Sommaire pour July 2018 de Linux Format

Jonni Bidwell I’ve revived my netbook with Arch 32 and the Wayland-powered Sway desktop. It only has a 2GB SSD so I only use terminal applications: Midnight Commander for file management, ncmpcpp to control my Pi jukebox, and the awesome coinget utility to lament my declining crypto worth. Shashank Sharma I’m running a customised Budgie with a disappearing panel at the bottom. My longterm love however is Gnome, but I dislike the Activities overview. Instead, my Gnome desktop features several Shell Extensions, including a categorised menu, to make it beautiful and efficient. Bobby Moss I’m a fan of MATE because it’s responsive and easy to use. I particularly like MATE’s appearance and layout in Trisquel and Mint, but you can customise these by right-clicking panels and editing their properties. Custom…

Nextcloud (https://nextcloud.com), the open source, self-hosted file share and communication platform, has scored a major win with the announcement that the German Federal Information Technology Centre (ITZBund), which oversees the IT services of the federal government, will be using its service. This follows a pilot scheme that has been running since October 2016 with 5,000 users. According to Nextcloud, the government went with them because it was looking for an open source solution from a European company that could guarantee no vendor lock-in, and wouldn’t provide access to the data it held to third parties. ITZBund will use an on-premises cloud, and it’ll be compliant with the General Data Protection Regulation, which came into effect on 25 May. As some have pointed out, the fact that Nextcloud is not a…

“The documentation may be a bit out of date”. That’s the common cry we hear when taking on a new client. That’s okay: we can document their setup ourselves, but that takes time. It’s much easier if we can start with their up-to-date documentation. The truth is most techies hate writing documentation, but those same techies recognise the value of good documentation. The documentation for git, Django, Python and Apache is excellent. The documentation for the Linux infrastructure within many businesses is poor and outdated, if it even exists. A typical workflow is to look something up internally, find it’s missing or incomplete, go through a process involving coffee and words you wouldn’t say in front of grandma, to finally finding the information. The “finally” is the killer: what the…

Lenovo is facing more controversy because owners of its Lenovo P2 smartphone were unable to install an official LineageOS 14.1 ROM to move away from Lenovo’s default Android 7.0 software. Despite having an official ROM, which can be downloaded from http://bit.ly/lineage-os, users for almost a year have said they’ve been unable to verify their Lenovo ID registration, the system that enables the bootloader to be unlocked. It’s annoying as it’s unlikely that the Lenovo P2 will receive official updates. Lenovo finally responded saying it was “looking into the issue.” Good news landed on the 11 May as the service appeared to be working again, but consider for future phone purchases!…

Alpinux, le LUG de Savoie Meets on the first and third Thursday of the month at the Maison des Associations de Chambéry, France www.alpinux.org Build Brighton Thursday evenings is open night. www.buildbrighton.com Sandbox Sandbox Digital, 5 Brasenose Road, Liverpool L20 8HL. Open maker night is Tuesday 6-9. Kids clubs are Monday (six to eight years) and Wednesday (eight to 12 years). www.sandboxdigital.co.uk Leeds Hackspace Open night every Tuesday 7pm-late, open day second Saturday of the month, 11am-4pm. www.leedshackspace.org.uk Horsham Raspberry Jam Park side, Chart Way, Horsham. www.facebook.com/hackhorsham rLab Reading Hackspace Unit C1, Weldale Street, Reading. Open sessions held on Wednesdays from 7pm. http://rlab.org.uk Huddersfield Raspberry Jam Meet every month at Huddersfield Library, typically the fourth Saturday of each month. www.huddersfieldraspberryjam.co.uk Medway Makers 12 Dunlin Drive, St Mary’s Island, Chatham, ME2 3JE.…

Q My my problem printer, the concerns HP OfficeJet the use Pro of 6970 on Ubuntu 16.04. The printer won’t work properly until I run sh hplip-3.17.11.run . This involves a dialog requiring the right answers from myself. When I get the answers right the printer works correctly using a USB cable. I’m unable to print by wireless even though the printer has that facility. I’ve found that HP printers in general work well with Linux. However, my main problem is that for no apparent reason the printer stops working and the hplip program has to be run all over again. Strangely enough, I ran Zorin from LXF226’s DVD, which identified the printer, found drivers and printed a file from LibreOffice Writer. All apparently without any involvement from hplib. Bryan,…

Feral has done a decent job for the Linux release. It’s running on the Vulkan renderer and as such that does require you to have up-to-date and compatible Nvidia or AMD drivers, but the effort is worth it. Even our aging Nvidia GeForce GTX 750 was happy to drive the game along at 1080p resolutions at 30fps, though with low detail defaults. As you’ll see from the hardware requirements – that don’t differ far from the original Windows ones – it’s a demanding modern game.…

