Tabla de contenidos para December 2018 en Linux Format

Jonni Bidwell Compute power corrupts. That’s why my work machine is a rickety box from 2011. It’d be nice to run some crazy distributed simulations, maybe have a go at predicting the weather. But what I’d really like is to never have to fight with captchas again, so if my botnet could help, then I’d care for it as if it were my own flesh and blood. Les Pounder If had a botnet at my command then I’d use it to trawl the internet for bargains at Dollar stores and Pound shops. But why would you do this, I hear you ask? Well, such shops are a goldmine for hackable project parts, especially around Christmas and Halloween. Matthew Hanson Having sat through numerous product launches from a certain fruit-themed company…

Although Facebook has been hogging the negative headlines recently, Google’s rival social network, Google+, hasn’t been having a great time of it either, with the search company finally pulling the plug in October 2018. For many people the writing has appeared to have been on the wall for a while now, with Google+ struggling for years to match Facebook’s popularity. While Google+ has remained popular with a small core of devotees, including many developers for open source projects, an internal memo has been revealed where Google admits that 90 percent of Google+ sessions lasted less than five seconds. That certainly paints of picture of people logging on to check Google+, seeing the lack of activity, and logging back off. However, it appears that the final nail in the coffin of…

Greg Kroah-Hartman has revealed details of the final release of Linux 4.19. In his announcement mail, Greg says that this latest kernel contains more changes than were present in each of the three previous releases. The developer also alluded to Linus Torvalds having taken a break from maintaining the kernel in this cycle, in order to address his abusive language and lack of empathy towards fellow programmers and users over the years. Linus is coming back for the 4.20 release and Greg explains how now is a good time for everyone to reflect upon how we can bring out the best in one another going forward. The recently added Code of Conduct is one means through, which an attempt is being made to set expectations. That Code of Conduct has…

“As ever it’s been frantic at LXF Towers. I’ve been helping by staying out of the way, more precisely I’ve been, courtesy of our good friends at the Linux Foundation, up in Edinburgh at the Open Source Summit. These folks know how to put on a show: so much to see, so many free T-shirts and project mascots, so many delicious snacks. My favourite part was the whisky tasting at Edinburgh Castle. No explanation required. And now for something completely different. Regrets, I’ve had a few. Most recently, I failed to credit George Merlocco for the image of his Painsaw – a chainsaw toy modded with a Raspberry Pi running Doom II – in my Open Source Game Engines feature in LXF242. George kindly gave his permission to use his…

Recent events (see last issue) have put the spotlight back on how people talk to each other, and how that can sometimes fall short of the civil discussions and behaviour we should expect. Now, Richard Stallman has announced the GNU Kind Communication Guidelines (http://bit.ly/LXFStallmanGNU), which are designed “to start guiding people towards kinder communication.” It’s certainly a noble idea, and unlike a Code of Conduct (which lays down rules to abide by), it deliberately focuses on being kind to each other. The guidelines state that “a code of conduct states rules, with punishments for anyone that violates them… the way we do this, rather than ordering people to be kind or else, is try to help people learn to make their communication more kind.” You can read the full GNU…

“Like all software, open source isn’t without bugs and issues. However, when it comes to scratching the itch and resolving or mitigating an problem that you encounter, it can be quite the satisfying adventure. Case in point was a bug I recently discovered in an application I was using. It wasn’t working as the documentation suggested, which was preventing me from completing my task. However, thanks to the code being readily available, I was able to determine what wasn’t working and work around it. But the story doesn’t end there. I was also able to come up with a suitable fix and submitted it “upstream” to be included in future versions of the tool, ensuring neither I nor anyone else would face this problem again. I’m not going to lie…

Build Brighton Thursday evenings is open night. www.buildbrighton.com Cornwall Tech Jam Second Saturday of the month alternating between Bodmin and Camborne. www.cornwalltechjam.uk Huddersfield Raspberry Jam Meet every month at Huddersfield Library, typically on the fourth Saturday of each month. https://huddersfieldraspberryjam.co.uk Horsham Raspberry Jam Park side, Chart Way, Horsham. www.facebook.com/hackhorsham Leeds Hackspace Open night every Tuesday 7pm-late, Open day second Saturday of the month, 11am-4pm. www.leedshackspace.org.uk Medway Makers 12 Dunlin Drive, St Mary’s Island, Chatham ME2 3JE. www.medwaymakers.com rLab Reading Hackspace Unit C1, Weldale ST, Reading, Open Sessions Wednesday from 7pm http://rlab.org.uk Glasgow Makers and Hardware Hackers Mitchell Library, Glasgow. https://m.facebook.com/groups/115303729096198 Teesside Hackspace Tuesday Evenings at Teesside Hackspace. www.teessidehackspace.org.uk…

Send your thoughts to the Linux Format dungeon server at linuxformat@futurenet.com and secure your chance to win an amazing 32GB Nitrokey Storage 2! The Nitrokey is worth a cool €149, has 32GB of hardware-encrypted storage, supports hidden volumes, secures your online accounts with onetime passwords, can encrypt emails, files and hard drives and is an open source, open hardware solution. Protected with AES-256 and RSA keys up to 4,096! Learn more at www.nitrokey.com.…

