Linux Voice [Issue 26]

Authors Linux Voice

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32 PAGES OF TUTORIALS
GO Use Google’s own language to create the programs of the future

ALAN POPE WE, THE PEOPLE
May 2016 £5.99 Printe d in the UK

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Inside the mind of top We hold this truth
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15
ISSUE 26 WELCOME

WELCOME TO LINUX!
The May issue What’s hot in LV#026
ANDREW GREGORY
Ben took the trip to London,
where the streets are paved with
gold, to get his hands on the new
and super awesome Raspberry Pi
3. Since then, he’s run every
benchmark he can think of on it!
GRAHAM MORRISON p22
A free software advocate
and writer since the late BEN EVERARD
1990s, Graham is a lapsed Go is a programming language
KDE contributor and author I’ve read so much about, but
of the Meeq MIDI step never had the confidence to give
sequencer. it a go. But our 6-page tutorial

M
takes you from complete
icrosoft has been in the Linux news quite a bit recently. beginner to ace image hacker.!
Firstly, by announcing that its SQL Server will run on Linux; p84
and secondly by announcing its own specialised version
of Debian Linux. Quite apart from what people may or may not think MIKE SAUNDERS
about Microsoft getting into Linux, this is a remarkable and With a new version of OwnCloud
monumental point in our favourite operating system’s history. If you out, new online bits for
were ever looking for a sign that Linux has made it, this is it. LibreOffice and the excellent
The question I’m now often thinking is, “What next?” Where’s the OnlyOffice, there has never been
next big challenge. Ben mentions in his feature on the new a better time to get away from
Raspberry Pi (p22) that more children are taking up computing at Google Docs.
p68
school. Open source is now the default. Even open data and open
government have become important keywords. But for me it’s quite
clear: the challenge is now holding on to this openness in the face of
big corporate investment.
Graham Morrison
Editor, Linux Voice

Linux Voice is different.
THE LINUX VOICE TEAM
Linux Voice is special. SUBSCRIBE
Editor Graham Morrison
graham@linuxvoice.com Here’s why… ON PAGE 56
Deputy editor Andrew Gregory
1 At the end of each financial year we’ll
andrew@linuxvoice.com
give 50% of our profits to a selection of
Technical editor Ben Everard organisations that support free
ben@linuxvoice.com software, decided by a vote among our
Editor at large Mike Saunders readers (that’s you).
mike@linuxvoice.com
Games editor Michel Loubet-Jambert 2 No later than nine months after first

michel@linuxvoice.com publication, we will relicense all of our
Creative director Stacey Black content under the Creative Commons
stacey@linuxvoice.com CC-BY-SA licence, so that old content
can still be useful, and can live on even
Malign puppetmaster Nick Veitch
after the magazine has come off the
nick@linuxvoice.com
shelves
Editorial contributors:
Mark Crutch, Juliet Kemp, 3 We’re a small company, so we don’t
Vincent Mealing, Simon Phipps, have a board of directors or a bunch of
Les Pounder, Mayank Sharma, shareholders in the City of London to
Amit Saha, Valentine Sinitsyn keep happy. The only people that matter
to us are the readers.

www.linuxvoice.com 3
CONTENTS ISSUE 26 MAY 2016

Contents
More Linux! More everything really, as long as we can play with it.

Regulars Cover Feature
News 06
We’re still waiting for Wayland, and Debian
will be late – but we can while away the 14
time playing games on MAME, which has
now been released under Free licences.

Distrohopper 08
All hail glorious Red Star, programmed in a
single night by Kim Jon-un himself after a
dream in which he learned C.

2016
Speak your brains 10
Literate dogs, our continuing shared
awesomeness, and a Russian doll of a
virtualisation question.

Subscribe! 12/56
Save money, get the magazine delivered to
your door and get access to 26 issues of THE YEAR OF THE DESKTOP
Linux Voice, in lovely DRM-free PDFs.

FOSSPicks 58
This is the year the Linux desktop becomes too pretty, to fast, too
Software that soars on the waves of functional for the computing world to ignore. We live in a golden age!
freedom like Lynyrd Skynyrd’s Free Bird
would if it were an actual bird.
Interview Feature
Core Tech 94
Asynchronous disk I/O – how your machine
does something while it’s doing else. We
can’t even walk down the street and chew 34 22
gum at the same time.

Geek Desktop 98
Now we know why we love Arch users so
much - they’re in touch with nature! Just
look at this desktop to see and then read
some of Evil Nick’s words of wisdom.

Alan Pope Raspberry Pi 3
SUBSCRIBE This man fixes bugs in Ubuntu phones. Now with built-in WiFi and a 64-bit ARM processor, the Pi is
ON PAGE 56 He’s the hero the world needs. tastier and more nutritious than ever.

FAQ Group Test
Zephyr 32 Privacy distros 50
The Linux Foundation jumps on The best bundles of the
another bandwagon: this week, tools you need to keep your
it’s the Internet of Things! communications private

LIBREOFFICE CALC
TURN TO PAGE 26
4 www.linuxvoice.com
ISSUE 26 MAY 2016 CONTENTS

Feature Tutorials

Workrave 66
Gamify your break times and save those
precious carpal bones from RSI.

OnlyOffice 68

Let’s fix Free Software! Flee Google’s tentacles and set up your own
cloud-based office system.
When the whinging’s done, it’s time to put things right. Here’s how we can heal the world.
Raspberry Pi 72
Get to grips with the powerful Linux
Reviews command line at the heart of Raspbian.

OpenStack 76
If you’ve 16GB of RAM lying around unused,
42 you too can build a cloud infrastrucure.

Philips Hue 80

NetSurf 3.4 CSS and JavaScript combine to give finesse
to our lightbulb controller.
Why borrow someone else’s rendering
engine when you can write your own
and build a lightweight replacement for Coding
Firefox completely from scratch?

OpenShot 2.0 43 Solus 1.1 44 OwnCloud Server 9.0 45
The power of crowdfunding The consumer-friendly good- This self-hostable cloud solution
brings us the latest version of this looking desktop OS is back, and does everything – and now it’s
Free Software video editor. it’s better than ever. even taking on Facebook.

Go 84
Those clever sausages at Google have a
written a smashing programming language.

Gaming on Linux 46 Books 48
Run, jump, shoot, plan tactics and win battles in This month we’re most excited about learning to Olde New Code 90
real time against friends and foes on the internet. code our games. Sharpe’s Opium War is going to be What’s next in the world of coding? Find out
Also, pretend to drive big trucks across America. the best-seller of 2017! with our soothsayer Juliet Kemp.

www.linuxvoice.com 5
NEWS ANALYSIS

NEWSANALYSIS
The Linux Voice view on what’s going on in the world of Free Software.
Opinion

Compliance?
Why is it so hard to follow the terms of a software licence? Well, it isn’t…

Simon Phipps software for users are actually a Using an open source component is
is ex-president of the comparative strength. Yes, industries with equally bound by law. But additionally:
Open Source Initiative
strong fiduciary compliance rules will want The licence aims to create a set of
and a board member
of the Open Rights to include their open source software in the liberties serving a community rather than
Group and of Open mix with the rest of their responsibilities. But a set of constraints serving a copyright
Source for America. even that burden is lighter than for holder.
proprietary software. Open source licenses Respecting the intent of the copyright
are standardised and non-negotiable, so owner is a matter of community
once you’ve learned about the ones in your conformity rather than iterative
business there’s nothing more to do. negotiation.

W
hat does “open source licence Flouting the intent of the licence is thus
compliance” mean, and does it It’s not a big deal… just as much a problem as breaching the
affect you? It certainly affects Maybe the people making a big deal out of precise definition of its terms.
VMware, which is being sued by the “open source compliance” really mean When you build a business model that
Software Freedom Conservancy. It also something else, then? Licencing maven flouts the intent of the copyright holders, you
affects Versata, which is embroiled in a Eben Moglen once shared a key insight into can expect trouble. Compliance is the act of
complex lawsuit surrounding copyrighted open source licensing. He explained that trying to flout that intent without actually
source code. What did they do, and should open source licences are best seen not as facing legal consequences. The reason the
the rest of us be worried? legal agreements but as “the constitution for VMware case in particular is so significant is
In the wake of those recent lawsuits I have a community”. While the licences we that everyone involved has understood from
seen more discussion of “open source encounter with proprietary software are the beginning that VMware’s interpretation of
licence compliance” than usual. Clearly the bilateral agreements – someone once the licence expressly aims to avoid needing
experiences of these companies have struck described them as “peace treaties” – open to engage with the communities from where
a chord, even if only with suppliers whose source licences are multilateral agreements it derives the driver support code.
business depends on fear of compliance describing a shared understanding of the
failures and mitigating that fear collaboration that’s taking place. … unless you make it a big deal
Licence compliance is a major and costly When you use a proprietary component This is clearly not a simple case of
issue for proprietary software, but the under bilateral licence terms, you do so accidental non-compliance or even one of
licence involved in that case is an End User knowing the intent – and prohibitions – of isolated wilful abuse, as both the Software
Licence Agreement (EULA), not a source the copyright holder. The way you use the Freedom Conservancy and the FSF have
licence delivering liberties beyond mere use. code is bound within the licence, and the implied. It’s likely that the root of the dispute
In fact, mere use of open source software is usage and abusage of the code is clear. If is a difference in outlook. VMware sees the
never contingent on compliance; it is freely you abuse the code, you can expect the next code as a commons to be legally ravaged,
granted by all open source licences. version to come with stricter licence terms while SFC regards it as a shared community
Of the many attributes of software or to receive preventive action from the property. The way the GPL is interpreted
freedom that could move to front-of-mind, it copyright holder. If you’re making an app for flows from those outlooks.
strikes me that the minimal licence Apple, it may well re-express the intent once Compliance – as applied to those trying to
compliance burdens for open source it sees how you try to circumvent it. blend the GPL with proprietary code – is not
primarily a matter of logic, law and licences.
When you build a business model that flouts It’s about trying to circumvent the
consensus of the community behind the
the intent of the copyright holders, you can code with clever legal loopholes and

expect trouble down the line linguistic sophistry. Is it any wonder that the
community wants to fight back?

6 www.linuxvoice.com
ANALYSIS NEWS

Raspberry Pi • Wayland • Steam • MAME • Mint • FFmpeg • Collabora

CATCHUP Summarised: the biggest news
stories from the last month

Raspberry Pi 3 is here Wayland will not be Steam on Linux reaches
1 The Raspberry Pi has now 2 default in Fedora 24 3 1,900 games
overtaken the Amstrad PCW Wayland, the replacement A decade ago, the idea of
(remember that?) as the UK’s most for the ageing X.org display server, Linux being a killer games platform
successful computer. Now we have a has seemed just around the corner for was... well, laughable to be honest.
new version, the Raspberry Pi 3, which many years now. Fedora developers But now, largely thanks to Steam, it’s
is 10 times faster than the original were hoping to use it as the default superb, and we have over 1,900 games
model thanks to its quad-core 1.2 GHz in their next distro release, Fedora 24, to choose from. Onwards and upwards!
CPU. In addition, it has integrated Wi-Fi but it turns out that it’s just not on par
and Bluetooth – so no need to add with X.org for features. It’s a shame, as
more USB dongles! This makes the Wayland offers many benefits in terms
dinky device very usable as a simple of simplicity and performance, but we’ll
home desktop machine. For Pi expert have to wait a bit longer. Wayland will
Ben Everard’s assessment of the new still be an option in Fedora 24 for those
gizmo, turn to page 22. who want the bleeding edge.

MAME released under Collabora Office 5.0 is Debian 9 “Stretch” release
4 Free Software licences 5 now available 6 date slips slightly
MAME, the rather awesome LibreOffice is great, but if you Debian often gets flak for
Multiple Arcade Machine Emulator, is want to roll out an open source office its slow-paced release schedule, but
one of our favourite projects, letting us suite in an enterprise, you’ll probably we appreciate that it makes the distro
relive the glory days of 1980s and want commercial support. Collabora super-solid and great for use on servers
1990s arcade machines. Until now, Office 5.0 is based on LibreOffice 5.0 (with and in enterprises. The next release,
MAME was released under a licence some extra goodies backported from Debian 9 (aka “Stretch”) will now
that restricted use in commercial 5.1) and comes with three years of arrive a bit later than expected, due
activities – to stop arcade operators long-term support. Meanwhile, to integration of the upcoming Linux
from building MAME cabinets, and Collabora is beavering away on a 4.10 kernel. The current plan is for the
keeping the original machines going. version of LibreOffice that works in the distro to go into “freeze” – so no more
Now MAME has moved to GPL and cloud, to compete with Microsoft’s features added – on 5 February 2017,
BSD, eliminating that restriction. Office 365 offering. with the final release to follow shortly
www.mamedev.org www.collaboraoffice.com after that.

Linux Mint website falls FFmpeg 3.0 released
7 foul to crackers 8 If you use VLC, Xine, Blender
We often recommend Linux or Google Chrome, you’re
Mint as one of the best distributions using FFmpeg. This provides libraries
for new Linux users, offering a polished and tools for handling a vast range of
desktop and plenty of support for extra multimedia formats – and it’s just going
drivers and multimedia formats (often from strength to strength. Version 3.0
via proprietary software, admittedly) brings about many improvements and
out of the box. But in late February the optimisations, such as 30 new filters,
Mint website was cracked and ISOs of VP9 hardware acceleration, a stable
the distro were replaced by a version AAC encoder, and a Cindeform HD
containing malware. The problem was decoder. Expect it in the next round
found early on, but it reminds us that of distro updates, or if you’re feeling
Free Software is only as secure as the adventurous, grab the source code here:
machines that serve it up. www.ffmpeg.org

www.linuxvoice.com 7
DISTROHOPPER LINUX DISTROS

DISTROHOPPER
What’s hot and happening in the world of Linux distros (and BSD!).

Subgraph OS
Secure and user-friendly

T
he recent security issues in Linux
Mint show that even the most
secure of operating systems isn’t
always secure enough. On the other hand,
an ultra-secure Linux distro that’s also easy
to use for the average user isn’t easy to
come by. That’s where Subgraph comes in,
offering an array of security features that are
normally only accessible to more
experienced users. Subgraph mitigates the
resource-hungry nature of such systems,
and it can be run even on lower-end
machines, making it even more accessible.
The distribution is aimed at journalists,
activists and others who may have good Subgraph OS could prove to be hugely useful for journalists and citizens of authoritarian regimes.
reason to require this level of security, but
might not have the technical knowledge to system imaginatively called Subgraph Mail, applications from each other, so if one is
set it up on an existing Linux distro or deal which integrates OpenPGP. As expected, the exploited, others are less likely to be
with distributions aimed at advanced users. distro also comes with Tor, which is used affected, reducing the chances of sensitive
Subgraph comes with the Security- with any application that performs information being accessed.
Enhanced Linux (SELinux) kernel module communications, through its inbuilt A final release of Subgraph OS was
preconfigured, already saving one major Metaproxy software, while applications supposed to be nearing completion back in
headache. It also has a variety of useful allowed to make communications are 2014, but as of 2016 it has yet to move past
features such as full disk encryption and limited. Another useful feature is a system the pre-alpha stage, though the developers
access to an in-house encrypted mailing called Oz, which isolates individual indicate that things are moving along nicely.

Red Star OS
Don’t actually install it

N
orth Korea’s homegrown Linux renamed with their icons changed, though
distribution has been undergoing some aspects have undergone more
some visual tweaks, dropping the substantial changes. Firefox has been
ancient default KDE 3 interface in favour of renamed to “Naenara” and is used to browse
something that looks like someone was sick the country’s “Kwangmyong” intranet, since North Koreans are apparently impressed by
on OS X. The distribution is only available in internet as we know it is only available to a excessive Compiz effects.
Korean, there is no 64-bit version and it is far small fraction of the population.
more oppressive than other state-sponsored Wine also comes pre-installed, presumably with things such as the firewall, among
Linux distros such as Cuba’s Nova and so that the regime could have a smoother other paranoid-fuelled additions. One thing
Venezuela’s Canaima, which also both transition when switching the country’s that the regime is keen to combat is the
feature newer software and desktop Windows computers to Red Star. The passing around of western film and music,
environments. The distribution consists Fedora-based system reboots itself or so Red Star also watermarks all files so they
mostly of existing software packages, throws errors if the user attempts to tamper can be traced. Nice.

8 www.linuxvoice.com
LINUX DISTROS DISTROHOPPER

News from the *BSD camps
What’s going on in the world of FreeBSD, NetBSD and OpenBSD.

