Índice para No. 159 em Linux User & Developer

This issue » Start doing DevOps today » Make games in Pygame Zero » Find the best backup solution » Win a FUZE workstation plus robot arm Welcome to the latest issue of Linux User & Developer, the UK and America’s favourite Linux and open source magazine. Embracing DevOps practices to speed up your software delivery is far easier than you think. It’s a buzzy term and the definitions can be hazy, but the benefits of this modern, agile way of working improving cohesion between the development and operations teams – can’t be ignored. This month, we explain just what DevOps means to you and give you a running start with three core tools: Docker, Puppet and Vagrant. Plus, we show you around the Docker-based distro CoreOS, which makes managing…

The development of PostgreSQL, recently released as version 9.5 Beta, has benefited from EU funding thanks to 2ndQuadrant’s dedicated work and coordination of a major research project called AXLE. 2ndQuadrant facilitates the development of PostgreSQL and is a world leader in PostgreSQL support services. The research initiative received €1 million in R&D funding from an EU FP7 grant and has served as a catalyst for the development of PostgreSQL. As the three-year project comes to an end this month, the team at 2ndQuadrant will have contributed more than 10 years of effort towards enhancing PostgreSQL through the AXLE project. AXLE (Advanced Analytics for Extremely Large European Databases) has brought together a diverse group of researchers, all focused on solving the needs of extremely large data analysis. With PostgreSQL at the…

Top 10 This month Highlights Ubuntu 15.10 Ubuntu absolutely dominated this month’s release figures, largely thanks to the simultaneous launch of its Desktop, Server, and Core variants alongside the various translated, task-focused and desktop-environment-specific official spins. Android-x86 5.1 RC1 While Android-x86’s Distrowatch traffic was down this week, larger drops in CentOS and Arch saw the port of Google’s Android Open Source Project (AOSP) hit the top ten chart. Linux From Scratch 7.8 Linux From Scratch is a freely-distributed guide to building your own distribution by Bruce Dubbs. The latest release includes an alternate version based around systemd. Latest distros available: filesilo.co.uk…

Mihalis Tsoukalos is a UNIX administrator, a programmer, a DBA and a mathematician. He has used Linux since 1993 “The problem that will be examined this month is how to add integers that are of arbitrary size. The programming language that will be used is C, but the techniques that will be presented are directly applicable to almost all modern programming languages. Two crucial questions will come up sooner or later: firstly, how do you deal with overflows? Secondly, will you support signed integers? Neither of them are difficult to answer, but the point is that you should think about them before you start developing your program because changes at a later stage will take more time. A rational choice would be to use an array to hold all the…

DevOps is the latest buzzword to hit the software industry – the practise promises quick delivery to customers with the least friction between various teams. As is to be expected, everyone wants to implement DevOps. But just like medicines that should be taken in a controlled manner and fixed doses, DevOps should be adopted in a phase-wise manner, keeping in mind major factors like human resources. Not doing so will only lead to chaos and misunderstanding among teams. The first step in order to properly plan DevOps implementation is to understand DevOps itself, and then the various factors related to it. In this feature we will do just that. We’ll begin with an introduction to DevOps, and best practices to make it work well, and we’ll follow with some tutorials…

Vagrant provides a method for creating repeatable development environments across a range of operating systems. It uses providers to spin up isolated virtual environments. The default provider is VirtualBox, but since Vagrant 1.6, Docker-based development environments have been supported too. Compared to other tools like boot2docker, which can help run Docker on non-Linux platforms, Vagrant has some important advantages: • Configure it once and run it everywhere – Vagrant is just a Docker wrapper on systems that support Docker natively, while it spins up a ‘host VM’ to run containers on systems that don’t support it. Users don’t have to bother themselves with whether Docker is supported natively or not; the same configuration will work on every OS. • Docker hosts are not limited to boot2docker (a VirtualBox image of…

