Innholdsfortegnelse for No. 162 i Linux User & Developer

This issue » Free live-booting DVD with 6 distros » Repair and recover broken filesystems » Harden your home/office network security » Learn pro development skills for Python Welcome to the latest issue of Linux User & Developer, the UK and America’s favourite Linux and open source magazine. This month, we’ve created a special covermount DVD for you containing six distros that can, between them, help you out in some of the most common (Linux-specific) situations. Need to re-partition one of your drives? There’s GParted Live. Trying to fix a faulty filesystem? Just run SystemRescueCd. Deploying multiple machines on your network? Give Clonezilla a whirl. Strengthening the security on said network? Use BackBox. We’ve considered those times when you need these solutions but, importantly, might not have access to the…

1 Notifications Plasma 5.6 brings with it a vastly improved device notification system, changing code which has stood untouched since Plasma 4.7 to improve the appearance and usability – in particular when unmounting a USB mass storage device for removal – meaning an end to annoying ‘orphan’ error message pop-ups. 2 Unity Launcher support Unity may be divisive, but it’s also widespread. “If there’s an API or library that works and is widely adopted, we’re happy to pick it up and add support for it in our software stack,” explained developer Kai Uwe. 3 Media applet The KDE Plasma 5.0 release included a media controller applet, but only for selected software. With Plasma 5.6, the MPRIS specification has been implemented to allow control of software from VLC through to Spotify…

With the Budgie desktop and Raven notification centre, what are your aims? I wanted something that was a modern take on the traditional desktop, but not too traditional. Right now, I’m going through a few different distributions and desktops just to see if I’m really doing the right thing. While a lot of them are very, very pretty, they’re too much in your face – ‘Would you look at all the work we’ve done down on this panel? And Jesus would you look at the gradients!?’ To me, that’s completely distracting – I want something that’s pretty but functional, so I can just get on with my job while the operating system gets out of my way. At the end of the day, the only purpose of an operating system…

“Where there’s a problem, and a general desire by a well-funded organisation to use commodity storage media, there comes a solution” Linus Torvalds finally released Linux 4.4, noting that only a small number of additional patches had landed with fixes following the many release candidate kernels, towards the very end of the development cycle. A last minute fix that “unbreaks” the x86-32 “sysenter” ABI (the interface through which userspace on x86 systems generally makes a kernel system call) was needed because Android systems don’t avail themselves of the conventional VDSO (Virtual Dynamic Shared Object) pseudo-library interface provided by the kernel that all other Linux distros are generally using – developers usually prefer their Android widgets acquired over the holidays to work with upstream kernels (if they are fortunate enough to…

1 SCAPY Scapy is a CLI tool written in Python. It can be used to forge or decode packets and then send them out in the network. 2 KISMET Kismet is a network analyser, packet sniffer and intrusion detection system for 802.11 wireless LAN. 3 WPSCAN WPScan is a black box WordPress vulnerability scanner. With it , you can check vulnerabilities in third-party themes, plugins, etc. 4 OPHCRACK Ophcrack helps you crack Windows passwords by using LM hashes through rainbow tables. 5 BEEF BeEF stands for browser exploitation framework. You can use it to assess the actual security posture of a target environment by hooking in web browsers and using them as client-side attack vectors. 6 SQLMAP Sqlmap automates the process of detecting and exploiting SQL injection flaws to fingerprint…

Tails is a live operating system focused on privacy. “Tails” itself stands for ‘The Amnesic Incognito Live System’. Amnesic here implies that there is no longterm memory storage and everything is forgotten. Incognito implies that identity is concealed at any point in time. HOW DOES TAILS WORK? As a live operating system, Tails, once it is booted from the DVD, runs entirely in your computer’s memory – ie RAM. Nothing is written to the hard disk, making it difficult for anyone to find out any trace of your activity. But what if there is a swap space configured on the system? Not to worry; Tails is configured with special care so that it deliberately doesn’t use the computer’s hard disks, even if there is some swap space. This means that…

