Linux Formatの November 2020 の目次

Jonni Bidwell “Fun” is subjective but despite all the fiddling and confusion I really enjoyed using docker-compose last issue to get Collabora Online, Nextcloud, MariaDB and Let’s Encrypt all working together. ’Twas like a string quartet performing Vivaldi’s Four Seasons, orchestrated container stylee. Nick Peers I’ve so many memories of fun Linux projects. Perhaps the most satisfying one in recent times was turning a Raspberry Pi into a multi-machine game emulator using RetroPie. Reliving all those old classics brought back so many memories of my – sob – lost youth… Les Pounder The ls command is used to list directory contents, but what happens if we type it backwards? The sl command will show a train moving across the screen. The -a and -f options show a flying train with…

“Earlier in September, the much-anticipated release of GStreamer 1.18 was made available, bringing with it a slew of notable features and improvements. This latest release adds support for High Dynamic Range (HDR) video information representation and signalling enhancements, which enables more colours to be displayed on HDR screens. We’ve also added support for more network protocols, in particular the RIST Simple Profile, AVB/AVTP, and a new RTP source and sink to easily set up RTP streaming via rtp:// URIs. And lastly, we’ve improved Windows support with plugins assisting the latest Windows APIs targeting UWP. GStreamer 1.18 brings a new high-level API calling GstTranscoder to easily create applications that can transcode media files between different formats, a new RTMP library to stream more reliably to online video services, and MPEG-TS muxing…

“Recently, I returned to a major Linux vendor after a year spent working at a microprocessor startup. I enjoyed my time in startup land, but I also came to miss the old life in which I was able to work with many people and vendors across the entire industry. It’s in collaborating with others that I feel we can best solve some of the big picture problems facing us all today. Among them life post-Moore. For the past few decades, those based in the software world have gotten a free ride via Moore’s Law in which computers got faster every year without us having to do much in return. In the past decade this has slowed dramatically, and it’s now headed toward a snail’s pace of improvement. At the same…

Get your free ebooks! Good news! The cover-mounted DVD will return for LXF270 (that’s the next issue) so this is the last batch of ebooks on offer. We’ve been clearing out the back of the bookazine cupboard in the West Wing of LXF Towers, so pickings were slim… Back to this issue, and due to the Covid-19 pandemic we’re unable to guarantee delivery of our usual Linux Format DVD. So to avoid missing vital printer slots we’re reluctantly dropping the physical disc. As way of replacement we’re still offering the DVD image as a free digital download – see below for more details – but also throwing in £50 worth of top digital bookazines. With this issue we’ve got four of them for you to enjoy. To claim your digital…

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 phantasm), 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…

Most modern desktop distributions such as Ubuntu, Linux Mint and Mandriva are anathema to power users. This is because these distributions aim to provide a ready-to-use environment to users without much intervention or interaction on their part. While this is certainly appreciable, especially for novice users, experienced campaigners might prefer more control over their Linux distribution. We’ll test the distributions on all the usual criteria such as documentation, installation, bundled applications and even package management. That’s because while power users might well be able to resolve dependencies manually, it’s neither smart nor efficient to do so. We’ll also discuss the ideal use case for these distributions and their longevity, which is reflected by the release policy, frequency of updates and stability. On top of all that, we’re looking for a…

For this Roundup we wanted to feature Void Linux and NixOS, two distributions that haven’t received much coverage in the past. This meant that we had to bump Gentoo from the list, which is often touted as a power user distro. And we don’t disagree. In fact, when last we discussed power user distros in LXF170, Gentoo Linux was the winner. It’s a highly configurable distro with an incredibly involved installation process. It’s not unlike NixOS in that regard, or even Arch Linux. Another popular recommendation, and one that found mention in the Roundup in LXF170 is Fedora. Our pet peeve with it, however, is that the project doesn’t provide an LTS release, and each edition is only supported for roughly 13 months – that is, until one month after…