“S
low and steady wins the race” is the
mantra behind BSD, in that updates
tend to be quite unexciting, but as a
result provide the stability and reliability for
which the operating system is famed.
DragonFly BSD saw such updates, with a
4.4.2 bugfix release after the meatier 4.4
update was released late last year. The
PC-BSD developers have released version
0.8.8 of the Lumina Desktop Environment,
consisting mostly of bugfixes and minor
tweaks that make it more straightforward to
set up, as well as out-of-the-box support for
NetBSD. The Lumina Desktop aims to hit 1.0
by July of this year alongside FreeBSD 11,
and will deliver a lightweight Qt 5 desktop
environment across Unix-like systems.
On the other hand, the FreeBSD team has The lightweight and customisable Lumina Desktop running on PC-BSD.
released a report highlighting the progress
made throughout 2015, and it’s pretty and X.Org, support for more ARM hardware coming to an end. Website maintainers had
substantial. Some achievements include and much more. reportedly been receiving harassing emails
assessing whether to accept GPLv3 code In the OpenBSD camp, it seems that a for years since the system uses Comic Sans
into the source repository, updates to MESA 14-year-old joke by developers may be Serif as the default font for HTTPD status
pages and some visitors were extra-enraged
The FreeBSD team has released a report when experiencing 404 errors in the font. A
patch has been offered and it has become
highlighting the progress made throughout apparent that the use of the font was an
attempt by some FreeBSD folks at “annoying
2015, and it’s pretty substantial hipsters into donating money” to the project.

MenuetOS and KolibriOS
Digging deep into the realms of obscure operating systems, we find MenuetOS
and its derivative KolibriOS. Both operating systems are ambitiously written
entirely in the FASM assembly language and are incredibly tiny. (Many
distributions of each operating system are small enough for their installers to
fit on a 1.4MB floppy disk!) On top of this, the systems can run on as little as
8MB for RAM and 1MB of disk space in the case of KolibriOS, while providing a
full graphical desktop environment. Needless to say, bloatware isn’t really an
issue here.
As if this weren’t impressive enough already, both systems can run on
incredibly old hardware (i586 processors) and still boot within a few seconds.
To show off even more, KolibriOS is capable of full 1080p video and comes with
more games than any other type of application, ranging from simple 2D
minesweeper-like affairs to the likes of Quake and Doom. Its video drivers are
based on the open source Radeon driver and are also shown off with support
for eye-candy such as transparent windows.
What immediately comes to mind here is the possibility of installing this on a
Raspberry Pi, though since both only support the x86 architecture, this would
unfortunately not be possible. Other things which aren’t possible include using
either MenuetOS or KolibriOS as practical working desktops, since they lack
basics like office suites, though there is a port of NetSurf (the go-to web KolibriOS makes even the likes of Puppy Linux (which is genuinely
browser for smaller operating systems) in the works for KolibriOS. tiny) seem huge and bloated by comparison.
These ambitious projects, which are currently offered in three languages and
support a multitude of filesystems, are worth keeping an eye on to track their 64-bit version of MenuetOS is released under a proprietary licence that allows
development. Both operating systems are licensed under the GPL, though the for non-commercial use only.

www.linuxvoice.com 9
MAIL YOUR LETTERS

YOUR LETTERS
Got an idea for the magazine? Or a great discovery? Email us: letters@linuxvoice.com

DOGITAL RIGHTS MANAGEMENT
Every month my copy of Linux Voice arrives via by my
neurotic, letterbox-guarding pet dog – always just about
readable by me, but at the same time badly enough
STAR traumatised to make it unfit for any kind of redistribution.
LETTER Just one of those things or a cunning low-tech
implementation of DRM via special dog attracting paper?
And will I be prosecuted for circumvention if I’m caught
with sellotape?
Simon French

Andrew says: Funnily enough, mine does the same. Our subscriptions team has no thumbs, so cannot take your
Here’s a gratuitous picture of the ravening beast. calls. Don’t phone him – turn to page 12 instead!

A WHEEL WITHIN A WHEEL BITS AND BOBS
I currently use SUSE “Tumbleweed” and Mint “LMDE” at Has anyone noticed the pushing of x64 distros,
home and I have been using Linux and free software for particularly with those other magazines that offer a disc
about 20 years. While I know my way around Linux and – hmm hope no one here started the trend, or act of
can sort out most problems eventually, I wouldn’t consider sabotage! That’s great and I make use of such a distro
myself to be a programmer or hacker. myself. No problem then. Well actually there may be. For
My work-supplied laptop is currently running Windows many Windows users are using 32-bit, state-of-the-ark
7 and will shortly be upgraded to Windows 10, with all of devices; don’t tell Microsoft!
its telemetry and privacy concerns. I have asked my work Doesn’t the push for x64 distros in Linux magazines go
if I could run my upgraded laptop on Linux, but they have against part of the message that we all are trying to give
said that I must run Windows for corporate security, out: namely that it’s easy to switch to Linux, which still
network, some proprietary programs and for support runs brilliantly on older systems.
reasons, which also means that I can’t have a Linux For many of us who are lucky enough to have newer
dual-boot option installed. machines then all is well. But I wonder if this switch has
As I value my security and privacy and trust just come a little to early, as I see that many people are
the security of Linux, as a suggestion, I happily using older machines, running Windows XP as
wonder if you would consider a project or well! What are your thoughts on this? Does it matter?
tutorial, whereby an existing Windows Oscar S
installation (eg the work supplied laptop)
could be run as a virtual machine under a Andrew says: If you’re trying to evangelise, the
non-installed Linux distribution (from say a way to do it is with 32-bit distros. A 64-bit distro
USB drive), allowing for the running of its native is nice to have for the already converted, but the
Windows corporate log ons, corporate printer poor huddled masses on old hardware running
access and drivers and exclusive proprietary unsupported Windows XP installations need
Windows programmes when required, but use Linux for all every chance they can get of having a working
other uses and also have the Windows privacy and system, and that
security concerns addressed by Linux, eg a firewall, means downgrading
without having to re-boot. If this is practical, I would think the OS to match the
that there could be other people in the situation where this hardware. Even 32-bit,
approach might be of interest. Linux is going to be a
Malcom, Scone massive speed boost
Andrew says: Noted. We’ll look into this. over old XP.

10
YOUR LETTERS MAIL

ELECTRONS
I just wanted to say a big thank you for offering your
magazine in PDF and ePUB formats. I’m partial to PDF
because you can mark it up and the markups stay with
the file, unlike with the ePUB format.
I recently cancelled all of my digital subscriptions with
Zinio because of numerous problems experienced over
the past four years, either with their app or with account
snafus. I recently tried a subscription with your main
competitor via Google Play Newsstand, but I’m not able to
verify my subscription, so I’m going to cancel that
subscription as well. I’m glad there are some companies,
such as Linux Voice, who know how to do digital
subscriptions right. Keep up the good work.
Kurt Meyer If you’ve
subscribed, you
Andrew says: Thanks for the praise! We are trying should be able to
our best. And in the UK, print magazines attract no read Linux Voice
VAT, whereas epubs and PDF incur a 20% tax to Her on any device you
Majesty’s Revenue and Customs. So we’re doing choose. That’s
the right thing (saving the trees, etc) despite being how we do things
round here!
incentivised not to.

MORE PRAISE!
I am sure you are tired of hearing how awesome you are,
but I will say it again anyway. You are awesome! Keep up
the good work.
And to put my money where my mouth is, I will
re-subscribe to the digital version once my current one
runs out. You guys need all the support you can get. Have
gotten some of my colleagues and friends to subscribe
also. That’s it. Hope this letter encourages more people to
do the same.
Gabriel Ozoani

www.linuxvoice.com 11
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www.linuxvoice.com 13
FEATURE 2016: THE YEAR OF THE DESKTOP

THE YEAR OF THE DESKTOP
2016
We spend a month
B
ack in the olden days, there were know what’s out there, and we’ve never taken
things called ‘desktop fights’, where a practical, visual look at what many of the
trying the most the merits of one desktop would be most common desktops offer, until now.
awesome desktops to pitted against the merits of another. The We’ve spent the last few weeks playing

to work out results were often polarising and seldom
led to any insight, and that was because
with what we consider the 10 most popular
Linux desktops, and we’ve attempted to
when best to use there couldn’t be one ‘best desktop.’ There look at each objectively, regardless of the
one, two or three. are just too many different ways to use your distributions we’ve been running them on. We
computer, and so many different kinds of haven’t been trying to work out which was
users. This is what makes Linux unique – if best, but rather we’ve looked at what kind
you don’t like something, you’re encouraged of users may be able to get the most out of
to improve it or try something new. them. Most of these desktops can even be
Rather than being corralled into one way installed alongside your current favourite,
“We’ve spent the of doing something, such as with Apple’s especially with one of the big distributions,
OS X and Microsoft Windows, for example, so you don’t need to make any significant
last few weeks we can all decide for ourselves depending commitment. Just give them a try and see
playing with the on our own requirements – whether that’s a what you think. The fact that you can do this
10 most popular command line interface for a Raspberry Pi is still amazing, all these years after the old
or a 3D cube running on KDE on a powerful KDE versus Gnome debate, and we can’t
Linux desktops” PC. But before you can decide, you need to encourage you enough to give it a go.

14 www.linuxvoice.com
2016: THE YEAR OF THE DESKTOP FEATURE

UNITY 7.4
Ubuntu’s desktop is moving closer to convergence with its mobile devices.

3
2

8 5

The one element that really by default, sending your searches to
differentiates Unity from other desktops Ubuntu servers and saving you from
Unity
is its all-powerful ‘Dash’ interface. One Amazon products being returned in
press of the Meta key or a click on the any lenses. But it also disables useful 1 Dash One click here and you can search

Ubuntu icon on the top-left and the integration with non-commercial everything, launch apps and explore content.
2 Lenses Data is pooled from all kinds of
default search scope appears, letting online resources like Wikipedia, which
‘aggregated scopes’, a little like having Google on
you quickly access your applications or is disappointing. If you want to turn it your desktop.
files. Clicking on the small icons below back on, the option can be re-enabled in 3 Powerful filters Focus on specific results using a
lets you view applications, files, videos the Security & Privacy panel. keyword search.
music and photos. 4 General settings As with Gnome, use this quarter

These are now called ‘Aggregation Dash, Dance, Prance of the screen for networking, switching users and
Scopes’, or lenses, and they’re Unity also does its own thing with settings access.
5 App store Not-Unity specific, but the UI and dash
aggregating content from different menus and window navigation. For
integration makes this a powerful feature.
sources in an attempt to make things many applications, all menus will 6 Dash Plugins Add more integration by by
easier to discover. The music lens has appear in the same place as part of the installing plugins.
the potential to include files on Google top panel, regardless of whether the 7 Settings One panel is used for all the major Unity

Drive, for example, or tracks held on application is windowed or near the top. settings, including turning on online search.
8 Panel Scale this and the top menu from the
Amazon, and the back-ends that bring Unless you’ve used OS X, which does
in this data are called ‘scopes’. Scopes the same thing, this can take some display config panel.
are a big part of the Ubuntu Phone getting used to. But it does help Unity to
operating system too, where they’ve feel the most integrated because most
become the central way of navigating applications look and behave the same.
through the operating system. GTK applications in particular, like
We’re also happier now that Ubuntu Firefox and LibreOffice, feel just at home
16.04 no longer enables online scopes on Unity as they do on Gnome.

www.linuxvoice.com 15
FEATURE 2016: THE YEAR OF THE DESKTOP

GNOME 3.18
A desktop that’s easy to use, minimalist and doesn’t get in the way.

3
1 2 4

6
7

VHS vs Betamax. Xbox vs Playstation. developer’s conference. Gnome doesn’t
Gnome 3 iPhone and Android. Technology is have scopes nor the persistent panel on
littered with rivalry, and it used to be the the left, and it’s taken a long time to
1 Activities Moving the cursor here, or using the case that Gnome and KDE were often reach maturity and acceptance, but it’s
Meta key on your keyboard, launches Gnome’s pitted against one another. But this definitely getting there. Each release of
overview of everything you’re doing.
battle was more for the media – like the last 18 months has been fantastic,
2 Search From the activities overview, you can

search and select files and applications.
Blur vs Oasis – than it was a reflection and we’re seeing it on more and more
3 Notifications Messages from your applications of the users and developers, and that’s laptops. The latest version includes
now appear here and re-appear with a click of the. because both desktops have always Google Drive integration and a lovely
4 User control Logout, change networks, enable done things differently. Gnome is for new calendar; the version before that
the VPN and open the settings. people who like to get things done, and updated notifications and improved
5 Workspaces These work just like virtual
that’s because there’s little in the way of Nautilus, the file manager.
desktops – drag your windows into a new space
distraction. By default, for instance, Desktop integration is another plus
and switch quickly with shortcuts.
6 Apps View See your running applications, or there are very few settings to tweak, but and one that can’t quite be rivalled by
choose from files and apps to launch. each and every option is considered other desktops. This is thanks to so
7 File manager Nautilus is an integral part of and important, from the built-in privacy many third-party projects choosing
Gnome, complete with tabs and integration with settings to the network manager. GTK, the toolkit used to develop
services like OwnCloud. Gnome, being used to develop their
8 Panel Choose between multiple windows and
Integration own projects, from Gimp to Firefox and
use the matrix to open the application launcher.
Gnome’s unique take on application LibreOffice. For advanced users, we also
launching and management, where a like the way the internal configuration
hotkey or screen corner is used to open options can be changed and updated
a shell, shares the same roots as in realtime, especially when using
Ubuntu’s Unity. Both desktops came gnome-tweak-tool, giving you the best of
from ideas shared at the same all worlds.

16 www.linuxvoice.com
2016: THE YEAR OF THE DESKTOP FEATURE

KDE PLASMA 5.5
A great choice for users who want a desktop that bends to their will.

4
2

7 6

KDE is one of the two desktops that is KDE’s great strength – there’s a KDE
most people associate with Linux, and tool or application for doing almost
KDE Plasma
while both Gnome and KDE started out everything, and many of these are near
looking somewhat similar, KDE is the the best in their class. 1 Widgets You can add multi-functional widgets to

only one to have stuck with a simple the background and to any number of panels.
2 Settings System-wide options are all in the same
launch menu and a panel at the bottom, Dolphins with lasers
place, and you can change almost anything about
so beloved by Windows XP users. The file manager, Dolphin, is the perfect anything.
Many of the default choices are example. You can quickly split views, 3 Plasma Search Press Alt+F2 to search the
sensible and hide the technical aspects preview multimedia files, scale the internet and local files, look up words and perform
effectively. The Settings panel, for icons and sort by any number of file calculations.
4 KDE Apps Applications such as Dolphin that use
example, offers the KDE-flavoured attributes, including image resolution
control over almost everything, from and album name, if you wish. The KDE’s libraries are well integrated with the system.
5 Konsole The shell can be launched separately, or
changing the theme, the panel, the terminal emulator is another example,
from apps like Dolphin and Kate.
background and icons to adding users, and is our favourite regardless of 6 Notifications KDE supports both on-screen
configuring the VPN and integrating desktop. It’s tabbed with split views, has notification and in-panel notifications.
online accounts. Each page is well bookmarks, profiles and an infinite 7 Panel Add as many or as few panels as you like,

designed and easy to use, and while the scrollback. But it’s the small things that floating, vertical or horizontal.
8 OpenGL and Wayland Scalable drawing is
icons themselves can be a little small, make the difference, like when you’re
we feel this integration is the best of searching for a word in the buffer the possible and Wayland support is coming soon.
any desktop. console highlights new instances of
There’s a KDE-flavoured app for that word as they appear, and these
almost every task, and if you’re a KDE small differences are littered
user, you’ll likely prefer the way those throughout KDE, whether it’s Digikam,
applications are built. Over and above the Caligre office suit, Krita illustrator or
the ability to configure everything, this simply re-configuring the dock.

www.linuxvoice.com 17
FEATURE 2016: THE YEAR OF THE DESKTOP

MATE 1.12.1
A retro desktop that’s now going from strength to strength.

Mate (pronounced ‘Mah-tay’) shares a similar origin to
Cinnamon, and that was Gnome 3 changing its 1

desktop – replacing the panel and launch menu with a 2
shell that acts much more like a launcher on a mobile
phone. Mate started out as a fork of Gnome 2.x,
whereas Cinnamon modified GTK 3, but both preserve
the original desktop metaphor of the previous era.
Mate, in particular, is brilliant for the many users who
liked the top/bottom panel approach of Gnome 2. We
tried the latest Ubuntu Mate 16.04 (a late beta at the
time of writing). It’s a lovely desktop that reminds you
just how polished Gnome was when it wore a
charcoal grey palette and chunky icons. It’s quick too,
reminding you that, for once, your computer is many
4
times more powerful than it was just 10 years ago.
The desktop wasn’t the only thing that forked: there 3

are Mate versions of many of the Gnome applications,
including the old file manager (Caja), the image viewer
(Eye of Mate) and the terminal emulator. It may sound Mate
like Mate is more of a time capsule from 2011, but it’s
not. GTK 3 applications work natively and the only real 1 Launch Menus Mate looks like Gnome from 2011, and that’s a good thing. 2 Panels All the same

differences come from usability and aesthetics, which applets are available and they’re all you need. 3 Mate apps There are native apps for Mate, just as
is something we’re very happy about. there are for KDE and Gnome. 4 Screen locking Windows can be locked to parts of the screen.

CINNAMON 2.8.6
People of the world. Spice up your life!

