Linux FormatMarch 2016的目錄

This issue we asked our experts: This issue we’re looking into hacking secrets, what’s your biggest or favourite Linux secret that you think everyone should know? Jonni Bidwell In the kernel’s menuconfig, if you search for a symbol then press the number corresponding to it in the results, you are taken straight to that option, rather than having to find your own way there. Almost exactly like you’d expect search to work, I know, but until recently this gem has eluded me. Nick Peers A hack of a different sort is this one, which I discovered while I was building a Raspberry Pi Zero-powered AirPlay receiver for MacFormatmagazine. I paired it with a £15 DAC from http://iqaudio.co.uk and the brilliant Pi MusicBox distro - result, stunning sound that’ll blow your…

"Ubuntu, in my mind, is one of the most important distros in the GNU/Linux world. (I say this as an avid Arch user.) Ubuntu has always prided itself as user-friendly, with its simple and intuitive Unity desktop environment. I remember when I first installed Ubuntu (version 9.04), and felt at home with the familiar Gnome 2 desktop. When Unity came out with 11.04, it shook up my world, and I despised the change. Love it or hate it, Unity has become one of the main faces of the Linux desktop, right there with Gnome, KDE, and now Mate. As much as some like to complain about Unity (I’m still on the fence myself), even Gnome’s Activities panel feels an awful lot like Unity’s Dash. In an OS where people get…

We were very pleased with the article about Lua in the last edition of Linux Format [Code Academy, p84, LXF205]. However, we would like to make an important correction: Lua wasn’t created only by Roberto Ierusalimschy (me); it was created by a team formed by Luiz Henrique de Figueiredo, Waldemar Celes, and Roberto Ierusalimschy. Currently I am the chief designer, but all important decisions about the language are still made by this team. Roberto Neil says: Absolutely and for the second time in one letter’s page I apologise for not giving full credit where it’s due. Again, there’s a tendency to think that projects are headed up by a single person or even if that’s not the case to think that they are. Even Linux itself, which owes a lot…

OSCON 2016 O’Reilly has been part of the Open Source community for many years, in fact the first OSCON took place in 1999! For 2016 the popular event takes place in Austin, Texas between May 16-19. Known to be a melting pot of ideas for real-world problems in security, open hardware and much more. OSCON provides something for everyone and covers every level of user and developer. http://bit.ly/OSCON2016 Liverpool Makefest 2016 The début event and surprise hit of 2015 is back and this year promises to be bigger and better! In 2015 Mark Feltham and Caroline Feltham-Keep organised a fantastic event that saw over 2,000 people attend. The last Makefest had a diverse range of activities, including robotics, drones and knitting. There was even a guest appearance of a Dalek…

As expected, since IFMEcan only transcode videos using the H.265 codec it brings up the rear in this test. The application also has a limited container support with the only two options being MKV (default) and MP4. QWinffand VLCboth support a wide number of formats because of using FFmpeg as their back-end, This supports a large quantity of codecs as well as a wide variety of video formats (MPEG1/2/4, DivX, WMV, Theora, etc) and audio (AC3, AAC, FLAC, MP2/3, etc). However, both QWinFF and VLC are limited to converting videos. Then there’s Handbrake which supports the H.264, MPEG-4, MPEG-2, VP8 and Theora video codecs. Unlike some of the other applications, Handbrake can transcode media from several sources of multimedia, such as DVDs and Blu-ray disks that don’t have copy protection.…

There certainly are Linux viruses, and there certainly is Linux antivirus software, but in general there’s still no need for any but the most paranoid home users to use it. This is mostly due to the fact that downloading unsolicited programs from the web is frowned upon in the Linux world. Using your package manager to download software is the preferred way to do things--it verifies the integrity and authenticity of everything it downloads, and you’ll never have to worry about it installing the Ask Toolbar [yet! – Ed]. In fact, the package manager, or rather frequent use of it (with a good backup policy), is the best way to keep your Linux healthy. The major distros are quick to patch against newly discovered security flaws and you should be…

Distributed Denial of Service (DDoS) is probably the least classy method out there for knocking a service offline. It’s also one of the most popular. Ultimately it involves bombarding a site with traffic from lots of different hosts (hence distributed) so that it’s no longer able to serve legitimate requests or just plain falls over. There are tools, such as Slow Loris and the Low Orbit Ion Cannon (LOIC), that you can use to direct the full force of your bandwidth at hosts of your choosing, possibly joining in an effort by like-minded individuals, but we really wouldn’t recommend doing that because it’s against the law. Most DDoS attacks now are carried out by hordes of compromised machines known as a botnet. There is some simple mathematics involved in DDoS…

