Linux FormatJanuary 2020的目錄

“When our business managers say they want backups, it’s our job to ensure that what they get is what they actually want. The easy answer is to set up some kind of backup and tell them it’s done. Next! The better answer is to ask them what they want to achieve. You can use your expertise and your experience to provide a better solution for the business. There’s lot to consider, such as the pros and cons of local versus on-site backups, but here’s two questions that will result in a better solution (and make you look good). Q1: What is the Recovery Time Objective (RTO), or how long we can tolerate a service being unavailable after a disaster? Q2: What is the Recovery Point Objective (RPO), or how much…

It seems like we’re getting spoilt for choice when it comes to new smartphones coming out that are built on open hardware and use FOSS. If you’ve been keeping an eye on the PinePhone, you can now order the “BraveHeart” limited edition for $149.99. This version is for developers and early adopters who can’t wait to get their hands on the device. The BraveHeart edition doesn’t come with the default Linux OS build pre-installed. The PinePhone comes with a 6-inch touchscreen with 1,440x720 resolution, a 64-bit quad-core ARM processor and 2GB of RAM. You can order it at http://bit.ly/ LXF258PinePhone.…

Linus Torvalds announced the release of Linux 5.4, noting that not much had happened toward the end of the development cycle, “which is just how I like it”. New features include support for kernel “lockdown” (the necessary bits for UEFI SecureBoot to be supported), drivers for a variety of recent Intel (Tiger Lake) and AMD (Navi/Renoir) GPUs, and initial support for exFAT filesystems. Also support for kernel “symbol namespacing” which declutters the way in which drivers share interfaces. Zombies Strike Back Early in 2019, a vulnerability was disclosed that impacts certain Intel CPUs, known as ZombieLoad (zombieloadattack.com). Part of the “MDS” (Microarchitectural Data Sampling) vulnerabilities, the attacker is able to reads stale data left behind in various internal CPU buffers and can infer the state of victim programs. During the…

Indexed I am enjoying my second year of Linux Format magazine, and because you cater for all levels of expertise and areas of computing, I can’t help but learn something in each edition. However, is there an index, either on or offline, to find specific information, instead of searching through at least 20 magazines, and counting, that I have? A good index, not a word search, would show whether the subject required was covered or not, otherwise a lot of that information and experience in the magazines becomes inaccessible. I appreciate the front cover and contents page show what each edition contains, but an index helps the user to find specific information. Andrew Shelton Neil says… Go to https://linuxformat.com/archives. This is a PDF archive of all LXF issues back to…

Q Renaming files I’m trying to write a Bash script to get rid of Windows-illegal characters on my external drive and replace them with an underscore, since Windows implodes if it finds one. Lauren Gordon A There are several ways you can do this using regular expressions with perl or sed, but the simplest approach is probably to use tr, the translate command included with all distros. The program works by giving it two lists of characters, then it reads text from standard input and replaces any character that is in the first set with the corresponding character in the second set. You just need a list of the characters to replace. For example: will replace any occurrence of x, y or z with _. Normally both of the character…

Desktop applications such as web browsers, media players and office suites often hog all the limelight and are at the centre of discussions about open source software. But the Linux ecosystem boasts a varied number of specialised software as well, aimed at a select group of professionals and hobbyists, and they are therefore considered of little importance by the masses. Audio editors is one such class of overlooked software. Traditionally thought of as the exclusive domain of musicians, the rising popularity of podcasts and vloggers has brought audio editors from the more obscure into the mainstream. Whether it’s combining audio files, trimming out unwanted sections or tweaking the pitch or tempo, the audio editors that are featured in this Roundup can do it all, and more. Although audio editors and…

Audacity’s Preference dialog window is split into more than a dozen different sections, such as Devices, Playback, Recording, Keyboard Shortcuts, and Import/Export. Each section is described in detail in the user manual and features relevant screenshots for easy assimilation of the information. There are also a number of plugins to extend the default functionality of Audacity. The application ships with four themes by default, and you can also create a custom theme. You’ll find to-the-point instructions on the wiki. One of its unique features is that you can control various aspects of the graphical interface with keyboard shortcuts, and the application also lets you define custom shortcuts. You can access the Preferences dialog box on Audacity and Ardour by clicking Edit>Preferences. Ardour also lets you tweak different parameters for more…