If you want to continue tinkering with threads, it is important to understand exactly what a process is and how it differs from a thread. A process is an execution environment that contains instructions, user-data and system-data parts, and other kinds of resources that are obtained during runtime. On the other hand, a thread is the smallest unit of execution schedulable by the process scheduler of the operating system. Each process is started with a single thread but it is allowed to create additional threads. Threads are sometimes called lightweight processes. A process creates a thread; apart from its own flow of control and stack, a thread shares everything with the process that created it: global data and other resources such as file descriptors and the current working directory. So,…

Perl uses the threads module to provide support for threads. The thrPerl.pl Perl program demonstrates how you can use threads in Perl. The first part of thrPerl.pl verifies that your Perl interpreter supports threads – if not, you might need to recompile it. The create() method creates a new thread and calls the desired function. Once again, the sleep() call is necessary because it gives time to the two threads to finish their job because if the program ends too early, the two threads will not have enough time to print the desired messages. The Perl thread implementation tries to be difficult to misuse but it is slow. Each thread uses its own Perl interpreter so Perl threads are called interpreter threads. As you can understand, they behave more like…

Resources MonoGame monogame.net Graphics programming is a great example of the old adage of history repeating itself: initially, developers created the entire rendering pipeline by hand. Then, advances in GPU hardware introduced the world to the concept of the fixed function pipeline: a system that handles the various graphical transformations automatically according to predefined parameters. Even though this new design pattern afforded a significant increase in performance, developers were left longing for the additional flexibility provided by being able to manipulate the individual steps of the graphics pipeline. GPU vendors solved this problem by introducing the programmable graphics pipeline. It differs from its predecessors in that the “vertex transformation” and “fragment colouring” steps are now handled by programs called shaders. This means that developers can influence the handling of the…

Resources Text editorGCC compilerPython compilerGo compilerSwift compilerRust compilerR softwarePerl interpreter Random numbers are useful in many different areas, including but not limited to sampling, numerical analysis and computer programming. This tutorial will use random numbers to generate random strings that can be used for creating secure and difficult-to-guess passwords. Additionally, you can concatenate the generated strings to produce random text that can be used as input for testing programs and the effectiveness of algorithms. Usually, a programming language can generate pseudo-random numbers. A pseudo-random number generator approximates the properties of a random number generator. Most of the presented code will be in C; you will first generate random numbers and then learn how to create strings from random numbers. Additionally, you will learn how to generate random numbers in Perl,…

Rust is another modern and very capable programming language with great potential –it claims to prevent segfaults, for one thing, and guarantees thread safety. The Rust code for producing random strings with eight characters is the following: The ‘random’ folder in your tutorial resources pack contains the various files for our Rust implementation. It shows the Rust project in action as well as the way to create the project using Cargo, which also allows you to build and manage Rust projects. The good thing with the Rust code is that you do not need to call a function for setting the seed, and it offers an easy way for defining the range of the numbers it must produce.…

It’s a plastic ring with LEDs around the outside, and it rotates at 500 rpm, 8.3 times per second Illusion To create a steady image, Evan and Kyle need to spin their 60-LED arc at 500 rpm. At this rate, there is no horizontal drift in the image. Frame A six-wire slip ring connects the frame to the power, clock and data wires of the spinning LED strip, which is mounted with 3D-printed couplings. FPGA While the Pi is used to drive the data feeding the LED strip, a Cyclone IV FPGA is used to regulate the DC motor so that it spins consistently. LEDs The DotStar APA102 LEDs update quickly as you can send data at any rate, which is then handled by the embedded LED microprocessors. Components list…

