interlaced video contains two fields of a video frame, captured at different times, in a single frame. Field 1 is contained in the odd-numbered lines, field 2 in the even-numbered lines, and supported displays show odd numbered fields in the first pass and even numbered ones in the second. Thanks to the persistence-of-vision effect, the eye perceives both as complete images. The downside of interlacing is that it can produce a visible ‘combing’ effect on digital displays if not handled…

If want to find all GridFS files that are stored in a database, you can query the system table that holds this information. GridFS uses two system tables, one for holding the filenames and another that holds the actual binary data of a chunk. (There’s an example screenshot on p86.) The default behaviour of GridFS is to use two collections with names prefixed by fs bucket: fs.chunks and fs.files. The following Ruby code inserts both a existing binary file and a text file that’s created on the fly as GridFS objects: You should look at storeGridFS.rb on the LXFDVD for the complete source code. The next section of Ruby code, which can be found in retrieveGridFS.rb, retrieves a previously inserted GridFS file using its file_id: As you can see from…

One of the more interesting methods provided by Sandbox.js is rotateCamera() . By keeping track of the number of ticks that have passed, it’s possible to set the X and Y coordinates along a range of values described by a sine wave, and in turn describe a circle in the X,Y plane. Math.sin will return a value between -1 and 1 for the number you give it. Math.cos will do the same, but offset by 90 degrees. If you apply Math.sin to both the X and Y coordinates, the resulting line plotted will be an eased diagonal line, going from -1 to 1 in both X and Y, then back to -1 , and so on. However, if you apply Math.sin to just one of the coordinates, and Math.cos to…

It’s that perennial question: how do you get your friends, family and companies to switch from Windows to Linux? The best way is usually to wait for Microsoft to launch a new improved edition of its operating system – like Windows 10 – that causes so much disruption and issues that people are dying to escape Windows. It seems that a mix of security, privacy and forced updates are ticking many people off. This makes it the perfect time to slip an LXFDVD into an unsuspecting Windows user’s drive and serendipitously it turns out that we have the ideal distro for Windows escapees to flee to in the form of Mint 17.3. Combining the cover disc and main feature this issue we’ve got the ideal starter pack for both people…

Just before the end of last year Linus Torvalds announced that Linux 4.4-rc5 had been released, with a – in his own words – “fairly bad core bug that was introduced in rc4 that is now fixed in rc5, but while that is a bit embarrassing, I don’t think that many people actually ever hit the problem ” Torvalds is a bit coy about what the problem actually was, though a pull request that can be found at http://lkml.iu.edu/hypermail/linux/kernel/1512.1/00772.html, which relates to a commit about “x86/headers: Make sigcontext pointers bit independent” could be highlighting the culprit. Anyway, with that problem out of the way it looks like the final release of 4.4 will be on time in early 2016, though there’s a possibility it could be delayed by around a…

ROSA DESKTOP FRESH R6 LXQT ROSA Desktop Fresh R6 LXQt has been released, the first lightweight edition of ROSA that features the LXQt (version 0.10.0) desktop, following on from the release of ROSA Desktop Fresh R6 KDE a few months earlier. ROSA’s focus on user-friendliness will now benefit from the new features of LXQt desktop, with LXDE support dropped due to the sluggishness of updates being released. To find out more about the release check out the notes at http://bit.ly/ ROsAFreshR6LXSt. ROCKSTOR 3.8-10 If you’re building your own NAS device – or flashing an existing one – then you may be interested to learn that the latest stable build of the Rockstor project’s CentOSbased distro is now available to download. The release has been a long time coming, but it seems…

Linux Presentation Day Do you remember your first time? Do you remember when you first stumbled upon Linux? For me it was the late 1990s and I dabbled with Corel Linux, a Debian based distribution (distro) that worked with the majority of my hardware. This started my Linux adventures but finding my local Linux User Group (LUG) helped me to learn more and socialise with like-minded people who enjoyed tinkering and exploring the world of open source software. In 2014, the Berlin Linux User Group (BeLUG) started a new event called Linux Presentation Day that offers the general public an introduction to the Linux-verse and provides support for well-known Linux distros, such as Fedora, Ubuntu and SUSE. This, it was hoped, would generate new Linux users who will support their…