Like Mate, Cinnamon was developed to maintain the
old desktop metaphor. But rather than forking Gnome
2.x, it built a new desktop atop GTK 3, forking
applications where necessary. The project was
1
started by the Mint development team, which is where
the most recent version can usually be found, but it
hasn’t stopped Cinnamon being ported to the vast
majority of other distributions.
Thanks to using a modern API, Cinnamon’s
minimalism doesn’t extend to its appearance or
adaptability. Fonts can be scaled, for instance, and
3 they can all be updated in real time using a slider. The
5 theme engine is equally responsive, and while there’s
nothing like the amount of control you find in KDE, you
2 can swap-out window decoration, icons, window
buttons and desktops – all saveable as a theme and
configurable through the settings panel. All this visual
Cinnamon finesse is because Cinnamon uses ‘Muffin’, a fork of
the Gnome 3 window manager, bringing together the
1 Window management Window snapping, hot corners and great screen rendering. 2 Native apps best of the classic design with modern graphics
and panels Each version of Cinnamon brings more modern convenience. 4 Applets Not as manipulation. We also love the way panel applets can
advanced as KDE’s, but more practical and less resource hungry. 5 App launcher This has a great be installed and even downloaded in-line, much like
interface, making it easy to find what you need without resorting to Unity’s Dash. you can with KDE’s own downloadable GUI elements.

18 www.linuxvoice.com
2016: THE YEAR OF THE DESKTOP FEATURE

XFCE 4.12
The best combination for speed and visual prowess.

Despite their lack of power, older computers used to
start more quickly. It would take a second or two for a
2 Commodore 64 to go from power switch to BASIC,
and the Amiga booted to Workbench in seconds if you
1 had a hard drive. Modern desktops seems to waste
much of their new power on shiny effects, drop
shadows and even wobbly windows, but this doesn’t
happen with XFCE. It’s a great-looking, powerful
3
desktop that doesn’t steal too many cycles from your
CPU, nor memory from your RAM, while still
managing to look sleek and modern.
XFCE is stable and comprehensive, including
everything you need, from session management and
4 an application finder to its low-resource yet super-
powerful Thunar file manager. Like KDE and Gnome, it
feels like a complete desktop, one that adds character
to the way you interact with your computer, even if all
you’re doing is launching full-screen applications. It’s
XFCE also stable and mature, with few changes being made
from one release to another. It’s easy to see why so
1 Thunar The all-conquering file manager. 2 Eye candy It may be austere, but there’s lots of visual many old Gnome users love XFCE, and why you don’t
potential too. 3 Panel items Add lots of new things to your panel. 4 Settings A mature set of think about it much. It does what it’s designed to do
settings panels can change almost anything. with very little fuss.

LXQT 0.10
Lightweight doesn’t always have to be built around the GTK look and feel.

When it first appeared, we were hugely impressed by
a desktop called Razor-qt. Built using very little but the
Qt 4.3 API, it felt like a super-slim version of KDE for
users who didn’t need anything other than a panel and
1
a launch menu. It didn’t even include a window
manager, although most of us used either KDE’s
KWin, or OpenBox. Which is why we’re happy to see 2

the project survives, merged with components from
LXDE and reborn as LXQt.
Like Razor-qt, you have to select a window manager
before starting, so this isn’t the most friendly desktop,
but this kind of choice doesn’t bind you to your chosen
environment in the way it does on Gnome or KDE, for 4
example, even though it’s perfectly acceptable to use
3
KWin with Gnome, or Mutter with KDE. This is also the 5
first of the really minimum desktops we’ve looked at.
Other than providing an environment for running your
applications, there’s very else little to see. There’s a
modifiable panel and launch menu, a GUI for sudo LXQT
privilege escalation, a new Wayland-compatible status
notifier and a brilliantly simple file manager called 1 File manager Fast, and works just like KDE 2. 2 Settings Native panels for changing most

PCMan. The rest of LXQt is simply an ultra-fast options. 3 Theme and Effects Basic but great-looking effects. 4 Powerful panel The panel can be
desktop built with a modern Qt look and feel. themed and widgets added. 5 Launch menu Open this with Alt F1 on the keyboard.

www.linuxvoice.com 19
FEATURE 2016: THE YEAR OF THE DESKTOP

ENLIGHTENMENT 17.6
If you miss gradients and you’re looking for darkness, this may be for you.
This is a famously lightweight resources, and it races along on
desktop that feels like it was modern hardware. You even get
designed by an Amiga demo to select the text size before you
crew. It’s full of widgets and get to the desktop, which is a
panels with shaded gradients brilliant feature if you’re running
and light flares. Everything this on a high DPI display, and
scrolls into and out of view like there are plenty of modules and
part of a parallax starfield, and configuration options to play
there are subtle animations with with. Even the window selection
almost every element, from the is unique, because you select an
menus to the battery widget. But application by rolling your cursor
this is still a powerful desktop over the window, which is
that requires relatively few enough to activate the process.

DEEPIN 15.1
Sometimes, looks are everything.
Deepin is a both a relatively new used to configure everything
Linux distribution and an from two-finger scrolling on your
associated desktop touchpad to keyboard shortcuts.
environment. It looks wonderful The lovely aesthetic of the
and behaves quite differently to user interface is carried over to
other desktops. In particular, all its suite of native applications.
settings are hidden within a There’s a music player, a video
vertical panel that takes up the player, an app store and a
entire right side of your screen, terminal. They all feature the
smoothly sliding into and out of same polished transitions and
view when you need it. It’s a little graphical finesse, making this
like the notification area in one of the best-booking
recent versions of OS X, and is desktops we’ve ever tried.

XMONAD
Minimalism is a feature.
To finish our look at desktops, see. Absolutely nothing. Press
we wanted to include one of the Alt+Shift and return and you’ll
several excellent tiling window get a full-screen terminal. Press
managers available for Linux. that combination again to get
These aren’t strictly ‘desktops’ another. Now press Alt+Space
because their main feature is the to switch between tiling modes.
lack thereof, but they perform And so it continues. It’s ultra-fast
the same function, giving you an and ultra-responsive, and after
environment to launch and you’ve learned a few keyboard
manage running applications. commands, and added the
Xmonad is written in Haskell xmobar and dmenu modules, it’s
and takes some getting used to. a brilliant way to interact with
To start with, there’s nothing to your computer.

20 www.linuxvoice.com
2016: THE YEAR OF THE DESKTOP FEATURE

WHICH DESKTOP IS BEST?
We recently asked our readers on the 300ms delay between workspace version that must not be named and
LinuxVoice.com to tell us which switching and a few other minor things, never looked back, because it just helps
desktops they preferred and why. We but it’s mostly vanilla Unity.” me get stuff done while not standing in
had many responses, and the answers Just working and ‘boring’ seemed my way.”
were as varied as you’d expect, with no important for users who just wanted to Electronic Penguin praised the
clear consensus on which desktop was get on and do their thing. configuration elements of XFCE: “To
leading, despite many commentators Jack “Gnome 3. Just gets out the way me it seems to… [have] the best balance
settling on one desktop or another. and lets me get on with things, as between functionality and systems
Here, we’ve selected a few of our well as looking good. The shortcuts resources staying out of the way.”
favourites. and keys just work for my brain, and I Tommi Helander and Peter Warrington
saif: “I like Unity. It seems to me so really like for Super maps to Activities both plumped for KDE, ith Peter finding
many people dumped Unity, and overview, and how I can drag and out about KDE 5 from our very own
Ubuntu along with it, because they drop windows between monitors and humble Linux Voice podcast. How
didn’t like change. Along with this came Workspaces.” that’s public service broadcasting?
an enormous amount of vitriol and hate Nick: “I love myself some Cinnamon. We used to wonder which desktop
for something that is what Linux is all Not just because the name summons would come to dominate, but it has
about…more choice and a platform for memories of Christmassy, winterly become clear that one of Linux’s great
innovation. Since the early days, Unity tastes, but also because it looks strengths is that there isn’t a single way
has improved and those who stuck sufficiently boring, so I can get some of doing things, and different desktops
with it helped it get better.” work done while not being distracted reflect the different needs of their users.
blahdeblah: “Unity, because Ubuntu just by wobbly windows. Joking aside, That so much choice still flourishes on
works out of the box nowadays, and I switched to it, when Gnome2 was Linux is something we can all be proud
I like boring. I’ve tweaked it to remove abandoned in favour of the Gnome of, and we think, celebrate.

CHOOSE YOUR PERFECT DESKTOP

UNITY GNOME KDE MATE CINNAMON
BEST FEATURES BEST FEATURES BEST FEATURES BEST FEATURES BEST FEATURES
1 Brilliant integration 1 Distraction-free desktop 1 Integration with many 1 Gnome at its old-school 1 The best of old and new
2 Consistent, clear and 2 Easy to use KDE/Qt applications best desktop ideas
easy to use 3 Very close to being a 2 Configure almost 2 Fast and lightweight 2 Excellent theme options
3 Convergence turns standard for Linux desktop everything 3 Modern and well 3 Built atop GTK 3, so
mobiles into desktops environments 3 Looks brilliant supported modern applications fit well

XFCE LXQt E17 DEEPIN XMONAD
BEST FEATURES BEST FEATURES BEST FEATURES BEST FEATURES BEST FEATURES
1 Very stable 1 Quick and responsive 1 Unique desktop 1 Looks fabulous 1 Tiny resource
2 Thunar is a brilliant file 2 A Qt/KDE look and feel appearance 2 Has its own collection of requirement
manager 3 Transparency effects 2 Themes are easy to custom software 2 Fast and efficient
3 Comprehensive without prohibitive system create 3 Simple, unified settings 3 Zero distractions by
configuration options overheads 3 Stable and fast make it easy to learn graphical frippery

www.linuxvoice.com 21
FEATURE RASPBERRY PI 3

RASPBERRY PI
D
Four years after the first board came out,
the Raspberry Pi enters the 64-bit world.
epending on how you count leap-year
anniversaries, 29 February 2016 was either
the fourth or first birthday of the Raspberry Pi.
popular with tinkerers who want a small low-power
computer and makers who are finding new and
3
around the Raspberry Pi, and the computer’s proving

Either way, four years have passed since the first went interesting ways to utilise the input and output
on sale and promptly crashed their online shop. capabilities in their projects.
We’ve watched the original board evolve first into However, the Pi is at its heart a board designed for
the B+, then the Pi version 2, and finally, on Monday education, and in this area there’s been huge progress.
29 February, the Raspberry Pi Foundation released Through its Picademy program, the Pi Foundation
the Raspberry Pi Model B version 3. The new board is training teachers, and we’re starting to see a real
promises more features and better performance for impact from their educational work. The number of
the same price ($35 or about £27) and the same size. students taking computing at A-Level (16–18 years
Sales have continued to grow, and with 8 million old) increased by almost 30% between 2014 and
units sold, the Raspberry Pi is now the best-selling 2015, and while there are many reasons for this,
British computer of all time. Unsurprisingly, these at least some of the credit goes to the work of the
sales figures mean that there’s a huge community Raspberry Pi Foundation inspiring students.

Through its Picademy program, the Raspberry Pi
Foundation is training teachers, and we’re starting
to see a real impact from their educational work

22 www.linuxvoice.com
RASPBERRY PI 3 FEATURE

THE RASPBERRY PI MODEL 3
A closer look at the new board.
Place a Raspberry Pi 3 model B next to a Raspberry Pi
2 model B and it’s hard to tell the difference. The most
obvious change is that the power and activity LEDs
have switched sides and in their place, a small,
innocuous white block holds the biggest difference
between the two devices – it’s an aerial. The Pi 3, with
its onboard Wi-Fi and Bluetooth, is the first device in
the Pi family to have integrated wireless
communications.
Most people with RasPis have been using USB Wi-
Fi, so the onboard Wi-Fi isn’t so much a new feature
as a cost saving of around £10, since there’s now no
need to buy a separate Wi-Fi dongle. There’s a second
advantage in that the data through the Wi-Fi will no
longer take up bandwidth on the USB bus. This leads
to better performance if you’re also heavily using other
USB devices, for example, streaming data from the
network directly onto a USB memory stick.
Bluetooth is probably less important to most people
than Wi-Fi. It will enable you to use Bluetooth mice
and keyboards (note: not all wireless devices are
Bluetooth-enabled, so check before buying). This will
also enable you to use Bluetooth audio in headphones
and external speakers.

Pi for all the projects
The Internet of Things (IoT) is a tech buzz-phrase example We don’t see this being a particularly popular
that’s rarely left out of press conferences in 2016, and option initially, because current IoT devices aren’t easy
the launch of the Pi 3 was no exception. With Wi-Fi to connect with this sort of setup. However, previous Eben Upton (centre)
and Bluetooth, the new Pi is more attractive in this versions of the Raspberry Pi have proved popular with from the Raspberry Pi
Foundation celebrates
area than earlier models. There are two parts to the small businesses developing new products, and we
the launch of the Pi 3
IoT: the things themselves, and hubs that are used imagine that this could well be the same. Look out for
with Claire Doyle and
to control the things. While the Raspberry Pi is small, Pi 3-powered smart home products in the near future. Richard Curtin from
cheap and low-power by computer standards, it’s The second big change is even harder to see: Element 14 (the company
large, expensive and high-power by IoT standards, the new System on a Chip (SoC). There are four manufacturing the new
and this makes it unattractive for most things that Cortex-A53 processing cores heart of the Pi 3 running boards).
could be connected to the internet. It is, however, at 1.2GHz. This compares with four Cortex-A7 cores
well provisioned to make an in-home hub for a smart running at 900MHz (overclockable to 1GHz) for the
home setup. A Raspberry Pi could control your previous model. The biggest difference between the
lighting over Wi-Fi and heating over Bluetooth, for two chips is that the new processor is 64-bit while the

Wild speculation
We’re not privy to the internal discussions of the and B. The model A is most useful for robotics due couple of years. The most obvious upgrade now is
Raspberry Pi Foundation, but we’re not going to let to its small size and low power, so adding wireless to the RAM, and we’re going to guess that the next
that stop us making some predictions about the communications to this will be a useful advantage. major release will be a 4GB version of the Pi 3, with
future. The simplest is that we’ll see new versions The next significant upgrade to the model B will a release in the first quarter of 2017.
of the model A and the Compute Module featuring be to the memory. The Pi Foundations’s been able One final piece of speculation is that we won’t
the new 64-bit SoC this year – this isn’t really a to upgrade so much in four years because it began see a significantly improved version of the Pi Zero,
guess, as the Foundation has already announced with quite an out-of-date processor. Even in 2012, at least, not in 2016. It would be too hard to hit
this on its blog. We’ll add to this the speculation the ARM v6 chip in the original Pi looked a little the price point with anything faster or with more
that the new model A will feature Wi-Fi and aged. The Pi 2’s chip brought the device far more features. That, and the name suggests to us that
Bluetooth. This is a guess based on the physical up to date, and the ARM v8 chip in the Pi 3 is really they didn’t release it with an upgrade in mind –
position of the wireless communications on the quite modern. It’s unlikely that the Pi Foundation what would they call it? A Pi 0.2? a Pi 1/2? (We
board – they’re up near the SD card, and this end of will be able to source a chip that is noticeably faster wouldn’t rule out the possibility of a Pi Zero + based
the board is almost identical between the model A than the Pi 3 at the same price point for at least a on the same SoC but with a few new features.)

www.linuxvoice.com 23
FEATURE RASPBERRY PI 3

Above: The Pi version 3
older one is 32-bit. However, at the time of writing, all B+, the power issues for USB devices have reduced
retains the four USB ports
and introduces power the Raspberry Pi operating systems were 32-bit and significantly, and we’ve found that we rarely have
control that can supply running on the newer chip in backwards-compatibility problems with the usual setup (mouse, keyboard and
more current to attached mode, so don’t take full advantage of the longer word Wi-Fi). However, if you’re using more than this, the
devices. length. We expect future distros to bring in full 64-bit extra half an amp may mean you can get by without
Above right: The small support, which should speed up the software though using a powered USB hub.
white rectangle in the we don’t yet know to what extent. Perhaps the most minor upgrade on the new Pi
top-left corner is the Wi-Fi The new Raspberry Pi comes with a reconfigured is to the SD card slot. On the new board, cards are
antenna that brings new
power supply unit that can handle up to 2.5 amps. pushed in and pulled out rather than pushed in, then
networking powers to the
This doesn’t really affect the board itself, because it pushed again to release them. It’s a minor change, but
latest Raspberry Pi.
draws much less power than this, but it does enable one that will please anyone who’s ever accidentally
the new Pi to supply more current to external devices, pushed an SD card on a running Pi and had it pop out
particularly USB devices. Since the release of the Pi 1 and crash the Pi.