There’s more to an Ubuntu release than just one distribution. Along with the official flavours, a new Ubuntu release fuels a number of derivative distributions, many of which release updates soon. Perhaps one of the biggest changes to this ecosystem is the dropping of the 32-bit ISO. While many Ubuntu flavours still provided 32-bit ISOs for download for the 18.04 LTS release, a number of them have stuck only to 64-bit for the current 18.10 release. These include Kubuntu, Ubuntu Mate, Ubuntu Budgie and Ubuntu Studio. Of course, the lack of a 32-bit installation medium won’t prevent existing 32-bit installations from upgrading to the newer release via the repositories. Besides the desktop releases, Ubuntu’s other major initiative, Ubuntu Server also gets a handful of upgrades. In its release announcement Canonical…

Since last we looked at office suites way back in LXF167, the quintessential productivity applications on offer for Linux users have undergone a sea change. For one, the applications now boast of a much better compatibility with proprietary formats. Another major development is the introduction of several online office suites similar to Google Docs. In fact, many major players, such as Microsoft Office and even LibreOffice, now offer online solutions. A desktop office suite typically comprises many different applications. There’s usually an program each for word processing, working with spreadsheets and making presentations. Some suites also feature a database or a note-taking application. Most Linux distros, even lightweight variants such as Damn Small Linux, ship with an office suite, or programs to provide the same tools. You don’t always have…

Word processor, spreadsheet and presentation application are three of the most commonly used tools in an office suite. Our selection of suites for this Roundup each offers other applications as well. Google Docs’s Forms can be used to quickly create some of the most common ones, such as contact, RSVP and party invite. The templates provide a vast selection of the commonly used ones across many different categories such as Personal, Word (job application, event feedback), and Education (assessment, worksheet). You can also use Google Drawings to create flowcharts and mind maps, but not artistic works. Calligra provides you with Karbon,a vector graphics drawing application, but the tool is no longer maintained. If you’re interested in a graphical application for building databases, you can try your hands at Kexi. Calligra…

1 Download virtualbox If you’re on macOS or Windows, head over to www.virtualbox.org and follow the download links. Then run the downloaded binary to install it. If you’re on Linux, VirtualBox is almost certainly in your distro’s repos. On Ubuntu, installing it is just a matter of sudo apt install virtualbox . Fire it up from the Applications menu (or however your OS calls it). 2 Create a new VM Hit the New button in the top-left of the VirtualBox interface. We’ll make an Ubuntu 18.10 VM, which we’ve called LXF-Ubuntu-VM here but you can call it whatever you want. Set the Machine Type box to Linux, and the Version box to Ubuntu (64-bit), unless you want a 32-bit VM. If you’re feeling confident, click the Expert Mode button, otherwise…

Power over Ethernet (PoE) is nothing new. In fact, it’s been with us for many years. But it has eluded the Raspberry Pi… until now. The PoE HAT is an official Raspberry Pi product and is designed to work only with the new Pi 3 B+, via the PoE pins present on that board. To use the PoE HAT, we need to attach the HAT to all 40 pins of the GPIO, and the four pins of the PoE header. We then supply power using the Ethernet connection, rather than using a micro USB power source. This necessitates using either a PoEcompliant switch/router or a PoE injector that will send 48V of power and data over a single Ethernet cable. Be careful using this with your network, because non-PoE compliant…

OUR EXPERT Mike Bedford’s interest in electronics predated his passion for computers. Now the two interests work hand-in-hand and have produced some satisfying results. When the first personal computers hit the street, many users were proficient at building electronic circuit boards. Indeed, some of the early models were sold as self-assembly kits. Needless to say, times changed and very soon, most PC users had no interest in, and no knowledge of, the inner workings of their computers. Now, thanks to the popularity of single-board computers (SBC) like the Raspberry Pi and Arduino, we’re coming full circle. Once again, technically minded computer users have a need to delve into electronics, but unlike those computer enthusiasts of the 80s the relevant experience in electronics is lacking. The purpose of this article is…

OUR EXPERT Nate Drake is a freelance technology journalist specialising in cybersecurity and retro tech. To an early 1990s computer user, terms such as Farallon Replica and Common Ground Digital Paper were only too familiar, as various companies fought a bitter format war to establish a common standard for viewing electronic documents. The turning point came in 1993 when Adobe systems made the PDF (Portable Document format) free of charge to the digital public. The standard is now maintained independently and these days most platforms come with a built-in PDF viewer, which virtually guarantees that a document created on one computer will appear exactly the same on another. However, there’s no way to easily edit a PDF once it’s created. If you’re the original designer of the document in question,…

Before you start setting all this up on your home system and if you want to play with small snippets of code, try online solutions such as Codepen and Jsfiddle. Codepen has a pleasing design and it’s easy to move around the desktop. For completeness, you have a window for HTML, one for CSS and finally one for JavaScript. Each window also has options to analyse your code in different ways. The features are Tidy, Analyse and Show Compiled. These are useful if you have a bad habit of indenting badly or just can’t figure out what you’ve done wrong. You can choose where you want your code to show. The three windows with code can be on the right, left or bottom. When you want to start your own…

Gnuplot can also plot continuous functions (so, “sin(x)") in two or three dimensions and we covered this kind of usage back in LXF210. You can put gnuplot commands in a script with a #!/usr/bin/gnuplot shebang and execute it. To concatenate the column header with another string, use some_string. columnhead(i). Note how it’s ‘head’ rather than ‘header’ in this context. User-defined functions are stored as variables prefixed with GPFUN and you can use print to see a function’s definition: print GPFUN_file.…