Depending on the type of data you are backing up, you will probably want to make sure it’s kept under lock and key. Some users may want to compress the backed up data especially if they need to move it to a remote location over the network or even the Internet. If these two characteristics are important to you then it’s best to look past Back In Time and LuckyBackup. Both of these backup tools don’t support any form of encryption and compression. (Adding support for both is on LuckyBackup’s roadmap but are fairly down the pecking order.) Gadmin-Rsync, in contrast, can do encrypted remote backups. Keys for these operations are created for each host, uploaded and then installed on the remote hosts using a combination of ssh-keygen/scpand SSH. Déjà…

There’s nothing worse than attempting to upgrade or install a new operating system only for something to go wrong. You can replace that gut-clenching feeling with one of minor irritation by making sure you’ve backed up your Windows installation (or just your data) before you begin, this will enable you to easily roll back to a working state if something goes awry. There are numerous backup tools for the job, but we’ve plumped for Redo Backup and Recovery, which works beautifully with both Windows and Linux installations – go to www.redobackup.org/download.php and follow the instructions to download the Redo Backup live CD in ISO format. Burning it to disc is simple: pop a blank disc in the drive, browse to the ISO file in Windows 10, right-click it and choose…

Switch on your PC and tap the key prompted to enter setup – usually Del or F2. Look for the FastBoot setting under Boot or Windows Configuration, then make sure it’s set to disabled. If you have problems getting Redo Backup to launch, you should also temporarily disable Secure Boot and potentially tweak the CSM settings in order for Redo Backup to work correctly – look under Boot, Security or Windows Configuration for these settings. When it comes to CSM, its settings may be hidden away in their own menu, where you’ll find references to the likes of PXE (pre-boot environment), GOP (graphics) and Storage (or SATA), as well as USB and PS2 if applicable. This allows you to selectively switch CSM on and off for specific devices as required.…

1 Install Grub Customizer Open a Terminal window and type the following commands: Once done, launch Grub Customizer by clicking ‘Menu’ and searching for ‘Grub’. 2 Change defaults Switch to the ‘General settings’ tab. From here you can change the default OS via the predefined drop-down menu, or select ‘previously booted entry’. You can also change the delay before the default entry is selected from this tab too – untick ‘Boot default entry after’ to pause Grubuntil an OS is selected. 3 Change Grub’s look To make a few changes to how Grub looks, switch to the Appearance settings tab where you can prettify the Grub menu by changing its colour scheme, fonts, default resolution and even apply a nice background image (Note: the image needs to be a PNG).…

If you plan to continue using Windows and Ubuntu alongside each other, it pays to set up a dedicated data partition, then make it easily accessible to both operating systems. Use GPartedfrom the Mint installer to set up a NTFS partition, then boot into Windows and browse to your user folder. Right-click each key data folder – Documents, Pictures etc – in turn and choose Properties > Location, then point them to the equivalent folder on your new data partition, moving the data across when prompted. You should also disable hibernation in both Windows and Linux – data written to the shared partition while one OS is in hibernation may be wiped when that OS is next woken up. In Windows, open a Command Prompt (administrator), type powercfg /hibernate off…

The best way to run applications in your new Linux Mint install is natively, but if there’s a specific Windows program you can’t do without then it may be possible to get it running. What you’ll need is a special program called Wine, which uses some clever trickery to use parts of Windows, enabling you to run many Windows programs as if they were native Linux ones. Winecan be a tricky tool to master, but thanks to the free PlayOnLinuxtool, you can get many popular applications up and running with the minimum of fuss. Open the Software Manager, then search for ‘PlayOnLinux. Click ‘Install’ and it’ll automatically download and install Wine. Once installed, launch PlayOnLinuxand allow it walk you through the first-use wizard. You’ll be left with a blank window,…