If you’re an organised sort then your media files might already be on some kind of file server. Perhaps you’ve followed our many storage-related tutorials and have everything nicely arranged on a RAID array in a box under the stairs. (living the dream!–Ed) This is fine, but a general-purpose file server sharing files over Samba (the best choice for a heterogeneous network) won’t do a particularly good job of streaming files to lots of users. It’s not what the protocol was designed for. It’ll work fine for a couple of users over Gigabit Ethernet, but accessing it remotely will be painful – especially as you start skipping through the file. Furthermore, some video players on some desktops still have trouble opening network links, and often end up copying the whole…

Back in 2018 Google announced it would be shutting its Google Play Music service, which gave you free storage for up to 50,000 music files. Combined with its web app for streaming them to wherever you are in the world, this service was (barring whatever shady analytics the company might be doing with data about people’s music tastes) quite a nice thing. Then in May 2020, it announced that shutdown would be happening “later this year” and provided tools to migrate users to its YouTube Music service. But if you want a new cloudy home for your music, one far from the clutches of the Alphabet corporation, consider setting one up on your own. Unlike streaming video, it doesn’t take much in the way of CPU power to run your…

OUR EXPERT Les Pounder is associate editor at Tom’s Hardware and a freelance creative technologist. He blogs about his discoveries at www.bigl.es. Sir Clive Sinclair is an English entrepreneur and inventor. You may know him for his quirky Sinclair C5 battery powered “velomobile”, which was set to solve commuters problems in 1985 (it didn’t). But he’s most famous for a range of consumer electronic products that bear his name. Sinclair Radionics was formed in 1961 and produced cost-effective electronic products such as pocket calculators and portable televisions. But in 1980 Sinclair released its ZX80 computer for £99.95 (£432 adjusted for inflation in 2020). It was marketed as the “first personal computer for under £100” and proved a cost-effective means to get your first computer and learn how to code. The…

OUR EXPERT Shashank Sharma is an avid Arch user and a trial lawyer based in Delhi. He’s always on the look-out for geeky memorabilia. ASSH connection is typically used to connect with remote machines. It works on a client/ server model, in that the machine being used to connect to a remote machine is called a client, while the latter is the server. To establish the connection with the remote machine, you must know its IP address, as well as the username/password to authenticate the connection. Because the connection is based on IP address, any change in the IP address automatically breaks the SSH connection, turning even mild-mannered users into rage monsters. Released under Apache license, Eternal Terminal can be used as a replacement for SSH. Its call to fame…

Nextcloud is only one of the services you can connect OnlyOffice with. You’re also able to use the editors within other popular sync and share platforms such as Confluence, Alfresco, ownCloud, Seafile, Plone, SharePoint, Liferay, HumHub and many others. You can install the free version of OnlyOffice’s online editors or choose the scalable commercial build and then just connect the editors with the required service using ready-to-use integration apps. If you need professional editing features for a family-size team, opt for Home Server. This is a special tariff plan that’s been put together for non-commercial home use. Detailed information about the range of OnlyOffice solutions can be found on the official website: www.onlyoffice.com.…

OUR EXPERT Simon Quain is a site reliability engineer who likes discovering open datasets online to play around with in the Elastic Stack. You’ve probably heard of Elasticsearch – the search engine that enables you to index and then quickly search through your data. You may have created a few visualisations in Kibana, the GUI for Elasticsearch, pointing and clicking your way through the sleek interface. What you may not have used is a lesser-known visualisation plugin called Timelion. Timelion is a fantastic visualisation creation tool that makes it possible to write out your queries in its simple and powerful expression language to display graphs. It’s used for displaying time-series data such as population growth or hits to your website. With Timelion, we can calculate moving averages, display the difference…

The power of Kibana is that you can save individual visualisations and then combine them into a dashboard. If they use a common time field, they can be combined from any index you have in Elasticsearch. Once you’re happy with your graph, it’s time to save it. Although you may not need much guidance in finding the Save button, a note on organising is necessary. It’s easy to create and save visualizations in Kibana. It’s not so easy to find them after you’ve created more than can fit in a list on one page. To fix this we recommend coming up with a structure now. “INDEX_NAME – VISUALIZATION_TYPE – GRAPH_TITLE” makes for a good one. Using the graph with the dynamic labels we created earlier as an example, you could…