OPERATING SYSTEM Haiku Version: R1 Web: www.haiku-os.org Haiku featured in our Alternative Open Source OSes Roundup in LXF200 and achieved second place. Even though this BeOS-inspired operating system has only attracted modest interest within the open source community since its inception during the early 2000s, changes are now afoot. This year the Haiku project accelerated its development and rolled out some great new features. A range of open source programs were ported to Haiku, all available through the marvellous Haiku Depot – a newly introduced package manager and software store. Previously, the lack of productivity applications was a recognised bottleneck, but now LibreOffice, Krita, Blender, Qmplay2 and dozens of other well-known OSS programs are able to run natively in Haiku. The new R1 release was hugely anticipated because the previous…

You can learn more about HTTP and HTTPS by reading the related RFCs, which are: tools.ietf.org/html/rfc2616 , tools.ietf.org/ html/rfc7231, tools.ietf.org/html/rfc2818  and tools.ietf.org/html/rfc2660. If your WordPress site still doesn’t work with HTTPS, then you should begin the debugging process by disabling all WordPress plugins. Usually, a WordPress plugin doesn’t permit HTTPS redirecting. If your WordPress site uses the iThemes Security plugin, you might end up seeing strange error messages when trying to access your HTTPS site. This indicates that there’s a redirect loop. In that case have a look at https:// darekkay.com/blog/ darekkay.com/blog/solve-redirect-loop-problemwordpress/ solve-redirect-loop-problemwordpress/  for the solution..…

OUR EXPERT Kent Elchuk is an experienced web developer and Linux enthusiast whose spare time includes programming and hydroponic food production. Forms are ubiquitous on the web. We use them to log in to Facebook, access our Wordpress Admin panel and ask a company about a specific product or service. This covers what we see in a browser. But that doesn’t explain how they work. So let’s get under the hood and take a closer look. By the time we get through this article, we’ll cover many of the intricacies of forms, such as writing code, so users can provide input and write more code to deal with that input after it’s submitted. On top of forms, we’ll cover details about security and web bots, thus revealing that there’s much…

As we were finishing this issue the news broke that IBM was to buy Red Hat. To some of our readers that might mean nothing; to others it could be as earth shifting as the UK government giving fracking companies the green light again. Red Hat is one of the longest-running Linux companies in the world. It’s also one of the most successful. But more than that, over the years Red Hat has placed itself right at the heart of many vital open source projects’ development. Gnome, Fedora, CentOS, Libvirt and Systemd are just a few that spring to mind. It’s this close relationship between the Linux ecosystem and Red Hat that has people rattled, because in recent years IBM hasn’t had the best reputation among some developers. As a…

Just as we were going to press, news landed that IBM is set to become the world’s biggest hybrid cloud provider with a $34 billion purchase of Red Hat, valuing the company at $190 per share. Red Hat will join the IBM Hybrid Cloud team as a distinct unit, with a statement from IBM pointing out that the company will preserve the independence and neutrality of Red Hat’s open source governance, development and culture. Jim Whtehurst CEO of Red Hat added, “Joining forces with IBM will provide us with a greater level of scale, resources and capabilities to accelerate the impact of open source – all while preserving our unique culture and unwavering commitment to open source innovation” The two companies are a good match. IBM has a long history…

“In last month’s issue, I mentioned that I’ve been using Linux for about 22 years. It was a couple of years of being a regular user before I built my first kernel, on what was an old machine (Intel 386) even for the time. The kernel was (much) smaller back then, but the single core machines were also much slower. A kernel compile was typically something started before retiring to bed. Doing anything for the first time can be nerve-wracking, but these days building and using your own kernels need not be! This is especially true for two reasons. First, distros make it straightforward to test booting a kernel by keeping multiple versions installed to choose from at boot time. Second, free built-in virtualisation on every laptop means you can…

“Doing your best to ensure that your Linux systems don’t go wrong is just good policy. Practising what to do if they do go wrong is what’s known as professionalism. To see an excellent example, albeit not a Linux one, search YouTube for “b757 engine failure” and locate the 9m37s clip of a Thomsonfly Boeing 757 ingesting a bird into the right engine just as the aircraft is leaving the ground. The video includes the radio transmissions made between the aircraft and the control tower. You have only to watch and listen to this video to know that the crew have practised this many times before in the simulator. They know what to do; they exercise the drill calmly and, yes, professionally. A major emergency at a critical stage of…

LinuxBoot was released last year with an aim of eliminating people’s reliance on proprietary UEFI firmware. Now LinuxBoot (http://bit.ly/LXFLinuxBoot) is turning its attention to servers. According to the Itsfoss website (http://bit.ly/LXFItsFOSS), the openness of LinuxBoot enables “server users to easily customise their own boot scripts, fix issues, build their own runtimes and reflash their firmware with their own keys” all without having to wait for vendor updates, unlike devices that run on proprietary UEFI firmware. Using LinuxBoot for Servers also enables servers to boot up in less than 20 seconds, considerably faster than UEFI systems, and is also more secure.…

Q The Elder Scroll(bars) Over the years many of us have grown up with the standard user paradigm consisting of scroll bars with up/down arrows associated with them. Click the up/down arrows to move by one line. Click in the trough above or below the slider to move by a page/ screen’s height. This applied to most operating systems including Windows and the many Linux systems that I have used: Mandrake, SuSE, Fedora, Ubuntu. Until, one fateful day, Ubuntu adopted Unity! At this point many of us jumped ship for the comfort of an interface that we knew and loved – the most familiar being Linux Mint with the MATE desktop offering a Gnome 2 look and feel. Imagine my surprise then, when I upgraded my wife’s laptop to Linux…