If you are going to be doing a lot of soldering then it’s probably worth getting a temperature-controlled soldering iron What you’ll need Raspberry Pi Zero microUSB power supply Soldering iron and solder Pi Zero adaptor bundle Monitor, mouse and keyboard (optional) USB Wi-Fi or USB Ethernet adaptor (optional) USB hub (optional) So you’ve picked up one of the tiny yet powerful Zeros, but before the coding fun can begin, you need to get more familiar with it. Don’t worry; we’ll walk you through the Raspberry Pi Zero, the required cables, how to prepare a NOOBS SD card, and how to solder the GPIO header onto the Pi. Once the Pi is working and booted we’ll show you how to get it working on Wi-Fi through the Raspbian user interface.…

You should try out at least one new programming language each year, and if you’ve yet to find 2016’s candidate, take a look at Picat, a rule-based multi-paradigm declarative language, which supports constraint logic programming (CP). Picat differs from logic programming predecessors like Prolog in having good support for functions, and adds many features which are implied by expanding the picat acronym: Pattern-matching; Imperative; Constraints; Actors; Tabling. It’s barely two years since Picat 0.1 had a stable release, so the maturity and stability of Picat are fine achievements. Naturally, it is not yet blessed with much in the way of library support, although what there is, such as JSON encoders, is useful. Development is steady, and installation is simple thanks to a statically compiled binary (weighing in at a relatively…

Live-booting is simply the process of loading up an operating system straight from a disc or USB stick. It’s incredibly handy in cases where the operating system installed onto your computer is broken in some way and unable to boot – you can, for example, use this disc to live-boot a distro like SystemRescueCd and then begin diagnosing the problem. To live-boot from your DVD, simply pop it into your optical drive and then power up your computer. You then need to access the boot menu that we’ve set up – on many computers you’ll need to tap the F12 key once you’ve powered-on the PC and before your main operating system kicks in. The correct key for your particular computer should be displayed on-screen during boot. You’ll then see…

“Linux on the PS4 actually makes a lot of sense, more than it ever did on any previous game console” Noted engineering team ‘fail0verflow’ has successfully booted Linux on Sony’s PlayStation 4 console, bypassing the protections the company has put in place against running third-party software and potentially opening the doors to novel uses for the device. Sony’s PlayStation family has a long history with Linux. The company released an expansion kit in 2002 which turned its PlayStation 2 console into a fully-fledged Linux personal computer, and its successor the PlayStation 3 launched with ‘OtherOS’ support for booting a number of Linux distributions. The company soon began worrying that developers would find a way to use the OtherOS support to play illegitimately copied games, however, and removed the feature in…

“The success of Linux is built on its status as a commodified kernel, and the reciprocity that the GPL encourages between individual and corporate contributors” The importance of the ongoing legal dispute between Cristoph Hellwig, Linux kernel developer, and VMware, the virtualisation company, cannot be underestimated. At issue is the right of an individual developer to license their code as they see fit, with the expectation that the terms of the licence will be honoured. At stake are the viability of free software and the GPL, and an industry built on the flexibility and accessibility of FOSS. Hellwig’s complaint against VMware is that Linux kernel code written by himself and other kernel contributors is incorporated in the proprietary elements of VMware’s ESXi hypervisor, and that VMware is refusing to comply…

Born on the 28th of April 1973 in Konstanz, West Germany, Ian Murdock is best known for founding the Debian Linux distribution – named for himself and then-girlfriend Debra Lynn, giving DEB and IAN – in 1993. The Debian project has stated that “Ian’s sharp focus was on creating a Distribution and community culture that did the right thing, be it ethically, or technically. Ian’s dream has lived on, the Debian community remains incredibly active, with thousands of developers working untold hours to bring the world a reliable and secure operating system. The thoughts of the Debian Community are with Ian’s family in this hard time.” Murdock’s death followed a stream of posts to his personal Twitter account claiming that he had been hospitalised following abuse from his local police…