De-mosaicing is a process of reconstructing a full colour image from the raw output of an image sensor. There are several de-mosaicing algorithms, including Bilinear, VNG, AHD and LMMSE, and the best way to tell them apart is to open a RAW image with different settings. RawTherapee has the largest set of processing options under the Raw Settings menu. Krita and digiKam feature easy-to-use RAW import dialogs that enable you to choose various de-mosaicing methods supported by LibRaw. Darktable sports its own, smaller set of de-mosaicing options you can choose from, while LightZone and AfterShot Pro both have only a single built-in de-mosaicing method which can’t be adjusted by users. Different de-mosaicing methods affect RAW conversion times and also some filters. De-mosaicing methods differ by the pixel patterns they produce…

Noughts and Crosses has traditionally been used as a teaching tool, not only for children, but for Artificial Intelligence. It’s possible to create a computer automation – known as a bot – that is unwinnable. It would be impossible for a bot to win every game, but at the very least it would cause a stalemate resulting in a draw. There are 765 different positions and 26,830 potential play-throughs (including board symmetries/rotations, reflections), so it would take quite some time to program them manually. However, it would be quite possible to program some basic machine learning so that the bot looks out for key moves and challenges them appropriately. Most Noughts and Crosses players will quite quickly pick up that it’s much easier to win the game by going first.…

Some people have gained the impression that Linux might not be fun. How did that happen? So this issue we’re putting the fun back into Lin(f)u(n)x! We’re not sure that’s actually going to catch on… For an age now, Linux has had access to a full suite of media capabilities and software. Over the years we’ve covered most of them, from the crazy TV-tuner packing MythTV, the undeservedly scandal-dogged Kodi, to Emby. All of them are fantastic options. For this issue we’re going to look at Plex. While no longer open source, it’s always treated Linux as a first-class citizen and delivers a super-slick media streaming experience across networks, devices and all media. You can use it for free and if you get on with it there are membership levels…

Q Backups and buttons I need some software like Rollback Rx, to create and restore snapshots or restoration points of the system without the need for an external drive. I’ve tried Timeshift, Duplicity, Back in Time and Systemback. Software for both Debian/ Ubuntu and Manjaro are welcome. I also have two questions about Gnome. How do I assign the Windows button to show the Application menu (9 dot menu): when I press Windows button, I’d like to open the screen showing all installed software instead of showing activities. I’d also like to have the Delete key move selected files to the bin, because while using Ubuntu this key is unresponsive. Terminal commands or Gnome extensions are welcome. Al A The programs you mention are all back-up tools, and backing…

Linux good! Having otherwise run Windows for many years but wanted to run Linux, I’ve never regretted taking the time to switch. I’m running an old PC using 32-bit Linux Mint. It’s both stable and fast. But now comes Mint 20 that only runs on 64-bit systems. I’m very sorry about this, because Mint has been my favourite operating system for many years. Where can I find a 32-bit system that’s still being upgraded? Hopefully someone can help with 32-bit, because otherwise many will have to buy new equipment. For me, Windows 10 is the worst operating system to date. Even though it seems secure, you still have no control over the system about what goes in and out. Long live Linux and hopefully someone soon finds new ways to…

NixOS follows a fixed schedule release and strives for two releases every year. A new stable channel is released roughly every six months. While there might be a whole host of changes between the two releases, the nature of the distro is such that you can keep your system updated without having to resort to a fresh install with each new release. Instead of following a fixed schedule for releases, Slackware prefers the fixed feature model. The project identifies a number of changes and features it wishes to implement in the next release. The new release doesn’t ship until all the changes have been incorporated and thoroughly tested. This can result in long gestation period between releases. To give you an idea of timescales, the current release of Slackware is…