For over 10 years, the main driving force behind Krita has been Boudewijn Rempt. As well as acting as lead developer and project maintainer, Rempt co-founded KO GmBH – which until 2014 published the paid version of the software, Krita Gemini, and provided commercial support to visual effects studios – and has organised the successful recent crowdfunding campaigns run by the Krita Foundation. Below, he tells us how the software has evolved during that time. I started using Kritabecause I needed to draw a map for a fantasy novel I was writing. I was already a Linux user, so I started looking around for a Linux application. Gimpisn’t really designed for painting, and MyPaint didn’t exist at the time, but there was this little application in the KDE corner called…

Although it isn’t as widely used as some of the other open-source graphics applications, Scribus (www.scribus.net) is a capable page-layout tool. One design professional using it in his commercial work is Dennis Groenewegen van der Weijden, who is the founder of Dutch studio DigidioMedia (www.digidiomedia.nl). Formerly a senior printer engineer and sales executive in the IT industry, Dennis initially began producing in-house marketing materials as a hobby, eventually stepping up to user guides and packaging. Despite being familiar with Adobe InDesign, he elected to use Scribusboth for major projects at his old firm and for DigidioMedia’s current jobs. “You can create beautiful things with InDesign, but it’s overkill on simple leaflets or brochures” he says. “There’s a lot of functionality you don’t use.” As well as promotional material, DigidioMedia’s work…

I hope that reading the last couple of issues will persuade you to give ELK a try to get a grip of your log processing. I thought I’d best list out some hints and tips I’ve come across while working with and researching ELK. In terms of hardware (virtual or not) for the Elasticsearch layer, the recommendation is to have 4-8 cores per node for a reasonably sized cluster, with 2-4GB of RAM. (As with anything, there is a certain element of finger-in-the-air here, depending on how much data is going to be processed.) I haven’t covered it at all here due to lack of space, but securing/encrypting traffic between Filebeatand Logstashmight be a requirement for your environment (and is generally a good idea), as well as stopping the various…

Citrix HDX, anyone? The blank glass-eyed stares back are to be expected, as generally that’s because Citrix is a boring business-related thing you wouldn’t think of in relation to the Raspberry Pi. But being business that means money and now that a Citrix dev has released a HDX Thinwire codec with full Citrix XenDesktop support, it means the Raspberry Pi 2 can be rolled out as a full thin-client solution supporting remote full-screen 1080p with real-time audio for $50. This system – that’s not officially supported by Citrix – has been fully implemented and is being used by ThinLinx (www.thinlinx.com). For large deployments the Pi 2 could become the defacto thin client standard. http://bit.ly/CitrixPiThinClient.…

In brief... A Raspberry Pi laptop solution offering an impressive level of portability and features that are aligned with the UK GCSE curriculum. But these features come with a hefty price tag and a number of rough edges to a relatively new software base. That said, this is a powerful package for those who can work around the issues. Right now the Raspberry Pi sports a plethora of portable options. September 2015 saw the release of the new touch-screen, and other companies such as Kano are working on their own portable setups. Pi-Top started life as a crowd-funded project and combines both hardware and software. The hardware is a sturdy plastic laptop shell (supplied as a kit) and includes a 13.3-inch HD (1,366x768) LCD screen with eDP interface, an 8GB…

Our expert Mayank Sharma was compelled to set up a working NAS so that he could store all his episodes of Friendsand watch them on his Pi media centre. Do you have a bunch of USB disks that you juggle between your various computers? Did you know that you can plug all of them into a Raspberry Pi, which you can then use as a network attached storage (NAS) box? Using the Pi as an always-on NAS box sounds like a wonderful use of the silent little device. However, setting it up as one used to be an involved process. That’s until the Debian-based OpenMediaVault (OMV) distro decided to roll out a version specifically tuned to the Pi. Once it’s up and running, you can configure and manage the distro…

The biggest threat to security is weak passwords. If you think you have good strong passwords, there are some tools that you can test them with. Hydra is a free brute-force password cracking tool which can attack single or multiple user accounts. Primarily a command-line tool, the password cracker also has a graphical user interface that can be used to create complex attacking patterns. Hydra can interact with a huge range of services including HTTP, IMAP, LDAP, POP3, RDP, SMB, VNC and more. Another popular password cracker included in Kali is John the Ripper. This is used primarily for exposing weak Unix passwords. Like Hydra, John the Ripper is a command-line tool but also has a graphical interface (called Johnny), which does a nice job of exposing its various command…