We’d love to try and answer any questions you send to lxf.answers@futurenet.com, no matter what the level. We’ve all been stuck before, so don’t be shy. However, we’re only human (although many suspect Jonni is a robot), so it’s important that you include as much information as you can. If something works on one distro but not another, then tell us. If you get an error message, please tell us the exact message and precisely what you did to invoke it. If you have, or suspect, a hardware problem, let us know about the hardware. Consider installing hardinfo or lshw. These programs list the hardware on your machine, so send us their output. If you’re unwilling, or unable, to install these, run the following commands in a root terminal and…

We’re running the latest version of all the applications on top of the Budgie desktop. WPS Office and OnlyOffice both provide Snap packages, so installation is a breeze. You’ll also find the latest LibreOffice and Calligra in the software repositories of many distros. This is why we haven’t tested them on the ease of installation. However, if your distribution doesn’t feature the latest Calligra in the repositories, we’ll caution you against attempting to install it manually. The compilation takes far too long, only to result in insurmountable errors. While we’ve tested the three common components of an office suite, we’re just as interested in other components on offer, if any. Another important factor is the support for different formats, including ODF, and even Microsoft Office’s proprietary format, and how they…

Productivity applications is a term that gets thrown around quite a bit nowadays. Until the 1980s, the world was still getting by on typewriters or pen and paper, but with the introduction of office suites, the oldest productivity applications changed how we use the computer at home and work. It’s no surprise, then, that there are very few jobs in the world today that don’t require basic skills with office software. While the suites all provide similar functionality in one or two component applications, they are distinct enough in their workflow that switching between them may involve quite a bit of learning before you’re comfortable using them for everyday use. If you’re only interested in a single office component, such as a spreadsheet or word processor, then refer to the…

There aren’t any other open source suites to consider save for the ones already featured in this Roundup. If none of our solutions work for you, check out the Apache OpenOffice suite. LibreOffice is based on it, but whereas the latter has continued to innovate, OpenOffice has stagnated in recent years. Based on Softmaker Office 2018, FreeOffice is another freeware suite, but as with WPS Office and OnlyOffice, it only features a spreadsheet, word processor and presentation tool. If you’re looking for a cloud-based alternative, there are a couple of others besides Google Docs, including the proprietary Zoho Office Suite and the host-your-own open source Tiki. The AGPLv3 licensed Feng Office Community Edition is another viable option. If none of these catch your fancy, you can grab individual applications, such…

Just as virtualisation took the world by storm in the late 2000s, so around five years later containers came to the fore. There are similarities as far as isolating systems and host-agnosticism are concerned. But containers are really very different animals to VMs. For one thing containers don’t strive to mimic a whole machine. They don’t include a complete OS and share the host’s kernel, so they’re much more portable. They’re also difficult to get a handle on. On the surface they’re similar to chroots or the BSD jails of old, but delve beneath and a web of jargon and complexity awaits. “Containers” in the modern sense refers to a general collection of kernel technologies, some vaguely competing runtime engines and a diverse array of storage formats. It’s easy to…

VirtualBox is a great choice for getting started with virtualisation. It has a catchy name, a friendly interface and it’s cross-platform, but there are other options on Linux, too. Many people actively avoid VirtualBox because of its association with Oracle (seen by some as a litigious corporate behemoth) which inherited the software from Sun, which it acquired in 2010. QEMU is a tool that’s much more aligned with standard Linux practices (y’know, interminable command line options, abstruse configuration files and unforgiving error messages). QEMU on its own is an emulator, but combined with the power of KVM it becomes a high-fidelity virtualisation tool. Elsewhere, Libvirt provides a platform for easy management of QEMU (and other) VMs. It takes the headache out of defining virtual networks and storage, and allows VMs…

Lately, Steam Play has been getting a great deal of attention from Linux gamers, and with good reason. It brings a whole raft of titles to the platform, most of which stood zero chance of ever seeing an official port. However, many of the officially blessed titles don’t perform as well on Linux as they do on Windows, and many other titles run into all kinds of bugs, which prevent them being played properly at all. Make no mistake, the Valve’s Proton Wine fork and DXVK sponsorship are great, but they’re not going to convince hardcore gamers to switch to Linux anytime soon. Even native Linux ports from the likes of Feral and Aspyr rarely compete performance-wise with their Windows counterparts. Virtual Function IO (VFIO) enables the Linux kernel to…

If you’re struggling to keep up with all these trends and abstractions, then you may be appalled to hear that the innovation is ongoing and relentless. With the rise of Cloud Native applications, you would be forgiven for thinking that nobody runs anything on bare metal anymore. Kubernetes (designed by Google but now developed under the aegis of the Cloud Native Computing Foundation) has been described as “the POSIX of the Cloud”, in the sense that it’s fast becoming the standard way to orchestrate and manage containers and VMs in an infrastructure-agnostic manner. Microservices are what you get when you apply UNIX principles to services running in the clouds: lots of containers each doing a small jobs (but doing them well) connected together to do complex tasks. The security of…

The step-by-step nature of the conventional cave surveying process means that errors steadily accumulate. As such, the calculated position of the end of a long cave passage could be subject to significant errors. One way of overcoming this problem is to use radio-location to determine the absolute location of the cave extremities and thereby double the number of fixed points. Normal radio is heavily attenuated as it passes through rock and earth. However, if a sufficiently low frequency is used, signals can penetrate the earth to a depth of a few hundred metres. This is a technology that’s used by cave rescue teams to coordinate their operations. It’s also the key factor of radio location. The process involves setting up underground transmitter and its associated loop antenna that generates well-defined…

