Linux User & DeveloperNo. 156的目錄

This issue » World’s greatest FOSS » Build-it-yourself open hardware » Biggest open source contributors » Tracking the International Space Station Welcome to the latest issue of Linux User & Developer, the UK and America’s favourite Linux and open source magazine. Open source has never been as crucial as it is now. Linux and FOSS are enjoying unprecedented celebrity as companies increasingly move to open source business models, embrace open means of developing new tools, and open up entire code bases to further improve the technologies that are powering our future. This month, we reveal the open source contributions from the world’s biggest tech companies (page 14). We also take a look at userland FOSS in our lead feature (page 18), selecting the best-in-class apps so you can ensure you’re…

Red Hat has officially released updated versions of its Ceph and Gluster storage products, Ceph Storage 1.3 and Gluster Storage 3.1, as the company looks to gain a larger slice of the big-data pie. “Open, software-defined storage is one of the best ways for enterprises to design and deploy data storage at petabyte scale,” claimed Ranga Rangachari, vice president and general manager of storage and big data at Red Hat, as the updated projects were unveiled during the Red Hat Summit 2015. “We continue to listen to our customers and today we respond with new Red Hat Storage products that help manage their exponentially growing capacity requirements, securely across the enterprise. With the new features in Red Hat Gluster Storage and Red Hat Ceph Storage, Red Hat delivers uncompromised performance…

“Linus Torvalds announced Linux 4.2-rc6 (Release Candidate 6), noting that he had been unhappy with the quality of previous release candidates, but was now encouraged by the improved state of play. In his announcement, Linus says, “Not only is RC6 finally shrinking noticeably, the issues I was worried about had fixes come in early in the week, and so I don’t have anything big pending”. This means that Linus now anticipates 4.2 to be a “normal” release cycle and thus available shortly after we go to press. Kdbus debate continues One of the bigger, more controversial sources of discussion in kernel development circles lately has been “kdbus” – the in-kernel implementation of the “D-Bus” IPC (Inter-Process Communication) mechanism, common on modern Linux desktop, server and embedded systems. D-Bus was originally…

TypeScript TypeScript, developed and maintained by Microsoft, is supposed to be a JavaScript superset. In simple terms, it lets you do far more things than JavaScript and, when you compile it, you get JavaScript code that runs on any browser. So, what exactly are the extra things you can do with TypeScript? First up, you can create enums in TypeScript, enabling you to create friendly names for number sets. Another important deviation TypeScript allows is the ability to use an object-oriented, class-based approach in programming. This means that instead of using functions as basic means of building reusable code, you can use the object-oriented approach for more modular code. This was just the tip of the iceberg though, as you can now dig deep on the official TypeScript language website…

LIBREOFFICE The successor to OpenOffice has long since established itself as the best Linux office software around, with just about every feature you’d expect from something like Microsoft’s pervasive product. Here’s a selection of the best applications included in LibreOffice and what they can do WRITER WORD PROCESSOR There’s a standard word processor in any office suite, however Writer does a lot more than other text editors you can find in Linux. It has all the formatting tools you’d expect, such as layout functions, advanced macro and mail merge tools that you find in the professional software versions. It does prefer to save files as .ODT, but you can change it by default to .DOC or .DOCX to be compatible with Microsoft. CALC SPREADSHEETS The equivalent of Microsoft Office Excel,…

KEEPASSX In the interests of security, we always recommend using different alphanumeric passwords for each of your online accounts (although having a base, perhaps phrase-based, password and then creating memorable permutations for your various accounts is another good move). Keeping track of them all can be a pain, so for simplicity and security you can use KeePassX. Store all your sensitive data inside an encrypted database, and keep it inside Dropbox or a secure server. You can then access that database from other devices and use a single master password to unlock everything you need from whichever device you’re using. TAILS We mention Tails a lot when it comes to security and privacy software, but with very good reason. It is without question the best distro out there for giving…