With the exception of darktable and Fotoxx, none of the other tools provide or support extending their functionality with plugins. While some LightZone users have long requested for a mechanism to extend beyond the default features, it seems unlikely to happen any time soon, if at all. However, both LightZone and Photivo can be configured as plugins for Gimp. This means that you can access LightZone or Photivo to edit images while working on your images in Gimp. The darktable wiki provides details on a number of plugins, but these are features that have already been added to darktable over time. The project uses the versatile Lua scripting language that you can use to write scripts to extend darktable. The darktable manual has an entire chapter dedicated to scripting with…

We’re big fans of the distribution development process. The effort that goes into collating the myriad pieces of software and libraries into a functional operating system deserves a lot of praise. Yet in their effort to ship with a product that’s good enough to please the majority of users, the out-of-the-box experience of virtually all distributions leaves a lot to be desired. Unlike proprietary operating systems, Linux users have greater control over their installations and don’t have to stick with the default options. In fact, the first thing you probably do post-installation is swap out the default applications with ones you’re more comfortable with. But you can just as easily replace your desktop environment (DE) without having to install a different Linux distro. Simply install a pre-defined group of packages…

This interview happened in October 2017, so here’s a summary of some developments that have happened since then… A new company, Moxa, joined the CIP in January. It’s an edge-to-cloud connectivity provider that provides solutions for factory automation, smart cities and monitoring. Also in January you’ll probably remember the Spectre and Meltdown attacks - which affect embedded ARM and Intel hardware as well as desktop CPUs - were disclosed. So the relevant patches are being backported to the CIP SLTS kernel. Some hardening features from the Kernel Self-Protection Project have been added, too. We’ve also had a few CIP kernel releases. In April Ben Hutchings released the latest one: 4.4.126-cip22. Kernel 4.4 was released in January 2016, and was initially earmarked for long-term support until February 2018. That was extended…

Last month my school, Penketh High School in Warrington opened the first state school makerspace in the UK, @SparkPenketh, and began embedding making within the national curriculum. We knew we’d done something big by opening the space and we knew it was important. It’s a place for kids to be able to ask questions and not just learn answers. There’s nothing like it in any other school in Britain at the moment and we want to change that. So we’ve launched the Society of School Makerspaces and are running the first UK Maker Education unconference, MakerNoise this 7 July at Edge Hill University, to give teachers a platform for change. Kids are so creative and buzzing with amazing ideas, but our education system quickly knocks that out of them in…

Raw data can be manipulated into a spreadsheet, and in this project we could have simply stored the collected data in a CSV (Comma Separated Values) file and used a spreadsheet to visualise the data, but with the power of Python and the matplotlib library we automated the process. Matplotlib is powerful and versatile. It can be used to create most forms of charts and graphs, which can be investigated and manipulated in real time, and saved for use in reports and online portals. But is matplotlib the only library to offer this service? Of course not. Another popular graphing library is called plotly (https://plot.ly) and this library can create HTML compliant charts and visualisations on the fly, even hosting them on the plot.ly website. So what’s the catch? Well…

As you dig deeper into machine learning, you’ll find yourself tuning how the model is trained and retrained to improve its performance. You do this by altering things like the number of layers in the network and the number of training steps. These are called hyperparameters. In machine learning, there are parameters and hyperparameters. Parameters are the data that the model turns into a prediction, such as pixels in the images and words if we’re doing text classification. Hyperparameters affect how well the model performs once trained. For example, we’re setting “how_many_training_steps” to 500 but it could be that 1,000 training steps would create a more accurate model, or maybe 300 is enough. Play about with it. Retrain the network using fewer training steps and then see if the confidence…

To extend the functionality of Byzanz without involving a graphical interface, go to http://bit.ly/byzanz-scripts and download the zip archive. The scripts inside (byzanz-region.sh and byzanz-window.sh) are based on ones provided by Rob W to the Ubuntu forums. The byzanz-region.sh scripts requires the xrectsel tool, which is used to identify the dimensions of the rectangular region you wish to record. This tool isn’t available in the software repositories of any distribution and must be installed from its Git repository. Before you install xrectsel, make sure you have all its dependencies installed – autogen , autoconf , libx11 and libx11-dev . Thankfully, these are offering the software repositories for most popular distributions. Now, you can install xrectsel by running the following commands: With xrectsel installed, you can run the byzanz-region.sh script with…

To create a generic handout page that contains a minified view of your slide-show simply head to File>Print and under the General tab you should see a myriad of options. Under the Print section there’ll be a drop-down menu next to Document, and you should change this from Slides to Handouts. The previewer should change to reflect your choice and you can customise your selection by defining how many slides display per page. Setting it to three slides will usually provide a lined text area next to each one for your audience to take notes. You can also change the order the slides appear in, to better suit your requirements too. However, this may not provide enough information for you. Many people provide supplementary information in the slide notes and…