The Automotive Grade Linux (AGL) project has announced four new members, all heavy-hitters in the vehicle industry: Subaru (a subsidiary of Fuji Heavy Industries), Mitsubishi Motors, Mazda Motor Corporation, and Ford Motor Company. “We are excited to welcome Ford, Mazda, Mitsubishi Motors and Subaru as the latest automotive OEM members of AGL,” said general manager Dan Cauchy. “In order to keep up with consumer demands for a modern infotainment system, car makers realise that they need to adopt an open source software development process to gain a competitive edge. We are glad to see the increased commitment being made by the automotive industry to advance AGL as the de facto standard for the connected car.” The companies join more than fifty existing members including Nissan, Jaguar Land Rover, and Toyota,…

When we spoke to Ikey, he revealed much of the fascinating back-story to the long and surprisingly troubled development of the Solus Project. From the work he began on the Linux Mint Debian Edition and the origins of SolusOS, to the EvolveOS name change and legal battle with, of all people, Ordnance Survey, to the coup staged against Ikey that resulted in the entire project going on a hiatus, you can read the full, uncut version of this interview at bit. ly/1PazsGO. If you’re interested in following Solus Operating System this year as work begins on the separation of the main repository into hardware-specific layers – a game-changing ambition in terms of traditional distro development – just head across to the official blog page for all the latest news: solus-project.com/blog…

If you have ever used a shared computer or borrowed someone else’s computer, it’s likely that you had some worries when you were finished – ‘Did I log out of all of my accounts? What if there is a key logger installed? Did I forget to clear the browser cache?’ Even aside from those concerns, using your own computer isn’t 100% safe, and there are still understandable worries around privacy. There can be cyberattackers trying to hack into your computer to get financial or other information without you even knowing about it. One good solution to such situations is using strong encryption while accessing the internet and discarding the operating system and all its contents after your work is done. Let us introduce you to live CDs. Installing an operating…

GParted is a lightweight operating system created to help you manage partitions on hard disk. With GParted, you can resize, copy, and move partitions without data loss. This way you can create space for new operating systems, reorganise disk usage, copy data residing on hard disks, and mirror one partition with another – all with great ease. It is important to note here that GParted Live is based on Debian Linux, but it is also available as a standalone application for various platforms like Mac, Linux, and Windows. Here we will focus on GParted Live only. CREATING A PARTITION To see GParted in action, let us start with the basic step of creating a new partition. As soon as you boot GParted from the live DVD, you’ll see the GParted…

Tails supports the Tor and I2P networks for online privacy. Though both of them are supposed to protect your identity online using cryptographic methods, there are several differences in their respective approaches to this question of privacy. Tor takes the directory-based approach, providing a centralised point to manage the overall view of the network, as well as gather and report statistics, while I2P uses a distributed network database and peer selection. Tor provides better anonymous access to the open internet while I2P provides a more robust and reliable network within the network layout. Tor also has a larger user base, with more volunteers around the world. Also, beware that your ISP can see that you’re using Tor or I2P (though they cannot determine the content of the traffic). To hide…

The thrGo.go program presents a complete example in Go – a very modern and capable programming language – so execute that script now. Go uses the notion of the goroutine, which is a lightweight thread of execution. As you can see in thrGo.go, you execute a function in a goroutine by using the go keyword, which will be executed concurrently. The thrGo.go program executes the printMessage function in two ways: directly and as a thread. The direct call is obvious, whereas the thread version is using the go keyword. This is a very practical and smart approach indeed!…

Resources Blender blender.org Images are a great way to convey information, but animations take this a step further. With animations, you can tell your whole story in a quick and easy-to-grasp way to your audience. Before we move forward to learn more about animations and tools to create them, it is important to understand that from a technical standpoint, animations shouldn’t be confused with videos – videos are generally shot using cameras and then presented to the audience with some sort of editing if required. Animations, on the other hand, are created from scratch, with computer technology if the animation is 3D. However, you can also find animations created on top of videos. In this tutorial we will learn one such tool that will not only help you create 3D…