Features of the Raspberry Pi Model B Version 3

9
7
10

6
4
3

1 Power and activity LEDs have moved to make way for Wi-Fi 2 Connector for official 7-inch touch display 3 Aerial for wireless networking 4 40-pin header with 26

addressable GPIO pins including UART, I2C and SPI functions 5 Mounting holes for Pi HAT extension boards 6 Four USB ports can supply more current than previous
Raspberry Pi models 7 Four-pole connector for audio and composite video output 8 Connector for official camera module (also available without IR filter for low-light
photography) 9 HDMI output 10 Micro USB power input can now handle up to 2.5A.

24 www.linuxvoice.com
RASPBERRY PI 3 FEATURE

BENCHMARKS
We find out just how fast the new Pi runs.

Raspberry Pi benchmark performance averaged by area
Time to complete compared to Raspberry Pi version 3 (percentage)

180

160

140

120

Pi 3
100 Pi 2 Normal
Pi 2 Overclocked

0
CPU Memory GPU

The Raspberry Pi 2 took 30–60% longer to perform the benchmarks than the new Raspberry Pi

At present, the Pi 3 doesn’t officially offer any time the Pi 2 took. The wired Ethernet port on the Pi 3
overclocking, while the Pi 2 can be overclocked from still goes through the same bus as the USB, so to get
900MHz to 1GHz. We tested the performance of the this level of performance, you have to use the onboard
Pi 3 against both of the configurations of the Pi 2. Wi-Fi, but it makes the Pi much more attractive as a
Our first set of tests compared the performance NAS controller. The new networking controller isn’t
of the key systems on the board: CPU, memory and going to lift the performance of the Raspberry Pi to
graphics. Each of these showed a significant speed the level that you’d expect from some of the other
up over the previous generation. The Raspberry Pi ARM boards that include gigabit networking or SATA
Foundation claims that the new board is 50–60% hard drive controllers such as the Odroid C2 or the
faster than the Pi 2, and our benchmarks support this x86 MinnowBoard, but it does bring much better
for the Pi 2 at default clock speed. Compared to an performance and enables you to keep benefitting
overclocked Pi 2, the speedup is about 30–40%. Since from the Raspberry Pi software and community.
both devices are quad core, this speed increase is
reflected in both single and multi-core performance. Better, better…
All models of the Pi have all their networking The new Raspberry Pi is faster than the previous
options on the same bus as the USB ports. This model, but it’s not the same step up as the transition
means that if you were heavily using the network and from the Pi 1 to the Pi 2, when we saw a six-fold
USB devices at the same time, you could run into increase in performance. The 30–40% speedup over
performance issues as this bus reached capacity. an overclocked Pi 2 is noticeable, but it’s not enough
On the new Pi, the onboard Wi-Fi is connected to a to really change the usage of the device.
different bus, so shouldn’t cause the same level of For us, the onboard Wi-Fi is the biggest feature
problems. In order to test this, we streamed data of the new device. Unless you’re specifically having
over a wireless network directly onto a USB memory performance problems, the Pi 3 doesn’t offer enough
stick. On the Pi 2, we used a USB Wi-Fi dongle. This new features to recommend abandoning a Pi 2 for it.
test simulated the performance characteristic of the However, if you’re in the market for a new single-board
Pi used as a network attached storage device (NAS) computer, the Raspberry Pi 3 Model B should be the
device. The Pi 3 transferred a 400MB file in 53% of the first device you consider.

www.linuxvoice.com 25
SECRETS LIBREOFFICE

SECRETS OF
LIBREOFFICE
LibreOffice Writer is capable of way more than simple text documents.

W
ord processors are one of the most under-utilised that should be simple enough for someone to pick up and use
applications – not because they’re rarely used, but without any training. In truth, a word processor is the most complex
because they’re rarely used to their full potential. Many bit of software that most computer users use.
people just use them as text editors with better font control, but In order to stay useable to beginners, many of the more advanced
they’re far more than this. A good word processor includes the features are hidden away. Linux Voice is here to shine a spotlight and
features of a desktop publisher, spreadsheet, drawing tool, text help you uncover the full power of one particular advanced word
formatter and Turing-complete language all into one neat package processor – LibreOffice Writer.

01 02

03
Formulas
Need to perform a
calculation in your
document? You could open up a
separate program, work it out, and put
the answer in, but that way, you can’t
see how you calculated the result when

01 02
Layout Drawing you go back. Instead, you can add the
Normal documents are laid If you need to add an Formula Bar (View > Toolbars >
out from top to bottom and illustration to your Formula) and embed the actual
from left to right. Adding text at the top document, there’s no need to switch to calculation in the document. Only the
will push all the content down, and it’ll a separate program: just enable the answer will appear in the text, but the
flow onto other pages if need be. This is drawing toolbar and sketch from within maths will be saved so you can go back
exactly what you want for most text Writer. The options are a little limited, and edit it in the future.
documents, but occasionally, you need but more than enough for a quick flow

04
a little more control over the layout. In chart or simple diagram. By keeping all Styles
Writer, you can add text boxes to specify the material in a single file (rather than Proper management of
exactly where you want the text to go including a picture created elsewhere), styles will make your
regardless of how the rest of the you only have to keep track of changes documents look a lot better. This
document flows. in one place. doesn’t just mean making stuff bold or
italic, but creating named styles that

If you need to add an illustration to your you then apply to your text as you
create your document. These named
document, there’s no need to switch to a styles enable you to update particular
styles across your whole document in
separate program: just sketch from within Writer one go, and by saving styles in

26 www.linuxvoice.com
LIBREOFFICE SECRETS

03 04

07
templates, you can ensure consistency to hieroglyphs. Linux Voice is reliably
across a range of documents. informed that the youth of today now
mostly communicate in small icons

05
Navigator known as Emoji. LibreOffice, ever keen
The Navigator is Writer’s to move with the times (even when that
most powerful document movement is towards anarchy), makes

08
management tool. It enables you to it easy to insert these abominations
manage the various parts of your into documents by placing a word
document from a single, dockable tool between two colons. For example,
set. Using the Navigator, you can see all :keyboard: will insert a picture of a
the aspects of your document and also keyboard. Why that’s better than just
move them around. For example, if you writing the word keyboard we don’t
decide to switch two sections of your know, but who are we to argue with the
document, you can use the Navigator’s forces of progress?
Chapter Up function to move a heading

07
and block of text up (or down) through Hybrid PDFs
the document rather than having to There are two ways you

08
copy and paste it manually. can share documents: Addons
PDFs and editable formats. The former Can’t find the feature you’re

06
Emoji method is great because it guarantees looking for? No problem.
Until the 3rd Century BCE, the layout (which is especially Writer has a plugin system that enables
text had no punctuation. important if the document needs to be people to extend the core with
Aristophanes, a librarian at Alexandria, printed); however, it’s difficult to edit. additional functionality. You can create
decided text was too hard to read The latter is useful if the document your own, but it’s far easier to grab ones
without and spaces or marks between needs to be edited, however, it can that already exist. Take a look at http://
any letters, so he introduced dots render differently on different setups. extensions.libreoffice.org/extension-
between intermediate, subordinate and LibreOffice allows a compromise center for a list of available options.
full points. Little did he know that he between these two extremes – hybrid That website also includes a range of
was starting a process that would lead PDFs – which are normal PDF files but dictionaries in case your LibreOffice
to symbols gaining ever more with the entire document embedded in install didn’t come with the languages
prominence in text and a gradual return an editable format that can be changed. you’re creating documents in.

www.linuxvoice.com 27
FEATURE THE LINUX VOICE MANIFESTO

THE LINUX VOICE
MANIFESTO
WHAT’S RIGHT, WHAT’S WRONG
AND HOW WE CAN CHANGE
FREE SOFTWARE
FOR THE BETTER
W
e often talk about the Free falling apart (eg if a lead developer were And why do some opinions turn into rabid
Software movement (and indeed incapacitated or the single licence on which hatred – like the obscenities and threats
the open source and Linux we depend was found to be unenforceable). hurled at Lennart Poettering for his work on
communities) as if everyone involved were So it’s good to have variety. But do we Systemd?
part of one big, cohesive group, where have too much sometimes? Does the vast Many Free Software projects have
everyone is marching in the same direction proliferation of desktops and distros help or introduced Codes of Conduct to mitigate
towards a land where software is free to hinder the GNU/Linux project when it comes this problem; some argue that they will
share and modify. And to some extent that’s to spreading the word? simply turn mailing lists into “safe spaces”
true: we all have broadly similar goals. But at where nobody can even criticise another’s
the same time there is so much disparity Prickly characters code, and the effect will be detrimental
– especially when you consider all the And then we have to think about in the long run. The goals are noble, and
different GNU/Linux distributions, projects, personalities. Hackers and software any attempts to make communities
licences and personalities involved. engineers tend to be rather blunt and direct more welcoming are to be applauded, but
Now, there’s definitely strength in diversity. in their communications, sharply criticising shouldn’t the quality of software be the most
If we just had one distro, one desktop the work of others if they feel that work is important factor in the end?
environment and one holding back a project (see the many So this issue we thought we’d look at
Free Software expletive-laden rants from Linus Torvalds as the state of Linux, Free Software and open

{ {
licence, we an example). Sometimes it helps to state source today, and put our take on it: what’s
would be at your mind and get things fixed instead of right, what’s wrong, and where we should be
Sometimes it helps
to state your mind
risk of our dressing up everything you say in cotton heading in the future. So – let’s put the world
instead of dressing community wool, but at what point does it go too far? to rights!
everything up in
coton wool, but at
what point does it
go too far?

28 www.linuxvoice.com
THE LINUX VOICE MANIFESTO FEATURE

THE GOOD
M
any of us began using GNU/Linux in the late
1990s, as the internet was starting to work
its way out of universities and into homes.
Back then, Linux on the desktop was rather rough, and
we didn’t have anything in the way of attractive and
integrated desktop environments. No, if you somehow
magically managed to get XFree86 working, you
ended up with a rather ugly FVWM desktop (or its
more Windows 95-esque AnotherLevel spin-off).
Rough edges aside, the GNU tools and Linux kernel
were impressive achievements back then. But the
big question was: is any of this sustainable? Can
businesses be built around Linux and Free Software?
Or is it all silly hippy commie “anti-American”
nonsense that will die out when programmers realise
they have to get bread on the table? (Sadly, that was
the argument from a lot of the proprietary software
world at the time.)
A few companies such as the German SUSE and
American Cygnus Solutions had demonstrated that
they could make money by selling and supporting
Linux, but it was Red Hat that really took the charge
and battled to get Linux into enterprises. Red Hat
was generally a good community player and today is
making megabucks with Linux.
But it’s not just about companies. In some
prominent cases, Free Software projects have been
largely abandoned by their commercial sponsors
Some people dislike
but taken up by communities and not-for-profit (through extensions) browser that achieved rip-
Systemd – fair enough.
organisations. Take OpenOffice.org, which ended up roaring success. Today its popularity is plummeting, But the sheer amount
in the hands of Oracle – and then passed on to the controversial add-ons such as Pocket are being of abuse that its lead
Apache Foundation. Today, Apache OpenOffice is chucked in to pay the bills, the interface is constantly developer, Lennart
effectively dormant. Fortunately, just as Oracle was being rejiggled and features are being removed (or Poettering, receives is
handing off OpenOffice.org, a new community-led dumped into about:config). worrying.
organisation called The Document Foundation was Maybe it’s time for a non-profit organisation to
created to work on a fork of the codebase, LibreOffice, step up and work on the code, like The Document
Today the Foundation has enough financial support Foundation did with LibreOffice. It’s too early to say
from donations that it can pay for infrastructure, if such an organisation could make enough

{ {
developers, documentation staff and more. It shows money from donations and merchandise
that even without the backing of a single big company, sales to fund developers, documentation, Maybe it’s time
a major open source project can still flourish. servers and all the other bits and bobs that for a non-profit
a project needs, but it could be worth a try. organisation to step
up and work on the
Power to the people Technology-wise, we have desktop and
Firefox code, as The
At Linux Voice, that’s what we’d love to see more of: productivity software well covered with Document Foundation
communities and non-profit organisations rallying Firefox, Thunderbird, LibreOffice, Inkscape, did with LibreOffice
behind big FOSS projects. It’s great to have Red Hat, Scribus, Gimp, Audacity and other tools.
Canonical, SUSE and co. paying developers to hack on Some may still have rough edges, but it’s
Linux and open source apps, but companies come possible to do almost every daily task on Linux.
and go. Also, goals and objectives can change: Firefox And of course, on the server it’s leading the pack by a
started out as a lean, fast and power user-friendly long way, so there’s nothing to gripe about there.

www.linuxvoice.com 29
FEATURE THE LINUX VOICE MANIFESTO

THE BAD
Compare this to FreeBSD, for instance, which has a
superb Handbook (www.freebsd.org/doc/handbook)
providing a reference to all aspects of the OS in a
single location.
Aggravating this problem is the variety of Linux
distros out there. We have nothing against specialised
custom distros that focus on a specific user, such
as penetration testing distros, distros for visually
impaired users and so forth. But spend half an hour
browsing www.distrowatch.com and what do you
see? 95% are distros that honestly don’t need to exist,
and could be recreated with an apt-get or Yum script.
If a distro is basically Fedora or Ubuntu with
a slightly different package set and a change of
wallpaper, does it really need to exist? No, we think. At
least, not in the open. Toying with distros is great fun
and if you make a spin of Fedora that you like – great,
have fun. But please don’t make a big song and dance
about it, upload it to a site, add it to DistroWatch and
other places. It just adds entropy to the ecosystem
and makes things confusing for new users when
they’re trying to choose a distro. We need a small
range of top-quality, distinct distros, not thousands of

O
FreeBSD’s Handbook is an ne of the greatest things about community- largely identical ones that only exist to boost the egos
excellent, well organised developed open source projects is that people of a few developers.
and single-stop-shop
can choose the bits and pieces they want to
for documentation –
something many Linux
work on. If you work for a proprietary software I want my new FooApp 2.0!
distros would be wise tocompany as a 9–5 job, you may have some awesome Then we have the problem of software distribution.
copy. ideas for the application you’re working on, but your There’s something fundamentally wrong when you
company has forced you to write boring test cases all install an OS such as Ubuntu, and have to wait six
day. C’est la vie. If you’re donating some of your free months before you get new releases of software. (Of
time to a FOSS project, it’s more likely that you’ll work course, you can mess around with PPAs, backport
on the components that interest you the most. repositories and other methods, but it gets messy.)
There is a downside to this, though: some of the We need a simple, streamlined and effective way for
more laborious aspects of FOSS development third-party app developers to push a button and boom

{ {
are often neglected. Take documentation – their app can now be installed on any distro with a
Who wants to write
as an example. Who wants to write that, single click. The now defunct Autopackage project
documentation when when you could be hacking new features, was making good progress in this direction, but few
you could be hacking optimising code to run faster, or working apps ended up supporting it. Since then, rolling-
new features, on graphics or sound for a game? So release distros such as Arch have exploded in
optimising code or documentation in the Free Software popularity, but they have potential sticking points in
working on graphics
or sound for a game?
community is something of a mixed bag. A large-scale enterprise deployments where long-term
few projects have superb docs, but in many support and absolute stability is vital.
cases they’re lacking or simply non-existent. Finally, another issue that needs tackling is
Because Linux is developed in “Wild West” developer mentoring – and making the community
fashion, with lots of groups (kernel, Glibc, GCC, X.Org) more welcoming in general. Now, this varies from
doing their own thing and distro vendors shoehorning project to project; some put more effort into helping
the results together, it’s hard to put together a new developers get involved in the code and submit
complete and integrated set of documentation their first patches, whereas other communities are
that covers every aspect of the operating system. more elitist and tend to look down on newcomers.