We haven’t talked much about media players, beyond streaming to a web browser or app. That’s all well and good, but it would be remiss of us not to mention the other options here. The venerable Kodi (formerly XBMC, the Xbox Media Center) is still alive and well (and so unfortunately are all the nefarious add-ons and repos that give it a bad name). Kodi can be installed on any distro, as well as tablets and other devices, but our preferred way to run it is on the Raspberry Pi, on top of either LibreELEC or OSMC. Kodi can connect to your Plex install via an add-on, or play music that you’ve already shared over your network. If you want to turn your Raspberry Pi into a stellar bit of…

25 AUGUST 1991 Linus announces on comp.os.minix Linus Torvalds, a 21-year-old student at the University of Helsinki, Finland, starts toying with the idea of creating his own clone of the Minix OS. 17 SEPTEMBER 1991 v0.01 Posted on ftp.funet.fi This release includes Bash v1.08 and GCC v1.40. At this time, the source-only OS is free of any Minix code and has a multi-threaded file system. NOVEMBER 1991 v0.10 Linux is self-building Linus overwrites critical parts of his Minix partition. Since he couldn’t boot into Minix, he decided to write the programs to compile Linux under itself. 5 JANUARY 1992 v0.12 GPL licenced Linux originally had its own licence to restrict commercial activity. Linus switches to GPL with this release. 7 MARCH 1992 v0.95…

The Astro Pi Challenge is an annual contest that gives you the chance to get your own code running on the International Space Station. Mission Zero, the competition route that’s aimed at entrants up to age 14, closes in March 2021 and so there’s still plenty of time to join in the fun. Mission Zero is an amazing way to get young students interested in space and computing, with the guarantee that your code will be run on the International Space Station for 30 seconds in 2021. For the first time this year there are changes to the Mission Zero challenge. The first is that teams are no longer obligatory. Individuals are now allowed to enter alongside the usual two- to four-person teams – with half the team being in…

OUR EXPERT Les Pounder is associate editor at Tom’s Hardware and a freelance creative technologist. Les blogs about his discoveries at www.bigl.es. The Raspberry Pi Camera is great fun to play with, and in this tutorial we’re going to use the camera with a push button that will choose a random filter for the image. We’ll be using the Bash terminal as our programming language, which is a great way to introduce the powerful scripting language. Hardware setup The Raspberry Pi Camera now comes in many different variations, and they all connect to the camera port of the Raspberry Pi, located just behind the Ethernet/USB ports. Open the camera port by gently lifting the plastic lock upwards, then insert the ribbon connector with the blue tab facing the USB/Ethernet ports.…

The UK in the 1980s saw computer use rise as the cost of the machines was reduced. A TV programme at the time, The Mighty Micro, predicted that the coming computer revolution would have a major effect on the industry and UK lifestyle. This led to the BBC starting a project, the BBC Computer Literacy Project, which aimed to provide content that would demonstrate how to use a computer. For this the BBC needed a computer with which learners could follow along with, and after discussing the idea with major names of the time – Acorn Computers, Sinclair Research, Newbury Laboratories, Tangerine Computer systems and Dragon Data – the BBC created its requirements and asked companies to submit their machines to see if they measured up. The Acorn team including…

Depending on the distribution running on your remote machine, you might not be able to create an Eternal Terminal session when you first run the et command. If you encounter a Could not reach the ET server: <ip address>:[port] error, this means that the remote machine doesn’t allow incoming connection on the specified port. You can either change the configuration to use a port, which is open for use, or alternatively open a port for Eternal Terminal. How you do this will depend on the distribution and the firewall utility. For instance, Fedora users can open a port with the sudo firewall-cmd add-port=2022/tcp command. You can list all open ports with the sudo firewall-cmd --list-ports command. If you’re using UFW however, such as on Ubuntu, you’ll have to run the…

It’s relatively simple to switch Scenes manually during your live stream, but you can configure OBS Studio to automatically switch scenes depending on which program windows you select too – perfect if your stream involves a screen-sharing demonstration spanning multiple applications or displays. One obvious case use is gamers wishing to demonstrate a game that has multiple executables. First, make sure all the program windows you need are open, then set up your Scenes – one for each program or program window. Once done, select Tools>Automatic Scene Switcher. At the top, select the program window you want to use as your ‘trigger’ in the left-hand drop-down, and the Scene you wish to switch to when it’s triggered from the right-hand menu, then click + to add it to the scene…