With the Raspberry Pi being deployed in so many different areas, one ability that’s been sorely missing so far has been a TV tuner. So it shouldn’t be too much of a surprise that the latest official Raspberry Pi Foundation expansion is just that: a digital TV tuner called the TV HAT. The device is available to buy on a Europe-wide basis (more regions will be added) now. It costs just £20 and is based on the Sony CXD2880 TV tuner that adds DVB-T2 reception to your Pi. Be aware that a Raspberry Pi 2 or better is recommended due to the processing overhead required. The TV HAT enables you to view live TV broadcasts directly from your Pi or streamed over the local network. The introduction of the TV…

OUR EXPERT Les Pounder is a freelance maker who works with organisations such as the Raspberry Pi Foundation to promote maker skills. Read his blog at bigl.es Stuck on what to watch this evening with the family? Fear not – with this project we can have our Raspberry Pi randomly choose a video for us to watch. So let’s start building and coding our own random video player! All of the code, and a detailed high-res circuit diagram can be downloaded from https://github.com/lesp/LXF244-VideoPlayer/archive/master.zip. Don’t be breadboard Building the circuit for this project is simple. We only require three buttons, connected to the GPIO at pins two, three and four, and each of these buttons also needs to be connected to GND. For this we can use a single GND pin…

Unlike most components, the value of a resistor is marked using coloured bands. There are actually two schemes: the original colour code that has three value bands, and the newer one that has four value bands. In both cases there are additional bands to these three or four, the extra bands defining the tolerance and, perhaps, the temperature coefficient. You’ll normally be able to ignore these extra bands, but it’s important to be able to read the value, in ohms. If there are three value bands, the first two represent the first two digits and the third is a multiplier: the number of zeros. If there are four value bands, the first three represent digits (the third digital will usually be zero) and the fourth is a multiplier. If we…

OUR EXPERT Shashank Sharma is a trial lawyer in Delhi and avid Arch Linux user. He’s always on the lookout for geeky memorabilia. There was a time when, for most people, the greatest fear of the modern world was catching a cold on public transport. But times have changed, and now our common dread is losing irreplaceable data – either accidentally, or through it being stolen. As more people opt for digital banking transactions done from the comfort and convenience of a cellphone, the manufacturers have had to resort to measures such as fingerprint sensors to help you guard your secrets on the mobile device. But what about all the other data on your laptops and desktops? One easy solution to gain peace of mind is to use encryption to…

One common reason for needing to edit a PDF is that you’ve been asked to complete and sign an electronic form. This is one of the few areas where Linux falls down, because users of Adobe Reader on other platforms can use its tools to create a digital signature. Fortunately, it’s not too difficult to sign a PDF the old-fashioned way using LibreOffice Draw. Bear in mind that you’ll have to write your signature using a mouse, unless you’re using a stylus-and-tablet setup. If you’ve not done so already, install LibreOffice and then open your PDF form. Next, click the Show Draw Functions button at the top right. These will now appear on the left-hand pane. Right-click anywhere on the pane and select Freeform Line, then make your mark on…

React is developed to handle user interfaces, so you should think of it as a part of your tool set, not the entire solution. To use React, you may want to consider what logic you need to combine with it. Combining React with a CMS is one way to go, and there’s even a web page (https://reactfordrupal.com) for this purpose. Drupal is not the only choice, though. Wordpress has an API that makes developing the interface straightforward. When you have NPM installed you can look for packages using the built-in search. The result is a long list of packages, so be sure to choose the react-dom for web pages, and react-native is for native environments. Packages that use React is an even longer list. In fact, the length alone should…

This article comes at a time when Flatpak recently enjoyed two significant developments. The first is the project’s v1.0 release, which came out on 20 August, 2018. As befits such a milestone, the press release (https://flatpak.org/press/2018-08-20-flatpak-1.0) called the new version “feature-complete,” with all the necessary resources for both developers and users. So in addition to the Flatpak commands we’ve mention in this article and support by most major GUI package managers, there are also tools to help developers package their applications as Flatpaks. If you’re a coder-type, check the “Build applications” section of Flatpak’s help (flatpak --help) for an idea of some of the utilities at your disposal. But the launch of another initiative is arguably more interesting. The WinePak project (www.winepak.org) project utilises Flatpaks to help ease the installation…

The colours used in the examples were chosen by gnuplot. It defines eight line types, which are styles that define the colour of each line (or box or whatever). These definitions may be customised using set linetype and others may be added. If a plot contains more lines than line types then it will cycle over the defined linetypes (so that line nine is the same colour as line one and so on). You can define more than eight line types and any defined line types take precedence over recycled ones: if you didn’t define line type nine then line type one would be used for the ninth line; if you defined line type 10 then that will be used for the 10th line, not line type two. To cycle…

The process of switching Drupal to use HTTPS instead of HTTP has many similarities to a WordPress site, so for the purposes of this tutorial, the http://www.mtsoukalos.eu web site will be used. First, you’ll need to create certificates for that web site, which have nothing to do with how the web site is implemented: Second, you’’ll need to set up Apache or Nginx as you did with the WordPress site. But this is where the similarities end, because after that you’ll need to make changes to the main configuration file of Drupal 7, which is located at ./public_html/sites/default/settings. php. The first change is adding $conf[‘https’] = TRUE ; at the end of the file and the second change is redefining the value of $base_url , which in this case will…