CPU At least a 64-bit 2GHz dual core CPU. Core count makes more of a difference: think eight cores or more as optimal. GPU Either AMD or Nvidia cards are fine: you will need at least 1GB of VRAM. If you plan to use your GPU for rendering, the more graphics memory, the better. RAM Blender needs at least 4GB of RAM, but at least 32GB is best. Display Blender will run at 1,280×768 resolution. A full HD display or 4K monitor will enable you to view a scene in full detail. Connectivity Blender makes good use of the middle mouse button, and one is recommended. A graphics tablet or pen display is also a must for sculpting and painting. Operating system Windows 7+, macOS 10.12+ and – of course…

For one issue only, welcome to Arduino User! When I received my first Arduino, it was a Christmas gift back in 2011, and I knew nothing about electronics and coding. I saw the Arduino and thought that I wanted to give it a go. So my first project was the “blink” sketch, which I made using a breadboard, LED and resistor. I made the LED flash but I was left a little lost. The Arduino is an immensely powerful tool to learn coding and electronics, I just lacked the knowledge and skills to take it further. So how did I learn to love the Arduino? Well, somewhat controversially it took the Raspberry Pi and Python to help me understand the power that a simple LED can bring. Let me explain.…

In the age of cloud computing, Chrome OS is the leader. It dominates the low-end PC market and is making inroads at the other end. Laptop Chromebooks, desktop Chromeboxes… it seems likely Chrome OS and Android will merge at some point. Chrome OS is built on the Linux kernel and derived from Chromium OS, its open source base. Chromium OS consists of a three-tier architecture: the browser and window manager; the kernel and drivers; and the firmware. Simple to use but reliant on cloud services, Chromium OS can be installed on a Raspberry Pi using FydeOS. Describing itself as a “future-oriented cloud drive operating system”, FydeOS is developed for several popular hardware platforms alongside the Raspberry Pi. Its developers view it as a superior version of Chromium OS, so how…

LineageOS isn’t the only version of Android compatible with the Raspberry Pi. Older versions of Lineage support the Raspberry Pi 2, but you’re unlikely to get the best experience with this. EmteriaOS (http://bit.ly/LXF258-emteria) is marketed as an “Industrial Android” operating system, but you’ll need to buy a €19 license to use it uninterrupted. An evaluation version is available to try out first. This has nag messages and an enforced eight-hour reboot to remind you to pay for the full version. It also features SSH support, updates and a static IP configuration if required, along with out-of-the-box support for the Official Raspberry Pi 7-inch Touchscreen. Whether you want to rely on EmteriaOS of course depends on your feelings about paid software, as well as organisations that put licenses on existing open…

If you have a simple Bash script that you want as a desktop extension, you might start writing a JavaScript equivalent – but wait! There’s an alternative: Argos. This extension is inspired by and compatible with the BitBar application for macOS. It takes any shell script and presents the output in the Top Bar. It can also create a drop-down menu for launching applications. To place the plug-in correctly on the top bar, you change the name of the script. For example, you can place a script to the left by changing it from script.sh to script.l.sh. The system is made specifically to be easy to implement. Inside the script, you name the extension by echoing echo “top” and adding a separator echo --- . Everything below the separator will…

In our look at the various types of logic gates, we restricted ourselves to gates with two inputs. However, you’ll remember that the sample gates in the online simulator initially had three gates, but we removed some of the circuitry to turn them into 2-input gates – and we also saw that Logisim gates have an attribute that defines the number of gates, from two to 32. The fact is that logic gates can have any number of inputs, and this can be achieved at the level of transistors – or, if you only have 2-input gates, you can work at the level of logic elements, connecting those gates together to produce gates with more inputs in various ways. For example, two 2-input OR gates can be used to create…