Resources GCC bit.ly/1QsGYe9 When we are developing software in the Linux environment, we often use C or C++ as the programming languages. The programs we write are normally referred to as the source code, and there is always a need to convert these source files into another computer language. Compilation is the process of converting the source code into a target language having a binary form, the purpose of which is to create an executable program. Compilation is often referred to as the translation of the source code from a high-level programming language to a lower-level language. A compiler is a specialised program that converts source code into machine language (also called object code or machine code) so that it can be understood directly by a CPU (central processing unit).…

Resources CoreOS coreos.com Containers are the standard for running software there days, so it was high time an operating system based on containers appeared. With CoreOS, this gap has been filled very well. Let’s dig a little deeper to try and understand why a new Linux distro is needed at all when the current ones handle containers well. The problem is the fact that, while it is easy to use containers on current Linux distros, they don’t play well when you need to manage (launch/destroy) several containers or link containers to create different back-end services. The new wave of containerisation, led by Docker, has made things lot easier – applications can now be easily deployed on almost any system. You just need the appropriate Dockerfile and Docker installation. But, if…

Resources Text editor GCC compiler Hash tables are a key component of computing and programming languages; they are being supported in almost any programming language, including AWK. Strictly speaking, a hash table is a data structure that stores one or more key and value pairs. A hash table uses a hash function to compute an index into an array of buckets, or slots, from which the correct value can be discovered. Ideally, the hash function will assign each key to a unique bucket, provided that you have the required number of buckets. As you will see, this rarely happens. In practice, more than one key will hash at the same bucket. The worst restriction of a hash table is that once you define the hash function and the number of…

Components list 12V power supply 12V-to-5V DC-DC converter 2 WiPi USB dongles Desk Raspberry Pi B+, USB sound card, 2.5W Class D amplifier, Gertbot, 2 stepper motors, 2m LED strip, capacitive touch sensor, 2 microswitches (on/off), mini speaker Computer Raspberry Pi 2, 2.8W Class D Amplifier, laptop LCD display, LCD display controller, 2 speakers Magic lamp Qi wireless charger, Qi wireless receiver, Adafruit NeoPixel Ring, Adafruit Trinket Wireless A NeoPixel Ring shines through this magic lamp when it is activated by the embedded Qi charger, which can also be used with mobiles Computer The display uses the Raspberry Pi 2, with a keyboard-and-mouse combo hidden on the underside of the desk with a Velcro mount Contactless Frederick made his own breakout board for the hover buttons, combining the Atmel AT42QT1070…

David Ames, who uses Pg0 to teach younger children to code at events across the UK, told us: “One thing to avoid when it comes to teaching kids is Object Orientation.” OOP (object-oriented programming) is partly abstracted away by Pg0, but it can’t be ignored. Perhaps the best approach is using Pg0 and some simple code to start, then dropping in a piece of OO when it’s needed to solve a particular problem. With the Code Club age group – about eight to eleven – feeding information to solve practical problems works well. It can work with adults, too – but there’s always someone who’s read ahead and has a few tricky questions.…

While playing audio and presenting images is all well and good, sometimes a video is the clearest way to display output. Luckily, pygame can help you with this, too. There is a movie object available that can handle the playback of MPEG-1 video files. The constructor takes a filename for the movie file: pygame.movie. Movie(filename). You can check the data and see whether there is video data or audio data with the helper functions has_audio() and has_video(). Movie objects do need to be displayed on some kind of surface. The default surface that the movie object will use is the display surface. If this isn’t to your liking, you can change this to a different surface with the method set_display(). This draws over everything on the surface, so you may…

Jon Masters is a Linux kernel hacker who has been working on Linux for some 19 years, since he first attended university at the age of 13. Jon lives in Cambridge, Massachusetts, and works for a large enterprise Linux vendor. You can find his brilliant Kernel Column on pages 16-17 this month. Richard Smedley has been helping businesses and community organisations of all sizes to move to GNU/Linux since the 1990s and doesn’t expect those he works with to share his love of Emacs. Well, maybe a little. This issue, Richard shows us how to code games with Pygame Zero (p.62) and shares more great FOSS (p.88). Nitish Tiwari is a software developer by profession and an open source enthusiast by heart, and he helps firms set up and use…