Serving static web pages from, eg, an Apache installation in Debian with the default settings isn’t likely to cause you any grief. But there’s always room for improvement. Let’s Encrypt (https://letsencrypt.org) now provides free and easy to use SSL certificates so that users can browse your site safely in the knowledge that it’s indeed your website, and that the traffic is encrypted. If you’re handling sensitive data on your site, (eg personal or financial details) then you’ll probably want to pay for at least a domain-validated certificate. But we don’t really solve problems by slapping certificates on them, we can also tweak the cipher configuration so that vulnerable or obselete encryption isn’t used. Adding following lines to the configuration will do this for Apache: This will prevent such attacks as…

SSH woes for sysadmins ‘Roaming’ code found in SSH clients which can expose private keys to malicious servers. A rather obscure but nasty bug came to light in the OpenSSH codebase in January 2016, involving some old functionality which had long been stripped from the server element of the software but which remained lurking in the client side of things. Discovered by Qualys, the code allowed a malicious SSH server in some cases to steal the client’s private keys. This was due to an undocumented feature of SSH: ‘Roaming’ which was intended to ease reconnection of temporarily dropped sessions assuming both sides supported it. All versions of the OpenSSH client from version 5.4 onwards have been affected by this bug, although it was quickly patched after its the disclosure. Adding…

Ahead of next month, I want to quickly add the host running Rancheritself to my infrastructure. Choosing the ‘Add Host’ button brings up a list of cloud providers available to me, but for this local setup I’m going to choose ‘Custom. If I haven’t logged out and back into the UI having set up access, I might get a warning about the IP address being reachable; in this case I can just ignore it. The UI gives me a command to run on the host I want to add to my Rancher infrastructure. In my case, this was: However, the Rancher documentation states that I need to add into that command – for that line above this would be I ran this via my Vagrant SSH session which makes the…

If you’re using a different desktop to Unity then you’ll find working with desktop icons isn’t quite the same experience. For starters, most other desktops include a handy tool for creating shortcuts direct from the desktop’s context menu – just right-click and choose ‘Create Launcher’ if you’re using Cinnamon, Xfce or ‘Create New Shortcut’ in LXDE. KDE Plasma requires you to set things up through its own launcher. Click the KDE button in the bottom left-hand corner of the screen, then locate the application in question through the pop-up menu. Right-click this and choose ‘Add to Desktop. This basically creates an icon widget, which works differently – however, if you’re familiar with Plasma’s other widgets, you’ll have no problems moving, resizing and even rotating the icon using the widget toolbar.…

It may seem strange, but if you’re struggling with start-up issues, you should attempt to take a backup of your hard drive before you perform any repairs – this means if you mess things up completely you can always roll back your system to the state it was in when the start-up problem first manifested itself. Of course, if you’re diligent and you back up your system regularly, you could always simply roll things back now to a working state, although bear in mind there may be data loss involved if your home folder is on the same partition as your Linux installation (as is the case with default Ubuntu installs). You’ll need a suitable backup device – typically a USB-connected hard drive – and a tool that takes a…

Throughout the Gentoo documentation you will see references to atoms. An atom is a package specification, like ‘gimp’ or ‘media-gfx/gimp. When installing files the category part is only compulsory if there are packages with the same name in different categories. You can also specify versions in an atom, which may be useful in places like package.use: The first matches any version of foo , the second only version 1.2.3 , the third matches that version plus any minor revisions - like foo-1.2.3-r1 , while the last one matches anything older than 1.2.4 .…

Our expert Rafeeq Rehman is an author and consultant with interests in emerging technologies, data science, IoT and information security. Hadoop Xxxx Get started with Big Data and Hadoop technologies using Cloudera Due to the massive amount of data collection occurring in ecommerce, manufacturing processes, website clickstreams, IoT and other sources, all types of business are looking for ways to capitalise on this data. This development has created a huge demand for a Big Data science skillset, which has seen more and more people trying to learn Hadoop and other Big Data technologies. However, building a working Hadoop environment isn’t a trivial task and takes significant effort especially for beginners. To solve this issue Cloudera, which is a major player in the Big Data technologies, has created a QuickStart virtual…

Our expert Mihalis Tsoukalos is a DBA, programmer, mathematician and Unix admin. In his spare time he likes to write technical articles and fight crime. The biggest surprise of the Apple Worldwide Developer Conference 2014 (WWDC) was the announcement of Swift, a new programming language that will – eventually – replace Apple Objective-C. The biggest surprise of WWDC 2015 was the announcement that Swift was to become an open source project. This tutorial is a gentle introduction to Swift and its various features through a few small but complete code examples. It’s most likely, you will find the installation process the most difficult part of this tutorial. Apple doesn’t provide packages for every Linux distribution (distro). Currently, only Ubuntu 14.04 and 15.10 are officially supported. If you have a different…