WEB BROWSER Firefox Version: 80 Web: www.mozilla.org/firefox Mozilla hasn’t published any monthly updates to Firefox for some time now. The regularity of such updates resulted in a laissez-faire attitude towards new features – a far cry from the early days of Firefox. However, this time the latest version feels special because among a regular collection of minor improvements there’s one that’s long been anticipated: GPU acceleration for X11. Not only is this feature specific to Linux workstations, it’s also narrow-specific – whether you run Wayland or Xorg as a daily driver. GPU acceleration was first introduced earlier this year in May for Firefox 76, and until now it remained a Wayland-only feature. Notebook users in particular will benefit from such acceleration – for instance, watching YouTube videos makes a big…

Elasticsearch stores your data in indexes. Kibana displays multiple related indexes together with index patterns. You can manage both of these in Stack Management -> Index Management and Index Patterns respectively. If you want to have a dark background theme for Kibana, you can go to Management> Stack Management> Advanced Settings>Dark mode and set it to On. Timelion expressions can become long and complicated. However, Timelion enables you to insert whitespace to make the expressions more readable. The Timelion expression box can be resized if necessary, too.…

OUR EXPERT Alexander Tolstoy is a long-time enthusiast of image editing using Linux. He hides his secret messages in Russian in underexposed areas of his photographs. Almost everyone is a photographer these days thanks to smartphones and affordable D-SLR cameras. Taking photos can be fun, but it can become so much more – whatever equipment you might own. From starting out as a novice photographer, you can become an enthusiastic hobbyist as your skills improve. You can even turn pro and make money from something that was once just a means of capturing a moment in time. Somewhere along the way, you’ll come across the phrase “shooting in RAW”. In this tutorial, the first part of a two-part series, we’ll explain what a RAW file is, how it’s an improvement…

OUR EXPERT Calvin Robinson is a former assistant principal and computer science teacher with a degree in computer games design and programming. During this series of tutorials we’ve been using Python to develop a range of retro video games. Python is an incredibly versatile high-level programming language with a relatively simple syntax; it suits our needs. Over the past few issues we’ve built a lunar space module landing game, a side-scrolling platformer, Pac-Man, the Game of Life and a 2D shooter. This issue we’ll build a very recognisable minigame, with challenges for those who want to take things a step further. Before we begin, we’ll need to make sure we have the latest version of Python 3 installed. For everyone running a Debian-based distro this is as simple as sudo…

Our completed game of Noughts and Crosses features two players, with different colours for each player’s pieces. However, we haven’t really built in a way to identify one player or one game from another. It might be nice to implement a leaderboard, to save top scores. We’ll need to get our players’ names every time they start a new game. We’ll need to create a new function, implement a couple of input()s and store the values in strings. We’ll name this function leaders , then call that function in restart() and at the bottom of our code before we draw our grid. Once we’ve got our players’ names we can save it into a text document with the score at the end of the game. Write out the text of…

“I was talking to a business the other day that I thought we (with my business hat on) may be able to help. “No," said the person I was talking to, “We don’t use Linux. We’ve moved everything to the cloud.” It was as if “Linux” and “the cloud” were mutually exclusive, but we shouldn’t be surprised. Businesses don’t want to run Linux: they want to solve problems: deliver faster, improve quality, lower the cost of doing business, and so on. Maybe Linux can help, but that’s irrelevant to them. We should remember that Linux is, for businesses, a means to an end rather than the end itself. That applies to other operating systems as well. So the correct answer to the person I was talking to would be to…

“Are architects the new kingmakers of the database world? To get market insight, Percona conducts an annual Open Source Data Management Software survey [http://bit.ly/lxf269sur]. When it comes to actual decision-making, architects (43 per cent) were flagged as most likely to decide which database technology would be used rather than devs down at 26 per cent. MySQL Community Edition topped the list of used open source databases. While MySQL is ticking along at 58 per cent, PostgreSQL continues to gain in popularity with an increase of six per cent to 52 per cent of installs, which likely stems from the reliability and performance features added to v12. Keeping organisations protected against significant lock-in continues to be a growing concern. Sixty five per cent of respondents indicated that it was a key…