1 Unity 8 technology Canonical’s new desktop environment, Unity 8, wasn’t quite ready in time for the release of Ubuntu 15.10. However, all is not lost because it is being made available as a technology preview, with the promise that it’s possible to try it out and cleanly revert back to the default Unity 7 if any problems are encountered. 2 Snapcraft tool Designed for use with the embedded- and cloud-centric Ubuntu Core spin, Snapcraft has been designed to make the building of Snappy packages as simple as possible for the user, whether they are doing so from scratch or by taking advantage of existing deb packages. 3 Ubuntu Phone updates Those running the Ubuntu Phone spin will be pleased to discover that they no longer need to manually update…

Dell has announced a new Internet of Things (IoT) gateway product, the Dell Edge Gateway 5000 Series, which brings support for Ubuntu Core and its Snappy management architecture. Announced back in 2014, Ubuntu Core is Canonical’s cloud- and embedded-centric variant of the Ubuntu Linux distribution. One of the key changes is its use of Snappy, a new management system which uses atomic transactions to allow any changes to be rolled back on demand. It’s this that has attracted Dell to the platform. “Snappy Ubuntu Core’s ability to automatically roll back to the last known working version of the OS is invaluable to our IoT customers,” explained Dell’s director of IoT strategy and partnerships Jason Shepherd at the announcement. “Should an OS update fail to boot due to any reason, Ubuntu…

Mitchell Hashimoto, founder of HashiCorp, is a developer obsessed with automation. He is the creator of Vagrant, Packer, Serf, Consul, Terraform, Vault, Nomad and Otto. He is a key DevOps community figure, a technical author, and a seasoned engineer with enviable experience in the fields of operations and research you run Otto today and you run Otto five years from now, it’s likely that different things will happen because we’re going to use current best practises. The main difference is that Appfile describes the application and Vagrantfile describes the machine. “What is Otto, in a nutshell? Its goal is to do everything as well as, if not better than, Vagrant could do from a developer perspective. And then we also added deployment. That’s the feature difference, but there are also…

1 Start your Rails project Initialise a new Rails application with out-of-the-box defaults: $ rails new 2 Compile and configure Otto’s compile step automatically detects the type of application as Rails and then prepares Otto to manage your app’s lifecycle. You can customise nearly every aspect of Otto’s behaviour by writing an Appfile. $ otto compile 3 Develop locally Otto builds and runs a local development environment, so you can easily test and make changes to your application: $ otto dev 4 Construct infrastructure Otto creates a base infrastructure according to industry best practises: $ otto infra 5 Build your application Otto packages your application and prepares it for deployment onto your infrastructure: $ otto build 6 Deploy Your Rails application is converted to running infrastructure – your app is…

Mihalis Tsoukalos is a Unix administrator, a programmer (for Unix and iOS), a DBA and also a mathematician. He has been using Linux since 1993 Resources Text editor GCC compiler Perl interpreter Go compiler Haskell compiler This tutorial will present the system calls and explain the techniques that will enable you to deal with files and directories in Linux. The stat family of functions and the stat structure that holds all important data are the centre of this tutorial. The majority of the other system calls here enable you to change most of the attributes kept in the stat structure. Although the stat family has four functions; stat, fstat, lstat and fstatat, only the first three will be explained here. However, all of them return the same information, which is…

As if Haskell was not good enough on its own, it can also call C code! Please note that Haskell is used as an example here as many other languages can also call C code. The following program (pid.hs) gets the process id using C code wrapped in Haskell code: Although you might not be familiar with the Haskell code, you should understand how extraordinary what just happened is: you used a C system call in a totally different programming language to get the information you wanted. Put simply, the c_getpid Haskell function uses getpid(2) to get the process ID. Using a slightly different approach, you can call your own C functions from Haskell code.…

The most common use of GCC is when there are multiple program files to be compiled. If we compile each and every source file separately then the time required to build the executable is significant. However, if we compile all the files at once, we can achieve a significant time saving. If we have some 1,000 files and have modified only one file, then rather than compiling 1,000 files, we just need to compile one file and link it with the object files to update the binary. This saves huge compilation time. You can go through a Makefile to understand how this can be achieved.…