Resources Campaign Chain campaignchain.com Documentation bit.ly/1eCn2bj Social media is one of the most important aspects of marketing today. An organisation can’t think of a marketing strategy without social media playing a massive role. But with the ever-increasing number of social media platforms, managing campaigns across different platforms is a big challenge. The high dependence on social media means there is a need to properly plan, execute and monitor the campaigns to measure the overall impact – you can’t just say a campaign did well just because you feel so. These issues are especially relevant for social media marketers who manage social media campaigns. As the need for social media marketers has gone up, the job has become far more complex. In this article, we will introduce you to CampaignChain, an…

Resources Text editor Gawk gnu.org/software/gawk Mawk invisible-island.net/mawk We will begin this tutorial with a touch of historical information about AWK; the rest of the tutorial will deal with more advanced AWK programming techniques such as the use and development of functions, BEGIN and END code blocks, etc. The name AWK comes from the names of its three authors: Alfred Aho, Peter Weinberger and Brian Kernighan. It is a handy pattern-matching programming language that is Turing-complete and was developed at the famous AT&T Bell labs. The biggest difference between the various AWK variants and the original version of AWK is that newer versions support a larger set of built-in functions and variables. Despite its many capabilities, AWK cannot solve every problem equally well. It is more suited for situations when you…

British ESA astronaut Tim Peake has been preparing and training for his stay on-board the ISS, which begins this December 2015. The ISS orbits at around 400km above our heads at an incredible speed of 17,150 miles per hour, so this means that the crew orbit the Earth every 92 minutes. As part of his six-month mission, he will run a number of Astro Pi experiments created by schools, each judged and selected by the ESA, the National Space Agency and Raspberry Pi. The Astro Pi HAT has been designed and built specifically for this mission and boasts an array of sensors and an 8x8 LED matrix. Each experiment will generate and collect data which will then be downloaded to Earth for analysis. In this tutorial, you will be introduced…

I hope you can help me. I use Ubuntu on one of my main machines and I like to use Empathy for my instant messaging as it integrates quite nicely with Unity. I get a problem though where every time I log in, it asks me to accept the “untrusted” certificate from my Facebook chat connection. I’ve clicked the check box to remember that I’ve accepted the certificate, yet this doesn’t seem to have any effect. Is there any way to get Empathy to properly remember this option? It’s not a huge inconvenience, but when my Internet gets a bit spotty, it can be extremely irritating. Thanks in advance! Chris Daley This seems to be a not all uncommon problem in Ubuntu and sometimes happens with Google accounts as well.…

Rob Zwetsloot studied aerospace engineering, using Python to model complex simulations, yet this is the least of his achievements. Having earned enough woolongs to complete his Phase V ship upgrades, undertaken in secrecy and seemingly planned for years, Rob has commandeered the now spaceworthy LU&D Flying Fortress forevermore, dubbing it the Vega Mega Station and sending it to near-Moon orbit. He was last seen arcing across the night sky in a brilliant roar of light, thunder and colour, headed for the station on a modified Gundam Rapiro, both giggling maniacally. Rumours of an immense battle on the dark side of the Moon are now being whispered across the web. Godspeed, sir. Jon Masters is a Linux kernel hacker who has been working on Linux for some 19 years, since he…

Canonical, creator of the popular Ubuntu Linux distribution, has settled its long-running dispute with the Free Software Foundation and the Software Freedom Conservancy over its intellectual property policy, by adding a ‘trump clause’ for GNU General Public Licence compliance. Under the revised policy, the GPL is to take precedence thanks to the clause specifically stating that “where any other licence grants rights, this policy does not modify or reduce those rights under those licenses” – a hard-fought conclusion to two years’ negotiations. The Free Software Foundation, however, is still not happy. “While the FSF acknowledges that the first update emerging from that process solves the most pressing issue with the policy – its interference with users’ rights under the GNU GPL and potentially other copyleft licenses covering individual works within…