Our expert Mihalis Tsoukalos is a DBA, programmer, mathematician and Unix admin. He doesn’t usually get paid in Mongolian currency but it’s definitely going to happen this month. Oh yes. Let’s dive deeper into MongoDB, a document-oriented NoSQL database that has become very popular. We’ll show you how to perform various administrative tasks, with the help of a dummy table we’ll create and populate with data, and we’ll also look at how to create a Replica Set. We won’t deal with Storage Engines as the commands for database administration are the same regardless of the storage engine used. However, if you’re using MongoDBon a production server you should study WiredTiger and MMAPv1. Additionally, beginning with version 3.2 of MongoDB, WiredTiger is the default storage engine. You can find information about…

We all know what a clipboard is: it’s an area of temporary storage for information that has been copied or cut from an application ready to be pasted into another, or elsewhere in the same, application. What’s not so well known is that desktop Linux has more than one clipboard. The one we have already referred to is the primary clipboard, this is what is used if you select something in an application and press Ctrl+c. The X display also has its own clipboard, often referred to as the selection buffer. When you select text in X, it’s immediately copied to the selection buffer. You can then paste it at the current position of the mouse cursor by pressing the middle mouse button (if your mouse has only two buttons,…

We receive several questions each month that we are unable to answer, because they give insufficient detail about the problem. In order to give the best answers to your questions, we need to know as much as possible. If you get an error message, please tell us the exact message and precisely what you did to invoke it. If you have a hardware problem, let us know about the hardware. If Linux is already running, use the Hardinfo program (https://github.com/lpereira/hardinfo) that gives a full report on your hardware and system as an HTML file you can send us. Alternatively, the output from lshw is just as useful (http://ezix.org/project/wiki/HardwareLiSter). One or both of these should be in your distro’s repositories. If you are unwilling, or unable, to install these, run the…

We live in the information age – yes, I just used a silly bit of hyperbole – but with many of us now living with so much of our live stored online the threat of information loss through theft or vandalism grows greater each year. The year 2015 is an ebbing memory, so it’s a good time to remember that some big security flaws were found within key areas of the GNU/Linux ecosystem. It’s reassuring that steps were quickly taken to both plug the holes and put in place systems to help mitigate this from happening again. But on a personal level what can be done to help protect yourself and your own information from the hacking threat? One old-school method is to educate yourself, which is why this issue…

Up until now AMD has only built CPUs using the x86 instruction set architecture, and it was often left in the wake of its main competitor, Intel. Back in 2011 the introduction of the 64-bit ARM instruction set ARMv8 sparked the idea of creating a new generation of ultra low-power servers. AMD has now finally entered the ARM race with the announcement of its ARM-based Opteron A1100 processor, which comes with eight 64-bit ARM Cortex-A57 cores, as well as 1MB of L1 cache, 4MB of L2 cache and 8MB of L3 cache. The processor will be able to use DDR3 or DDR4 RAM up to 128GB, and it’s aimed at entry-level servers. AMD hopes that the range of I/O supported by its new ARM processor: two 10Gigabit Ethernet controllers and…

ROSA R7 ROSA R7 Desktop Fresh has just been released with a new customised KDE 4.14.8 desktop environment. Other new features from the previous R6 release include programs such as the Kupbackup software, and numerous media codecs. Meanwhile KWallethas been removed from the default installation. LTS Kernel 4.1.15 is used and the X.Org Server has been updated as well. For the full release notes, and to download the distro, head over to http://bit.ly/RosaDesktopR7. TAILS 2.0 The live Linux distro that specialises in anonymous web browsing using the Tor network – has just reached version 2.0. This new version is available to download from http://bit.ly/TailsDL, and it’s based on Debian “Jessie” 8.0. New features of Tails include the ‘Classic’ mode for the Gnome Shell and an update to Tor Browser 5.5…

The Greatest Show on Earth The Maker movement sweeps across the UK. The Maker movement is in full swing in the UK and we’re seeing a rise in the number of maker events: From Liverpool Make Fest, to Mini Maker Faire in Manchester and Derby. But the main event is Maker Faire UK which takes place on April 23-24 in Newcastle Upon Tyne. This two-day event sees an astonishing number of visitors, some ten thousand attended over the weekend in 2015. It also attracts the cream of the projects and there were over one hundred makers from around the world at the event last year. Maker Faire UK has a vast range of makers that traverse the spectrum of abilities, skills and disciplines: from simple hacks using LEDs and buttons…