An extra level of protection in forms is to check for words in the body of an email message. Thus, we can discard any message that contains words such as Viagra, SEO, holiday and free. Never trust user input. When building forms, especially those for which data will be inserted into a database, we can use built-in PHP functions like htmlspecialchars(), htmlentities() and sanitise filters from https://bit.ly/2QNRDam . Keep in mind that data transferred over SSL(https) is encrypted while Http is plain text and can be captured with Wireshark over Wi-Fi. Forms are a great way to gather leads from web users without revealing our email address, which would makes us more prone to appearing on spam lists.…

In this article, we’ve seen how spamming can be applied to single URLs and can be utilized by simply running the PHP file that uses curl to fetch a URL and automatically submit a form. Since the form data normally gets sent to an email address, the user could ask generic questions such as pricing, or enquires related to services. From the site owner point of view, the form would normally be answered by a friendly email. This friendly return email could end up on a spam list that will haunt the email address for years to come. In addition, the email could end up on lists that are sold to other people too, thus having a spammer multiplying effect. These email lists can be deposited into mysql databases in…

USING THE LXFDVD Using Linux for the first time can be very confusing. It’ll be unlike anything that you’ve likely used before, especially if you’re used to Microsoft Windows or Apple Mac OS. Generally our DVDs are designed to be run directly, which is to say that when you first power on your PC (or Mac) it should “boot” from the DVD – so before Windows or Mac OS even starts to load – with Linux running directly from the DVD. This trick is known as a Live Disc. It enables you to try out the various versions of Linux without having to install or change anything on your PC. Just remove the DVD, restart your PC and it’ll be exactly as you left it. While many systems will boot…

Advanced Bash Scripting Guide Go further with shell scripting. Bash Guide for Beginners Get to grips with the basics of Bash scripting. Bourne Shell Scripting First steps in shell scripting. The Cathedral and the Bazaar Eric S Raymond’s classic text explains the advantages of open development. The Debian Book Essential guide for sysadmins. Dive Into Python Everything you need to know. Introduction to Linux A handy guide full of pointers for new Linux users. Linux Dictionary The A-Z of everything to do with Linux. Linux Kernel in a Nutshell An introduction to the kernel written by master hacker Greg Kroah-Hartman. The Linux System Administrator’s Guide Take control of your system. Tools Summary Overview of GNU tools. GNU Emacs Manual Six hundred pages of essential information! Producing Open Source Software Everything…

“Last month at Open Source Summit in Edinburgh, The Linux Foundation awarded 31 Linux Foundation Training (LiFT) scholarships to deserving individuals from 21 countries. LiFT aims to increase diversity in open source technology by providing access, at no cost, to online and in-person training and certification exams for underserved demographics and geographies. Since 2010, The Linux Foundation has awarded over 100 scholarships providing specialised, technical training to deserving individuals. More than 900 applicants vied to be selected in one of the nine categories offered. This year’s selected pool of talent represents the potential for greatness in future participation in the open source community. The ages of the talented recipients ranged from 17 to 53, with the average age being 26 years old, reflecting the interest in open source across generations.…

The 4.19 kernel adds upstream mitigations against the L1 Terminal Fault (L1TF) vulnerability present in certain recent Intel CPUs. The vulnerability enables an attacker to exploit carefully crafted “not present” Page Table Entries (PTEs) used by the kernel to manage translations between the virtual memory addresses it understands, and underlying physical hardware. The x86 specifications say that Page Table Entries marked as “not present” can be re-used by the Operating System for its own purposes, such as tracking data that has been “swapped” (paged) out to disk (and hence “not present”). In exploiting L1TF, the hardware is tricked into (briefly) speculating that these otherwise ignored entries are valid translations, allowing an attacker to speculatively read from memory to which they would not normally have access. This is similar to Meltdown,…

For anyone who’s been wary of using Android because of privacy concerns, a recent report by the Financial Times (https://ig.ft.com/mobile-app-datatrackers) will do nothing to allay those fears. The article claims that nearly 90 per cent of free apps on the Google Play store share data collected from your phone with Google’s parent company, Alphabet. Google is adamant that it has strict privacy policies in place to ensure that no app violates Google’s policies on privacy. However, this isn’t the most reassuring statement, seeing as these apps are sharing data with Google itself. Researchers have released a paper on the data sharing that mobile apps are involved with, with Professor Nigel Shadbolt, who led the research team telling the BBC (http://bit.ly/LXFBBCAndroid) that “People [in businesses] are desperate to get as many…

PRIMTUX 4 This Debian-based distro, which was created by a team of school teachers for use in the education sector, has been updated. It now sports a unified look that can be customised using the HandyMenu. There has also been improvements to parental controls, making this a more tempting distro to use for student PCs. Check out the release announcement (in French, so you may need to use Google Translate if you’re not au fait with the language) at http://bit.ly/LXFPrimTux. OPENINDIANA 2018.10 The latest snapshot of this open source operating system based on OpenSolaris is now available to download from http://bit.ly/LXFOpenIndiana. This new version updates the MATE desktop, as well as upgrading many of the applications to their latest versions. Also included in the update is Python 3.5, along with…