The Linux Foundation has launched an automated census project for the Core Infrastructure Initiative; a move it hopes will identify new critical projects which could benefit from funding and support. “Measuring software security is an ongoing struggle that’s notoriously difficult given missing or messy data,” explained Jim Zemlin, the Linux Foundation’s executive director, at the launch. “There’s no perfect set of metrics to guarantee that software is secure or not. The Census Project brings the power of the open source collaboration to help fill this massive gap, which will provide a useful barometer for assessing software from a security point of view. We look forward to feedback in order to improve the census itself.” Developers and security experts alike are asked to participate in the project, under the coordination of…

There have been talks about open source thinking going mainstream for quite some time now, but talking doesn’t always mean something. To really check if there has been growth, innovation and adoption of open source software, we need to take a close look at big companies that dictate the ways web and related technologies are shaped. But, there are few questions – why should large corporations bother with open source? What is the benefit for them? Isn’t open source already free? The first thing to understand here is the way technological innovation works – it’s all about compatibility and interconnectivity. Today it’s almost impossible to create something new that is completely, truly standalone. At some point in time, software has to talk to some other software to get things done.…

When Mark Zuckerberg wrote the first line of code for Facebook, he did it in PHP and used MySQL as the database. Facebook may have moved miles ahead, but one thing has not changed – the company’s support for open source culture. Or rather, it has increased with time. Note that Facebook doesn’t just share some tools to push its website – instead it open-sources its own stack (virtual machines, languages et al). Head over to its official GitHub page and you will find 274 public repos. It’s very difficult to choose just a few of them for this space, but here are some of the more interesting initiatives. HHVM, aka the Hip Hop Virtual Machine, is one of the most talked-about open source projects from Facebook. It is designed…

Node-RED – your new visual tool for IoT The tech industry is always on the lookout for the next big thing, and the Internet of Things is surely one of them. Node-RED is a visual tool for wiring the Internet of Things. Created by IBM’s Emerging Technology team, this tool provides a browser-based flow editor that makes it easy to wire together flows using the wide-range nodes in the palette. Flows can then be deployed to the runtime in a single click. Built on Node.js, Node-RED works on a selection of predefined nodes. These nodes can be social, like Twitter, email, IRC etc; network nodes, like HTTP, TCP, UDP etc; hardware nodes like Raspberry Pi, BeagleBone Black; and storage nodes like Filesystem, MongoDB, MySQL etc. Started in 1911 as CTR…

Facebook and Google recently ended their support for the XMPP API, which means that messaging clients such as Pidgin can no longer officially connect to the services. A new Google solution is in the works but there’s no word from Facebook yet. However, James Gebloski provides a work-around plugin for Debian and Ubuntu that will help you connect the Pidgin client to your Facebook account. 01 Plugin setup First navigate over to /etc/apt/ sources.list.d and then create the file ‘jgebloski.list’. Open it up in a text editor and add the following line: … replacing <version> with one of the following, depending on your distro: Debian_8.0, Debian_7.0, xUbuntu_12.04, xUbuntu_14.04, xUbuntu_14.10 or the newer xUbuntu_15.04. 02 Repo key To add the repository key, enter the following commands into the terminal: 03 Non-XMPP…

Resources python-ardrone bit.ly/1eQ7XTz pygame pygame.org/news.html Firmware 1.5.1 for the Parrot AR.Drone If you’ve ever tried to properly fly a Parrot AR.Drone with an iOS device, you’ll probably know how inaccurate it can be. With the touch controls, it’s not always obvious if they’re working or not, and although with a lot of practice you can get used to it, it’s never quite exact. The drones are quite smart, though. There are several functions you can use to make one take off, land and hover, using various sensors to enable you to do this safely. All of these, along with the flight controls, are just code when you get down to it. While it’s not quite an open API, people have managed to hack together libraries that access the AR.Drone, enabling…

Resources LibreOffice libreoffice.org Using office software for very specific tasks, you can end up sticking yourself in a rut with the way you work. You do the same thing the same way every single time, not considering any other methods that might make it faster, better or more efficient. When you write several letters or documents a day for work, or maybe create spreadsheets with regularity, you don’t really ever need to learn new techniques. We all get stuck in our ways. It’s sometimes difficult to comprehend just how powerful and feature-full LibreOffice can be, especially when you’re treating it as you normally do and not making the most of what it has to offer. On a day-to-day basis, you may have no idea about macros, creating indexes or doing…