This article uses a variety of tools in addition to LibreOffice, all of them installed in the usual way with apt-get. Here’s a quick summary, subdivided by the LibreOffice application that’s the target of the notes conversion process: Writer: Pandoc (for markdown conversion); retext (a great markdown GUI editor); libjs-mathjax (a maths extension used by retext); xpdf (a PDF viewer). Draw: Graphviz (for drawing graphs); GNU plotutils (for managing gpic diagrams); plantUML (a Java library for generating UML diagrams). ImageMagick’s family of image utilities is a must. Impress: Pandoc for Windows! This embarrassing inclusion is explained in the text. Look for version 2.0.5 or later. Calc: csvkit. Base: csvkit again; mysql (or MariaDB); libmysql-java (a MySQL JDBC driver). Pandoc and the JDBC driver require JDK version 1.8 (also known as…

EMAIL CLIENT Mailspring Version: 1.7.2 Web: https://github.com/Foundry376/Mailspring Most of us tend to check for new emails via smartphones, otherwise we use desktop web browsers. The niche for legacy standalone email clients has shrunk during the last decade, but the fight is not over. Thunderbird, Evolution and KMail still have lots of advanced features for both home and enterprise users. There used to be one more prominent email client of that kind, Nylas N1, which we reviewed in LXF221. Back in 2017 it became defunct and was soon reborn as Mailspring. The original Nylas application was based on Electron and sported a JavaScript engine inside, which, truth be told, led to a big performance loss. Although Mailspring is very similar to Nylas, its core has been rewritten in C++ and runs…

If you make a mistake in your code, keep an eye on the LEDs. Micro:bits have their own debugger built in, so the error will scroll across the LEDs, starting with the line number. The micro:bit uses Micro Python. More info and tutorials are available at https:// microbitmicropython. readthedocs. io – including help with text, images, buttons, I/O, music, gestures, directions, and also storage. Using crocodile clips on 0 and GND, you can attach a pair of headphones or speakers and introduce sound to your micro:bit. Import the music module and play music.…

Linux remains the number one destination for hackers: white hat, black hat or any colour in between. A key part of that is the ability to engineer open source code to do your bidding, but also that the tools are open source and available under open licenses. With Jonni fully refreshed and updated from his sabbatical now – packing a techno boat to live on – he’s crowbarring Kali Linux onto the DVD and writing up a handy guide to using its hacking playground the Metasploit framework. We’re not saying you’re going to become elite hackers overnight, but it might offer a sense of how systems become vulnerable and the basic ways you can stop attacks. A while back (perhaps even when I started) many thought Linux was only good…

There’s word on the grapevine (reported by Richard Hughes of Red Hat at http://bit.ly/LXF258fwupd), that Google will begin to request that Chromebook makers use fwupd, an open source firmware updater, if they want to get the “Designed for Chromebook” certification and branding. Hughes should know, considering he’s the lead developer of fwupd, though as he mentions in his blog post, Google has not currently been in touch with him. Instead, he’s heard the rumours from “several” sources. As Hughes states, the move “does make a lot of sense for Google, as all the firmware flash tools I’ve seen the source for are often decades old, contain layer-on-layers of abstractions, have dubious input sanitisation and are quite horrible to use.” He also suggests that some hardware makers may feel “mild panic”…

Back in 2014 the Debian Technical Committee decided to switch to systemd as the default init system for the distro, a decision that was contentious but many hoped would end months of heated debate. It seemed that the decision had put the issue to bed, but in November 2019 a general resolution (GR) was called on what level of support will be given to other init systems. While no one really wanted this issue to pop up again, it seemed like a bit of an inevitability once it became clear that the Debian project had not been able to offer full support for alternatives to systemd because of a lack of developer interest. This led to Sam Hartman, the Debian project leader, stating that he was “working with a number…

“I’ve left Red Hat after 13 years. During that time, I rose from being a kernel programmer, working on driver subsystems, to being responsible for the Arm server programme (that lead to the RHEL for Arm systems), and then the lead in security side-channel mitigations for vulnerabilities such as Spectre and Meltdown. Red Hat is an amazing place to work, and indeed I never thought that I would ever leave. I even (still) have the license plate “REDHAT” in my home state of Massachusetts. But then came the opportunity to join a startup. I’ve never been a big believer in “hardware” and “software” people, or the artificial barriers that we can create between one another, and the blame games that can result from lack of communication. In my new role…