As with all tasks, once you’ve got a fair amount of mileage under your belt using a transcoding process, you’ll probably want to chip off some time from the method and convert video via the command line. In fact, some applications, such as QWinFF and FF Multi Converter are only graphical front-ends to powerful command-line libraries that don’t offer an interface of their own. IFME calls itself a ‘GUI-CLI hybrid, and you can use the graphical interface to set up encoding tasks and save the queue in an XML file. You can then quit the application and ask it to process the saved queue from the command-line without invoking the graphical front-end and thus save valuable system resources. Note that, however, there’s virtually no information about this on the project’s…

Not satisfied with our list? Your distribution’s repository are flush with various other options. One of the first ones you should look at is WinFF which has a straightforward interface as. Another FFmpeg-powered transcoder is FFmpeg YAG. This project is still marked as alpha and its solitary release doesn’t seem to offer anything unique over the competition, but it’s worth a look. The Curlew transcoder is also based on FFmpeg and is quite popular. However, its last stable release was in 2014 and the latest 2.0 version has been in beta since the middle of last year. There’s also MakeMKV which is primarily a Windows application but its community of users have ported it and created a Linux version as well. If you’re looking to rip DVDs, you can also…

Apparently the future is coming and apparently it involves connecting your fridge to the internet. We don’t doubt it’s very convenient to have your fridge ordering more milk when it decides you’ve run out, or being able to turn your heating on just as you’re leaving work, or automating tasks like watering the dog and feeding the plants. Unfortunately, the technology that’s going to enable a lot of this is a disaster waiting to happen. It’s all going to be based around network-facing embedded systems that for the most part offer no means of being patched: Yes, most of these will run ARM or MIPS-based Linux but much of the hardware will rely on binary drivers. As such when security flaws are found (and they will be found), there will…

Most distributions (distros) come with reasonable security settings out of the box, but there’s always room for improvement. Furthermore, as more services are enabled so too are new attack vectors, thus you need to check which services you are running, either through top or by running $ systemctl status on a Systemd-based system. Disable anything you don’t need, and investigate anything you don’t understand. The most popular configuration is the LAMP stack (or equivalent), which requires only Apacheand MySQLto be running. Of course, you will also want SSH to be running too otherwise there would be no way for you to do any kind of administering. We mentioned this before but it’s even more pertinent for sysadmins: Keep your packages up to date! People jump on new vulnerabilities as soon…

“Strong encryption (public key cryptography) has ruffled feathers on both sides of the Atlantic.” Coding history should have taught us one valuable lesson: Programmers will make mistakes (actually other humans do this too). String, buffer and heap overflows have all been around a long time and as long as humans are involved it’s hard to see things changing. Sure, we can all start using new-fandangled, type-safe, memory-safe and thread-safe languages like Go, Rust and Swift, but we’ll just introduce new classes of bugs. And the bad guys will find new and inventive ways of exploiting these. Even as we are putting the finishing touches to this article, a new bug ( actually two: CVE-2016-0777 and -8) have been discovered in OpenSSH. Writing at the beginning on the 20th century, Nikola…

When it comes to art and literature, my web server logs are usually not the first place that I’d consider looking for inspiration. Just before the end of last year though my servers (and millions of others) had the following intriguing poem dropped onto their storage devices: “DELETE your logs. Delete your installations. Wipe everything clean. Walk out into the path of cherry blossom trees and let your motherboard feel the stones. Let water run in rivulets down your casing. You know that you want something more than this, and I am here to tell you that we love you. We have something more for you. We know you’re out there, beeping in the hollow server room, lights blinking, never sleeping. We know that you are ready and waiting. Join…

“Very useful for managing files on remote servers.” The ability to browse your local filesystem is a cornerstone of personal computing and it’s been here for a long time, starting with ancient Unix consoles. Traditional file managers aren’t a cutting-edge technology, even if they do look trendy – and ‘material’ – now, so why not try upgrading to something next-gen and use a client-server architecture for managing your files? Sprut.iois an outstanding application that implements such an approach and it’s very useful for managing files on remote servers, transferring data between remote computers and handling hosted sites etc. Sprut.io has been a proprietary product for a while, but recently the developer, Beget Inc, has opened-sourced the code and put it into the regular Github repo. Sprut.iowas written using Python and…

“Convert FLAC sound files into MP3 using a FUSE file system.” Many audiophiles and connoisseurs of high-fidelity sound prefer uncompressed, or at least lossless file formats to MP3, and the main choice here is perhaps FLAC (Free Lossless Audio Codec). Music tracks compressed with FLAC are quite small, yet there’s no great loss in any detail. Sometimes there’s a need to transcode FLAC files to MP3, simply because your target device or an application doesn’t support the goodness of FLAC. But what do you imagine a file format’s transcoder to look like? A command-line tool? A GUI with lots of tabs and buttons? A service menu for your file manager? Or maybe a heavyweight wave editor? Think different, because now we’re going to convert FLAC sound files into MP3 using…