Why Python? It’s the official language of the Raspberry Pi. Read the docs at python.org/doc “There are many projects around the Internet that use the Raspberry Pi as the engine for ticker-type displays. In this way, you can keep track of all of your Twitter or Facebook feeds. This month, we will take a look at another ticker service, specifically RSS feeds. While we could start with first principles, looking at making raw network connections and parsing the returned RSS data, that is a bit beyond the scope of such a short article. Instead, we will look at using the Python module ‘feedparser’, or the ‘Universal Feed Parser’. This module will abstract out the lower level complications and enable us to focus on actually playing with the RSS data. True…

Q: Are there any issues with certain graphics cards on Linux? A: These days, pretty much all AMD/ ATI, NVIDIA and Intel graphics cards will work fine out of the box on a Linux distro. Drivers and modules in the kernel for it are generic enough, and most distros are very smart in loading the right drivers once they’re installed. Q: What’s the deal with the NVIDIA drivers? A: NVIDIA drivers are not as open as some of the AMD drivers, so while there is an open solution for NVIDIA that a lot of distros use (called Nouveau) it is not always as good in every situation as the restricted, proprietary drivers. These can be accessed fairly easily though and are only restricted as they carry extra license agreements. Q:…

To access FileSilo, please visit www.filesilo.co.uk/linuxuser 01 Follow the instructions on-screen to create an account with our secure FileSilo system, then log in and unlock the issue by answering a simple question about the magazine. You can access the content for free with your issue. 02 If you’re a print subscriber, you can easily unlock all the content by entering your unique Web ID. Your Web ID is the eight-digit alphanumeric code printed above your address details on the mailing label of your subscription copies. It can also be found on your renewal letters. 03 You can access FileSilo on any desktop, tablet or smartphone device using any popular browser (such as Firefox, Chrome or Safari). However, we recommend that you use a desktop to download content, as…

“The concept of ‘intellectual property’ and its ownership is a subject that has always been beset with paradoxes. Information wants to be free, and copyright wants to impose limitations on the distribution of information. But in the ephemeral world of the Internet where information and ideas are stored and shared in digital formats, the ownership of ideas and information really has little meaning. As the creative industries have found, when the distribution of a creative work is no longer restricted to a hardcopy format, such as vinyl or paper, it becomes harder to impose rules on its distribution. If a product is worth anything, it is copied and pasted into infinity, and lack of scarcity diminishes its monetary value, sometimes to almost nothing. The artist or creator, always a prisoner…

Top 10 (Average hits per day, 6 July – 5 August) This month Highlights BackBox Linux 4.3 The latest release brings a new Ubuntu 14.04.2 base, an improved installer with logical volume manager (LVM) and full-disk encryption options, RAM wiping at shutdown and reboot, and new exciting tools including beef-project, btscanner, ophcrack, and wpscan. Android-x86 4.4-r3 The third stable release of this unofficial, x86-centric, Android KitKat variant brings improved performance for tablets and netbooks and additional drivers in the newer 4.0.8 kernel. Red Hat Enterprise 6.7 Red Hat’s latest commercial offering brings improvements including a new cluster configuration analysis tool, clufter, plus LVM cache supportforboostedperformanceusinglow-costSSDs. Latest distros available: filesilo.co.uk…

“This article is about finding prime numbers up to a maximum. Although the problem of finding prime numbers looks relatively easy, a lot of debugging took place during the writing of this article. Prime numbers are mainly used in cryptography but they are also being used in coding theory, random number generators, error correcting codes and hashes. The limit is given as a command line argument to the program. As command line arguments are passed to the C program as strings, the following C code converts the string to an integer: None of the programs check for errors on the input; they just assume the given command line argument is an integer greater than zero that contains no ASCII characters, spaces or other Unicode characters. Also, a function named isPrime()…