Build Brighton Thursday evening is open night. http://buildbrighton.com Cornwall Tech Jam Second Saturday of the month, alternating between Bodmin and Camborne. www.cornwalltechjam.uk Thingqbator An IoT-focused makerspace, meeting weekly at The Shed MMU. mcr.thingqbator.org Leeds Hackspace Open night every Tuesday 7pm-late. Open day second Saturday of the month, 11am-4pm. http://leedshackspace.org.uk Huddersfield Raspberry Jam Meet every month at Huddersfield Library, typically the fourth Saturday of each month. Huddersfieldraspberryjam.co.uk rLab Reading Hackspace Unit C1, Weldale St, Reading, open sessions Wednesday from 7pm. http://rlab.org.uk Horsham Raspberry Jam Park Side, Chart Way, Horsham. www.facebook.com/hackhorsham Medway Makers Meet every 3-4 weeks on a Sunday. Full details at: http://meetup.com/Medway-Makers Maidstone Hackspace We hold open evenings every Wednesday from 5.30pm-8pm. https://maidstone-hackspace.org.uk Glasgow Makers and Hardware Hackers Mitchell Library, Glasgow. www.facebook.com/groups/115303729096198…

Send your thoughts to the Linux Format dungeon server at linuxformat@futurenet.com, be picked as Letter Of The Month and win* a 32GB Nitrokey Storage 2! The Nitrokey is worth a cool €149, has 32GB of hardware-encrypted storage, supports hidden volumes, secures your online accounts with onetime passwords, can encrypt emails, files and hard drives and is an open source, open hardware solution. Protected with AES-256 and RSA keys up to 4,096! Learn more at www.nitrokey.com.…

The so-called Unix principle is that each program should do one job and do it well. This means that carrying out a task may mean using several programs in turn, but how do we get the data from one program to the next? The answer is a pipe, which is pretty much what it sounds like – a conduit that carries the data, something like Here program1 works on the data, but instead of sending the output to a file or the terminal, it goes through the pipe, represented by the vertical bar, to program2. That does its stuff and sends it on to program3, which does whatever is needed and writes the finished product to a file. Here’s a simple but useful real-world example of a pipe in action.…

Working with audio files can be resource-intensive, depending on the operations you perform. We’re running these applications on a quad core machine with 12GB RAM. Although you can get good performance on 4GB RAM or even less, for editing operations such as the kind you can perform with these applications, more is always going to be better. As our focus is on novice users, we’re interested in projects that don’t force users to opt for a particular distribution. Apart from ease of installation, documentation is hugely important to help new users acclimatise to the vast feature set of each of these projects. We’ll discuss some of the most useful features these tools offer and whether their interface is intuitive or if it gets in the way of creating memorable scores.…

You’ll find a surprising number of applications aimed at musicians and hobbyists in the software repositories of most popular distributions. Since we last covered audio editors, way back in LXF69, a number of projects have shut up shop. Many have not seen a new release in years, with no clear word on whether they are still in development or been abandoned. Rosegarden is a music composing and editing application. If you’re overwhelmed with a powerful DAW like Ardour, this can be a good alternative. There are also applications that can help you become a masterful DJ, such as Mixxx. If you’re interested in creating your own music, Firnica is one alternative to LMMS. If you have a good understanding of music notations, Musescore (see p64) is also worth investigating. It…

If you followed our handy guide on the previous pages, then you’ll already have augmented your Kali Light installation with Nmap, a port-scanning utility par excellence and a vital part of any pen-tester’s arsenal. As mentioned on the DVD page (there will be the standard complement of two next month) it’s possible to ‘upgrade’ this to the full-fat Kali with apt install kali-linux-all , but there’s no way we could provide even the pithiest summary of the 14GB of tooling that command would bestow upon you. If you just want the most popular tools, then apt install kalilinux-top10 will only cost your VM about 600MB. We’re going to play it frugal and only install what we talk about, because that’s how we roll. For our first trick, we’ll install Rapid7’s…