One Sunday morning in February, I woke up very early at my home in the south of France. I decided to switch on the BBC Click show, it had a report called ‘Can anyone do Tech DIY?’ by LJ Rich. The report was all about the Maker movement, hackspaces, Arduino and, last but not least “a nod to the runaway success of the Raspberry Pi” The Raspberry what? Thus began my journey and today I’m pretty well ‘plugged in’ with what’s going on over here in France even though I’m certainly no expert, just the biggest Raspberry supporter. I’ve been running the Rhône Valley Raspberry Jams with friends since February of last year, and we’ve just had our sixth event. I’m also actively involved in the development of Code Club…

Although it doesn’t take too much effort to install and configure the OwnCloudserver from scratch, there’s a couple of ways to save time and effort. The chaps behind PetRockBlog (http://blog.petrockblock.com) have written a script that automates the whole installation process. The script downloads and sets up an OwnCloudinstallation on top of a Raspbian distribution. However, unlike the tutorial, the script uses the Nginxweb server instead of the Apacheweb server. To use the script, install the required components with: Then download the script with which creates a directory called OwncloudPie. Move into this directory with $ cd OwncloudPie and make the script executable with: Then execute it: Now you’ll need to give it some time to download all the components and configure your server for you. Once you’ve installed OwnCloud from…

Our expert Nick Peers has been playing around with computers for over 30 years since the days of the BBC Micro and Dragon 32. His programming skills remain rudimentary. Ubuntu Manage and create desktop shortcuts with customised icons The desktop is a convenient place for shortcuts to favourite applications (known as launchers), system tools and even folders and files. You can even store files and folders directly on the desktop if you wish, although that’s not traditionally seen as good practice unless it’s a short-term measure. In this tutorial we’re going to break down how desktop icons work, plus reveal how to add, delete and manage the icons you place on there. We’ll also show you how to customise your icons to make more (or less) visible, including how to…

Our expert Nick Peers has accumulated more stomachclenchingly painful hours dealing with startup problems across so many operating systems than he cares to remember. Ubuntu Xxxx Troubleshoot common boot problems with the Boot-Repair tool Start-up problems. That moment when – having expected yourself to be getting on with your day’s work or entertainment – you find yourself staring at a cryptic error message, or even worse, a blank screen. No matter how many times you press reset or restart, the same impenetrable barrier blocks your path. So, what can you do? Start-up problems come in all shapes and sizes, and they can be difficult to track down. There are, however, some sound principles to use that will resolve many errors, and in this tutorial, we’re going to look at the…

Our expert James Hunt is an open source developer working at Intel’s Open Source Technology Center on the Clear Linux distro. Procenv Xxxx Understand what environment a process runs in for system testing This month we will look at a command-line tool called procenv. It was written to solve specific real-world problems, but it’s also useful in many scenarios. First, a digression. Imagine the following scenario: It’s 7pm and ace programmer Alice has a problem: she’s fixed a critical customer bug, but the Test Department have told her that the application now crashes on startup on the test server. Alice wonders how this is possible as both systems are using the same OS version, and the app works perfectly on her development system. Unless she can work out quickly how…

For many businesses, data is the ‘currency of the future’ and an essential element to remain competitive, expand their business and become a leader in their industry sector. Storing, processing, and decision-making based upon massive amounts of data requires a paradigm shift in terms of the technologies. No longer can we rely on centralised relational databases where storage and processing is done in one place. Today, the data is too big to be collected and stored in one place. So, instead of bringing data to a central place, we keep the data distributed and bring the computation to where the data is. Big Data technologies are designed for managing and processing massive and distributed storage of data using commodity hardware and networks. Big Data technologies are at the core of…

Swift values are never implicitly converted to another type which makes your code less buggy. You should always use curly brackets (or braces) { and } even for blocks of code that only have one line. As we mention in the tutorial, the most powerful control statement in Swift is the switch statement. As Swift also supports functional programming, a Swift function can return another function as its value! Additionally, you can use any Unicode character as a variable name. So, eg you can say: Swift understands when a variable that was declared as var never changes its value and prints the following warning: Swift also supports the while and the repeat-while statements which is similar to the do-while statement used in C.…

Sharding is a method for storing data across multiple machines. Shards store the data whereas config servers store the metadata of the cluster. Query Routers, which are also called mongos instances, interface with client applications and direct operations to the appropriate shard or shards. MongoDBdivides the shard key values into chunks – they aren’t related to GridFS chunks– and distributes the chunks evenly across the various shards. MongoDBdistributes data at the collection level. In order to shard a collection, you need to define a shard key, which is either an indexed field or an indexed compound field that exists in every document in the collection. MongoDBuses range-based sharding because it’s better for answering queries and, sometimes, is better for keeping your data sorted. You can combine sharding with replication. As…