Build world-class hybrid apps with Crosswalk As more and more new devices are launched every year, there is an increase in the overall number of types of devices. This means more devices for app developers to support. If you are an app developer, you already know how tough this is. Crosswalk from Intel is an open source HTML application runtime for iOS, Android, Tizen and Linux. Crosswalk lets you use standard HTML5, CSS3 and JavaScript, features and APIs (that you’d use when building a website) to create your app. You can also add custom features provided by the platform you are developing for – this means, the best of both worlds. Intel is one of the core members of the Tizen technical steering group; platinum sponsor for the OpenStack foundation,…

Using Linux for any kind of computing purpose is genuinely feasible these days, unlike the dark ages of the Noughties. With excellent, large communities around different distros and software, many apps and programs have been created that can fit a wide variety of purposes. While some of the best apps may rise to the top of the pile, you may not always be looking at that specific pile. With that in mind, we’ve put together a guide for the very best Linux apps that you can get for all of the major uses. From office workers to gamers and even scientists, there are plenty of great pieces of software for anyone wanting to use Linux.…

DOTA 2 The sort-of sequel to a free mod for a game made by a different company, Dota 2 has a weird origin. Once you get past that though, you find an excellent MOBA that makes it a great alternative to League of Legends. It has been fully embraced by the eSports community too, with regular high-stakes tournaments and leagues to play in. If you’re not the highly competitive type though, you can still enjoy it casually. MARVEL HEROES We swear to you that Marvel Heroes is actually pretty good, despite what your initial assumptions might be. The game lets you be one of an ever-expanding line-up of Marvel characters and heroes as you repeatedly left-click on bad guys to try and save the world. It takes its cues from…

What you’ll need Jumper wire 2mm wire Heat shrink tubing Soldering iron Wire cutters/strippers Hair dryer/heat gun PiRadio PirateRadio.py script Back in the 1960s, offshore boats were used to broadcast what was then known as ‘pirate’ radio: unlicensed broadcasts that provided an alternative to the BBC’s light program (as the most populist radio station was then known). Pirate radio was a revolution that inspired Radio 1 and commercial broadcasting, but these days you don’t need a boat to pursue your radio DJ dream – just a Raspberry Pi. Add a basic DIY antenna, an SD card with some MP3 tunes saved to it, plus a script to automate playback, and you can follow in the footsteps of John Peel and Tony Blackburn. This is a 50-50 project, one that has…

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While running a make file or build, a number of files are generated (let’s say from a tool) and placed into /sam/path/code/. If the user then modifies an aspect of the files, they are overwritten by the newly created files. As a result, the timestamps on all of the files are then updated, leading to some problems where not all of the files are compiled. For some reason, it seems to be using these timestamps to determine what needs to be included when compiling and won’t work when recompiling. How do I make it recompile all the files, if the make file is looking at the timestamp of each file even though most of the code files are not modified at all? Sam Hammond You can actually force the makefile…

YOUR BONUS RESOURCES ON FILESILO THIS ISSUE, FREE AND EXCLUSIVE FOR LINUX USER & DEVELOPER READERS,YOU’LL FIND THESE GREAT RESOURCES… » 4 Latest distros, including Korora 22 and OSMC, reviewed from pages 82 and 84, respectively. » 16 Best FOSS packages, including SeaMonkey, Calibre, Eclipse, TeXstudio, Grisbi, KeePassX and more. » Watch The Linux Foundation, Red Hat and Raspberry Pi video guides, tutorials and webinars. » Code and assets for this issue’s tutorials, including the Astro Pi ISS tracker, drone flight path and more. LENGTH OF VIDEO TUTORIALS: 20 HOURS www.filesilo.co.uk/linuxuser FILESILO – THE HOME OF PRO RESOURCES DISCOVER YOUR FREE ONLINE ASSETS A rapidly growing libraryUpdated continually with cool resourcesLets you keep your downloads organisedBrowse and access your content from anywhereNo more torn disc pages to ruin your magazinesNo…