BETT 2019 Bett is an annual show taking place in London’s ExCel at Victoria Dock on 23-26 January next year. The focus of Bett is education, but it also plays host to many technologies. At the STEAM village (Science, Technology, Engineering, Art and Maths) there are representatives from the Raspberry Pi Foundation, micro:bit, Arduino, github and Microsoft who are all there to demonstrate their latest projects for educators and eager hobbyists. More details at the Bett website: www.bettshow.com. PARIS OPEN SOURCE SUMMIT Les Docks de Paris is where you’ll find the European open source summit, which is on 5-6 December. An estimated 5,000 participants will be visiting 170 stalls from all areas of the open source community. There will be a conference and speakers from all over the open source…

Not so secure I’ve been an on-off user of Linux for many years. Initially, I was tempted by the magic of Knoppix 3, succumbing to the power of openSUSE 10 and enjoying the fun of Puppy 5. More recently I’ve discovered MX Linux 18, which seems to work flawlessly on every single PC. But I’ve always come back to Knoppix, now at version 8. I must add that I’m still very much a novice Linux user. I use Knoppix all the time now. It’s become my day-to-day working desktop. I save my changes to a persistent data file that gets saved on exit and loaded on boot. It’s so easy to use, with everything pre-installed, but is it safe? Is it safe to use any live distro online in this…

Q Exactly website what ? is going on with your Anonymous but concerned browser A Good question. After years of neglect our poor server fell over, and we’re going to be moving things in-house. A sad day, especially given its tremendous (decade-long) uptime, but it no longer makes sense for us to rely on the generosity of UKFast to provide resources that the beleaguered Linux Format team don’t have the resources to maintain. For now the old server has been tenuously been brought back to life, but don’t be surprised if it falls over again, or turns into a pumpkin. Also, someone (Jonni?–Ed) needs to re-code our subscriber archive, which is non-trivial. So when the new site launches it’ll likely do so without a portal to access historic PDFs.…

Judging by the nature of work that these programs perform, you’d think they’re fairly easy to use. While this is true for the most part, especially for the straightforward offerings of Google Docs, the other applications may require some guidance. Such as when you’re trying to figure out how to install plugins on WPS Writer, or if there are even any on offer! While all the applications are cross-platform, WPS Writer’s Linux edition doesn’t get the same attention as its Microsoft counterpart. This is why you may find solutions to certain problems in the official documentation that don’t apply to the Linux edition. For instance, the official Help will tell you how to use the Mail Merge feature, but it isn’t even available on Linux. There isn’t much documentation on…

Virtualisation has been around since the mainframes of the 60s, where the activities of one program were separated from another. Later, IBM’s CP-40 introduced the notion of a hypervisor and the ability to run multiple OSes concurrently. Virtualisation proper took off in earnest in the mid-2000s, when 64-bit processors appeared with explicit features for running guest OSes more efficiently. Being able to virtualise machines (in theory) made sysadmins’ lives much easier. Whole systems could be snapshotted, backed up and restored as easily as files. Critical updates could be tested in a virtual sandbox, which vastly reduced the possibility of things catching fire when they were rolled out to physical systems. Multiple VMs could exist on the same system, yet for all intents and purposes be isolated from one another, improving…

The Virtual Machine Manager GUI enables us to choose the QXL video device with the click of a button. However, it also enables us to go one better and match (and perhaps even surpass) VirtualBox’s 3D acceleration capabilities. In our interview with Collabora’s graphics guru Daniel Stone (see LXF243), he mentioned the VirGL (pronounced Virgil) project, and its use in Chrome OS’s CrosVM hypervisor. VirGL can pass OpenGL calls directly to the host’s GPU, allowing 3D acceleration within the guest. Activating VirGL from virt-manager (see over the page) is surprisingly easy: from the Video section just select Virtio as the model and tick the 3D acceleration box. Then in the Display Spice section change the Listen type to None (VirGL doesn’t work over TCP), and check the OpenGL box. You…

For this trickery to work some vaguely modern hardware is required, and even with modern hardware things sometimes go awry. The graphics card used by the host can be anything, even integrated graphics. If you have two discrete GPUs, then you’ll want to be familiar with the key combination for entering the BIOS/UEFI because your machine will almost certainly try and boot from the wrong graphics card. The guest’s graphics card will need to support UEFI (the motherboard needn’t) since we’re booting with OVMF. It’s possible that an updated GPU BIOS is available from the manufacturer (some people have reported success by just asking them), which you can pass to QEMU rather than flashing your graphics card. Generally anything manufactured after 2012 will be fine. Your motherboard must support IOMMU…

Just recently I, along with many others, won the John Pinner award at PyConUK. This award is named after the creator of PyConUK who sadly died in 2015. John was a role model for the Python community and he gave his time and effort to the community for no reward. John will be sadly missed. In his honour, the John Pinner awards are given to those in the community who never receive the recognition they deserve. My award reflected the work that I undertake in the UK community, helping children to learn Python and take their first steps to becoming a maker. But the awards got me thinking more about communities. They are the lifeblood of boards such as Raspberry Pi and Arduino. Without a community they’re just lumps of…

In this project we used the Keyboard Python library to emulate a keyboard using just the push buttons that controlled playing, pausing and stopping video playback. The Keyboard library can be used to press any keys, so we can automate multiple key presses all from one push button. The library can also be used to write text to the screen. But the most dangerous function of this library is that it can be used to record every key press on the target machine. These key presses can be recorded to a list, then saved to a file and then used for nefarious purposes. Of course, recording the key presses of a user, without their consent is illegal and can land you in a lot of trouble. So don’t do it!…