30 www.linuxvoice.com
THE LINUX VOICE MANIFESTO FEATURE

THE ROAD AHEAD
U
ltimately, we – as in Linux Voice, or indeed
any other supporters and advocates of Free
Software – can’t force anybody to do
anything. And that’s a good thing. As mentioned, most
FOSS developers work on their projects because
they’re passionate about it, so nobody can simply tell
them to shift their attention to something that doesn’t
interest them in the slightest.
What we’d like to see, though, is a concerted effort
to get more people involved in the less trendy aspects
of FOSS development – like the aforementioned
documentation and testing jobs. How about a
non-profit Linux Documentation Team supported
by donations from companies and the wider
FOSS community, which funds efforts to improve
documentation across Free Software projects?
This is no silver bullet, but arguably it’d be a much
more effective way to improve documentation than
the current state where one person occasionally
contributes docs to KDE, another to GCC, and so forth.
Centralising and focusing efforts with a well organised
funding drive could make a significant difference.
Another thing we’d like to see is more consolidation. 2.0.0 Major release with significant new features or Inkscape is polished,
Wouldn’t it be great if two groups that worked on codebase changes. featureful and already used
extremely similar projects considered merging them? 2.1.0 Minor release with small feature changes. by many professionals –
so why has it spent over a
That’s easier said than done, of course, and there are 2.1.1 Point release, exactly the same as with 2.1.0
decade at version 0.x?
often personalities and politics at play. At FOSDEM but with only bug/security fixes
in 2014, we asked the developers of Mageia and Some projects are guilty of using point releases to
OpenMandriva – two very similar follow-up distros to squeeze in new features or interface changes, which
the once-famous Mandriva – if they would consider is just wrong. Users – especially in enterprises –
merging. There was lots of umming-and-ahhing, should be confident that a point release won’t break
references to minor differences between the distros, any workflow or require documentation changes, but
but not much enthusiasm for the idea. merely fix issues. It’s sensible, consistent, and enables
big companies to keep software up to date without
Vision Thing fear of breakages or random changes.
Again, we can’t tell people what to do. But there are so And finally, let’s get some FOSS apps that are
many projects out there that exist due to “not invented already widely used to version 1.0! It’s really frustrating
here” syndrome, or petty squabbles, that could easily that Inkscape, one of the best Free Software apps
be brought together for the benefit of us all. Perhaps out there, is still at 0.91 despite being developed for
we need some kind of FOSS Dispute Arbitration body around 15 years. Inkscape is feature-rich, stable and
that takes an objective look at two projects that have polished, so release 1.0 already and tell the world!
split due to non-technical reasons, and that can bring Yes, it’s not up to us to tell the Inkscape team

{ {
them together without hurting the egos of those what to do, but a 1.0 release would be much
involved. more attractive to non-FOSS-insiders, There are many
Something else that needs to be unified is version especially those on Windows or Mac OS X. projects that exist
numbers. This is another topic on which everyone So that’s how we see the FOSS world due to “not invented
has their own opinion, but it would help the FOSS improving. We’re in a good state, but here” syndrome, or
petty squabbles,
ecosystem if we standardised on the meaning of each there’s still a lot to be done. But we’ll leave that could easily be
number in a release. Our proposal, which is already our final words to those wisest of sages, brought together
used by many projects, would be like this: Bill and Ted: “Be excellent to each other.”

www.linuxvoice.com 31
FAQ ZEPHYR

Zephyr
The Linux Foundation has a new project under its control,
and it’s one that doesn’t actually include any ‘Linux’.
at the big enterprise level, all of which real-time operating system for use on
GRAHAM MORRISON have some interest in the success of resource-constrained systems
Linux, from Google (gold member) and supporting multiple architectures,”
SUSE (gold member), to IBM (platinum according to the publicity. The Zephyr
Those of us born in the grim member), Intel (platinum member) and Project is the Linux Foundation’s
1960s and 1970s of industrial Oracle (platinum member). Incidentally, attempt to grab a little of the zeitgeist.
Britain will already know what it costs $500,000 to become a
Zephyr is – a car built by Ford that platinum member, and $100,00 to Sorry, what is this Internet of
was designed to look like a sullen become a gold member. Linux Voice Things thing again?
sci-fi robot on wheels. Surely a FAQ has got some way to go before we can You know how it seems almost
is unnecessary? afford either of those. every device now has an IP
We remember! The Zephyr was address – your watch, your fridge, your
like the Ford Anglia’s eccentric Doesn’t the Linux Foundation mobile, your set-top-box, your television,
aunt! But no, unfortunately, this is the have a habit of creating your central heating, your car, your
wrong kind of magazine to take that projects like this? smoke alarm, your music player? These
image further. Zephyr is just one of As far as we know, it’s never are the ‘things’, and it’s predicted that
those words that has been used for created a project named after a over the next few years, we’ll have far
countless things, from a light westerly British car before, but it’s certainly more connected things. No one is quite
wind to the codename of a Soviet spy. chased plenty of emerging sure what this future of IoT dominance
Quite why the Linux Foundation chose technologies by creating collaborative will look like, but lots of experts agree
it for its latest project is out of our projects in their honour. that it’s going to be huge. If you’ve got
search scope. an idea, buy the domain name now.
Does that mean this project is
The Linux Foundation! So, about another ‘emergent What does the Internet of
there’s a link to Linux then? technology.’ Things have to do with the
Yes! It’s the latest project to be Yes. If we asked you to guess Linux Foundation, and more
announced by the Linux we’re certain you’d say ‘internet of specifically, the Zephyr Project?
Foundation, the trade association that the things.’ And you would be correct. Linux is obviously going to be an
promotes the interests of its members “Zephyr Project is a small, scaleable integral part of this revolution for
the same reasons it’s been the central
No one is quite sure what this future of Internet component in both the cloud and
smartphone revolutions. It’s open
of Things dominance will look like, but lots of source, small, and secure. Anyone can
build their own projects using Linux and
experts agree that it’s going to be huge put them into lots of tiny bits of

32 www.linuxvoice.com
ZEPHYR FAQ

hardware without having to buy a single
software licence. But the Zephyr Project
isn’t Linux. It’s built on a tiny kernel
designed to run on tiny systems. The
kernel and modules can run in just 8kB
of memory, for example, which is half
the space in an expanded ZX81!
The kernel is the part of the operating
system that turns inanimate hardware
into something on which you can run
applications – it’s the Linux in GNU/
Linux, and Zephyr is built to breathe life
into those small things that need an IP
address. Zephyr has also been
designed to be a real-time operating
system, which is something Linux finds
hard . A real-time operating system is a
serious endeavour, as they’re often
used in life-critical timing situations. The Zephyr Project is a real-time operating system for tiny devices that provides APIs and connectivity
They’re designed to prioritise data to help you build tiny connected devices (Image source: zephyrproject.org).
above all else, such as feedback from a
heart monitor or medical equipment. Cloud Native Foundation, which aims to
It’s tempting to say Linux struggles with Does that mean there’s no “drive the adoption of a new set of
this because of PulseAudio, but that Linux source code in Zephyr? common container technologies
isn’t true. Linux is just too complex. When you look through Zephyr’s informed by technical merit and end
source code, most of the files are user value, and inspired by internet-
What kind of devices does attributed to Wind River Systems, Inc, scale computing.”
Zephyr run on? which is itself a subsidiary of Intel The Linux Foundation’s current
At the moment, the kernel runs (Linux Foundation platinum member). emphasis is on spreading the
only on specific boards, although Wind River specialises in operating “collaborative DNA of Linux to other
that seems to have more do to with the systems for small devices and has industries, companies and other
project only just starting. It can already developed its own commercial projects,” according to the Foundation’s
generally run on x86 CPUs, ARM v7-M version of Zephyr, something it’s calling Executive Directory, Jim Zemlin, and we
and v7E-M boards, and the ARC EM4 the ‘Wind River Rocket’ OS. Zephyr itself can see how that might include
instruction set found on the Arduino has been released using the terms of real-time operating systems and small
101. But If you wanted to play around the Apache 2.0 licence, which is kernels, even when there’s no Linux link.
with the project, the best way to do this considered only asymmetrically
would be on your normal PC or laptop compatible with the GPLv2 licence used Where can we find out more
using the Qemu 2.1 emulator to run the by the majority of the Linux kernel. That about the project?
kernel. You’ll need to know what you’re means the two projects are unlikely to Considering it’s only just been
doing and augment the installation with share the same code, although with announced, there’s already a
your own code before it will do anything such a difference in emphasis, that great deal of information about Zephyr,
meaningful, but that’s the idea behind would seem unlikely anyway. and we highly recommend you take a
the Iot – connect small sensors and look at the excellent documentation
write bits of code to do something Why would Zephyr be hosted that goes along with the project
clever with the data. by the Linux Foundation? (https://www.zephyrproject.org). In
Our cynical selves might say that particular, the part of the
Does the Zephyr kernel have launching Zephyr as a documentation that takes you through
anything in common with the collaborative project under the auspice the application development workflow
Linux kernel? of the Linux Foundation is an attempt is very useful. If you have some coding
Other than being hosted by the to bring a platinum member’s project skills, we’re fairly sure you’ll be able to
foundation that employs Linus into the realm of wider industry build something, even without any prior
Torvalds, very little. This is perhaps best exposure and adoption. But the Linux experience in micro- and nano-kernels.
illustrated by the download size for both Foundation always seems to want a
source code trees. The tar.gz 1.0.0 project a project for every facet of Anything else you’d like to
release of the Zephyr kernel from technological development. There’s add?
March 2016 is a 6.8MB download. The Dronecode, for example, an open Did we mention that it costs
equivalent March 4.4.4 release of the source platform for Unmanned Aerial $500,000 to become a platinum
Linux kernel is 83.3MB. We daren’t think Vehicles (UAVs). There’s Automotive member and $100,00 to become a gold
about number of lines of code. Grade Linux for cars, and there’s the member of the Linux Foundation?

www.linuxvoice.com 33
INTERVIEW ALAN POPE

ALAN POPE
LUNCH WITH MR CONVERGENCE
Graham Morrison drives out to the Saxon settlement of Ferneberga to meet
Ubuntu community manager and fellow Linux long-suffering podcaster.

I
t’s been a year since the launch of the driven and organic approach to its growth, heart of this as a community manager at
Ubuntu Phone – the launch where you slowly introducing new models and new Canonical, but you may also know him
could actually start buying the devices. partnerships while supporting the hackers from such podcasts as the long running
Since then, Canonical, the company behind and developers who want to play, whether Ubuntu Podcast, of which he is co-founder
both Ubuntu and the phone’s operating that’s a port to a new device or building and co-host. We didn’t need much of an
system, has taken a very community– new applications. Alan Pope is at the excuse to meet up for a chat and a coffee.

Your role at Canonical seems very exciting place to be, and I think Nowadays, if you look around at
quite multi-faceted. similar to many user groups where you FOSDEM there are a lot of (Apple)
Alan Pope: I work in the community had enthusiasts and new people and Macs, some of which are running Linux.
team, and that means that I work with a people asking technical questions, A lot of them are not. The people who
bunch of other community managers. getting together and doing demos – all are running Linux, either on those Mac
Canonical has a number of community that kind of stuff. or on the die-hard Thinkpads, they’ve
managers in the community team and There was a lot of that in the early probably only needed to put a USB key
we have a manager of the community days of Ubuntu and there were a lot of in and it worked. Or if they were really
team – David Planella, and then there’s people contributing to the platform lucky, they went out and bought it and it
myself, Mike Hall, Daniel Hallback, – people who were packaging software works. So the motivation for you to go
Michael Hall, Nicholas Skaggs and that goes into the archive, or maybe to a user group and help someone edit
David Callé, and we all have our areas of doing translations for stuff that goes their Xorg.conf is much lower, because
focus. But mine is mostly core apps on into the archive, or doing that stuff is a solved problem.
the phone, but we spread ourselves a documentation or writing How Tos. That doesn’t mean there aren’t other
little bit away from whatever our area of There was a lot of that in the early days, problems for us to solve; it’s just that
skills is. Daniel is mostly working on and I think a lot of groups – not just the lower-level stuff is a lot easier now.
Snappy at the moment, and David Callé Ubuntu – a lot of communities seemed You can go and get a USB key and
mostly works on documentation, but to have moved on from that ‘Getting the put it into almost any computer – any
we all pull together and organise things Platform Done’ to other roles. distro – and it just installs. We, as in
like events, or do Q and As and stuff like Ubuntu, and lots of other communities
that. We each have a specialist area but We’ve had the year of Linux on atrophied our community a little bit,
we go beyond that. the desktop! because they’ve moved on to more
AP: Yep! Job done [laughter], we’re all interesting things. Maybe that’s
Does the phone community, for finished now, let’s move on. I don’t know
example, consist of ordinary
users or perhaps companies?
exactly what it is. I know a lot of
communities are seeing drift. Years ago
You can put a USB key
AP: I think of our users as extraordinary if you went to a tech conference, in almost any computer
[much laughter!]. something like FOSDEM or SCALE, or
any other tech conference that has a and it just installs
But after being involved in the Linuxy-bent to it, it was all Thinkpads
community side of Ubuntu for and Dells, and you knew everyone in hardware hacking and they’re into IoT
such a long time, starting with– that room was running some version of and Raspberry Pi, or something else
we’d imagine user groups discussing Linux and that they’d probably had to that’s more interesting than what they
the desktop and the operating edit their Xorg.conf to make it work. Or used to do, or maybe they’ve moved on
system – that must have changed? use Ndiswrapper, or some wacky stuff to the Mac because it was too much
AP: It has, and in the early days it was a like that. faff to get Linux working. I don’t know

34 www.linuxvoice.com
ALAN POPE INTERVIEW

www.linuxvoice.com 35
INTERVIEW ALAN POPE

exactly where those people have gone unanswered questions, and sit there and interesting things that most people
but I miss them! and answer people’s questions. I had on their phones don’t do. It’s quite good
no idea who these people were, or fun to do that.
The computing trend has also where in the world they were, and they
moved away from the asked all kinds of things like “How do I So there’s the same category
computer and laptop and towards get my wireless working?” of ‘hackers/users’, it’s just now
smartphones and mobile computing, they’re aligned to more modern
you’ve followed them in your role at Hence your memory for technology rather than the desktop
Canonical. Ndiswrapper! or getting Linux to work?
AP: Yes, totally, and so I now install AP: Exactly! It’s still raw in my head. AP: I think so. And a lot of those people
Ubuntu on a machine and then use it as And that documentation we wrote all might use Ubuntu or they might not.
a tool. This is one reason why I can’t get those years ago for Ndiswrapper is no We get people on our mailing lists who
my head around people who are longer applicable because wireless now use Arch Linux, who want to develop
constantly distro hopping. There is a just works, generally. apps for Ubuntu, or maybe they use
level of learning you get from trying I remember one woman who asked a Fedora and they bought an Ubuntu
different distros, sure, but I just can’t get question that her husband had a piano phone just to see what it’s like. And it’s
my head around people who are like, and liked to make music and wanted to
“This icon is in the wrong place – I’ll
wipe the distro and start again.” I use
get this particular piece of music
software working on Ubuntu, and so I
We get a community of
the Linux desktop as a tool to do my job went off and installed it on my machine interested people coming
and so the desktop is not particularly and fiddled around and got it working,
interesting to me any more, and I think and then replied to the question – going along for the ride
that’s probably true of a lot of people. back and forth a few times. And I know
It’s not super-interesting any more. that question is archived back in the early days, and there are things that
mists of time in Launchpad don’t work yet – it’s not quite finished.
Was there a time when the somewhere, and it was really refreshing
desktop was super-interesting to talk to brand-new users about Is it every going to be finished?
to you? something that they needed help with AP: Is anything ever finished!
AP: Totally! When I started contributing and I could help with just a few lines on There is no version ‘n’ where there is not
to Ubuntu (2005–2006), I was working a page. But now we get people asking, a number higher than ‘n’. I’ve yet to see
where I had a lot of downtime, and I “How do I do this on Ubuntu Phone,” anything finished in the software world,
would spend a huge amount of time and yes, that is where the interesting so I think we’ll continue iterating. But it’s
answering support questions online. stuff for me is now. fun when I get people sending me
We have a thing on [Canonical’s] People are saying, “How do I make screenshots of mockups or whatever of
Launchpad called ‘Launchpad Answers.’ my app do this?” or “How can I make an app they’ve created, or they’ve
And I would go there on a daily basis my app run forever,” or “How do I do created a new design for an existing
and just look for the new and SSH on my phone,” which are all cool app. I want to grab hold of those people
and point them in the right direction
and then show them the tutorials for
getting started on Launchpad, or show
them where the source code is.
I had that just this week. Someone
pinged me on Telegram and said, “I’ve
had an Ubuntu Phone for over a year
now, and I’m quite interested in getting
involved in developing the core apps.”
Someone has come looking to
contribute, and sure enough I pointed
him in the right direction and now he’s
contributing to our calendar app. It’s
stuff like that that people can easily get
started on on Ubuntu Phone.

Do you think part of the
motivation behind the Ubuntu
Phone was to keep that community
Where the desktop was, the of people who want to contribute
phone is now, says Alan,
themselves, as well as getting the
stroking the rich mahogany
Louis XV escritoire. platform on Chinese OEMs, for
example?

36 www.linuxvoice.com
ALAN POPE INTERVIEW

Alan used to use Red Hat,
then moved to Debian when
a bloke he knows told him
Debian was “quite cool”.
Well done that man!