Resources MariaDB bit.ly/1l6olCB MariaDB repository bit.ly/1RDTBYp For those who believe in open source software, and prefer not to use software from big corporations, MariaDB is an excellent database choice. It’s the same as its predecessor, MySQL (now owned by Oracle), so if you learn one, you are, by extension, simultaneously learning the other. This article will teach you the basics to get started with MariaDB. If MariaDB is not already installed on your server, you can download it from MariaDB’s site or use MariaDB’s yum repository. Connecting to MariaDB We’ll use the mysql client to interface with MariaDB. From the command line of the server, enter the following: The --user option is for specifying the user name. You should create and use another user, but to keep this article simple…

Go is a modern and very efficient systems programming language that allows you to produce random numbers and strings with the help of packages. Execute the ranGo.go script: As you can see, Go uses the math/rand package for generating random numbers. Once again, you need to provide a seed to the random number generator, which in this case is the following: The value that the previous command produces is the UNIX epoch time and has the following form: Should you wish to generate more secure random numbers in Go, you should use the “crypto/rand” package, which implements a cryptographically secure pseudo-random number generator. Find out more at: golang.org/pkg/crypto/rand.…

While you could simply write some code that runs on a standard computer and a standard Linux distribution, this is usually not optimal when trying to handle all of the data processing that a robot needs when dealing with events in real-time. When you reach this point, you may need to look at a dedicated operating system – the Robot Operating System (ROS). ROS is designed to provide the same type of interface between running code the computer hardware it is running on, with the lowest possible overhead. One of the really powerful features of ROS is that it is designed to facilitate communication between different processes running on the computer, or potentially over multiple computers connected over some type of network. Instead of each process being a silo that…

You can identify sources based on their frequencies With such a small physical footprint and a low power requirement, the Raspberry Pi is a perfect platform that you can use to build your own scientific equipment. We will look at how you might be able to use your Pi to monitor and analyse sounds in your environment. This is useful if you are listening for particular sounds. You need a Raspberry Pi, some kind of USB microphone, and some kind of USB wireless connection if you want to check on the monitoring process remotely. The specifics of the hardware are up to you, but you should be able to use almost anything that is available to you. This article will focus on the Python code that you will need in…

What you’ll need Pi Zero USB portable power supply USB Wi-Fi dongle Micro USB convertor Hat or other clothing of your choice Old LED Christmas lights Wearable tech is an ever-growing industry, bursting with smart watches, fitness gadgets and pulse-rate necklaces. For many, this technology is nothing new; enthusiasts have long created their own wearable versions. Clothes that light up on contact, masks that change voices and weapons that glow! In this tutorial you will use your old Christmas LED lights, Python and the Pi Zero to modify a hat that lights up when you receive a specific tweet from your timeline. The Pi Zero is the perfect size and can be embedded into the clothing. You can customise the project for your own wearable tech, perhaps shoes that light…

You know those pieces of software that you surprisingly come to find as totally indispensable? The ones that once you discover, you’re always telling people about, but once upon a time you had somehow never heard of yourself? If you spend any time needing to convert text documents between formats, Pandoc could be about to become just such a ‘How did I ever manage without it?’ utility. Pandoc will take files written in Markdown, reStructuredText, textile, HTML, DocBook, LaTeX, MediaWiki markup, TWiki markup, OPML, Emacs Org-Mode, Txt2Tags, docx, ODT, EPUB, or Haddock markup and convert them to various TeX, HTML, Office or other formats, as well as custom formats via Lua extensions to Pandoc. Pandoc-citeproc provides automatic citations and bibliographies. A read through the notes on recent releases will show…