Tmuxis controlled by key commands. Commands are introduced with Ctrl+B followed by the specific command key. You can change this in the configuration file if your muscle memory has been conditioned by screen. Common command keys are: 1 D disconnect from the session 2 C create a new window 3 N switch to the next window 4 P switch to the previous window 5 0-9 switch to that numbered window 6 & kill the current window 7 " split the current pane vertically 8 % split the current pane horizontally 9 o switch to the next pane 10 x kill the current pane 11 Cursor keys move to the pane in the indicated direction 12 : enter tmuxcommands manually…

One way to maximise your host PC’s resources is to run your virtual machine headless. This means there’s no way of interacting with that VM on the host PC; instead, you access it remotely using the Remote Display Protocol (RDP). First, make sure you have the VirtualBox Extension Pack installed – this provides support for VirtualBox’s implementation of RDP – then enable it on your VM via Settings > Display > Remote Display tab by ticking ‘Enable Server. You’ll need to change the default port (3389) if you’re setting up multiple VMs in this way – choose unique ports for each between 5000 and 5050. Once it’s configured, you can launch your VM from the Terminal via one of two commands: Alternatively, hold Shift as you click the VM in…

Our expert Nick Peers has amassed a vast library of digital video and spent many hours playing around in a quest to find the perfect encoding settings. He’s still looking. Video Vxxx deo encoding encoding All you need to know about codecs and converting video The days where your media collection consisted of video cassettes or optical discs are long gone. Why clutter up your living room when entire digital video collections can be housed within a single hard drive? Pair this data with a media server such as Emby , formerly known as Media Browser, [see Features, p32, LXF204] and you can keep your entire collection at your fingertips – no more disc swapping or sitting through endless trailers. It all sounds wonderful, but do you really want to…

In case you don’t want to write any code yourself, you can save and retrieve GridFS files with the help of the mongofiles command line tool that comes with the MongoDBdistribution. $ mongofiles -d LXF put abinaryFile 2015-11-18T21:45:51.567+0200 connected to: localhost added file: abinaryFile $ mongofiles -d LXF get abinaryFile 2015-11-18T21:45:56.674+0200 connected to: localhost finished writing to: abinaryFile $ mongofiles -d LXF list 2015-11-18T21:46:01.635+0200 connected to: localhost abinaryFile 7168 $ mongofiles -d LXF delete aBinaryFile 2015-11-18T21:49:37.759+0200 connected to: localhost successfully deleted all instances of ‘aBinaryFile’ from GridFS The list command allows you to see all the GridFS files that are stored in the LXF database. Should you wish to get a binary file using its _id you’ll need to use the get_id command. Similarly, you can delete a GridFS file…

This month we answer questions on: 1 Broken X after Kubuntu Update 2 No headphone output 3 Local address resolution 4 Installing a Pi distro 5 Replacing distributions * Saving script configurations 1 Kubuntu Update disaster Q I updated my Kubuntu 14.04 system with the Muon Updater and now I’m no longer able to boot the system to the desktop. The boot up gets as far as displaying the Kubuntu logo, which fades up to blue-white about six times. At that point the monitor is put into power-saving mode. There are occasional dim flickers from the separate /home drive’s access LED. I also note that during the updating, Muon displayed a message to the effect that it was going to remove the Nvidia driver for my (old FX5200) graphics card.…

Android is the most popular operating system in the world, but it’s far from perfect. The Replicant operating system is based on Android, but replaces all the proprietary software in Google’s mobile operating system with free software alternatives. It also closes a number of backdoors found in Android, and while Replicant still has its issues, it’s an inviting choice for people who mistrust Android. Thankfully it’s also easier to get as Qibre Computer Hardware (http://qibre.co.uk) is selling mobile devices with Replicant pre-installed. The store has pledged that 20% of its annual profit from selling these particular devices will go back to the Replicant project. Let’s Encrypt, a free open source and automated certificate authority has just hit 100,000 certifications, only a few weeks after it entered public beta – which…