Steganography is a process of hiding information such as messages, files and images in other files or images. The advantage of using Steganography is that it’s nigh-on impossible to tell if any image or file holds secret information. Compare this with regular cryptography, such as the one deployed with Tomb to create the keyfile. Due to its very name, having a .key extension, the keyfiles can easily be identified, and subjected to attacks such as brute force to break their password protection. Wouldn’t it be great if you could mask your keyfiles within seemingly benign files? Thankfully, Tomb makes it quite easy to bury keyfiles within JPEG images, using the steghide utility, which you can install from your distributions software repositories. Once installed, you can use the tomb bury -k…

OUR EXPERT Mats Tage Axelsson started his adventures in Linux using an IBM Thinkpad and floppy disk setup. He still tries to squeeze the most out of ageing hardware, the cheapskate. A web server is a hefty collection of software running in a rack server, which – unsurprisingly – few of us have at home. So when you want to make a new web page, you have to use an online service to test your CSS code, such as Codepen or Jsfiddle. However, these services are usually limited to handling small code snippets, and more advanced code becomes cumbersome to develop using these tools. With greater complexity comes other risks, such as compatibility. If you hope to be a professional coder, you’ll need to know how to use a few…

OUR EXPERT Aaron Peters wishes he was a programmer, but sadly has to settle for telling programmers what to do in the form of software documentation. Linux has made great strides in the area of software compatibility. Or, more accurately, software is available more consistently across the various distributions and their native package formats. Yet this still requires the hard work of packagers. They need to take an application and tweak it to fit the specific needs of different distros, and even different releases of the same one. However, a few new universal package formats have emerged, bringing the promise of “package once, run anywhere” (on Linux, anyway). Flatpak (https://flatpak.org) is among the contenders Mayank Sharma reviewed in LXF234, and it’s got a lot going for it. In this article…

OUR EXPERT John Lane consults and writes about Linux, usually on a ThinkPad in the garden with a cold beer… They say a picture is worth a thousand words, something you’ll appreciate if you need to compare buckets of numerical data. We did this in LXF243, when we made storage benchmarks, and we used gnuplot to do it. In this tutorial we'll show how you can use gnuplot to plot and chart your own data. gnuplot is a tool for presenting data. It has nothing to do with the GNU Project, the name being a compromise that could quite as easily have been llamaplot (see gnuplot.info/faq para 1.2). It doesn’t use the GNU GPL, instead preferring its own open source license: We’ll use gnuplot to present some input data as…

As well as the default interactive window output terminal, gnuplot supports many other output options, including PNG, PDF, EPS (Postscript) and LaTeX. You can list what’s available with set terminal or print GPVAL_TERMINALS . Note how terminal in this context refers to the graphical output device, not to the text terminal you’re using to interact with gnuplot. Changing the output terminal is a two-step process that selects a terminal and output file: Supported options depend on the chosen output terminal. You can use the integrated help to see the supported options, for example: You can set terminal options individually using set termoption . As an example some terminals have an “enhanced” text mode where text strings are interpreted so that you can specify things like subscripts and superscripts. Disabling this…

OUR EXPERT Mihalis Tsoukalos is a UNIX expert and the author of Go Systems Programming and Mastering Go. You can reach him at www.mtsoukalos.eu and @mactsouk. So, you want to convert HTTP sites into HTTPS ones? Then you’ve come to the right place! For this tutorial, an existing WordPress site will be used as the main example, but most of the presented information is generic. The process of switching an HTTP WordPress site to use HTTPS is relatively long, but it’s not difficult to follow – you just have to be precise and patient. Additionally, you’ll see how to instruct a Drupal 7 site to use HTTPS as well as a static web site, which in this case will be the web site of the Monit monitoring tool that runs…

HTTPS’ key advantage is that it’s faster than HTTP. However, there are some more technical reasons why HTTPS is better than HTTP. A malicious person can redirect HTTP traffic to fake websites in order to steal usernames and passwords using a technique called DNS hijacking or DNS redirection. HTTPS can prevent DNS hijacking, which can happen on web server machines as well as other networked devices such as switches, routers and modems that communicate using HTTP. Additionally, adverts or other content can be inserted into an existing HTTP page without the original page knowing anything about it. Similarly, mining software can be inserted and executed to an HTTP page without the owner of the page knowing about it. All these nefarious actions come under the umbrella heading of man-in-the-middle attacks,…

Session control can keep track of user activity and can help bail us out if manual users become problematic. We simply add the following line of code to the top of our file in order to work with sessions: The session control we’re about to use will only enable someone to fill out our forms once, because the session is created after the first form submission and subsequent visits to that page will recognise the session and bypass the mail() function. To add session control, we can wrap the following else code bracket around our previous checking code: The code shown above translates into plain English. It’s PHP code that reads, ‘If the session variable called ‘sent’ exists, do nothing, otherwise go ahead and run the rest of the stuff…

BEAUTIFUL BEGINNER DISTRO Elementary 5.0 Juno 64-bit The Elementary OS team has been carving itself a fine legacy as building one of the most polished distros ever created for Linux. For its latest release it cemented that by jumping from v0.4 to v5.0, to herald Elementary OS moving from a work-in-progress to an OS ready for daily use. Elementary OS is based on Ubuntu (find out more about the latest version of that on the right), and stands apart from the crowd by providing a finer crafted, easier to use and more consistent desktop experience. A key part is the custom desktop called Pantheon, that’s been developed over the years using the latest open source technology. The evolution for 5.0 includes a bunch of exciting enhancements. Night Light introduces display…