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…

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…

Package manager apt, as featured in Debian, Ubuntu, and Linux Mint, has received a serious performance boost in its latest release, thanks to the work of developer Julian Andres Klode. Klode discovered that apt’s handling of Pdiffs, the files used for differential files applied to packages, sources, and other files in an apt archive, was far from optimal despite the introduction of performance-boosting read buffering in December of last year. Discovering the problem in the software’s ReadLine method and working through a series of modifications, including modifying the buffer length and removing the use of the memmove function, Klode worked on a fix which has had a dramatic effect. “I measured the run-time of apt-get update, excluding appstream and apt-file files,” he explained in a blog post on the changes.…

Top 10 (Average hits per day, 15 December – 18 January) This month The traditional end-of-year slowdown has hit, but the new year has still had some impressive new releases Highlights KaOS 2016.01 Built around the latest stable KDE Plasma release, the new KaOS release includes new widgets such as the Colour Picker and Disk Quota, restores support for legacy system tray icons, and shifts to Noto as the default font. Linux Mint 17.3 KDE, Xfce A two-for-one release, the Linux Mint community celebrated the new year with KDE and Xfce spins of the distribution boasting support for UEFI BIOS, though not Secure Boot, and support through to 2019. Tails 2.0 RC1 The first release candidate for the privacy-enhancing Tails 2.0 brings with it a switch to Icedove for mail…

“It is not enough to compress the text; you should also be able to decompress it and bring it back to its original state” The subject of this month’s column is text compression. The purpose of compression is to make a given amount of data take up less space. There are two kinds of compression: lossless and lossy. The lossless compressing perfectly reconstructs the original data whereas lossy compression reconstructs an approximation of the original data in order to improve the compression ratio. As this column is about compressing text, lossless compression will be used. The benefits you get from compressing text and other data are less disk space and faster file transfers on a network. The disadvantage of compression is that in order to use a compressed file, you…

“You have to be realistic in supporting yourself,” Ikey explained, “and, let’s be honest, Solus is a fucking expensive project to run. In the last year alone it cost me several thousand pounds… To avert that with Solus 2, people who are supporting us on Patreon and things like that are going to get early access to the builds. We’ll be doing the public milestones and everyone can use those. For people who are supporting us we’ll be giving them a dedicated email address where they can get support from us, and we’ll be announcing up-to-the-minute releases for them so they can be keyed into the release immediately.” So if you use Solus, why not help pay the bills and head to Patreon?…

Resources Text editorGCC compilerGo compilerPython interpreterPerl interpreter Put simply, threads are smaller and lighter entities than processes and programs. Threads are created by processes and have their own flow of control and stack. A quick and easy way to compare a thread to a process in your own mind is to consider a process the running binary file and a thread a subset of a process. Both their advantages and disadvantages can be found in their lightness; it is the job of the developer to use them appropriately and efficiently. This tutorial will present the system calls and explain the techniques that will allow you to deal with threads. Programming threads is a difficult and challenging subject; however, this tutorial will try to present the necessary information in a simplified…

Although Python has two modules for thread manipulation, the threading module is much more powerful than the thread module. The threading module uses the Thread class that implements threading and offers the required methods. You can find a complete Python program that uses the threading module in thrPython. py. You start a new thread using the start() method of your object that is based on threading. Thread. Although this approach is simple, the Go version is still relatively simpler.…

Another slicing tool Blender offers is the Knife. It differs from Bisect in the way that it lets you select where the new edge is created. Rather than pre-selecting features and then drawing a line to cut through all of the features at once, you are able to select individual features as you go. To use Knife, go into Edit Mode and under the Tools tab on the Tool Shelf on the left, select the Knife option. Your cursor will turn into a knife shape and you can then select where to cut simply by left-clicking with your mouse.…

Resources FreeRdp 1.0.1 bit.ly/1lzjAl7 Rookit Hunter bit.ly/1Vb7xqz Chkrootkit chkrootkit.org Information Security is such a leading and demanding area of expertise. Plenty of books out there will tell you what to do to defend your own systems against the bad guys, but no matter how many steps you take to prevent your systems from being hacked, every now and again security-related incidents are reported to you. It does not matter whether it is an email message or an odd entry in a log file; you are obliged to analyse each incident and come to a conclusion: is it a false positive or has someone already gained unauthorised access to your computer or system? This is a difficult task most of the time, but cheer up! Luckily for you, once in a…