AP: I think it’s more a by-product of rather than a core goal. We do want you weren’t working for Canonical,
what we’re doing. While Android is open to have a community and we want to so what led you to Ubuntu?
source and Apple’s iOS is not, they’re have people interested, and without AP: I was having problems with my
still very similar in the way that they’re those people interested, you know, Philips webcam that meant I had to
released – there’s a lot of development ‘tech people’ who are willing to write keep re-compiling the driver every time I
that’s done internally and then at a big documents on GitHub about how to updated Debian’s kernel. That frustrated
conference somewhere, the ‘thing’ is manage your phone or create apps, me, and my friend from my local LUG
announced with great fanfare. A short then we’d be in a difficult place. (Hugo!) said, “You should have a look at
while after, in the case of Google, it’s Half of the apps that ship on the this Ubuntu thing, it looks quite cool.” I
thrown over the wall and there is your phone, by default, were written by downloaded Ubuntu late 2004, early
new software. people in the community, not by people 2005 and started using it and thought it
We aren’t doing it like that, very at Canonical. Without those people, was great. I’ve never really had to really
deliberately, which means that people where would we be? We wouldn’t compile the kernel since then.
see the warts and all as we go along. If have a calendar, a clock, a music app, That was a milestone because I
we’d closed the doors, brought up the a document viewer! Those things never had to go through that faff just to
shutters, and said we’re not going to are important to us. And similarly, get a thing working. Obviously I still
show you anything for another year, those people in the community then compile kernels now and again for
people would see a big change in what contribute to the core as well. There various reasons, but I’ve not had to just
had happened between last year and are people who have contributed for a webcam. But the thing that
this year. Whereas we’re iterating over a to the web browser – recently the attracted me more was, yes, the
year so that people see the individual browser had a UI revamp and one community. There seemed like a really
changes, and people blog about an icon of the contributors of that, a student positive vibe around Ubuntu while at
change, or they blog about the colour of living in Italy called Ricardo, he helped the time I found there was a bit of
something changing, or they’re implement the new UI on our web negativity around Debian – you could
interested in a bug that affects them. browser. The community is very get chastised for asking the wrong
Whereas that doesn’t tend to happen in important to us and those people are question in an IRC channel, or you
Apple Land or Google Land. enthusiastic. They come and go, we’ve could get berated on a mailing list for
We get a community of interested noticed, over the years but we’re still saying the wrong thing the wrong way
people coming along for the ride as there for them when they come back. and that disappointed me.
we’re doing this development. I think Some people loved Debian – they
it’s a by-product of what we’re doing – Ten years ago, when you were loved the rigidity of Debian’s rules, and
the fact that we’re doing it in the open, helping people on Launchpad, that’s fine, but I didn’t really like that. I

www.linuxvoice.com 37
INTERVIEW ALAN POPE

like the look of Ubuntu and people a massive community around that, and working on one device to make that a
seemed good fun. people love doing that and people love really good ROM, and then move on to
I was contributing in the community hacking, but I don’t distro hop. I want to the next one, so we end up with a line of
for a long time; up until 20011/12, I have a thing that I can hack on that I devices that are of a similar state.
was in various leadership positions in don’t need to keep flip flopping all over Bluetooth works on all of them, Wi-Fi
the Ubuntu community, and then I took the place to be happy. On my desktop, works on all of them, accelerated
a step back and thought, “Am I doing I’ve done that and I’m on Ubuntu and hardware works on all of them, but it’s
the right thing here?” I was doing my I’m happy there. On my phone, I quite difficult when that’s quite a specialist
paid job in the day and this volunteer like the fact that on Ubuntu Phone I task, porting Ubuntu to a phone.
stuff in the evening – I’m doing a lot don’t have to install all these random
of volunteer stuff and I was thinking I ROMs and I can hack on my phone, Is the community getting
needed to consolidate. I stepped down because I like being able to hack on my larger?
from a few of the positions. phone and do all kinds of cool AP: I think there are a few things in this
interesting things. Just being able to platform that are missing or that are
Did you intend to leave the SSH into my phones is quite cool.
community completely? We’ve been banging the
AP: I kind of did. I resigned from a The launch of Ubuntu Phone
couple of positions and I actually got a had a big impact on those ROM convergence drum for a
personal message on IRC from Mark
Shuttleworth [Founder of Canonical/
communities.
AP: I think possibly we should have
long time now
Ubuntu] asking me whether there was engaged with the ROM community, if
any background story, or whether there we want to call it that, perhaps a bit not fully fleshed out or fully finished,
was any reason why I was leaving later. I think we engaged a bit too early that have bugs in them. And I think as
because when people quit en masse, because the sand was shifting a bit at time goes on and we fix those, and also
sometimes there is a back story, and the time and so a lot of people saw that we, Canonical, have agreements
there may be a reason and you might what we had on the phone and then with partners with more devices, it
want to find out more, or whether it’s they took that and ported it to other becomes more interesting to people.
fixable. He messaged me and asked if devices. And then various technical When there’s only one device on the
there was any reason and I said I just decisions we made changed the way planet, it’s a lot harder for people to get
need to focus, really, because I’m the platform worked, and so none of interested, and it’s also harder when
spreading myself too thin. At that point, those images work any more. those devices aren’t available in every
he said there might be a role for your country. There’s huge demand in the
focus at Canonical. Some month or two Things like the Nexus 10 and US, for example, where we don’t have a
later, a job came up and I joined. Nexus 5? good story for a phone you can use
I had actually applied for jobs at AP: That’s slightly different because we over there yet. In the future we will, I’m
Canonical a couple of times before, but only had one person maintaining that. It sure of that.
I was unsuccessful, and Canonical do would be great if we had a pool of When you look at the number of
have a history of hiring from the people. But what happens in the people Google has to throw around at
community. There are a lot of people Android community seems to me that Android, or that Samsung has to throw
who work at Canonical who previously you have one guy who makes his ROM at Tizen, and we’re a 700-people
were students who worked on Ubuntu and then someone else forks that and company – that’s the entire company,
packages, for example, and were hired makes his ROM, rather than multiple not just the people who work on
in. There are a lot of people in Canonical people work together on one really Ubuntu Phone. People who work on
like that and so I was one of those. good one. There are groups that have Ubuntu Phone are in the tens, it’s not
Sometimes people say that the Ubuntu emerged from that – like Cyanogen – hundreds, so it’s an upward struggle
community is shrinking – that’s partly but it would be great if we could have and we are punching above our weight.
because Canonical is hiring them all! groups of people working together. You look at the size of our stand at
There’s a guy called Marius who did a Mobile World Congress [perhaps the
Do you still feel just as excited port to the OnePlus One and a couple of biggest mobile event in the calendar] it
by the phone? other devices, and he’s now working on was humongous, showing off
AP: I’m not a big fan of Android. I’m not the Fairphone 2, and he has a whole community ports, community code.
a massive fan of iOS. I especially don’t bunch of other phones on his list that One of the best demos I’m told was the
like the whole going and downloading a he’d love to get to, but he’s just one guy. music app, because we’ve recently
random ROM from some obscurely Whereas in the Android community one created a converge version of the
named guy on the internet and flashing person is focused on getting a ROM music app so that it works on tablets,
that on my phone because it will give working on their one device because phones and when you rotate it it
me better battery life. Or I get another you’re scratching an itch – you’re trying behaves differently. And that was one
ROM that gives me better access to get it to work on that device because of the better demos given at MWC. The
controls on my phone and having to that’s the one you have. What we would demo was written by an Oxford student
seek out these phones. I realise there’s rather do is have multiple people in the UK. It wasn’t created by us. We

38 www.linuxvoice.com
ALAN POPE INTERVIEW

If you’d like to see a port of Ubuntu
on the Fairphone 2, or indeed any
other device, you can go to
https://ubports.com to find details
of how you can get involved.

gave him some design input but he into Ubuntu? from Debian to Ubuntu I no longer have
created that in his spare time, and AP: If we find a bug in Network to compile my webcam driver. Now,
those people who are willing to create Manager or PulseAudio, the packages with PulseAudio, I can have Skype open
something cool and interesting to that are on the phone are the same – well maybe not now! – Mumble, I can
demo to other people will start getting – it’s the same package as from the be playing a Flash video, I can get
other people in, as well as the porting (Ubuntu) archive. If you do a dpkg -l on notification sounds from my browser.
community as well. the phone, you’ll see Network Manager And so on the phone with the bug we
and PulseAudio. had, it turns out that when the phone
Was convergence always There was a fun bug we had maybe gets a notification it makes a ‘ting’
intended to be part of the eight months to a year ago. We couldn’t sound and then the phone goes back to
Ubuntu Phone operating system? figure out why the phone would sleep. Then you get another notification
AP: It’s funny because I was clearing sometimes suddenly start screeching and it goes back to sleep again. When
out my old email last night and I did a really really loudly. I had this at a recital the phone goes ‘ting’ the first time,
search for everything older than the concert at my daughters school and PulseAudio is playing that noise
beginning of 2016 to archive off my just out of the blue my phone just through the sound card.
GMail, and it showed up some emails started screaming at me! A real Then the phone goes back to sleep
from 2011 and I saw an email entitled, high-pitched wailing noise and it took a but PulseAudio carries on sending the
“Convergence Demo” and “Convergence lot of digging to figure out that it was a zeros to the soundcard because it
devices” and stuff like that, and that PulseAudio bug. It was the fact that anticipates there’s more audio coming
was five years ago, so we’ve been PulseAudio was never really designed down the line for a period of time. The
banging the drum for a long time. But to be on mobile devices like this. CPU goes to sleep and then you get
it’s only now coming to the point where another notification – the CPU wakes
you can plug your keyboard and mouse Was it ever designed to be on a up and starts sending zeros to the
into a device or Bluetooth attachment, desktop though? soundcard and the soundcard freaks
and use it like that. It’s taken a long time AP: No comment! I love PulseAudio! out and you get this screeching noise.
to get here and there have been a That bug was fixed and that fix will
couple of diversions long the way. What do you like about ripple down to the desktop in the same
PulseAudio! way because it’s the same package,
Does much of what goes into AP: It just works. For no other reason and it’s the same with Network Manager
Ubuntu Phone get rolled back than in the same way when I moved and GStreamer.

www.linuxvoice.com 39
LISTEN TO THE PODCAST

WWW.LINUXVOICE.COM

BUY MUGS AND T-SHIRTS!

shop.linuxvoice.com
INTRO REVIEWS

REVIEWS
The latest software and hardware, rigorously bashed against a wall by our crack team.

On test this issue . . .
42
NetSurf
3.4
With all the new features it
keeps adding, Firefox is at
risk of evolving itself out
of existence. If you agree,
try NetSurf: it’s small, fast
and could be the One True
Andrew Gregory web browser to take back
Needs some spare time in which to play with the web.
his Flotilla kit from Pimoroni.

S
pring is in the air, which means a
few things. First, there’s a fresh
release of Ubuntu on the cards,
reminding me that I really must get
round to putting Ubuntu on my
smashed (again) Nexus 5 smartphone.
Second, there are many, many things OpenShot 2.0 43 Solus 1.1 44 Owncloud server 9.0 45
to be done. Last month the Linux Voice In the already packed world Arising from the ashes of The workhorse of any cloud
team launched a Kickstarter campaign of video editing, can this SolusOS, Solus looks like a good infrastructure, Owncloud gets
to get a children’s coding book crowdfunded offering stand out? bet for the desktop user. better with every release.
published. We failed to reach our target,
but the idea is still a great one. We need
more coding materials, more volunteers
at Code Clubs, more online resources.
Group test and books
It’s the future, and with Beep Beep Yarr!
we want to help make it happen. It’ll
take a little longer, but we’ll get there,
because it’s worth doing.

Brown rain
Spring is when projects arise, blinking
from their winter slumber. The
allotment needs work if we’re going to
get the potatoes planted in time. The
weather station needs building,
websites need to be coded, words need
to be written, businesses launched. Booooooooooooooks!!!! 48 Group test – privacy distros 50
And, as always, Free Software makes it If you learn how to program games, you’ve learned The tools are out there to ensure your privacy, but
possible. Now let’s get stuck in! how to program anything – at least, that’s the why install them yourself when someone else has
andrew@linuxvoice.com theory. We just like shooting things. made these user-friendly distros for you?

www.linuxvoice.com 41
REVIEWS WEB BROWSER

NetSurf 3.4
After getting frustrated with Firefox, Mike Saunders needs a fast, light web browser.

F
Web www.netsurf-browser.org irefox has always been one of our favourite viewing the Wikipedia page for Linux, NetSurf only
Platforms Linux, Unix, RISC OS, FOSS projects (and in fairness, it’s still very needs 76MB. Multiply that over many tabs and you
Haiku, AmigaOS, Atari
good), but recent changes to the interface, save a lot of memory.
License GPL v2
coupled with the addition of unwanted features like In addition, NetSurf offers most of the basics you
the Pocket integration for saving offline content, have expect in a browser: bookmarks, cookie management,
started to annoy us. So while it’s still our browser of pop-up and advert blocking, Do Not Track, and even
choice for most cases, we’re always on the lookout for a smattering of JavaScript support. In this release,
something else. And NetSurf has been on our radar for JavaScript is provided by the Duktape engine, but
a while. Unlike most browsers doing the rounds, it the results are a mixed bag due to a limited set of
doesn’t use an existing HTML rendering engine like bindings. Some sites are fairly functional, whereas
WebKit, Blink or Gecko – but instead has its own, built others struggle or just don’t work at all.
from scratch. NetSurf has come on in leaps and bounds from
NetSurf is designed to be highly portable and usable the 3.3 release we tried last year, and works well
on old machines running relatively obscure OSes. So for casual browsing of simple sites, but it still gets
if you’re still battling on with an old Amiga or Atari, or confused in places. Of course, creating a HTML and
you’re rocking with a Haiku OS or RISC OS installation, CSS rendering engine that covers the ever-growing
then NetSurf provides a fairly robust browser. It’s also specification is a mammoth task, and all of the
scorchingly fast and friendly with your RAM banks: developers of NetSurf are working on it out of passion
whereas a freshly started Firefox munches up 221MB rather than as a paid job, so the achievements they’ve
made already are to be applauded.
What we say is: definitely give NetSurf a try. It won’t
work flawlessly on every site you visit, but for those
times when you just want to spend a bit of time on
Wikipedia, Reddit and other text-oriented sites, you’ll
find it fast, sleek, and very pleasant to use.
JavaScript support may be Making great progress, and usable on plenty of
disabled when you first not-too-demanding websites, but still glitchy in
start NetSurf – to enable it, places.
go to Edit > Preferences
and the Content tab.

42 www.linuxvoice.com
VIDEO EDITOR REVIEWS

OpenShot 2.0
Ben Everard needs to edit his many cat videos, can OpenShot enhance the cuteness?

O
n 17 April 2013, The OpenShot project raised Web www.openshotvideo.com
Developer Jonathon Thomas
$45,028 in a crowdfunding campaign to and contributors
develop version 2.0 of this video editing Licence GPL v3
software with a target to release in December 2013.
Development slipped, and the final version didn’t
come out until early 2016. Version 2.0 represents
almost three years of work to just about every area:
the rendering engine has undergone a major rewrite,
the interface has moved from GTK to Qt, and the
software now runs on OS X and Windows as well as
Linux. Hopefully this will bring in a larger pool of users The new Timeline dialog is
which in turn will mean more people to find bugs and perfect for making video
develop patches. slideshows from a
There are only a couple of new features in OpenShot collection of photos.
2.0 – most of the work has been tidying up the
existing features rather than adding new ones. The The problem is that the last three years have seen a
Split Clip and Timeline dialogs do make it easier to renaissance in open source video editing. Pitivi has
construct videos, the former being used to manipulate also had a significant funding drive, Lightworks on
long videos and the latter used for constructing Linux is now considered stable, and Kdenlive continues
videos out of a large number of short clips. to improve. In this competitive landscape, the new and
Our biggest complaint with earlier versions of revamped OpenShot can still hold its own, particularly
OpenShot was the stability. During our editing with with people who only do occasional video editing,
OpenShot 1.x, we found that crashes were part of the because the interface is engaging and easy to use.
normal workflow. OpenShot 2.0 did crash during our
testing, but nowhere near as frequently. A great interface pushes OpenShot to the front
Had OpenShot 2.0 met its delivery target of of the increasingly competitive field of Linux
video editors.
December 2013, it would have been without a
doubt the best video editor on Linux at the time.

www.linuxvoice.com 43
REVIEWS LINUX DISTRO

Solus 1.1
SolusOS is dead – long live Solus! Mike Saunders examines this desktop distro.

Y
Web https://solus-project.com ou may recall SolusOS, a newbie-oriented uses some components of Gnome, so it’s somewhat
Platforms x86-84 Debian-based distro that used the Gnome 2 analogous to Cinnamon on Linux Mint.
Price Free
desktop with a bunch of custom add-ons. While Budgie looks lovely, it has its limitations.
SolusOS was abandoned in late 2013 due to a lack of Launcher icons in the top panel, for instance, don’t
development manpower, but the project has recently have tooltips, so you can’t be sure what they do
been revived under the name Solus. Now, given that without clicking on them. If you want to install Solus
there are more desktop-focused Linux distributions in from live mode, you need to click the blue down arrow
existence than there are atoms in the universe, why button – but that same button is also shared by the
are we covering Solus here? Software (package) Installer in the menu. Similarly,
For starters, it’s extremely polished. So many there’s little in the way of customisation to be done –
distros simply take Gnome, KDE or Xfce, chuck on a forget about context menus for the panel or many of
custom theme, and leave it at that. Solus goes a lot the notification area icons.
further by incorporating its own written-from-scratch Otherwise, Solus provides a handful of FOSS
desktop environment, Budgie, which is now available desktop apps: Firefox, Thunderbird, VLC, Rhythmbox
in some other distros such as Arch. Solus “focuses and various Gnome utilities. We were surprised to see
on simplicity and elegance”, with a sleek program no office software installed by default; most users
menu and notification centre – but fortunately it’s would expect that, and it’s not like the distro is trying
not a victim of “not invented here” syndrome. Budgie to squeeze onto a single CD.
In all, we like Solus for its attention to detail and
focus on good presentation (remember – this is a
feature), from the website through to the desktop
itself. Finding the right balance of usability for both
newbies and more experienced users is going to be
tough, but with a bit more work, it has the opportunity
to be the Ubuntu or Mint of its generation.
The main menu is
attractive and well- An ambitious distro that could lead the pack
designed – it’s just a when it comes to the desktop, but needs more
shame the distro doesn’t refining and a better out-of-the-box experience.
include more apps as
standard.