Linux Format is proud to produce the biggest and best magazine that we can. A rough word count of LXF193 showed it had 55,242 words. That’s a few thousand more than Animal Farm and Kafka’s The Metamorphosis combined, but with way more Linux, coding and free software (but hopefully less bugs). That’s as much as the competition, and as for the best, well… that’s a subjective claim, but we do sell way more copies than any other Linux mag in the UK. As we like giving things to our readers, each issue the Star Question will win a copy of one of our amazing Guru Guides or Made Simple books – discover the full range at: http://bit.ly/LXFspecials. For a chance to win, email a question to lxf.answers@futurenet.com, or post it…

Android to Linux Q I have Ubuntu 15.10 and Mint 17.2 installed on my desktop computer. They run perfectly except when I connect my Medion tablet via USB, which is just not recognised by either OS and vice versa, although if I plug a USB in with photos on it the Linux OSes will all recognise it. I’ve phoned the makers and they say it will only work with Windows. Since I do not run Windows, or ever intend to, can you tell me if there’s a way round this problem? John Jackson A Android devices do not mount as mass storage devices in the way that USB flash drives do. The reason for this is that only one OS can mount a filesystem at a time, otherwise changes made…

There should has been a tutorial on running Linux on a router in this issue of Linux Format. However, just as I was finishing it, I did something I had already warned against in the tutorial and bricked the router I was using for testing. After much searching of forums and wikis, I found a solution in the form of a YouTube video. This explained clearly how to upload new firmware using the router’s recovery mode and TFTP. The author had gone to the trouble of dismantling a router and attaching a serial USB adaptor to the router’s motherboard to show exactly what was going on, then intentionally bricking a working router to show how the fix worked. It was a nice piece of detective work, well explained. The author…

System tools Essentials Checkinstall Install tarballs with your package manager. Coreutils The basic utilities that should exist on every operating system. HardInfo A system benchmarking tool. Kernel Source code for the latest stable kernel release, should you need it. Memtest86+ Check for faulty memory. Plop A simple manager for booting OSes, from CD, DVD and USB. RawWrite Create boot floppy disks under MS-DOS in Windows. Smart Boot Manager An OS-agnostic manager with an easy-to-use interface. WvDial Connect with a dial-up modem. Reading matter Bookshelf Advanced Bash-Scripting Guide Go further with shell scripting. Bash Guide for Beginners Get to grips with Bashscripting. Bourne Shell Scripting Guide Get started with shell scripting. The Cathedral and the Bazaar Eric S Raymond’s classic text explaining the advantages of open development. The Debian Administrator’s Handbook…

“With the switch to openJdK, android will be getting a more up to date and feature-rich codebase, as well as support for Java 8.” Oracle’s copyright infringement court case against Google over the use of Java in the Android operating system has been dragging on for a while now, and it looks like Google has offered an olive branch in order to avoid further conflict. The antagonism between Google and Oracle stretches all the way back to 2007 when the beta version of the Android mobile operating system was released. This early version of Android included APIs that were built with the standard edition Java Platform (J2SE). While this didn’t initially cause any legal complications – even the CEO of Sun Microsystems (the company that developed Java) congratulated Google on…

While AMD is showing off its first ever ARM-based processor, support is growing for an open source processor alternative, with big names such as Google, HP and Oracle being attached to RISC V. Based on the original RISC core from 25 years ago, RISC V is an open source effort to enable a new class of processors and SoCs, with Linux and NetBSD being supported so far. Other embedded OSes should come later this year. Right now RISC-V aims to be completely open, as well as attempting to avoid “overarchitecting”, which is increasingly common in some modern microarchitectures. To find out more head over to http://riscv.org. Canonical has just scored a huge victory over IBM and Microsoft with the announcement that AT&T, the US’ second biggest telecoms company, will be…

ZFS!?! Being a user of ZFS and O3X I read your Roundup with huge interest [p24, LXF203]. I find your conclusion for ZFS and btrfs to be totally crazy and almost like you meant laptop and not desktop in this sentence: “The most advanced file system, but too heavy footed for desktop use”!?! What the frog!?! ZFS is the ideal FS for any workstation with four or more drives at least for Mac and SmartOS, are you saying that the Linux implementation is no good? The zpools will fully remove the need for partitioned drives, as the pools will span several drives, letting the pool stripe several physical drives to increase speed. Files no longer critical for operation can be put in a separate compressed pool. Remember pools are not…