Resources Plasma 5 desktop The holy wars between KDE and Gnome users seem to be long over, perhaps because of a massive migration of the latter to Cinnamon, but many of the rest still love their KDE installation for being fast, configurable and feature-rich. But KDE 4, first released seven years ago, is moving aside to free the way for the shiny new Plasma 5, the next-generation hardware-accelerated desktop with a sleek modern look, yet retaining the much valued ‘Swiss Army knife’ approach, which always inspired KDE users and developers. Just like the aging KDE 4, Plasma 5 is a modular desktop made of plasmoids that can be rearranged in any way. The desktop itself is a converged shell, which adapts to different target devices on the fly. Together with…

As far as we can remember, the first attempt to clear the visual difference between Qt-based and GTKbased apps was taken in Red Hat Linux 8.0 with the introduction of the Bluecurve theme. Nowadays, the problem is still present: modern GTK2 and GTK3 apps don’t quite fit well into the KDE desktop. There are various workarounds for this issue, including the QtCurve theme, which works well for GTK2 but has poor support for GTK3. Another option is to use the Orion GTK theme, which looks similar to Plasma 5 Breeze (the default theme) but still has huge visual inconsistences with it. Luckily, we have a working port of the Breeze theme to GTK at github.com/dirruk1/gnome-breeze, covering both light and dark variants. Simply copy the theme into either ~/.themes or /usr/share/themes…

Hash tables use linked lists for storing their data. Is it mandatory to use linked lists? No, but linked lists have many advantages. Linked lists are really good at sequential searching, especially when used with C pointers; they are a simple and elegant data structure that can dynamically grow, do not need any extra space apart from a few pointers, and are good at insert operations. Finally, they do not need too much housekeeping, provided you don't delete elements from a hash table often. However, linked lists have disadvantages. If a linked list has many elements, reaching the last element of the list can be really slow. Additionally, linked lists can be really slow when dealing with sets with a large amount of elements: one way or another, a linked…

What you’ll need Pygame Zero Pygame Pip Python 3.2 or later Games are a great way of understanding a language: you have a goal to work towards, and each feature you add brings more fun. However, games need libraries and modules for graphics and other essential games features. While the Pygame library made it relatively easy to make games in Python, it still brings in boilerplate code that you need before you get started – barriers to you or your kids getting started in coding. Pygame Zero deals with all of this boilerplate code for you, aiming to get you coding games instantly. Pg0 (as we’ll abbreviate it) makes sensible assumptions about what you’ll need for a game – from the size of the window to importing the game library…

There’s a new version of Pg0 in development – it may even be out as you read this. Pg0 creator Daniel Pope tells us “a tone generation API is in the works,” and that at the Pg0 PyConUK sprint, “we finished Actor rotation.” Contributions are welcome – not only to the Pg0 code, but more examples are needed not just to show what can be done, but to give teachers tools to enthuse children about the creative act of programming. Pg0 has also inspired GPIO Zero, to make GPIO programming easier on the Raspberry Pi, with rapid development occurring on this new library as we go to press.…

What you’ll need • Pi-Mote IR control board bit.ly/1MdpFOU • Remote controlled robot In the previous issue (158) we looked at how to create a hack to control your TV using the Energenie Pi-Mote IR board and a Raspberry Pi. We return to the world of the IR board, only this time we use it to record signals from a remote control robotic toy and combine these with pygame commands to enable you to control your robot from your Raspberry Pi. Since the code is Python-based, you can then develop it further, use social media to control the robot with tweets, or install Flask to create a web interface accessible from your mobile phone. 01 Update the boot file Before booting up your Raspberry Pi, attach the Energenie IR board…

Good text editors tend to be focussed on workflow for coding, or to be simplified letter and document writing tools. TEA manages to embrace both worlds, being a decent enough word processor – opening .odt, .rtf and .docx files, plus AbiWord, KWord and other formats – and a better alternative to default code editors like Gedit. Syntax highlighting includes everything from TeX and LilyPond (see screenshot), through Lua and XML, to NASM and Verilog. Binaries are available for most platforms, as this is a long-established project, though surprisingly little known. TEA uses several Qt libraries, and can utilise aspell or hunspell for spellchecking duties – relatively minimal requirements for any editor or word processor. The first thing you’ll notice is, in addition to conventional horizontal tabs for multiple files, vertical…