Not PDF I try to be paperless at home: scanning my letters, bills and other important documents to an encrypted folder on my computer and shredding the paper when I can. I have always used the PDF format with scanner programs like gscan2pdf and office programs such as LibreOffice. However, recently I came across the file format called DJVU. It seems to produce a similar document to PDF, with text over image files and can save documents with smaller file sizes than PDF. It appears to be a more open/free format and has a number of converters and readers (eg Evince) both in Linux and Windows. I’d love to use it but I can’t find a GUI to merge and modify documents as I can with PDFs in PDF Mod…

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 Egham Raspberry Jam Meet at the Gartner UK HQ every quarter. 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 , Liverpool. http://liv.lug.org.uk/wiki Manchester Hackspace Open night every Wednesday at 42 Edge St in the Northern Quarter of Manchester. http://hacman.org.uk Surrey & Hampshire Hackspace Meet weekly each Thursday from 6:30pm at Games Galaxy in Farnborough. www.sh-hackspace.org.uk Tyneside LUG Meet from 12pm, the…

Specs... OS: Ubuntu 14.04 64-bit, Red Hat 6.7/7, SUSE 11 CPU: 3.0 GHz Intel Xeon E5-2623v3 (quad-core, 10MB cache, up to 5GHz with Turbo Boost) Graphics: Nvidia Quadro K2200 4GB DL-DVI RAM: 32GB DDR4-2133 Storage: 1TB HDD, 256GB SSD Ports: USB 3.0 x8, USB 2.0 x2, mini DisplayPort (1), RJ-45 to integrated Gigabit LAN x2 Weight: 13.61kg Size: 174mmx 457mmx513mm (WxDxH) – 5U rack mountable option available Over the past five years the aesthetic of the business workstation has changed dramatically from the lackluster copy-paste machine to something more appealing to the eye. The HP Z840 Desktop Workstation has the look of a modern, simple and sleek tower. The sides are a gorgeous brushed aluminium with the HP logo imprinted into the metal. On top, the HP Z840 has two…

Many desktop distributions (distros) ship with a backup tool (including the ones we’ve covered). Linux Mint, eg uses its own MintBackuptool, which has a simple user interface and packs in loads of functionality. You can even install it on top of other compatible distros like Ubuntu via a PPA. Similarly, Mageia includes the draksnapshot tool, which can be accessed via the Control Center, and can be used to backup individual files as well as the complete Mageia installation. There are several backup tools that were once very popular with Linux desktop users but haven’t been updated in quite a while, such as fwbackup, Backerupper and Simple Backup Solution. If you aren’t averse to command line-based tools, there’s Obnamand you can also use rsyncand duplicity that power some of the tools…

1 Boot and select backup Boot from your Redo Backup CD or flash drive, clicking ‘Start Redo Backup’ when prompted. When the main screen appears, click the ‘Restore’ button. First, select the partition on the physical disk your backup is stored on, then click ‘Next’. Click the box to open the ‘Select Backup Image’ dialog, then browse to the folder you placed your backup in, select the backup job file and click ‘Open’. 2 Restore PC Click ‘Next’, then select the drive that contains your Windows installation. The entire drive will be overwritten with your backup, so read and digest the warning before clicking ‘OK’. Wait while the drive is restored to the state it was in when you took the backup. As with the backup process, this can take…

1 Launch GParted Boot your Mint install media. When the desktop appears, click the ‘Menu’ button in the bottom left-hand corner and in the Search box type ‘GParted’. Click the GParted entry when it appears to launch it. Verify your Windows drive is selected (/dev/sda) – you should see at least two partitions, the largest of which is your Windows partition. Right-click this and choose Resize/Move. 2 Free up space for Linux Click on the right-hand slider and drag it left to free up enough space for your Ubuntu install – leave at least 10GB free space for Windows. Once done, click ‘Resize/Move’ followed by the ‘Apply all operations’ button, selecting ‘Apply’ when prompted. Wait for the partitioning to complete, then click ‘Close’. Double-click the ‘Install Linux Mint’ shortcut. Select…