Blackpool Makerspace 10am every Saturday, 64 Tyldesley Road, Blackpool. https://blackpoolmakerspace.wordpress.com Bristol and Bath LUG Meet on the 4th Saturday of each month at the Knights Templar (near Temple Meads Station) at 12.30pm until 4pm. www.bristol.lug.org.uk Dundee Makerspace Open night is every Monday from 6.30pm, Unit 5, Vision Building, 20 Greenmarket Dundee, Angus DD1 4QB https://dundeemakerspace.co.uk Edinburgh LUG Meet on the 1st Thursday of the month at the Southsider pub, West Richmond St. www.edlug.org.uk Hull LUG 1st Tuesday every month at 8pm in Hartleys Bar, Newland Ave. http://hulllug.org Lincoln LUG Meet on the third Wednesday of the month at 7:00pm, Lincoln Bowl, Washingborough Road, Lincoln, LN4 1EF. www.lincoln.lug.org.uk Manchester Hackspace Open night is every Wednesday at 42 Edge St, in the Northern Quarter. http://hacman.org.uk Northern Ireland Raspberry Jam 2nd Saturday of…

While all the video transcoders in the Roundup are more or less straightforward to use, you will likely want to refer to their documentation before trying some of their advanced functionality. VLChas a skeleton interface for the transcoding function and its documentation is no different. The project has a single page dedicated to the topic on its wiki and that tends to cover transcoding using the command line more than navigating the graphical interface. VLCoften refers users to its streaming function which is very similar to the transcoding one and this trend continues on the official forum boards as well. FF Multi Converter doesn’t fare much better, it has a minimal wiki which lists the available presets and has brief guides for installing the application from source and on Ubuntu.…

“Attacks are rarely launched against individuals, which is to say they are not personal.” Much as we’d wish the opposite were true, the Internet is not all rainbows and unicorns. It’s not that the rainbow and unicorn communities aren’t thriving online – they are, but what’s equally alive and well are the nefarious hackers who aspire to steal, extort, deface, infect or corrupt whatever digital assets they can lay their grubby paws on. Your computing power, websites, passwords, contacts lists and, of course, your credit card details are all sought after by internet scoundrels, who will use all manner of techniques to access them. Sometimes these might be simple social engineering tricks – sending phishing emails that look like they’re from your bank – or they could be something more…

Unfortunately, no matter how meticulously you plan your defenses there’s still the possibility that you’ll end up becoming a hacking victim. You might be alerted because your website is defaced, or because you can no longer log in (via SSH or any web control panel). You might get an angry phone call from your server host saying that you’re participating in DDoS attacks. If you explain the situation to them they’ll probably understand and be able to provide help. If you are able to log in then you should, as a precaution disable any services. Next you’ll want to download your system, webserver and database logs and spend several cups of tea trawling through them. If you’re lucky you’ll be able to pinpoint the exact moment the breach took place.…

One of the neat features of Grub 2 is that it can boot directly from an ISO image. Apart from allowing magazines to produce really nice multi-boot cover discs, it also means you can have a rescue or live CD always ready to boot. Not only is it faster than booting from an actual CD/DVD (or even a USB stick) but it saves all the time scrabbling though the stuff on your desk to find the right CD. This requires that the distro supports booting from an ISO. Most do, although the syntax can vary. All you need to do is create a copy of 40_ custom and add the appropriate menu definition. Here’s an example for System Rescue CD (I always keep an ISO of that in boot): and…

RancherOS uses cloud-config for its configuration, which is a pretty common standard on Linux, of course, and will generally be parsed on startup by a supporting distro. Files relating to this can be found under the path /var/lib/rancher/conf/. In order to amend this configuration though, the recommended process is to use the ros command, eg $ sudo ros config export will dump the current config out to the command line. Adding a --full flag to that command dumps out even more info (internal and default settings), such as the settings for system-docker and suchlike. The cloud-config format is YAML and therefore reasonably readable by humans. All the settings come under the ‘rancher’ key which ros can configure by using the set and get sub commands. So eg setting DNS for…

Sonic Pi is a great way to introduce Ruby to children, but as we know, many children are hooked on Minecraftand spend copious amounts of time playing the game. But did you know that Sonic Pi can also be used to control Minecraft, in a similar manner to the Python library? For this you’ll need both Minecraft and Sonic Pi open. This is possible on all Raspberry Pis but for the best results come use the Pi 2. In Sonic Pi we can integrate the Minecraftcommands into our composition, eg we can teleport Steve two blocks into the air, and this will happen to the beat of the music by adding mc_teleport(0,2,0) . Thanks to James Robinson from the Raspberry Pi Foundation, the Sonic Pi can be set to react…