Besides Sway, another tiling window manager is Way Cooler. Check it out at http://way-cooler . org . There’s also the Qt5-and Weston-powered Orbital. See https: // github.com/giucam/orbital for more details. Vulkan may in the future offer some respite for the GBM vs EGLStreams debate. This feature request https://github.com/ KhronosGroup/Vulkan-Docs / issues/294 proposes adding a side extension which allows for writing device independent (as long as the device supports Wayland) Wayland Compositors.…

OUR EXPERT Mats Tage Axelsson still tries to squeeze the maximum out of ageing hardware, the cheapskate… The interplanetary file system (IPFS) isn’t for colonising Mars, but rather to create a freer, robust system for the web. Indeed, its developers refer to IPFS as the permanent web. Let’s find out more about this blockchain technology… The web’s IP protocol was designed to work without a central server. This was partly due to the risks of nuclear war. By design, anyone can connect a computer to the net and add a server. There is a caveat though: most communication goes over a small number of services owned by large corporations. While these are not evil by default, they represent a central point in the system and, as such, can be exploited.…

OUR EXPERT Dr Sinitsyn is a lapsed KDE committer. He likes building Linux clouds and writing articles. The way we used the internet has changed drastically over the past 20 years. Back then, nobody cared too much about encrypted communications, As e-commerce and similar web sites started to grow, the need for encryption became evident. So Netscape designed a protocol called Secure Sockets Layer (SSL). The idea was to add encryption at the transport layer so any application-level protocol, be it HTTP, email (POP3/IMAP/SMTP) and now DNS (see https://bit.ly/2JQzxRC), can leverage it easily. The original SSL was a proprietary protocol, but IETF took over newer versions that became standards. SSL 3.0 was the last one, and future improvements over the protocol were called TLS (Transport Layer Security). TLS 1.0 is…

This Administeria covers a dozen of sysctls, /proc entries and other knobs you may use to tweak the virtual memory subsystem. Below is a quick summary for your records: vm.max_map_count The maximum number of memory maps a process may have. 64K should be enough for anyone. vm.admin_reserve_kbytes How much memory in kilobytes to set aside for a superuser, so they can always spawn a process. vm.user_reserve_kbytes The same, but for regular users. This leaves them free to kill a memory hog themselves. vm.overcommit_memory Whether Linux should check if it’ll be able to fulfil the memory allocation or just let it go and see if it works out later. vm.overcommit_kbytes How much RAM, in kilobytes, processes can use. This doesn’t include swap, which is always available. vm.overcommit_ratio The same, but expressed…

You can learn more about Vega and Vega Lite at https://vega.github.io / and at https://github.com/ vega/vega , respectively. And you can find some sample data sets at https://github.com/ vega/vegadatasets . Vega Lite offers a more compact and higher level grammar than Vega. As a result, use Vega Lite when it can do your job and when you know that you will not need any of the features that are offered by the Vega grammar only. The Vega online editor is at https://vega.github.io/ vegaeditor . Similarly, you can find the Vega Lite online editor at https://vega.github. io/editor/#/. These two editors can help you experiment with the Vega and Vega Lite…

Are you enjoying the Bionic Beaver yet? After two years of a faultless 16.04 LTS install, my work PC sailed smoothly along with an error-free upgrade to 18.04 LTS. So long Unity, hello Gnome. Was it Gnome sweet Gnome for you, or more a case of here today, Gnome tomorrow? Ok, Gnome more bad puns… But that’s one of the points of choosing Linux and open source: you have a choice. Don’t like the desktop? Then dump it for something you do like or why not enhance it, so it is something you like. In certain quarters there certainly seems to be a underlying distaste for the Gnome project. It’s not one we agree with, but if you don’t like those design choices, there’s no lack of alternatives to choose…

A private collection of Matrix homeservers will span the French government as it develops a fork of Riot.im (https://about.riot.im) the secure open source instant messaging service. The fork will be used as a basis for its own official secure communications client, replacing WhatsApp and Telegram. As the Matrix team notes in the blogpost (http://bit.ly/matrix-riot) announcing the news, “Matrix’s decentralisation and end-to-end encryption is a perfect fit for intra- and inter-governmental communication.” Combined with the news (above) about the German government using Nextcloud, it’s another great example of a public body seeing FOSS as a means to create affordable software and services that are open to their citizens. According to the government’s press release, the drive to create this open and secure instant messaging tool was led by the Interministerial Department…

The BBC is a well-known institution when it comes to producing TV and radio, but it’s also a big contributor to open source projects, as its BBC Open Source website (www.bbc.co.uk/opensource) demonstrates. It’s now revealed that it will be publishing some of its software that has been developed in its IP Studio project (www.bbc.co.uk/rd/projects/ip-studio) as open source. One of the aims behind the BBC’s IP Project is to transmit and receive broadcast-quality media over IP networks, and this involves figuring out how to send IP packets of data at speeds of between one and eight Gigabits per second for uncompressed High Definition and Ultra High Definition media. The project discovered that the Linux kernel’s standard sockets library was causing a bottleneck due to the high computational cost of copying these…