44 www.linuxvoice.com
OWNCLOUD REVIEWS

OwnCloud Server 9.0
Graham Morrison takes another great leap away from Facebook and Google.

T
he progress OwnCloud is making is almost Web https://owncloud.org
Developer OwnCloud Inc.
unbelievable. Not only is the project going Licence AGPLv3
from one major release to the next, cramming
great new features into each update, its user base has
grown from 2.4 million in 2015 to 8 million in 2016.
This is completely unprecedented, but also perhaps
understandable. It’s a slick, professional, beautiful
data repository for all your files. It synchronises with
your desktop and phone, adds context via calendar,
contacts and even document editing plugins, and can
of course be self-hosted. As we’ve mentioned before, You can now edit
we use OwnCloud extensively to put the magazine documents collaboratively,
together and it has never failed us. and it works well even on
Version 9 was as easy to install as previous low-end servers.
versions, at least manually. You download the latest
version, copy over the config and your data, and a scalability”, implemented with help from CERN. We
web server restart instantiates the upgrade. The only also really liked the new sharing options which now
thing left to do is re-enable any third-party plugins you include tags and better permissions – you can even
need, a procedure that we found much quicker and search by tags. You can also leave comments in
more responsive than with previous versions. We also photos shared with you, which we think is a significant
noticed a big improvement in the latency between step towards a self-hosted Facebook/Google+
updates on the server and updates on our local replacement, as is the cooperative document editing
Linux client. You could be editing an ODT document, with annotations. It’s all brilliant.
for example, and within a few seconds you’d see
your updates pushed to your local copy. The same The rapid user-base expansion and new features
make this release stable and full of collaboration.
happened when we added files. These performance
upgrades could be thanks to the much touted “better

www.linuxvoice.com 45
REVIEWS GAMING

GAMING ON LINUX
The tastiest brain candy to relax those tired neurons

RUN. JUMP. SHOOT. XCOM 2
A worthy successor to one of the best strategy games out there

Website http://store.steampowered.com/app/268500
Price £34.99

X
COM: Enemy Unknown was hugely
successful, so expectations for its
sequel were extremely high. Thankfully,
these expectations have been met and often
Michel Loubet-Jambert is our Games
Editor. He hasn’t had a decent night’s exceeded. Firstly, there are no drastic changes
sleep since Steam came out on Linux. from its predecessor, and given that it received
universal praise, that’s probably a good thing. Missing that 90% accuracy shot reminds you that

I
t’s been anticipated for a long The most fundamental difference is the change XCOM 2 is as unforgiving as ever.
time now, but OpenGL’s of circumstances, where instead of
successor, the Vulkan API, has
spearheading a trans-national defence team and it does feel like a new experience with
finally been released in what
promises to be a huge leap forward against alien invasion, it now focuses on a much continuity from where the previous game left off.
for Linux and cross-platform gaming leaner rebel team working to overthrow the alien Combat remains the least changed aspect,
as a whole. Along with the release, regime after its successful invasion. This with the base-management experiencing the
Nvidia has provided drivers with provides a far greater sense of urgency and most changes. One criticised change is that
Vulkan support. There are no drivers
resourcefulness to a game in which humanity some missions now have turn limits, though this
currently released on the AMD side
(despite the company having was already the underdog. does add a sense of pace and urgency to parts
developed the Mantle API on which XCOM 2 strikes a careful balance between of the game previously lacking it. The turn-based
Vulkan is based), though their release making the game familiar enough so as not to tactical combat and the management aspects of
is imminent. anger fans with drastic changes, but not subtle the game provide that much-appreciated variety
The cherry on the cake is that this
enough that it feels like a lazy upgrade of its and detail, all held together by a fun plot and kept
release comes with an update of The
Talos Principle: the first Linux game predecessor. It does a great job in this regard, interesting through steady progression.
to support Vulkan. Current
performance is not game changing,
but given the beta state of the drivers
and a game which was built around
DirectX 11, it is very encouraging in
this early stage. There is also already
talk of DOTA 2 being shifted to
Vulkan, as well as a few others.
Currently, DirectX 12 is only
supported on Windows 10, which
accounts for around 13% of desktop
operating system usage. With Vulkan
supporting myriad operating systems
and versions, this alone provides an
obvious and significant advantage
over the proprietary alternative and
no doubt will prove to be attractive
and cost-efficient for developers
looking to publish across platforms.
Wonky close-ups and shooting
With developers hopefully opting to
through walls still occur, but still
develop solely on Vulkan and not on
DirectX with a subsequent OpenGL aren’t that annoying.
port, this should mean more games
for us at similar performance to those
on Windows, if common sense can XCOM 2 feels like a new experience with
overcome the network effect.
continuity from the previous game

46 www.linuxvoice.com
GAMING REVIEWS

Firewatch ALSO RELEASED…
A gripping mystery that really hits the mark
Website http://store.steampowered.com/app/383870 spend the summer. There are no other
Price £14.99
physical characters in the game, and
the only human contact is a relationship

E
very so often a game comes along which develops through the walkie talkie
that shows the true merit of video to another firewatcher named Delilah.
games as an artistic medium. Without giving too much away, the plot
Firewatch is one of these. revolves around the mysterious and
The game immediately sucks the player sinister goings on in the surrounding area,
Dying Light: The Following
in with a harrowing backstory of a Henry while Henry comes to terms with his DLC content is often not worth mentioning, but
and his wife Julia. Within minutes, Henry unsettling past. The Following is so massive it could easily be a
(the protagonist) finds himself traversing Firewatch is recommended to just about standalone game. Additions include a huge
the Wyoming wilderness to arrive at a anyone who enjoys a good story and new map, drivable vehicle, new weapons, a new
lone firewatching tower where he will doesn’t crave constant action. story and more. Like the base game, the story
is poor at best, but it does extremely well in
providing endless entertainment to an already
very entertaining game.
http://store.steampowered.com/app/239140

Firewatch’s graphical style Agatha Christie – The ABC Murders
manages to be both beautiful The crime and mystery genres tend to work
and light on resources. rather well with point-and-click mechanics,
and it’s great to see such a game based on
literature. The game has some lovely visuals,
good voice acting, nice music and captures the

American Truck Simulator
essence of the novels. Graphically, it does
suffer from some aliasing issues, even on
highest settings, but this can be forgiven if
The game that shouldn’t be great, but is you’re after a solid “whodunnit” story.
http://store.steampowered.com/app/374900
Website http://store.steampowered.com/app/270880/
Price £14.99

S
“
imulator” is often a euphemism for
“niche”, “parody” or just “terrible”,
but the Truck Simulator games have
been there to remind us that this isn’t
always the case. This latest instalment
is no exception and brings trucking to Like everything in the States, the trucks are
its spiritual home in the United States. flamboyantly big.
It’s time to put Johnny Cash on the truck Superhot
Re-imagining the FPS genre, Superhot is a
radio and watch the diners and motels having the nice gaming mechanics of
game in which time only advances as the
pass by on the way to San Francisco. building a logistics company from scratch player moves, which makes things very
How a game series in which one drives on top of the driving. interesting indeed. Add in some stylised
sensibly at the legal speed limit for long Thankfully, this isn’t just a reskin of Euro graphics, take away mechanics like
stretches has become so popular defies Truck Simulator 2, adding plenty of content regenerating health and ammo drops and you
have a game that’s proved to be insanely
conventional logic, but to those who have on top of the new locations and trucks.
popular. Now you can play a shooter in which
played this or its predecessors, it makes The cities are more fleshed-out than in you can have a coffee and file a tax return
perfect sense. Playing American Truck its predecessor, with more buildings and between killing enemies.
Simulator, for a lot of people, is a great way landmarks, which only adds to what feels http://store.steampowered.com/app/322500
to unwind and listen to music, all the while like a more genuine trucking experience.

www.linuxvoice.com 47
REVIEWS BOOKS

Learn Game Programming With Ruby
Ben Everard knows that creating a game is just the first step to being beaten at it.
Author Mark Sobkowicz
Publisher Pragmatic Bookshelf
Price £15.99
ISBN 978-1680500738

B
efore turning to a career writing to construct the internals of the game
about open source software, this from scratch. This makes it more of a book
reviewer had a brief stint teaching about programming than a book about
English as a foreign language. It taught me learning one particular games development
exactly one thing about getting students framework. Learn Games Programming With
to learn a new subject, and that is that by Ruby starts a little too quick for someone
far the most important thing is to get your who’s not programmed before, but it
students interested in the topic. If they’re makes a great second book to get new
excited to learn about something, it doesn’t programmers thinking a little more about
really matter how badly you convey the the best ways to structure their programs
information. Learn Game Programming with after they’ve mastered the basics. The
Ruby is really a book about learning object book’s getting started guide only covers
oriented programming, but it uses games OS X and Windows, but all the libraries used
to get new programmers excited about the are cross platform and work on Linux.
subject.
Rather than use a games library, Mark A fun way to build up your programming
skills. Learn Game Programming With Ruby focuses
Sobkowicz builds all the games using just on 2D games such as vertical scrolling space
a media library and shows the reader how shooters. Fine by us!

Secure Your Node.js Web Application
Ben Everard secures web apps with an axe – cut the network cable and you’re safe.
Author Karl Duuna
Publisher Pragmatic Bookshelf
Price £23.99
ISBN 978-1680500851

S
ecurity is vital for web applications some peculiarities that make it vulnerable to
– it’s a subject we’ve covered many these attacks in unusual ways, and if you’re
times in Linux Voice. Most of the developing Node.js then you need to know
older web technologies – such as PHP what to avoid to stay secure.
– are already well known from a security Secure Your Node.js Web Application
perspective, and there are many resources doesn’t go into much depth about the
to help developers know what mitigations to different types of attack, and ideally we’d like
take to ensure that their software remains to see some examples that aren’t trivial and
secure. Node.js is much newer, and this is contrived. Software security is a complex
the first book to really go in to the security topic, and security problems are often
implications of writing sever-side code subtle and hard to spot. This book will help
in JavaScript (which is a very different readers avoid most basic mistakes, but it’s
prospect to writing secure client-side not detailed enough to help developers write
JavaScript). really secure code.
The basic techniques used to attack
Node.js are the same as those used to
attack other server-side technology: code Not as in depth as we’d like, but currently the best
option available. Apparently, attacking a website requires
injection, authentication-bypass, cross-site a transparent touchscreen and a hood to
scripting, etc. However, JavaScript has obscure your face.

48 www.linuxvoice.com
BOOKS REVIEWS

OpenStack Cloud Computing
Graham Morrison just can’t get his head out of the clouds. Also released…
Author Kevin Jackson, Cody Bunch, Egle Sigler
Publisher Packt Publishing
Price £31.99
April 2016
ISBN 978-1782174783

3D Printing Designs
L
earning about OpenStack
can be a challenge. It’s a 3D printing is still going
from strength to strength
complicated subject, and that
and getting cheaper every
complexity seems to be increasing year, but there aren’t a
each year, mirroring its growth. The great deal of quality
main problem is its scale, both in examples to follow. This
terms of what there is to learn and book focuses on creating
an octopus pencil holder,
its requirements. It’s not a simple
which looks great from
case of installing a few packages or the cover, and should also
experimenting within the confines get children excited too.
of a virtual machine, and that makes This book promises to
learning about OpenStack and playing This is a great book if you’ve ever take you from Blender
models to final object, Everyone needs a good
with new ideas difficult. thought about trying OpenStack.
step-by-step. pencil holder.
We discovered this while writing
our own tutorial on getting started within the book should be easy to
with OpenStack (see p76), and while understand, and unlike with
it is possible to install the system on Canonical’s own (excellent) installer, by
a single relatively powerful machine, performing each step yourself, you Efficient BPM Applications
it negates the reason why OpenStack learn more. When you create the We were initially drawn to
has been so successful – the ability tables used by Keystone in SQL, for this because of the title
to scale from just a few machines to example, you know what those tables – BPM to us means beats
thousands. And while OpenStack’s are doing and how they fit into the per minute, and we can
think of lots of ideas for
documentation is very good, what entire OpenStack ecosystem, slowly creating some lovely
we really need are some practical chipping away at its complexity. crunchy beats. But no,
examples of various deployments. With all the ingredients covered, and this isn’t that BPM, it’s
keeping with the cookbook metaphor, apparently Business
Cooking with OpenStack there are plenty of specific ‘recipes’ Process Management. If
you already knew that and
We didn’t have the space in the title littered throughout the book. The cover think we’re crazy for
above, but this is the third edition of a mentions 110, and it does feel like mentioning beats,
the OpenStack Cloud Computing almost every step gives an alternative we’re guessing this book BPM != Business Process
Cookbook. The ‘cookbook’ part is example for each step. This is the is for you. Management.
important, because OpenStack, in most impressive part about the book,
particular, is very modular, and each of although you’ll likely need a more
those modules can be thought of a explanatory book if you want to take
single ingredient. To this end, the book your OpenStack installations further. Reunited States of America
starts off looking at each module in Background information here is kept
What perhaps shoudn’t be
turn – Keystone, Glance, Neutron, to a minimum so that you can rapidly surprising is that this
Nova, and Swift. Starting with progress from one example to another, book is being published by
Keystone, the authentication and while providing only the bare details of one of O’Reilly’s partners,
identification module, says a great what each bit if text. But this level if and could have some
deal about the attitude of the writers, detail is perfect for our short attention exposure in some of its
more technical audiences.
dealing with the vital and thorny spans. There are some excellent We’ll avoid the politics,
subject of security first, before moving explanatory diagrams littered but we’re always
on to the more practical modules. throughout, and there’s a ‘How it interested in ideas that
The book uses the Ubuntu Cloud works’ section after covering each are designed to bring
Archive, which hosts the OpenStack concept, but mainly, the book just people together rather
than move then apart,
installation packages for Ubuntu. It’s teaches you how to get on with it. which is exactly what this
the same installation of Ubuntu we book promises to do. Coming to America.
An excellent way to get OpenStacked.
used for our own tutorial, and so the
code examples and the explanations

www.linuxvoice.com 49
GROUP TEST PRIVACY DISTROS

GROUP TEST
Since Harry Potter’s invisibility cloak is of little use on the internet,
Mayank “Griffindor” Sharma checks out some distros that will do the job.

On test Privacy distros
U
p until the Snowden leaks, still exposed to all sorts of privacy
IprediaOS the proponents of privacy leaks and security intrusions as
URL www.ipredia.org attacks were digital soon as we go online. The mere act
Licence GPL and others outlaws firmly on the wrong side of of surfing the web and using the
Latest release IprediaOS 1 the law. However, much to our various online file sharing services
A live distro built on the I2P chagrin, we suddenly found and social networking sends out
anonymous network. ourselves in the midst of an more information to unintended
information age where invading our recipients than you can imagine.
JonDo Live-DVD privacy has not only become a Over the next few pages we’ll
URL www.anonymous-proxy-servers.net/ state-sponsored practice but has look at different Linux distros
en/jondo-live-cd.html also become a mainstream that take steps to ensure your
Licence GPL and others business model. anonymity and protect you against
Latest release 0.9.88.2 Despite the ensuing hue and cry, inadvertent leaks and breaches.
This distro offers multiple privacy tools. apps and websites by vendors on All these distros are designed
the IT high street continue to gather with privacy protection as their
Lightweight Portable Security information about us, usually
without our consent. As users of
primary objective, but ensuring
privacy often comes at the price of
URL www.spi.dod.mil/lipose.htm
open source software, the all-seeing usability. Since the distros on test
Licence GPL and others
eye of the developer community take different approaches to privacy
Latest release 1.6.4
A privacy-centric distro from the US shields us from the nefarious protection, we’ll be on the lookout
Department of Defence! practice of bundling backdoors for the distro that guarantees
and malicious code prevalent in utmost safeguards with minimum
Tails closed source software. But we’re disruptions to our way of working.
URL www.tails.boum.org
Licence GPLv3+
Latest release 2.0.1
We’re exposed to all sorts of privacy
The most popular distro for privacy
seekers that anonymises via Tor.
leaks and security intrusions as
soon as we go online
Ubuntu Privacy Remix
URL www.privacy-cd.org Anonymity vs Privacy
Licence GPL and others
Privacy and anonymity are two different is when you are non-identifiable whereas
Latest release 12.04r1
concepts that are often confused with privacy is concerned with your ability to
A modified Ubuntu distro for creating an each other. While they are both becoming cut off yourself selectively.
isolated environment. increasingly necessary as our online To illustrate, if you visit a website via
movements are constantly tracked, Tor, that website will not be aware of your

Whonix it’s vital to understand the differences
between them.
real location, in essence concealing your
identity. However, if you visit a site via
URL www.whonix.org Privacy is the ability to keep some Tor and then log into your account, you
Licence GPL and others things to yourself; in contrast, anonymity are no longer anonymous. But by routing
Latest release 12.0.0.3.2 is when you want people to see what your request via an encrypted network,
Takes a unique virtualised approach you do, just not that it’s you doing it. In you haven’t revealed your destination to
terms of our digital existence, the most any intercepting party (such as your ISP),
to privacy.
important distinction is that anonymity thus maintaining your privacy.