The real advantage of commercial cloud services, such as Dropbox, is that you can access data stored within them from any computer connected to the internet. However, by default, a self-hosted OwnCloudinstallation is only accessible from computers and devices within the local network. That’s not to say that you can’t access your private cloud from the internet, though. The trickier and expensive solution is to get a static IP address from your ISP and then poke holes in your router’s firewall, or you can set up Dynamic DNS in your router or local machine. The smarter way, however, is to use a tunnelling service, such as PageKite. The service uses a pay- what- you-want model. As a non- commercial user, you can use the service for free by filling out…

If you’re looking for a quick and easy way to change your icons, then consider switching to a different icon set, which replaces many – if not all – of your existing icons with new, consistently designed ones. Install the Unity Tweak Tool from Software Center, then do a web search for ‘icon set ubuntu’ to find a suitable icon set to install, eg to install the Moka icon set, do the following: Once installed, open Unity Tweak Tool and select Icons. You’ll see a large selection of different sets to choose from – the existing ones don’t make many radical changes to their appearance, but choose Moka and you’ll immediately see the difference. You’ll also notice that the change affects any desktop shortcuts you’ve created using an application’s default…

Our expert Neil Bothwick has a great deal of experience with booting up, as he has a computer in every room, but not as much with rebooting since he made the switch to Linux. Gentoo Xxxx Going beyond installation and learning how to manage packages From time to time, we write a beginner’s guide to getting started with Gentoo, I know this because I’ve written at least one myself. These generally follow the first part of the excellent Gentoo Handbook to create a working system. After that the user is left to read the manual and fend for themselves, so here we will look at the core element of Portage and how you use it to maintain a Gentoo system once the installation period has passed. The name ‘Portage’ actually…

The idea for procenv resulted from two itches that I was experiencing regularly, both of which relate to the Upstartinit system, as previously used by Ubuntu. First, I wanted an assertion tool to be used for scenario testing. Upstarthas excellent unit tests, but I wanted to create a set of Upstart‘jobs’ to run on a real system. These jobs would assert every attribute of the job environment that was expected at ‘runtime’ (the Upstartjob environment has to conform to a very strict definition, as documented in the upstart(5) man page). My original thought was to write a tool that could be fed a statement; if the statement was false, the tool would display an error and exit.However, I disliked the idea of passing such statements to the tool. A cleaner…

The QuickStart virtual machine is built on the CentOS 6.4 Linux distro. The VM includes Hadoop core components (Hadoop Distributed File System (HDFS) and the MapReduce Framework) and a number of supporting applications from the ApacheFoundation. The VM also includes some applications from Cloudera. The virtual machine has all necessary components pre-installed and configured in such a way that you can power on the VM and start using it immediately without going through any configuration process. The latest version of the QuickStart VM automatically also starts Firefox to help you use many tools directly from the web browser. The browser has a Favorites bar pre-configured with all the links that you would need for learning. As mentioned earlier, the core of Hadoop is HDFS and MapReduce framework. On top of…

Closures are similar to blocks in Objective-C and to lambdas in other programming languages. Strictly speaking closures are small self-contained blocks of functionality that can be passed around and used in your code. Closures look pretty much like a function declaration, and that’s because functions in Swift are just named closures! One important difference between closures and functions is that once a function has been defined, its name cannot be reassigned whereas the name of a closure can be reused so you cannot be sure that a named closure does the same thing throughout the entire program execution. Closures are used because they are more compact than regular functions especially when used in combination with other functions such as map.…

Having a backup strategy is essential because all systems will eventually fail. Although using MongoDBsharding and replication can minimise the need for a backup, bad things can happen at any time. Additionally, if you’re running a single server process, then it’s mandatory to take regular backups. The two main utilities are: mongodump and mongorestore and they can help you backup and restore a MongoDB database, respectively. The screenshot (pictured, left) briefly shows off the use of mongodumpand mongorestore. The mongorestore command was executed with the --quiet parameter in order to hide all log output.…

We often give a solution as commands to type in a terminal. While it is usually possible to do the same with a distro’s graphical tools, the differences between these mean that such solutions are very specific. The terminal commands are more flexible and, most importantly, can be used with all distributions. System configuration commands often have to be run as the superuser, often called root. There are two main ways of doing this depending on your distro. Many, especially Ubuntu and its derivatives, prefix the command with sudo , which asks for the user password and sets up root privileges for the duration of the command only. Other distros use su , which requires the root password and gives full root access until you type logout. If your distro…

What do you do if you think your computer isn’t running as fast as it should? We’re not talking about download speeds here but the overall responsiveness of the desktop. The chances are that there’s some process sucking up more than its fair share of CPU cycles, memory or both. There are various tools you can use to look at this, including several graphical desktop monitors, but the standard tool is top. This runs in a terminal, so you can use it anywhere – including over SSH – and it’s part of the toolset that you’ll find in every Linux distro. Run top with no arguments and you’ll see a list of processes, ordered by CPU usage, with some system information at the top of the display. After some general…