ARCHLABS 2018.05 This Arch-based distro with Openbox and its primary desktop interface has just been updated, dropping LightDM (which can be reinstalled if you miss it), as well as ditching the deprecated gksu software and replacing them with pkexec. All the ArchLabs-related packages have been refreshed, with particular attention given to Jgmenu which, as the release announcement (http://bit.ly/archlabs-2018) states, is “developing into one of the best menu utilities out there for Linux”. Get the latest version from http://bit.ly/get-archlabs. FEDORA 28 The popular distro from Red Hat has a new version that’s packed full of important changes. Perhaps the biggest new feature is the inclusion of the Modular repository, which enables you choose between different versions of certain software. The team has produced documentation for using modules (which can be read…

Retag me I have approximately 400GB of music (thousands of albums) backed up to my dual HDD NAS drive. I’ve collected this over my 62 years on this planet. However, after several house moves I’ve lost the original media. Do you know of any software that will tag artist and titles to make searching easier. Hopefully en masse? I’ve used Soundhound to identify obscure tracks, but it’s very labour intensive retagging one track at a time. I have the titles of most various artist albums. Upon opening them I get track one through to track 20 etc with no indication of who or what, and sometimes have to use Soundhound to identify. I would love something that identifies and/or allows me to copy and paste to retag these. All of…

OGGCAMP Sheffield will play host to Oggcamp 2018 on 18 and 19 August. Over the years the organising team has organically become one with the community and now we find that the community are organising the event. Beyond the traditional two days of talks, workshops and stalls, Oggcamp is an expression of admiration for Linux and the community. We urge you to go and enjoy the event, talk to new people and learn more about their projects. More details and ticket information is on the website: www.oggcamp.org. GUADEC The Gnome conference this year takes place in Almería, Spain from 6 to 11 July. The conference is all about the Gnome desktop and applications that rely upon it. At GUADEC you can expect talks and workshops based around the Gnome ecosystem,…

Q boot My machine into Arch is and able Ubuntu to dual-16.04 LTS, which I won’t be upgrading right now, based on the following experience… Whenever there’s an Ubuntu kernel update it updates both the GRUB and the boot menu, and this process takes inordinately long (in one case I waited 10 long minutes and finally ended up manually killing the os-prober process, which seemed to be stuck using 100 per cent resources). I really don’t need Arch entries on my Ubuntu GRUB, since I can (and prefer to) choose Arch from the UEFI menu. Can you tell me if it possible to persuade Ubuntu not to interrogate my other partitions and save some time here? John T Ripper, via email A This bothered me for some time, and I…

AMD’s Ryzen was a very long time coming. So much so, some industry observers worried whether AMD would survive long enough to bring it to market. But AMD did, and here we are just over a year later. In the meantime, the original Ryzen CPU family inserted a flying nocturnal insectivore up the metaphorical nightdress of the PC processor market. And now we have AMD’s second-generation Ryzen processor in hand. AMD is back, and it’s all for the better, even if you don’t buy an AMD CPU. Competition is good for all. It’s arguably a stretch to characterise the Ryzen 7 2700X chip as truly second gen. Architecturally, the narrative involves Zen+ while previous Ryzens were Zen. But there are no changes to the physical design, no new features, no…

Perhaps because of the pervasive reach of social media platforms in our everyday life and cheap internet connectivity, photography has become an integral part of our everyday life. Once thought of as the domain of professionals mucking about with ISO settings and aperture on their rugged Canons and Nikons, many cellphones now offer the same features, and even enable you to shoot images in the pro Raw format. Not only must one use a cataloguing software to make sense of all these photographs, but occasionally also an image editor. You can use the image editors featured in this Roundup to enhance your images, and even colourise a black and white photo! GIMP is a beloved image editor with a vast array of features, and is one of the most popular…

With proper understanding and some creativity, you can use image editors to radically transform your images. For instance, you can use the blur effect that most image editors provide to add a bokeh effect to your images. But you can’t do that unless you know how to use the feature, or worse still, can’t locate it within the interface. Apart from a FAQ, darktable also provides PDF user manual in several languages including English and Spanish. There are also screencast tutorials and a community driven wiki. You can access the DigiKam Handbook online or download the PDF for offline reading. It provides information on everything from supported formats, to using the tool efficiently. Irrespective of the tool that you decide to use, spend some time with the handbook to get…

LXF: Tell us more about Board at Desk YK: B at D is a VM that provides an easy way for developers to test Linux kernels from their local workstations. We don’t create everything for this project. It uses Kernel CI and LAVA - both open source projects used by Linaro and the kernel community - which we put together on this Debian VM to create a test infrastructure. Kernel CI is an automated system for the building of Linux kernels linked to large board farms. This enables each company to use a common test environment that can be used easily (they can test boards from their desks), and it’s quite good for us. We can share the same test cases and also share results for the CIP kernel. Shared…