One of Linux’s strengths is that you’re not tied to a single desktop. If you’ve installed Ubuntu rather than Mint you’ll find it comes with a very different desktop environment in the form of Unity. It’s still reasonably familiar to use, but you will have to make a bigger effort to master it. If you’re struggling to acclimatise to Unity, and would rather use Mint’s Cinnamon desktop instead, then you can easily do so. First, open a Terminal window and type: This will add the Cinnamon repository (repos) to Ubuntu, then download and install it. Once installed, you need to click the ‘Settings’ button in the top right-hand corner of the Unity desktop and choose ‘Log out’ to return to the login screen. You’ll see a little Ubuntu icon appear…

1 Take notes Go to https://appdb.winehq.org, find the program you wish to install and verify the version you’re installing is compatible (if it’s not listed, but earlier versions are compatible – experiment!). Also make a note of any comments about additional installation requirements, such as gdiplus.dll. Now visit the program’s website and download the program installer if you don’t have an installation disc. 2 Set up virtual drive Open PlayOnLinux, select Install and then click ‘Install a non-listed program’. Click ‘Next’, select ‘Install a program in a new virtual drive’ and click ‘Next’ again. Name the drive after your program, click ‘Next’ and then tick the relevant options – in most cases just ‘Install some libraries’ before clicking ‘Next’. Leave the 32-bits option selected for compatibility reasons and click ‘Next’…

Artists looking to create vector images have more open-source tools available to them than those working in almost any other field of graphic design. But for visual effects pro, Glenn Melenhorst, there is only one real option: Inkscape (www.inkscape.org). “I’ve always been one of those people that enjoys digging into new software, and I’ve tried a lot of vector drawing programs over the years” he says. “One of the attractions of Inkscape has been its consistency. It’s always been a reliable go-to for me” Melenhorst, whose day job is visual effects supervisor at Iloura, the firm responsible for the digital effects on movies like Ted and Mad Max: Fury Road, first came to Inkscape while looking for an alternative to Adobe software. “My wife works with Illustrator, so we owned…

1 Ben Prunty: Fragments ( http://benprunty. bandcamp.com ) Prunty is best known as the composer for smash-hit indie game FTL: Faster Than Light. The album cover for his latest album, Fragments, was created in Krita by Sylvia Ritter. 2 Discworld cover illustrations ( http://bit.ly/ piperpratchett ) Arguably the highest-profile use of Krita, Katarzyna Oleska’s illustrations for publisher Piper Verlag’s German-language editions of Terry Pratchett’s Discworld novels. 3 Ed ( http://bit.ly/chrisjones_ed ) Chris Jones’ photorealistic short film tells the story of a man who discovers he’s actually a puppet. The 3D models were textured in Krita, then animated in LightWave. 4 Pathfinder illustrations ( http://alexandrusabo.ro ) Concept artist Alexandru Sabo uses a completely open-source workflow for his freelance work,…

Raspbian SSH key woe Weak SSH host keys likely on Pi, free certificates for all, and controlling your containers with Minecraft. According to reports in the Raspberry Pi forums, there’s an issue in the November 2015 release of Raspbian with potentially weak SSH host keys. It is caused by a hardware random number generator not being available when the system is first booted, which results in low entropy (the amount of random data available to the kernel). The recommendation is to apply a patch (when one becomes available) and possibly regenerate host keys. According to others on the forum this actually highlights an issue with many embedded systems/IoT devices where the entropy gathering capability can be low. Weak SSH keys can allow attackers to decrypt traffic between affected devices. Red…

As your ELK adoption grows it may become useful to dump a cache of data into it for some reason. Perhaps you had a year’s worth of syslog data backed up for audit purposes (and occasionally had to grep your way through it to satisfy the forces of evil… I mean, deal with a request from the security team). Elasticsearch provides a RESTful interface over the internals of Lucene, of course, and we can use a provided ‘bulk’ API to handle this kind of situation. This takes a bit of upfront planning, however – your data might need mappings creating internally (which can be done via CURL as well – take a look at the Elasticsearch online documentation). Once you have figured that out (which fields you want to be…

Just in case you missed it, the go-to operating system of choice for all Pi boards has received an update. The latest Raspbian image was released partly to support the Pi Zero release [see Reviews, p20 LXF206] but it included a number of cool updates: Gnome Packages graphical package manager is now default, whoop! Node-RED is an Internet of Things tool from IBM. GPIO Zero is a handy library for easy GPIO access and a new version of Scratch for the Pi (see p62). www.raspberrypi.org/downloads/raspbian.…