Greentime Hu, senior manager at Andes Technology, posted version seven of a patch series, adding support for the vector ISA extension to RISC-V. The patch series is based upon version 0.9+ of the hardware spec, meaning that it could still change before being finalised. Shakeel Butt (Google) posted a thread titled “Machine lockups on extreme memory pressure” in which a heavily loaded server with thousands of active network connections would occasionally wedge hard and fail even to properly run the OOM (Out Of Memory) killer. It led to interesting discussions.…

The command line provides an efficient way to get things done, You can use the cursor up key to revisit the previous commands you entered, but the shell offers so much more. Bash, along with other shells, maintains a history file of the last 500 or so commands you typed. The exact number is determined by the HISTFILESIZE and HISTSIZE environment variables. We generally set these to 1,000, but you don’t want to be hitting the up key hundreds of times to find the invocation of a command you used last week, so press Ctrl-R instead. This starts the history search. Start typing part of a command and it’ll show the most recent match. As you type more the match improves. If you want an earlier match, press Ctrl-R again.…

Application menus are a terribly subjective thing. Dislike for modern, full-screen application menus such as used by Gnome is a matter of public record. Even elementary’s lovely menu is not to everyone’s taste, or if it is then the need to press two keys to open it is not. In the previous release Enso shifted from a fork of elementary’s Panther Launcher to its own offering, dubbed Launchy. It’s traditional in the sense that there are categories on the right, but traditionally where you have a menu button the expectation is that the menu will appear somewhere near to that button, not pop up in the middle of the screen. But that’s Launchy’s way. This probably isn’t jarring if you summon it, traditionally, with the Super key, but the first…

There are many titles and recognitions bestowed upon individuals for their achievements and success. We often hear about and indeed celebrate our favourite actors and sports personalities being so recognised. But there’s one title, that of being a power user, which users can bestow upon themselves after judging themselves worthy. This is because there’s no identifiable formula to determine what constitutes a power user. Does the ability to configure any manner of hardware on your Linux distribution make you one? Maybe it’s when you can patch the kernel to be able to use the webcam on your laptop. About the only thing that’s known for certain about power users is that they’ve been working with Linux for long enough to be intimately familiar with it. Which makes it possible for…

Debian’s website is home to vast documentation in the form of tutorials, user manual, wiki and more. You’ll also find a list of companies/individuals that can be tapped for professional support. Because of its popularity on desktops as well as servers, there’s also a dedicated system administrator’s manual and the distro is also the subject of many books. Slackware also boasts of thorough documentation and the official book is available online, but you can also purchase a physical copy. You’ll also find a basic FAQ about the installation on the website. Although there aren’t any official forum boards, the project recommends the dedicated board on LinuxQuestions.org, which is a vast repository of useful information on a range of topics, be it hardware setup or software configuration. If you’ve never encountered…

Hi, I’m Gary, and I’ve been programming computers since the age of nine on my ZX Spectrum. When the Raspberry Pi was released I was quick to adopt and have since bought all their iterations. While I use a Pi 4 as a desktop to prototype projects for my blog, I prefer to deploy with the Pi Zero’s due to its size, cost and power. Traditionally I’ve always used Python and until late haven’t really used the GPIO nor engaged with electronics projects. Historically I’ve used the Pis as low-cost Linux boxes and run them as mini servers (including Minecraft servers for the kids). However, during the Covid-19 isolation and stay-at-home policy I decided to order some electronic sensors to further learn about the IoT. I already had lots of…

Typically we would use Python with the Raspberry Pi Camera, but as proven in this tutorial, raspistill is a powerful and useful tool for projects that need just a quick solution. We’ve had a look through raspistill’s man page and found a few useful switches… • To quickly take a pic and save it as image.jpg. This is mainly used to test the camera: • Take pictures in low light. Note that this will slow the frame rate: • Change the quality and resolution of the image, with 100 being the best quality: • Set the opacity of the preview window. This is useful when using the camera and it encounters a problem: • The final option uses the timelapse switch to auto generate a timelapse that lasts 30 seconds.…