CrossOver is a commercial version of Wine provided by CodeWeavers, available for macOS and Linux. There’s also a beta version available for ChromeOS (for Intel Chromebooks only), which uses the Android subsystem. It has its own installer for Windows applications, replete with all the tweaks and DLL substitutions necessary to run them smoothly. Thanks to some proprietary additions CrossOver boasts the ability to run things that standard Wine cannot, most notably Office 2016, but many games too. Besides this, CodeWeavers also perform extensive testing of popular applications on CrossOver, to ensure new software works and that new CrossOver releases don’t introduce regressions. And they provide technical support too. Proceeds from CrossOver contribute to Wine development, and they pay many of the Wine developers’ salaries. CodeWeavers also provide the infrastructure for…

OUR EXPERT Dan Frost leads R&D projects in edtech, writes about emerging tech and blogs about tech and business at blog. thebaseline.co. Want to build something clever using machine learning and some fairly serious tools? Good. We’re going to use Google’s TensorFlow to construct a neural network that can identify images seen by a PiCamera. You don’t need to know anything about machine learning and along the way you’ll learn some key concepts and start getting under the hood. We’ll be using a PiCamera, but you can still do most of the tutorial even if you don’t have one. TensorFlow is Google’s machine learning framework and is used by engineers for research and to build production systems. This is a powerful tool and there’s an unlimited number of ways of…

A trained neural network is able to take in a piece of data, such as an image, that it hasn’t seen before and output a prediction about what the data is, such as a category of flower, fish, car or whatever it’s been trained on. The process of training takes heaps of training data, which in this case is images labelled by what’s in them and tunes all the nodes in the network to accurately categorise all that training data and new data. This is done by turning the image into a huge number of parameters, which you can think of as each pixel or groups of pixels. Inside the network, there are weights and biases that determine which pixels and groups of pixels are used to identify which category…

OUR EXPERT Bobby Moss creates online documentation for well-known enterprise virtualisation and Linux products. Presentation software is hardly the stuff of legends. Unless by legends, you mean legendary dull afternoons spent in a meeting room watching uninspired slide after slide slip into the virtual dustbin of oblivion. It doesn’t have to be this way. Done correctly, slide-shows can be a powerful way to share information, draw attention to important messages and ensure people working together have the same understanding so projects can get completed faster. It can also be done in a way that doesn’t bore everyone silly! Now this is the part where I’d normally say, “And this is where LibreOffice Impress comes in,” but the choice of technology in this case is only one part of the equation.…

1 Start rehearsals Automate your presentation by going to Slide Show>Rehearse Timings. If you’re using a dual-monitor setup you’ll see the full screen presentation and the slide assistant with a large timer indicating the current runtime. Rehearsal will begin immediately, so you should ensure that you’re ready to begin before triggering it. Exit at any time by pressing Escape. 2 Set your timings There are two ways to set timings; One is to click the timer you see in the bottom-left of the active full-screen slide during rehearsal, and the other is to set your slide’s transition to start after a predetermined time interval. You can preserve the latter during rehearsal by simply clicking anywhere else on the slide or using the arrows on the timer screen. 3 Press play…

Up until late 2016, the Nvidia proprietary driver had no support for Wayland (or indeed kernel modesetting, which forced users to watch their systems boot in an ugly low resolution). Now there’s Wayland support, but it’s far from universal. All of the open source drivers have opted to use a method called Generic Buffer Management (GBM) for communicating with Wayland, and this method is supported by all the major desktops. But Nvidia has come up with its own method called EGLStreams. Clearly it has its own technical reasons for doing this, but it makes life difficult for the community (see KDE developer Martin Flöser’s post at https://blog.martin-graesslin.com/blog/2017/10/plasmawayland-and-nvidia-2017-edition ). As it stands, EGLStreams is only supported by Gnome (since 3.24) and Sway (although this will be removed soon) and through experimental…

The Alexandria platform has been created for publishing digital content. Artists place their content there and set a price for their work. Any fees are from the Bitcoin blockchain and nothing else. It’s still in beta but active at https://alexandria.io/publisher/index.html#. You can run the platform in the browser and not actually know you’re using IPFS. If you check the settings you’ll see the option to use your local gateway as well as the public gateway. Shopping on the platform works from the beginning in the browser. With IPFS installed you can start publishing your works immediately. Artists pay a small fee in Florincoin (not another one!–Ed) to publish artefacts, as they’re called on Alexandria. There are also native binaries for Linux that you can download. The binary requires IPFS and…