It might be surprising that a hacker collective was able to gain access to the SWIFT network, even if they were masquerading as a respected organisation and doing so via an access service. One might suppose that one needs specialist equipment or authentication to do this, but no, all that’s required is not getting caught. The SWIFT network is one of a number of Very Important Networks that the modern world relies on, yet one that’s open to abuse by sufficiently bold or ingenious attackers. Other such fireholes include SS7, the aging language that telephone networks use to communicate with one another. This has been exploited to various effect, for example in 2017 hackers used it to bypass two-factor authentication (2FA) for compromised bank accounts and misappropriate funds. The popular…

www.blender.org The official site hosts software downloads and feature news. https://builder.blender.org Try new tools early with alpha and beta builds. www.blendernation.com Daily news and art breakdowns, plus lots of links to free online training. https://blender.community/c/today Community-curated news, with separate boards for many European languages. www.blenderartists.org Get advice from artists in the best-known Blender forum. https://cgcookie.com A commercial Blender platform, with 1,000s tutorials. www.blendswap.com Free assets for users, from models to tech resources. https://blendermarket.com The main marketplace for Blender’s growing library of commercial add-ons. https://fund.blender.org Support the Blender Development Fund.…

Using the Raspberry Pi as an introduction to Chromium OS is a lot cheaper than buying a Chromebook. But what do you need to know? Well, the OS is centred around a 3x3 grid launcher; from here, apps can be launched, but in most cases an internet connection is required. Remember, this is a cloud operating system, and while some apps will run locally without remote content, many won’t. Pretty much everything else is as you would expect. Mouse-driven and easy to use, Chromium OS also comes with a handy bunch of keyboard shortcuts. Open apps are placed on the Shelf and these can be quickly switched-to using Alt+1 to Alt+9. Alt+Tab cycles open apps, Alt+[ and Alt+] pin open apps to the left and right of the desktop. This…

A GUI text editor or word processor enables you to select and manipulate a chunk of text in one go. You can select words, lines or even entire blocks or paragraphs and perform any number of operations, such as cut, copy or paste. Vim’s visual mode lets you perform the same function. To ease selection of text you want to operate upon, the Visual mode itself provides three distinct modes: Character, Line and Block. From the Normal mode, press V to enter Visual mode. You’ll notice -- VISUAL -- at the bottom left of the vim interface. This is the Character mode, and lets you select the characters you want to operate upon using the cursor keys. The text you want to operate upon can be spread across multiple lines.…

Why use your keyboard or mouse to enter notes when you can do it with your MIDI keyboard? Ubuntu 18.04 ships with decent MIDI support: connect your keyboard to PC via a MIDI cable or interface then verify it’s been detected in Ubuntu with the terminal command: $ aplaymidi -l This should provide information about two ports: MIDI Through and your MIDI device with the port name <device> MIDI 1 . Now open MuseScore and select Edit>Preferences > I/O. Select PortAudio – you’ll notice everything is currently blank – and click OK. Return to the I/O preferences tab, and this time you’ll see the dropdown menus are now populated – you need to set ‘MIDI input’ to ALSA,<device> MIDI 1. Click ‘Restart Audio and MIDI Devices’ and click OK again.…

It might not be something that you’ll need to understand how a microprocessor works – indeed, this would undoubtedly be something that would be done in software – but a good exercise to help consolidate what we’ve seen so far is to build a 7-segment LED decoder in Logisim. Logisim has a 7-segment display as part of its library of components but, for this exercise, it’s too clever. What we mean by this is that it inputs a 4-bit signal and illuminates the appropriate segments to display the hexadecimal digit corresponding to the binary number on its inputs. In other words, it already includes the decoder that we’re suggesting you design. Instead, therefore, you’ll have to use seven separate output pins or LEDs to represent the seven segments. To make…

Base essentially acts as a GUI frontend for databases, which can either be embedded or external to LibreOffice. Historically, Base’s embedded DBMS was the Java-based HSQLDB, although there has been a gradual move towards the C++ based Firebird DBMS since LibreOffice 4.2, and HSQLDB has been deprecated since version 6.1. Base can work with a range of external database systems, including MySQL, MariaDB, SQLite and PostgreSQL. Choosing which one to employ mostly comes down to a matter of personal choice. MySQL or the very similar MariaDB offers a good command-line interface, powerful SQL features and comes with plenty of documentation. For an example of what it can do, see Andrew Mallett’s tutorial in LXF191.…