Now that Apple has made Swift an open source project, you can use Swift on a Linux machine to generate random numbers. Take a look at the source code of ranSwift.swift. The output that ranSwift.swift produces should be similar to the following: As you can see, you can easily convert the output of ranSwift. swift into a string using the same approach with the one used in genString.c. Please note that the "import Glibc" code allows you to use existing C functions in your Swift code – it this case it is needed for calling the random() function.…

The underlying philosophy of Unix is to build small, specialised programs that do one job extremely well. You then chain these together to build more complex behaviours. There is no reason why you shouldn’t use the same philosophy within your Python scripts. There are several utility programs available to use with very little work on your part. The older way of handling this was through using functions like popen() and spawnl() from the os module, but a better way of running other programs is by using the subprocess module instead. You can then launch a program, like ls, by using: This gives a long file listing for the current directory. The function run() was introduced in Python 3.5 and is the suggested way of handling this. If you have an…

While Django is one of the most popular frameworks around for doing web development, it is by no means the only one around. There are several others available that may prove to be a better fit for particular problem domains. For example, if you are looking for a really self-contained framework, you could look at web2py. Everything you need to be able to have a complete system, from databases to web servers to a ticketing system, are included as part of the framework. It is so self-contained that it can even run from a USB drive. If you need even less of a framework, there are several mini-frameworks that are available. For example, CherryPy is a purely Pythonic multi-threaded web server that you can embed within your own application. This…

For a lot of scientific problems, you need to play with your data in an interactive way. The original way you would do this was to use the IPython web notebook. This project has since been renamed Jupyter. For those who have used a program like Mathematica or Maple, the interface should seem very familiar. Jupyter starts a server process, by default on port 8888, and then will open a web browser where you can open a worksheet. Like most other programs of this type, the entries run in chronological order, not in the order that they happen on the worksheet. This can be a bit confusing at first, but it means that if you go to edit an earlier entry, all of the following entries need to be re-executed…

The whole point of using a Raspberry Pi and building your own environmental monitor is to have something that can operate independently and away from any available amenities. This is fine if you are only interested in recording and storing the data that you are collecting to look at it later in an offline fashion. But what if you want to check in on your monitor and see what it is actually measuring? In this case, you should be able to connect some type of USB device that allows it to connect to the internet. This could be as simple as a Wi-Fi dongle, if you have a Wi-Fi network nearby, or something that operates over the cellular networks for more remote access. Once you have your Raspberry Pi connected…

The Need Awakens Hi there. I’ve been struck with inspiration and I’m hoping you can help me out… Someone bought me a Raspberry Pi 2 for Christmas and I also saw Episode VII over the holidays – now I want to build a Star Wars robot! Any ideas where I can start? I’ve used the original Model B before for file and media server projects, but I haven’t tried my hand at robotics yet. Hope you can help. Cat Hi, Cat. Sounds like an awesome goal – we’d love to help! First things first: if this is your first time putting a robot together, it’s probably worth having a test run using a simple kit. The CamJam EduKit 3 (camjam.me/?page_id=1035) is a great place to start because it only costs…

01 Grab a new ISO Either use the hyperlinks on this issue’s DVD to navigate to a distro’s website or search online for the distro you want. Download the ISO file from the website. If you’re not sure if you need a 32-bit or 64-bit version, go with the former to be safe. 02 Open or install Brasero Brasero is the most popular open source disc-burning utility. If it’s not already installed on your distro, locate it in your distro’s repository and install it. Then open the program and select ‘Burn image’ from the Projects tab on the left. 03 Burn your disc image On the Image Burning Setup menu, click the first box – marked ‘click here to select a disc image’ – and navigate to the ISO you…