Adventure games predate the home computer – both as command line software on the mainframe and paper-based role playing games (RPG) – but they really came into their own in the PC era, with some excellent Dungeons & Dragons-inspired titles. Online versions with thousands of players have stretched the genre, but a great way to go back to basics is to use RPGBoss to create your own. RPGBoss is a cross-platform RPG creator, written in Java and licensed under the AGPL3. The real advantage with Java software is that you can just download the software and run it anywhere (it works with OpenJDK as well as proprietary Java). That said, we ran into the usual display weirdness we often encounter when a Java GUI tries to make sense of living…

Got a deal you think we should list? Whether you’re a hosting firm or a happy customer who wants a favourite provider listed, drop us a line with the details! linuxuser@imagine-publishing.co.uk Dedicated server listings Dedicated and Shared server listings Sponsorship opportunity Bring attention to your brand by sponsoring this section. Contact Luke Biddiscombe on +44(0)1202 586431 GET YOUR LISTING HIGHLIGHTED! CONTACT LUKE luke.biddiscombe@imagine-publishing.co.uk +44(0)1202 586431…

YOUR BONUS RESOURCES ON FILESILO THIS ISSUE, FREE AND EXCLUSIVE FOR LINUX USER & DEVELOPER READERS,YOU’LL FIND THESE GREAT RESOURCES… » Four latest distros, including the newest Ubuntu and its MATE respin for the Raspberry Pi 2. » 20 excellent FOSS packages, including everything in our reviews section plus the tutorial tools. » Watch The Linux Foundation, Red Hat and Raspberry Pi video guides, tutorials and webinars. » Code and assets for this issue’s tutorials, including everything you need for the Pygame Zero game. 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 library Updated continually with cool resources Lets you keep your downloads organised Browse and access your content from anywhere No more torn disc pages…

Richard Hillesley writes about art, music, digital rights, Linux and free software for a variety of publications When Edward Snowden joined Twitter, he gained over a million followers in one day. He is notorious to some, a hero to others, and yet his greatest contribution has been to reveal the extent to which hacking, in its pejorative sense, is the preserve of government agencies. These agencies claim to be working for ‘our own good’, but are instead busy setting malign standards for everyday surveillance of our citizenry. The pejorative use of the word ‘hacker’ probably originated in the tabloid coverage of the exploits of Kevin Poulsen (who hacked his way into the US Department of Defense’s ARPANET, the precursor of the Internet, when he was 17 and was later labelled…

Buyers for the UK Government have signed a commercial agreement with Collabora Productivity that will see open source productivity software used on desktops, mobile devices and cloud servers, in a bid to save money on proprietary equivalents. Set up to offer LibreOffice products to enterprise users, Collabora is shortly to launch a cloud-based, browser-accessible version of the package dubbed CloudSuite. This, and a customised version of LibreOffice created specifically for governmental use – GovOffice – will be available to all non-profit-making governmental organisations. “Moving to the cloud, adopting open IT standards and saving the taxpayer money are three key Government objectives achieved by today’s agreement,” claimed Michael Meeks, Collabora general manager. “Collabora will work with The Crown Commercial Service to raise awareness of the benefits of the Open Document Format…

Microsoft’s Mark Russinovich has placed a call-out for Linux professionals to send their CVs to the company, as his Azure cloud computing division eyes expansion. Microsoft has traditionally competed against open source software in general and Linux specifically, with a series of leaked memos in October 1998 – known as the ‘Halloween Memos’ – proving particularly aggressive. In recent years, however, the company has revised its stance. Speaking during a keynote at All Things Open, Azure chief technology officer Russinovich pointed to considerable growth in the use of Linux on Azure and his company’s need to support this. Jokingly asking any Linux experts in the crowd to pass up their résumés, Russinovich claimed that the company is eager to fully support the open source community – a far cry from…