Micro:bits are perfect for Morse code communication. Instead of using images or strings to light to LEDs, we can use the flash command to light up the entire LED grid for a set amount of time. The following code will display a full flash for 10ms: We could then take this and introduce a selection to make the micro:bit flash for different lengths, depending on what letter we want to represent. We can represent dots with short flashes and dashes with slightly longer flashes. For the purposes of this example a dot is 5ms and a dash is 10ms: After developing Morse code statements for each letter of the alphabet, we can then set up a loop to recognise each incoming letter, or only send single letters at a time.…

If you installed MySQL without setting a root password, you can try mysqladmin -u root password newPassword , where newPassword is your new MySQL root password. If this doesn’t work, there are a lot of recipes on the internet you can try in order to reset MySQL’s root password. We tried using curses to write the code in this project, but curses doesn’t properly handle accented characters which the world of databases has in abundance. Accented characters are 2-, 3- or 4-byte UTF-8. Terminal is a static class - one that doesn’t get instantiated or destroyed. You call the class methods with the class name: Term inal::display Caption(“He llo, World”). If you want to reference a specific colour you say Terminal::BLUE. Terminal uses escape sequences that produce bright colours on…

“Seasons greetings penguinistas! This issue I again try my hand at hacking, which ties in nicely with a) our interview with polyglot hacker Christina Quast and b) a massive databreach at the Cayman National (Isle of Man) Bank by Phineas Fisher. They’ve gained notoriety by hacking Hacking Team and Gamma Group (both plyers of surveillance tools used by repressive governments and police forces). Even if you don’t like the means here (which are obviously illegal), they are on some level justified by the ends. These grey areas are nothing new. Robert Morris (of ‘Morris worm’ fame), Clifford Stoll (see The Cuckoo’s Egg) and Peiter ‘Mudge’ Zatko (of Boston hacker collective the L0pht and later DARPA) all probably bent the rules to some extent but also did great things. A new…

“Over 2019, I’ve had the opportunity to lead work with Boris Brezillon on the Hantro VPU driver, which supports video decoding on Rockchip RK3288, RK3399 and NXP i. MX8MQ SoCs. The results of some of this work was made available, in the media subsystem of Linux kernel 5.4. This kernel release introduces support for H.264 decoding on RK3288, and also VP8 decoding on RK3288 and RK3399. Popular RK3288-based platforms include ASUS Chromebook Flip and ASUS C201 Chromebook, so this change brings Chromebooks one step closer to running upstream, reducing the upstream/downstream gap. Recent efforts to improve upstream kernel quality, such as KerneCI.org (now a Linux Foundation project), and Syzbot (continuous fuzzing), are more mature, identifying bugs that security attacks vector. Early bug identification allows the community to fix the issues…

Ying Huang posted “autonuma: Optimize memory placement in memory tiering system”. These patches aim to teach Linux about the difference in NUMA (Non-Uniform Memory Architecture) behaviour between traditional DRAM (normal RAM) and persistent memory (sometimes called “PMEM”). Linux already supports automatic placement (and migration) of memory across server sockets to place it closer to where it is being used and these patches extend that fundamental concept to migrating pages between DRAM and PMEM based upon their usage type. Stephan Muller posted “Linux Random Number Generator”, a completely new “RNG” implementation divided into two parts (a primary and a secondary seeded from the first) that plumbs right into the existing /dev/(u)random interfaces. The aim is to improve the quality of random numbers while also solving for boot-time needs prior to having…

Q tractor hosts a wiki with dedicated manuals on different topics, such as introduction, learning its usage with an example session, a run-through of the different menus, and others. There are also how to’s on MIDI composition workflow and a couple of others. The wiki serves as a single hub for all documentation on Qtractor and also features a user manual. As well as a Getting Started guide and a wiki-hosted user manual that you can download as a PDF file, LMMS also provides a list of video tutorials hosted on YouTube. These include an introduction to Piano Roll, the basics of FX Mixer, using the Automation Editor, creating different genres of music such as dubstep, house, trance, and tutorials on music theory. You can also ask for help on…