You might be surprised to know that I’ve stayed with Netscape since 1997. I think the first version we had in high school was 3.x, but I don’t remember for sure. I stuck with Netscape when it lost the battle for the web to Microsoft. While people around me were switching to Internet Explorer 4, I discovered Mozilla. More specifically, it was an open-source codebase of the then-cancelled Netscape Navigator 5. Around 2000, it was a bit bloated and buggy, yet beautiful: imagine a blueish, smooth rounded interface in a world of grey rectangular buttons. And all of this was “self-hosted” using web technologies, such as now-deprecated XUL, RDF and JavaScript – so many years before Electron became pervasive… I remember how Phoenix (now Firefox) was born as an attempt…

In Linux, you have a multitude of tools to track processes, including their memory consumption. ps, top or vmstat are all common examples. All of them typically reveal some well-known metrics. RSS is perhaps the most important one. It stands for Resident Set Size, and it’s how many bytes the program keeps in RAM. Naturally, that’s not the same as VSIZE or Virtual Size, which is the size of the process virtual address space. VSIZE increases when the program maps a file or an anonymous page, RSS grows when a process brings a page into memory and shrinks when it’s released or put into swap. In these cases, VSIZE is typically left unchanged. More technically, RSS is the sum of file-mapped pages, anonymous pages and shared memory. Hardcore hackers would…

Vega and Vega Lite enable you to have layers in your plots. The layers.html file will showcase how you can add layers in the output of Vega Lite. Notice the use of the layer block that defines two independent objects. Apart from the use of the layer keyword, the internal format that’s used in the layers.html file is as follows: All the magic happens by defining two different objects inside the layer block. Each object can have its own type of mark and its own encoding blocks. Finally, the options in the resolve block specify that the scale domains of the two layers should be united so that the axes and the legends of the two layers can be merged. If you comment out the resolve line, the generated output…

OUR EXPERT Kent Elchuk is a full-time web developer and Linux enthusiast whose many hobbies include programming and hydroponic food production. We’re going to look into how you can modify a Wordpress site to ensure that it’s been built for speed. However, before we get into the details of how to achieve this goal, we’ll first take a closer look at understanding why it’s a crucial concept by looking at Wordpress’shistory and its ways of doing things. Although it seems like an eternity in web development years, Wordpress was really just beginning to show its face around 2003, when it was dormant code that was taken over as an open source project. Since then it’s experienced such momentum that it’s risen to the top of the content management systems popularity…

“Whether it’s porting code from Windows to Linux, or dealing with network filesystems served by Windows machines, native case-insensitive support for the main Linux filesystems is a feature that’s been long-awaited by those performing these important tasks. While it’s true that Windows has had this support for a long time (since the early days of the primitive FAT filesystem), and Linux previously introduced basic insensitive support on XFS, FAT and NTFS, there’s never been a full UTF-8 normalisation and casefolding infrastructure enabling Linux to perform real-world, language-aware, case-insensitive lookups. Efforts that aim to remedy this situation and make Linux a friendlier platform for the gaming community are now underway. As part of this initiative, Valve and Collabora are proposing code to support optimised UTF-8 casefolding natively for the main Linux…

With work starting on the next long-term support version of Ubuntu (20.04 LTS), Canonical CEO Mark Shuttleworth has announced that it will “kick off that journey with the Cosmic Cuttlefish, soon to be known as Ubuntu 18.10.” According to Mark’s blog post (which can be read at http://bit.ly/cosmic-cut),the focus of 18.10, along with other releases in the run up to 20.04, will be on security. Ubuntu runs on such a diverse range of devices, from desktop PCs, to servers and embedded computers, and Mark points out that there’s one thing that every community wants, no matter what device they use: security. With recent high-profile security lapses like Meltdown and Spectre, it’s good to see Canonical take this so seriously. However, the blog post doesn’t go into specifics, but we’ll hopefully…

“ Many software development job listings today ask for proficiency in Kubernetes, but it’s difficult for companies to find qualified individuals to fill these roles. That’s why, after the successful launch of the Certified Kubernetes Administrator exam in autumn 2017, CNCF has launched its certified Kubernetes application developer (CKAD) exam and complementary training course: Kubernetes for developers. A certified Kubernetes application developer can define application resources and use core primitives to build, monitor and troubleshoot scalable applications and tools in Kubernetes. Meanwhile, the new Kubernetes training course teaches how to containerise, host, deploy and configure an application in a multi-node cluster. Our hope is that through accessible, online training and certification resources, we can help more individuals become proficient in these technologies, and start to close the talent gap. The…

Three, two, one… ACTIVATE! Learn what happens when Pi-robots clash This month we heard from Michael Horne, co-organiser of Pi Wars, an annual Raspberry Pi robotics competition. In Cambridge, on 21 and 22 April, Michael, Tim Richardson and an army of volunteers led by head judge Dr Lucy Rogers from Robot Wars and the Guild of Makers welcomed 65 teams of roboteers to the fourth Pi Wars. On the Saturday, 29 school teams battled it out on the courses and were also judged for technical and artistic merit. There was also a special prize: The HAL 9000 Award for the robot most likely to take over the world! The overall winners were from Doctor Challoner’s Grammar School in Amersham with teams from London and Aberdeen in second and third place.…