Atlas is HashiCorp’s only commercial product, funding its eight open source projects. Mitchell tells us that Otto to Atlas is like Git to GitHub – it gives you a core workflow, all the primitives, a lot of the complex logic. Eventually, it will give you a full UI to Otto. Atlas will also be the collaboration platform for Otto, checking that nobody else is deploying a particular application at the same time as you, and enabling you to control which applications people can deploy, and even the times at which they can deploy them. Atlas will also be able to run a lot of the Otto commands for you, enabling you to offload activities and, for example, close your laptop while an otto deploy is running.…

Jon Masters is a Linux-kernel hacker who has been working on Linux for some 19 years, since he first attended university at the age of 13. Jon lives in Cambridge, Massachusetts, and works for a large enterprise Linux vendor, where he is driving the creation of standards for energy efficient ARM-powered servers “Linus Torvalds announced the release of version 4.3 of the Linux kernel, noting that things had seemed to be a bit busy with fixes towards the end of the development cycle, but that “doing the actual numbers shows that that really was just my subjective feeling, probably due to the kernel summit and travel back home from Korea”. The latest kernel includes several exciting new features – the PIDs controller and user space page faults are among them…

Agile enlists clear guidelines about software development processes, but sometimes they prove insufficient for the needs of modern organisations. Let’s take a look at a few simple tips and tricks to help you implement DevOps principles while staying within the Agile framework. Product backlog: A simple way to enable better communication among teams is to add extra fields related to different teams – such as development, testing, infrastructure – in the product backlog. This makes sure everything is documented and there is minimal scope for miscommunication. Scrum of scrums: Scrums are an integral part of Agile methodology. A meeting of scrum masters of different teams, ie the scrum of scrums, can make sure people from different teams are in sync. Done definition: Adding operations-related items to the done definition of…

We’ve talked about how easy it is to create a Docker container for applications and deploy the container. Let us now create a container from scratch to understand the steps involved. As an example, let us create a container for MongoDB, an open source cross-platform NoSQL database, used very frequently by enterprise applications. To start, create a file named as Dockerfile in the directory where you want to create the image: Then open the file in your favourite editor and start adding the instructions. First, set the base image as Ubuntu using FROM ubuntu:latest. Then declare the maintainer of the Dockerfile: Let’s now complete the installation prerequisites: Then install MongoDB: MongoDB also requires a data directory. Create it using: Finally, expose the relevant port from the container to the host…

It would be useful to know how Perl deals with files and directories. Download and inspect find.pl, which shows the implementation of find.c in Perl. As usual, the Perl version uses fewer lines of code than C to do the same task. As Perl has many modules, it is recommended to use one when it helps you do your job. Nevertheless, this implementation does not use any Perl modules in order to be closer to the C implementation. Each time find.pl discovers a new directory, the directory is added to an array in order to process it later on – a very clever approach, indeed. The program matches the pattern, which is the second command line parameter of the program, against the current filename. If it is a match then…

As it is always good to know that you have many alternatives for doing systems programming, another example in a different programming language will be presented; this time it will be Go. Go has many packages that can deal with files and directories that will make you write less code, which also means fewer bugs. The presented program (walk.go) implements the core functionality of find.c – which is traversing a directory structure and visiting all its directories and files. The logic is more or less the same as in find.c. It is interesting to notice that there are many lines of code for error checking – when writing systems software it is truly important that the programmer is checking the return values of all functions and making sure that everything…

Compilation is an important aspect of the software development process and compilers are extensively used to create executables whenever we are working on huge code base. In this tutorial, we take a look at the compilation process and how to use popular compilers (GCC for compiling C programs and G++ for compiling C++ programs). We also explain compiler optimisation and learn how to use various optimisation levels that will significantly improve the performance of our programs. GCC and G++ are the most widely used compilers, partly because of the fact that both of these happen to be open source compilers.…

KRunner is a handy tool for launching commands. Besides running Linux shell commands, KRunner instantly searches for GUI applications and offers all matches as you type. Then, it looks up system settings entries, Plasma widgets and folder names as well. For instance, if you type ‘music’ or ‘play’, KRunner will show all media players capable of music playback, your default music folder, the music plasmoid and also related sound settings. KRunner can also be used as a search tool alongside Baloo5 (both share the same engine), as it displays the documents whose names match your entry. Of course, this is all expected, but let’s add some magic. KRunner can do web browsing! Type your favourite web address starting with ‘www.’ and select the search result – the address will be…