We have a funny relationship with the word ‘hacker’ here at LXF Towers. On the one hand, anyone that’s ever fiddled with Linux or meddled with Arduino (or even exited Vim successfully) has, as far as we’re concerned, earned the right to call themselves a hacker. The mainstream media, and indeed our beloved management bods, have other ideas. They would have it that a hacker is a morally bankrupt criminal, intent on misusing technology to foment chaos, steal people’s savings and commit fraud. Certainly there are people that do those things (hedge funds?–Ed), but there are also people (‘white-hat hackers’) that use the same techniques to help people bolster their defences or even recover from an electronic intrusion. Companies invest significant sums paying individuals to penetration-test their networks and socially…

One of the best ways to learn about exploits is to find a vulnerable system and attack it. Unfortunately, unless you own that system this approach is also very probably illegal. So don’t do that. You can craft your own vulnerable system. It’s pretty easy to get hold of a Windows XP virtual machine (and also perfectly legal – you can extract such a thing from XP Mode for Windows 7 installer at www.microsoft. com/en-us/download/details.aspx?id=8002) or an old Ubuntu ISO, but it’s at best time consuming and at worst annoying to find suitably old software to install on it and set it up in a vulnerable way. Fortunately the good people at Rapid 7 have done all the work for you and condensed it all into a virtual machine (VM)…

Kali Linux’s motto is “The quieter you are, the more you are able to hear”, which it turns out is not just a handy phrase for quietening down small, noisy childlings. Stealth is as important a weapon as any fancy zero-day vulnerability in any hacker’s arsenal. Joshua may have brought the walls of Jericho crashing down with the sounds of trumpets, but hacking isn’t like conquering Canaan. One needs to move in the shadows. Mass port scans are typically quite noisy. A keen-eyed system administrator pouring over logs could easily spot them, or more likely has written some intrusion-detection script to detect them and block the offending host. For this reason Nmap enables you to do atypical port scans. And if you run it as root, this is in fact…

Christina Quast is an independent security researcher from Germany who speaks and programs in lots of languages. She’s been attending and presenting at all kinds of infosec conferences and various hacker challenges over the course of her studies. Currently she’s based in Nice, France, where she works as an embedded systems engineer and brings her expertise in security to that field. She’s worked on Embedded Linux kernel drivers, as well as getting U-Boot to play nice with embedded hardware. As part of her master’s project and previous studies, she wrote code for the Large Hadron Collider at CERN, in particular a Wireshark plugin for dissecting LHCb particle detection data, and later ported the LHCb RICH particle identification algorithm to the Xeon Phi platform. Linux Format: So you’ve just gotten your…

When you read about Arduino it often seems it’s all about people building crazy projects in their bedrooms or sheds with enough glowing LEDs to light up the dark side of the moon. The boring truth is that Arduino requires as much code to get projects working as any software tool, while commercial implementations need constant updates and tested rollouts. That’s where Constant Integration/ Constant Development (CI/CD) approaches come in. As part of this, GitHub (where plenty of people store their code) developed its Software Development LifeCycle (SDLC) system called GitHub Actions. Arduino has taken this and created scripts that enable you to integrate the Arduino CLI into the workflow. The example they’ve developed means that each time there’s a Git commit or merge, you’re able to get a GitHub…

In the past, writing Arduino code was done via the Arduino IDE on the desktop. This has not changed and it is still the most popular way, but in this tutorial we used the new Arduino IoT Cloud, the latest way to write projects for your Arduino. It works with all Arduino boards and the ESP8266 range of boards. For this tutorial we used the free tier – and found it rather restrictive. Compilation, used to check that our code is free of bugs, is restricted to 200 seconds per day. So rather than checking the code before upload, we had to just upload and wait for an error to appear before the upload started. We were also restricted to one thing, so were unable to replicate the project for…