The ZX range of Sinclair computers had many peripherals. The ZX Interface 1 module provided an additional 8KB ROM, an RS-232 serial port and a network interface in the form of the proprietary ZX Net. The ZX Microdrives, a type of tape loop cartridge offered 85KB of storage, but were expensive and prone to failure. They could be fixed using a blob of plasticine to ensure they stayed firm in the slot. Famously there was a printer, the ZX Printer, which would use a roll of aluminium-coated black paper on which the text was etched using a small electrical current that would cause the aluminium to evaporate and reveal a black character. The printer was powered directly from the computer using the expansion bus, but ZX81 users needed to use…

OUR EXPERT Nick Peers wonders if there’s a future in live streaming for a greying tech journo who can’t stand the sound of his own voice. Live streaming is an increasingly popular medium, enabling you to produce content that’s shared in real time and – if your online provider supports it – available afterwards for those who missed the live show. If you’re looking to make your next online live stream something special, then take a look at OBS Studio (www.obsproject.com). Not only can you easily combine multiple video and audio sources into a single stream, OBS Studio provides you with a means of breaking down your stream into specific sections, making it easy to seamlessly switch between different sources and screen setups. Crucially, it works with all the major…

Make use of OBS Studio’s Profile menu to set up customised channels and settings. Each profile doesn’t store any information about Scenes or Sources, but it does record your streaming channel keys as well as your general preferences. You can rename, import/export, and duplicate your Profiles. OBS Studio’s developer community has created a range of plugins to add new transitions, effects and other elements to the main program. See https:// obsproject. com/forum/ resources/categories/obs-studioplugins.6.…

As well as working with data in your Elasticsearch indexes, Timelion can work with external sources. An excellent one is the World Bank, which describes itself as providing “Free and open access to global development data”. The World Bank provides datasets on a range of topics. These are called indicators. To work with World Bank data you replace the .es() function with the .wbi() one instead. This function takes two parameters. The first is the ISO code of the country in question and the second is the indicator that you want to work with. You can leave either parameter out and obtain data for the world combined and an indicator of GDP by default, respectively. To see what indicators are available you can go to https://data.worldbank.org/indicator. As an idea of…

There’s little sense in setting your camera to shoot in RAW format (or RAW+JPEG format) on a sunny day, unless you want to manipulate the results significantly. In contrast, any other situations where automatic in-camera image processing may fail are a good reason to go with RAW. This may involve taking photographs in subtly lit rooms, capturing an artist at work in a dark studio, shooting starry skies and so on. Some types of electric bulbs may mislead the camera’s auto white balance logic, resulting in yellowish or greenish skin tones. Such defects are hard to fix in JPEGs, but RAW files give you more opportunities to improve the end results. Taking pictures in the dark also means that you might want to push the ISO value higher in order…

If you want to take things a step further, try adding a background image to the game board providing different coloured squares – maybe black and white like a chess board. A fully working copy of our code is available on the Linux Format website under our Archives page. If you’re struggling at any stage throughout this tutorial, you may download and compare. An interesting challenge might be to create an automatic player two, a so-called BOT, to enable a single player to play the game. Hint: this will involve use of the ‘random’ method.…

Hot hacking distros We put the best hacking distro through their paces, so you can head out with the ideal hacking toolkit in hand. Build a Linux gaming box It’s not all work work work (unless you’re Jonni) so take some downtime and fire up a fully fledged gaming PC. Embedded Linux We experiment with embedded Linux running on the Raspberry Pi, so you can make your projects even lighter! Emulate the Atari ST We’re hitting peak 16-bit with the advent of the awesome Atari ST. Relive the days of TOS, MIDI interfaces and SpeedBall. Contents of future issues subject to change. We might be trapped in Lockdown 2.0 West Country Drift.…