Q Debian box drops Dropbox I installed Dropbox on Debian a while back. Now I’m seeing a message saying it’s old and an upgrade is available. However, Synaptic tells me that it’s up to date. I’m using the Debian repos provided by Dropbox (at http://linux.dropbox.com/debian), but it looks like Dropbox doesn’t support them anymore – its website only mentions Ubuntu and Fedora. Synaptic wants to install dropbox_2015.10.28 , which seems awfully old. There are a couple of other versions on the directory listing for their repo (1.6.* and 2.1.*), but they all have the same date, which is confusing. I’m using MATE on Debian Jessie. Guy, via the forums A Hello Guy, the Dropbox packages work much the same way as Steam packages do. The package itself just provides an…

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…

Many of the tools featured in this Roundup pushed out a new releases back in March/April of 2018. As such, these new releases aren’t yet available in the software repositories for most distributions, which still feature older versions. With this in mind, we’ve installed the latest releases of all the packages using Appimage packages, where available, or via PPA repositories on top of Ubuntu 17.10. Image editors can work with the Raw file format that pro photographers use, as well as a variety of more commonly recognised formats, and boast a vast set of features. We want a tool that doesn’t hinder workflow with a complicated interface by including many features out of the box. We’ll test these tools to see if they offer any assistance to users by providing…

Image editors can’t be treated like other software, where we dock points for a cluttered interface. This is because each of these tools are chock-full of features and presenting them is always going to be challenge. You will find menu bars, tabs, sidebars, and buttons, or some combination of them, littered in the interface for each of the tools featured in this Roundup. It’d be unfair to these tools for us to declare any one style or appearance as superior to the others, because each of these tools boast of vast user communities, which suggests that there are ample number of users who favour their user interface. Suffice to say, you’re unlikely to get very far with any of these tools unless you spend some time with the documentation familiarising…

Few people will argue that you can’t go wrong with Gimp, if you’re interested in a mature and feature-packed image editor. It’s been around for years and boasts of a vast user community. The project is also incredibly well documented, and the subject of several books, and you can also find tutorials and videocasts online. Krita is also an excellent option, but would appeal more to budding artists. Although the program has been primarily designed for painting and animation, you could still use it for performing some basic image editing. If you spend a lot of time with raw images, you’ll appreciate RawTherapee. Its non-destructive image editing and batch processing abilities make it popular with pros. Although it hasn’t seen a new release in a few years, UFRaw is another…

There’s lots of hidden productivity that will be lost on a casual or a first-time user, because it involves some customisation. First up, like Gnome, KDE has its own Online Accounts menu, with the ability to integrate about a dozen different services, including several popular ones like Google, Skype, Telegram, Twitter and more. Then there’s KDE Connect that glues your Android device to the KDE desktop. Once set up, you’ll be able to transfer files between the two and see your notifications from the Android device on the desktop. You’ll also be able to send and receive text messages from KDE without ever picking up your phone. You’ll need to install the KDE Connect app from the Google Playstore on your device and then pair it with its counterpart on…

Linux is a perfectly adequate replacement for Windows. We’d go further and say it’s vastly superior, in almost every way. Yet sometimes some people have just cause to run Windows applications. This might be because Karen from accounts has sent a Word document full of macros and tables and oddly named fonts that needs to be returned, along with accompanying TPS reports, by the end of the day. Some people want to play games not available on Linux, whether they’re classics from that have long been abandoned, or triple A releases that may never make it to the penguin side. Many people have a dual-boot arrangement or a separate Windows machine altogether, but rebooting or moving to another room is a chore. Wine can also be useful helping people migrate…

OUR EXPERT Les Pounder is a freelance maker who works with organisations such as the Raspberry Pi Foundation to promote maker skills. He blogs at www.bigl.es. Have you ever been into a store and seen one of those “How did we do today?” machines. You know, the ones with green smiley faces and red unhappy faces. Those machines are used to gather information from shoppers in real time, and will hopefully lead to better consumer experiences. So that got us thinking: “Could we build one with a Raspberry Pi?” Turns out that the answer is yes, and we can generate lovely graphs using a Python library called matplotlib. Better still, this project is remarkably simple so let’s get started, shalll we? Pinned down The hardware build for this project consists…

The “bottleneck” layer refers to the final output layer that does the classification. In our example, it’s what divides the images into types of flowers, fish, cars and so on. If you see errors, make sure pip and Python are the same version, and make sure the version of TensorFlow is compiled for your version of Python. Retraining the model can take hours. To avoid your terminal session being killed, use ‘screen’ to persist the session. You reattach to the session with ‘screen -r’.…