Quake is available on almost any device. You’ll find versions of it on Windows, macOS, Linux, Android and more. But it isn’t always as easy to set it up. If you’re using Quake On LAN, the nQuake client for desktops is the best option. Simply boot the server, launch the client, input the server IP address or hostname, and it’s time to play. It’s not quite as simple if you’re using the Quake III release for Raspberry Pi. Android users, for example, can use the various versions of Quake III available on that OS to connect to a Raspberry Pi running Quake III as a server – but not nQuake. Conversely, Quake On LAN is a QuakeWorld, Quake II and Quake III Arena server, so you would expect the necessary…

When listening back to your compositions, MuseScore makes use of SoundFonts to render a pretty good facsimile of what they’d sound like with actual instruments. It comes with a single built-in SoundFont that provides over 128 instruments, sound effects and drum/ percussion kits. This SoundFont adheres to General MIDI (GM) standards, which means instruments are correctly mapped, so your piece should sound the same on other computers. To tweak the sound of your virtual instrument(s), press F10 to open the Mixer panel, where you’ll find a range of controls spanning however many instruments you’ve set up in your piece. Use the Master Gain slider to control the overall volume, and adjust the relative volume of each instrument using the sliders. Above this is a pan control for shifting the instrument…

Once you’ve started tweaking your GNOME environment, you may think everything else is a barren desert. This is not necessarily a bad thing, though – it means lower CPU and fewer distractions for you. However, some features are really useful, so how do you balance things? Well, with the Suckless (see LXF254) dwm window manager (https://dwm.suckless.org), you get a desktop only. There is nothing fancy at all. To make it work better, you can compile in a few features and add dmenu. You can also do fancy things with xsetroot and dwmstatus, and a bunch of user-supplied status monitors. The dmenu software is useful to handle lists that appear as a drop-down in X. It is usually used for starting applications, but has a range of possibilities beyond that. Its…

Why not try SmartSim? It comes pre-installed on the latest Raspbian image, as well as being in the Raspbian repository. While it appears to have an enthusiastic following, especially among RPi users, we found the user interface to be far from intuitive. If you have a breadboard and a few basic components that you use for Raspberry Pi interfacing, you could try building real OR gates or AND gates. Although the circuits for logic gates that we simulated do work, they are not the actual circuits used in CPUs. Most processors use MOSFET transistors instead of the bipolar transistor we used. They also use more transistors to improve the performance, for example their fan-out, which is the number of other inputs their outputs can connect to.…

The elephant in the room for text-based note taking is LaTeX, a document preparation system. It’s undeniably the best tool for preparing academic reports, but perhaps a little excessive for everyday needs. Using a good LaTeX editor, such as Gummi (https:// github.com/alexandervdm/ gummi), reduces the learning curve. The PPTX files that Pandoc generated were imported by LibreOffice Impress with no errors. However, the same file opened by PowerPoint 2010 generated an error. In the resulting dialogue box, clicking the Repair button followed by Open allowed the files to be opened.…

CODING CODING ACADEMY Micro:bit ACADEMY The BBC micro:bit is an open-source micro computer. Launched in 2015/16, the BBC gave UK secondary schools the opportunity to apply for one free unit for each Year 7 pupil. The idea was that every child could keep their micro:bit for free and develop a taste for coding. Many readers will remember the original BBC Micro from our school days (1981-1994), an Acorn computer used for programming in BASIC. The micro:bit is its spiritual successor, designed to be cheap, adaptable, and a fraction of the size, ideally to be used alongside a PC or Raspberry Pi. The micro:bit features 25 LEDs, two programmable buttons, as well as a non-programmable button, an accelerometer, magnetometer, Bluetooth Smart Technology and five Input/Output rings that are ideal for attaching…

Type g++ --version to see if C++ is installed. Type mysql --version to see if MySQL or MariaDB is installed. Use your package manager to install the following packages if you don’t already have them. You can find the world database schema at https:/dev.mysql. com/doc/index-other.html. Download and unzip world.sql. To start MySQL or MariaDB (if necessary): To set the root password for MySQL (if necessary): To find out on what port MySQL/MariaDB is listening: This should indicate 127.0.0.1:3306, which is localhost on port 3306. The port number should match the value shown in the sAddress argument to the Database ctor . Try to log in to MySQL or MariaDB with mysql -u root -p and enter the root MySQL password. This password is not necessarily the same as the Linux…