Our expert Les Pounder travels the UK working with the Raspberry Pi Foundation’s Education team. He loves hacking with Raspberry Pis and toys. He also writes a blog at http://bigl.es. September 2015 saw the release of Raspbian Jessie, and with it the Raspberry Pi Foundation released its own version of Scratch. In this project we’ll learn more about Scratch and use it to hack together a space game, which we will control using our very own controller. For this project you’ll need any model of Pi, the latest Raspbian, three momentary switches, Male to Female jumper cables, three 220-ohm resistors, a breadboard and three LEDs. We’ll start by building our controller. We’ll connect our buttons to the breadboard and then use the jumper cables to attach one corner of the…

You can flesh out OMV and add a bunch of features to make it more usable. The distribution supports quite a handful of official and third-party plugins, which you can install and enable according to your needs and requirements. To browse a list of all the officially supported plugins, head to System > Plugins. The page lists over 40 plugins, which are divided into categories such as Administration, Backup, Downloaders, Filesystems, Network and so on. One useful option is the downloaderplugin, which can download files into the NAS, and includes several downloaders such as Aria2 and Youtube-DL. This plugin is well complemented by the transmission plugin, which downloads torrents via the Transmissionapp. You should also enable the clamav plugin, which gives you the ability to scan your NAS for viruses.…

Our expert Mayank Sharma is not working as a sysadmin – 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. Build Xxxx a router Install the Zeroshell distro to turbocharge your network You can use the Zeroshell distro to roll out various useful network-related services, if you are responsible for a bunch of networked computers on a small LAN. The Zeroshell distro will transform any computer into a multipurpose server that offers a lot more services and flexibility than you can wring out of most off-the-shelf routers. Zeroshell is a Linux distro that provides various essential network services from DHCP and firewall to VPN and load-balancing. It has a RADIUS server for WPA2 authentication and…

Moving from screento tmuxis fairly straightforward, although some of the concepts are approached differently. The most noticeable initial difference is the shortcut key: screenuses Ctrl+A. Personally, I think tmux’s choice is better and it does not conflict with the shell’s use of Ctrl+a for “go to the start of the line”, so I use Ctrl+b in screentoo. But if Ctrl+a is ingrained in your muscle memory, put this in tmux.conf: If you really don’t want to learn any new keystrokes, tmuxcomes with a file called screen-keys.conf. Copy this to one of the default locations to get screen-compatible key mappings, but bear in mind that it covers only those functions available in both screenand tmux.…

Our expert Mihalis Tsoukalos is a DBA, part-time snake milker, programmer, mathematician and Unix admin. He enjoys writing technical articles and confusing people with inaccurate bios. NoSQLdatabases are designed for the web and don’t support joins, complex transactions and other features of the SQL language. MongoDBis an open source NoSQLdatabase written in C++ by Dwight Merriman and Eliot Horowitz which has native drivers for many programming languages, including C, C++, Erlang, Haskell, Perl, PHP, Python, Ruby and Scala. In this tutorial, we’ll cover the MongoDBdrivers for Python and Ruby. The MongoDBdocument format is based on JSON, and the JSON structures consist of key and value pairs and can nest arbitrarily deep. If you’re not already familiar with JSON, you can think of JSON documents as dictionaries and hash maps that…

Our expert Dan Neame is a JavaScript programmer at Brandwatch. He’s a WebGL aficionado with a love of gaming. Follow him on Twitter @cham or visit http:// dan.nea.me to see more of his work. For this tutorial, we’ll show you how you can use HTML5 Audio and WebGL to create an MP3 visualiser that runs in the browser. Note: this tutorial assumes an intermediate understanding of JavaScript. Three.js (MIT licence) is a Javascript library that makes easy work of doing 3D stuff in the browser; it abstracts away all the technical constructs and will enable us to work with things such as more intuitive objects, viz. cameras, lights and materials that allow us to render using either WebGL or an HTML5 canvas. WebGL is a fairly modern JavaScript API which leverages…

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…