OUR EXPERT Shashank Sharma is of the view that there’s no such thing as too many Terminator series/stories. A technologically challenged friend called to say they couldn’t get Opera’sVPN feature to work. To suggest desktop sharing was out of the question. Thankfully, Byzanz offered an easy solution – creating a GIF screencast showing the exact steps to using VPN on Opera. With Byzanz, you can create a screencast of either the entire desktop or of the specified area. You can even set the duration for the screencast and have the nifty little tool save the output as either a GIF image, or as OGG Theora or FLV flash file, if you also want to record audio with the screencast. Another reason why screencasting may be preferred over desktop sharing as…

If you have an iPhone or Android device you can remotely control presentations from your smartphone using a mobile app called LibreOffice Impress Remote. Once you’ve installed the app, launch LibreOffice Impress and head to Tools>Options. Then navigate to LibreOffice Impress>General and then ensure that the Enable remote control box is checked. This enables inbound access from your smartphone and adds useful menu entries you will need later. Next you should pair your smartphone with your workstation, and the fully supported way of doing this is by using Bluetooth. If you’re using a desktop rather than a laptop you may need to add an extra USB dongle for this to work. To pair them, enable Bluetooth on both devices, make them visible to each other and then use your distro’s…

OUR EXPERT Jonni Bidwell is enthralled by the new error messages that all these Wayland compositors enable, but still slightly sad about his fancy graphics card that conflagrated. Wayland, apart from being a small town in New England, is a next-gen display protocol. It will eventually replace the venerable X server, which has been at the heart of *nix graphics since way back in the 1980s. You may have heard about Wayland already, because there’s roughly equal measures of excitement and consternation surrounding it. Ubuntu 17.10 shipped with Wayland as the default graphical session on hardware that supported it (which at the time was almost everything except Nvidia devices using its proprietary drivers). Ubuntu 18.04 also ships with a Wayland session, but because it’s an LTS release and users are…

Besides the Gnome application suite (and any modern GTK, or Qt application), there are a few apps that have native Wayland support. If you want a lightweight terminal, for example, then Terminology (from the Enlightenment desktop) is a good bet, as is the popular Termite (which you’ll need to compile yourself). You could then run everything in a terminal, which earns you many geek points. For example, you can play music with ncmpcpp, browse the web with Links or manage files with Midnight Commander. That’s not everyone’s cup of tea though, so let’s continue. Screenshots used to be a Wayland bugbear, but not so with swaygrab(which is installed with the sway package). It can even capture video too. If you’re more interested in watching videos, then MPV(a popular descendant of…

To program for IPFS you need either JavaScript or the Go language development libraries installed. Other implementations are planned or underway, but they’re not available for the time being. Because this is the distributed web, node.js and similar programming frameworks are useful. Some exciting projects include Brave, a web browser with ad-blocker built-in. The browser supports ad-blocking and even a micropayment system, which enables you to choose your favourite site and support them. Naturally, they support IPFS natively. Another one is libp2p-webrtc-star, a project that aims to bring signalling to webrtc, which was never built with a method for peers to find each other. This was a deliberate choice to make sure they didn’t conflict with existing systems. Now webrtc has another alternative approach to finding each other. Then there’s…

Version: 2.10 Web: https://github.com/GNOME/gimp/releases The Gimp development team has finally delivered Gimp 2.10 to the FOSS community. After spending some time exploring it, we’re happy to say that there’s a raft of great new tools and features on offer. Although this comes as no real surprise considering that we’ve been using version 2.8 since 2012. A lot can happen in six years… Once you get past the cute artistic splash screen, a lot of the new additions quickly make themselves evident. To start with, the main toolbar now features the new icon set, while several extra icon sets can be added via Gimp’s preferences dialog. The most noticeable new addition is the Warp tool, which enables you to apply a range of impressive distortions to your imagery, especially if you…

OUR EXPERT Mihalis Tsoukalos is the author of Go Systems Programming and Mastering Go. You can reach him at www.mtsoukalos.eu and @mactsouk. Let’s take a look at Vega and its lighter version, Vega Lite. Both are grammars that are used for visualisation tasks. Strictly speaking, Vega Lite is a grammar that’s based on Vega, just as LaTeX is based on TeX. The main advantage of using Vega Lite is that it involves writing less code than Vega. Using a grammar for visualisation has both its advantages and disadvantages. The biggest disadvantage is that you’ll have to learn the rules and the restrictions of that grammar before you can use it. On the other hand, once you learn the grammar, you’ll work faster and be more productive because you’ll only need…

In time you’ll learn how to add labels to your charts, which will enable you to improve the vegaLiteExample.html file and make it look more professional. The new version of vegaLiteExample.html will be called labels.html and it will also use layers! The most interesting part of the code of labels.html is the layer block and more specifically, the following code from the layer block: The value of fontSize defines the size of the text whereas the value of dy enables you to place the text where you really want by moving it in the y-axis. The dx field, which isn’t used here, will enable you to move the displayed text in the x-axis. The actual values that will be displayed are specified by the following piece of code: In the…