Resources MonoDevelop monodevelop.com Working with GTK is a pain: its handle-function-driven coding paradigm might have looked cool in the time of Palm OS, but it looks hopelessly dated now. Vala attempted to improve the situation by providing an object-oriented wrapper for most GUI classes. This led to more compact code, but it’s miles away from true RAD (rapid application development); seeing your user interface as you work on it is a true productivity booster. Visual Basic was always a leader in this respect. The very first version of the product ran under DOS, but it did not skimp on providing a WYSIWYG-GUI editor. Even though Mono contains a runtime emulation for Microsoft’s Windows.Forms namespace, MonoDevelop’s WYSIWYG editor is based on GTK. Since that framework is just as cross-platform as Mono,…

This part will talk a little bit about how Python implements hash tables, which are called Dictionaries. The following Python code illustrates the way Python deals with dictionaries: The first line defines a new dictionary variable named Hash. The next three lines put data into the dictionary. The last two lines print all values found in the hash dictionary. More or less, the Python approach is similar to both Perl and AWK approaches and you should have no problems understanding it.…

In situations where Pygame is used boilerplate and all with young people, great results can also be achieved (see Bryson Payne’s book), but Pygame and Pg0, despite their use as powerful educational tools, are also good for creating games for coders no matter what stage of learning they are at. Great games are all about the gameplay, driven by powerful imaginations generating images, animations, sounds and journeys through game worlds. Good frameworks open up this creative activity to people who are not traditional learners of programming, which is an area where Python has long excelled.…

“There may be many times when you want to use multimedia within your interactions with an end user. You may want to display a really interesting bit of video or have your program chat audibly with the user. In both of these cases, there are lots of modules available to enable you to work all of these other forms of data. However, a truism about programming is to ‘find the easiest way to do something’. Here, this means if you can find a single framework that provides everything you need, you should probably use it. This is the role that the module pygame fills. This isn’t to say that you will be able to do everything you may want to do using pygame, but you should never undersell the worth…

Welcome to our latest FUZE BASIC tutorial. If you haven’t already gotten hold of this programming language, FUZE BASIC can be downloaded for free for both Linux and Raspberry Pi users from fuze.co.uk/getfuzebasic. So why should you bother to learn BASIC? Well, BASIC (Beginner’s All-purpose Symbolic Instruction Code) was instrumental in starting the computing revolution back in the Seventies and Eighties. Thirty years on and BASIC, or in this case FUZE BASIC, presents a modernised version of the original classic. Now with updated commands for advanced sprite and media handling, the removal of goto and gosub commands as well as line numbers, and the fact that on modern hardware it races along, it still remains one of the easiest introductions for users wanting to jump into the world of programming.…

Sometimes you don’t realise you need something until you discover it and start using it. FLoM, which has just made the small leap to version 1.0.0, is one such useful tool. It serialises your processes to enable scripts and shell commands to be synchronised – either locally, in a single user system, or over a network. If you’ve come to the limits of what can be done by command concatenation and creative use of sleep or cron, this could be what you need. Installation is the usual configure and make, then make install with root permissions – there are no library dependencies to hunt down. Just as the nice program enables you to set priority, FLoM lets you run a command with a specific serialisation. Getting started is easy –…

Amid all the glamour of recent developments in containers and hardware-assisted hypervisors, the humble QEMU – which can emulate many architectures entirely in software, through dynamic binary translation – is almost in danger of being overlooked.The recent release is a good excuse to remind ourselves what this wonderful piece of software will do. Unlike container solutions, which enable you to share your (host) operating system’s kernel with the guest OS, QEMU emulates an entire processor and system architecture. This is great for everything from developing for Raspbian to testing compiles across multiple architectures. It’s also handy for playing old games on FreeDOS, or other old and neglected platforms. Asto speed issues, in most installations QEMU defaults to Linux’s KVM, where available, and the benchmarks show it to be pretty speedy.…

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…