50 www.linuxvoice.com
PRIVACY DISTROS GROUP TEST

Security Qubed
From virtualisation to compartmentalisation.

Q
ubes OS is an interesting distro for desktop. The install-only distro is based on The VMs in Qubes are known as security
security conscious users. The distro Fedora and allows the user to install either domains or AppVMs. Each of these has a
divides the computer into a series of KDE, Xfce or both the desktop environments. different level of security and are defined
virtual machines or domains using Xen that The architecture of Qubes is different in a template. By default, Qubes installs
are cut-off from one another. Each virtual from that of a chroot environment in which with three domains – work, personal, and
machine only has access to the services the systems share hardware resources untrusted, though users can add more
that it needs to perform the designated such as network cards. Besides the minimal through Qubes VM Manager. The distro
function, thus limiting the potential security graphical desktop, everything else in Qubes takes some getting used to and new users
threat. Despite all that virtualisation wizardry, including network cards and even disks, are should read through its documentation to
Qubes offers a coherent and streamlined separate virtual machines. wrap their heads around the distro.

Whonix
Whole new world.

W
honix is very different from the
other distros in this group test.
The distro is in fact a pair of
Debian-based virtual appliances that you
must run simultaneously, in two separate
virtual machines. The Whonix-Gateway is
used for configuring Tor, and its only task is
to route traffic via the Tor anonymising
network. This machine has two virtual
network interfaces – one connected to the
internet via NAT, which is used to
communicate with the Tor network, and the
other network interface is connected to a For an even more secure implementation, you can deploy the Gateway on the physical hardware of
virtual LAN. The other machine is the one machine and run the Workstation on virtual hardware inside a different host altogether.
Whonix-Workstation, which is the desktop
you are supposed to use for browsing and the Tor browser but doesn’t ship with one by the Pidgin IM, not just for the installation
other tasks. The iptables rules on the default; instead the icon brings up a script instructions but for some best practices to
Whonix-Workstation force it to only connect to download one from a list of stable, new ensure anonymity and pointers to related
to the virtual internet LAN and redirect all and hardened releases. There’s also Xchat additional privacy-enhancing components.
traffic to the Whonix-Gateway. This scheme for IRC but surprisingly no app for instant In addition to information on the bundled
prevents apps from ever knowing the user’s messaging. Then there’s the WhonixCheck components inside the distro, the Whonix
real IP address or accessing any information app, which scans the current installation and wiki also makes for a good read for anyone
on the physical hardware. tests the Tor connection. interested in stopping inadvertent leaks.
At first launch both Whonix-Gateway and Be aware that installing updates will take There are several Whonix variants. You
Whonix-Workstation take you through a longer on Whonix than on other distros, as can download the Gateway and Workstation
brief setup wizard to familiarise you with the they are routed via the Tor network. While as VirtualBox images and import them on
project and set up some components, such Tor frowns upon using the network for either Linux, Windows or Mac machines.
as the repository. If you have the resources, certain activities like downloading torrents, Instead of using VirtualBox, Linux users are
the Whonix developers suggest you run they have no issues with Whonix using the encouraged to instead download the two
multiple instances of the Workstation VM, network for downloading updates. Whonix machines as KVM images.
one for each task. You can also install Whonix on top of
Whonix doesn’t have very many apps but Solid underpinnings QubesOS mentioned in the box above.
the ones it does are tuned for guaranteeing The distro is based on Debian 8 Jessie,
privacy. For example, the IceDove email whose repository you can use to install VERDICT
client ships with the Enigmail extension any additional packages. It’s a good idea to A unique, albeit
resource-intensive
for encrypting email. There’s also KGpg for refer to the documentation on the project’s solution to the problem.
managing keys. The distro has an icon for website before installing components like

www.linuxvoice.com 51
GROUP TEST PRIVACY DISTROS

Ubuntu Privacy Remix
’buntu and privacy?

T
he two biggest threats to Talking of TrueCrypt, UPR has
security and privacy are the something known as Extended
internet and the data-sniffing TrueCrypt volumes. In addition to
trojans and scripts on your hard disk. storing regular files the extended
The Ubuntu Privacy Remix (UPR) distro volume also stores the configuration
is a radical solution that works by and user data of LibreOffice, Evolution
cutting access to both of these. With and GnuPG. This helps you overcome
UPR you get an isolated environment the disadvantage of losing your
that can be used to work on sensitive app settings that’s most commonly
documents or highly infected ones. associated with Live distros. Another
The developers have stripped noteworthy customisation is the Use the godmode boot option to gain superuser access
support for all sorts of networking distro’s homebrewed front-end to with the sudo su command.
hardware from the distro’s kernel, which GnuPG, which focusses on encrypting
has also been tweaked to ignore all ATA and decrypting files. To guard against UPR is an ideal platform for anyone
hardware such as hard disks. (You can cold boot attacks, the distro wipes the looking for a system that’s truly
still read files from optical drives and computer’s RAM when you shut down. off-the-grid and provides an isolated
removable USB drives.) If you plug in a The distro has all kinds of apps, from habitat that segregates the working
USB drive, you can create an encrypted LibreOffice and VirtualBox to the Gimp environment from the files on the
TrueCrypt volume on the drive using image editor and the VLC media player. computer’s disk.
the distro to save and read documents. The latest UPR is based on the Ubuntu
UPR mounts all removable media as 12.04 LTS release and uses the Gnome VERDICT
well as the TrueCrypt volumes with 2 desktop. It also bundles detailed A wonderful option for
anyone looking for an
the noexec option, which prevents the setup and getting started guides to isolated environment.
execution of programs from the media. orient new users.

Lightweight Portable Security
Straight from the horse’s mouth.

T
he Lightweight Portable to use DNSCrypt, which prevents
Security (LPS) distro is created DNS spoofing by authenticating
by the Software Protection communications between the
Initiative (SPI) under the direction of the computer and the DNS resolver.
US Air Force Research Laboratory LPS includes a handful of apps.
(AFRL) and the United States There’s the Firefox browser, which is
Department of Defense. They’ve equipped with the HTTPS Everywhere
designed it for telecommuters who and User Agent-switching extensions.
need to access secure government There’s also a PDF reader and a
networks from unsecured remote bunch of remote desktop software The goal of the developers is to put out new LPS release
locations. To this end, the distro works including the Citrix Receiver and VMware at least once every quarter.
with DoD-issued Common Access Card View. These are complemented
(CAC) and Personal Identity Verification by a smattering of apps such as a decorations has been designed to ape
(PIV) smartcards for accessing barebones text editor and an image the proprietary OS to give the DoD
restricted government websites. viewer. The SPI also produces a Deluxe spooks the look and feel of a familiar
Just like the Ubuntu Privacy Remix, edition of the distro which is the same environment. For further assistance,
LPS also uses a modified kernel that as the regular release but additionally the project’s websites contains
prevents interactions with the local includes LibreOffice and Adobe Reader. thorough FAQs as well as a Quick Start
hard disk. The distro includes the Although LPS uses the Xfce 4 guide and a user’s manual .
public edition of the Encryption Wizard desktop, it’s been tweaked extensively
app created by the AFRL, which can to resemble Windows XP. Everything VERDICT
A privacy-focussed distro
encrypt and decrypt individual files from the layout of the desktop, with some fascinating
and even complete directories. There’s complete with the Windows- customisations and tools.
also an option to force the distro hallmark Start button, to the window

52 www.linuxvoice.com
PRIVACY DISTROS GROUP TEST

JonDo Live-DVD Be incognito on the go
Proximus prime.
Privacy on a stick.

F
reepto is a Debian-based distro that’s
available as a live image designed to be
transferred on to a USB disk. The distro
includes a tool to create an encrypted
persistent storage partition on the free space
in the USB disk. Freepto is chock-full of all the
popular digital invisibility tools as well as the
popular desktop productivity tools to enable
you to use the distro as your everyday
desktop. There’s everything from LibreOffice
and Gimp to VLC and Audacity. For everything
else, there’s the Synaptic package manager
and Debian’s extensive repository of packages.
Unlike with regular distros, software like
Pidgin, Xchat and Filezilla are configured to
work over the Tor network. The distro includes
the Tor browser and also a regular Iceweasel
installation that’s equipped with privacy-
enhancing plugins such as Disconnect,
Adblock Plus and HTTPS Everywhere.
You can use JonDo’s controller to select from any of the listed mix cascades. Freepto also contains a set of tools for the
privacy-conscious users. There’s BleachBit for

J
onDo Live is a Debian-based distro proxy for anonymity, including Pidgin and zapping temporary files, Gufw for tweaking the
built on tools that are designed Thunderbird. There’s also the privacy- firewall, TorTP to force any app to route via Tor,
specifically for masquerading your enabled JonDoFox browser, which is TrueCrypt to work with encrypted storage, MAT
identity online. The core piece of software configured to route traffic via the JonDo for stripping metadata from files, and tomb,
in the distro is the Java Anon Proxy (JAP) proxy and also includes a number of a command-line file encryption utility. The
more commonly known as JonDo. The privacy and security themed browser add- distro also includes a user’s guide, but it’s only
app anonymises your connections using a ons. If you’re using the Tor proxy instead, available in Italian and Spanish. This shouldn’t
proxy service in order to conceal your there’s the Vidalia client for establishing stop new users from experimenting with the
origins. The Java-based client for the and managing the connection to the Tor distro, since it’s pretty much like a standard
proxy is available for various platforms network as well as apps such as the Tor desktop distro and fairly intuitive.
including Linux, BSD, Windows and Mac. browser and TorChat designed to facilitate
The live distro offers users the option communication over the Tor network.
of using the JonDo or the Tor proxy to
anonymise your network traffic. JonDo Something for everyone
routes your traffic via encrypted channels Besides these network-specific apps, the
through a mix of multiple servers. distro also hosts several other privacy-
While this routing ensures privacy and focussed and general purpose apps such
anonymity, hopping through the servers as ZuluCrypt, KeePassX, Jitsi, Qtox,
means your surfing will take noticeably LibreOffice, Gimp, Skype, VLC and more. To
longer. Although anyone can hop on the avoid setting up account information
JonDo network via a free cascade, you repeatedly on all these apps in a Live
can pay a small fee and instead use a distro that can’t be installed to the disk, the
premium mix that in return promises distro includes a nifty little app that rolls
increased speed and better anonymity the configuration of several apps into a
by routing traffic via more servers. compressed tarball. Ferry the tarball via a
Furthermore, the free mixes only allow USB disk and upon reboot extract in inside
traffic on port 80 and 443 (for HTTP and the home directory of the Live distro.
HTTPS). For everything else, such as 5222
for Instant Messaging and 21 for FTP, you VERDICT
A good collection of
need to subscribe to the premium mix. anonymous apps for Freepto is built using the Debian Live Build tools
Many of the included apps in the distro multiple proxy networks. by the hacktivist group Av.A.Na.
are preconfigured to use the JonDo

www.linuxvoice.com 53
GROUP TEST PRIVACY DISTROS

Tails vs IprediaOS
Which one does a better Keyser Soze?

T
he Debian-based Tails (The
Amnesiac Incognito Live
System) uses Tor to create an
encrypted channel to the internet to
preserve your privacy. You can install
Tails to a USB disk and use the
remaining free space to create an
encrypted persistent partition to store
settings and files.
Tails has the usual cocktail of apps
that you’d find on a regular Linux distro,
as well as some unique ones such
as the Electrum Bitcoin wallet, the
Gobby collaborative editor, GtkHash to
generate and verify the checksums of
transmitted files and MAT (Metadata
Anonymisation Toolkit) for zapping
metadata information from files.
Unlike many other distros however, Tails doesn’t interact with a computer’s hard disk, so nothing is saved to the computer you’re running on.
Tails bundles the Synaptic package
manager for fleshing out the desktop. the distro. Just like it does with Tor, the the biggest difference between I2P
This task requires admin access, which distro will connect to the I2P network and Tor is that while Tor is used to
is disabled by default but can be set in the background. When it’s done, fire anonymously browse the regular
up using the Tails Greeter app. The app up the bundled I2P Browser in Tails, internet, the primary objective of I2P
can also be used to spoof your device’s which takes you to I2P’s browser-based is to create and allow access to the
MAC address to avoid it being used to control panel. hidden network of eepsites. Again for
uniquely identify you. On shutdown, comparison, eepsites with the .i2p TLD
Tails wipes the computer’s RAM to To P or not to P are what .onion sites are to Tor.
safeguard against cold boot attacks. IprediaOS is to the I2P network what The distro includes a ready-to-go
Another anonymising network that’s Tails is to the Tor network. The distro webserver that’s online as soon as
occasionally pitted against Tor is I2P can be used to connect to the I2P you’re connected to the I2P network.
(Invisible Internet Project). You can network and also includes some tools Besides websites, the network hosts
access the I2P from Tails by passing that can be used to access the various various services such as anonymous
the i2p boot parameter when starting services on the I2P network. Perhaps email and anonymous file transfer.
I2PSnark is the name of the network’s
Bittorrent service, which can be
accessed via the network’s Python-
based client called Robert. Sharing
torrents is a popular activity on the I2P
network, unlike Tor, which frowns upon
the use of the network for this purpose.
IprediaOS uses the Gnome 3 desktop
and is one of the few privacy-centric
distros that can be easily installed
to the hard disk. The distro however
includes an older version of I2P, so
your first order of business should be
to update to the latest release before
connecting to the network.

VERDICT
TAILS LINUX IPREDIAOS
A well-packaged distro Built around I2P but
Linux distro built hasn’t been updated
around Tor. for quite some time.

To get the most out of IprediaOS, users are encouraged to peruse its documentation.

54 www.linuxvoice.com
PRIVACY DISTROS GROUP TEST

OUR VERDICT
Privacy distros
T
he requirements for digital While we applaud Whonix’s
privacy and anonymity are compartmentalised approach to the
highly subjective. You might issues at hand, setting it up requires
prefer a secluded computer cut off a fair amount of work. The distro
from the internet to work on and comes with a learning curve that’s
pass along encrypted documents. steeper than some of the other You can easily combine JonDo with other anonymisation services
In such a case, your choice of distro solutions on offer and also requires such as Tor.
will be very different from a greater system resources.
whistleblower who wants to Tails is one of the best-known
anonymously email a bunch of distros for anonymity and privacy. 1st JonDo Live-DVD
documents without revealing his It’s built on the Tor network, is
name or location. regularly updated and equips you Killer feature: JonDo and Tor
Given the US Government’s track with the right tools for staying www.anonymous-proxy-servers.net/en/jondo-live-cd.html
record when it comes to ensuring invisible both online and offline. Experience the best of two anonymising networks and a host of
privacy it’s difficult to suggest the If you force us to pick one distro, relevant tools.
Lightweight Portable Security distro it’ll have to be JonDo, even though
to anyone, especially since there to make the most of the JonDo
are far better alternatives on offer. network, you’ll have to subscribe to 2nd Tails
Then there’s IprediaOS, which loses a premium mix. A JonDo network
out simply for being outdated. If offers several advantages over Tor Killer feature: Tor and I2P
you do need to use the I2P network, and I2P. For starters you can select www.tails.boum.org
the Tails distro does a better job your mixes. Secondly, although If JonDo doesn’t impress you, then use this.
than IprediaOS. The Ubuntu Privacy the servers don’t keep logs,
Remix has a very limited use case. compromising one server in the mix
While its use of encrypted USB will not reveal your identity, because 3rd Whonix
disks for securely ferrying files of the architecture of the network.
means it’s not completely cut off In case you’re still not convinced, Killer feature: Unique architecture.
from the rest of the world, the lack the distro can still be used to www.whonix.org
of internet access limits its use for connect to the Tor network, so you A notable distro for the experienced privacy campaigns.
everyday online tasks. win both ways.

Because of their nature, the 4th Ubuntu Privacy Remix
requirements for digital privacy Killer feature: Disconnected and isolated.
and anonymity are highly subjective www.privacy-cd.org
A truly standalone distro for powering a secure workstation.

The Freenet project
Freenet is a peer-to-peer system a Freemail email address and configure
5th IprediaOS
designed to facilitate anonymous sharing your email client to send mail via this
of information on the internet. The address. Similarly you can create an Killer feature: I2P
network enables users to communicate account on Freenet’s Sone microblogging www.ipredia.org
using a platform that cannot be service, the FMS forums, and the FLIP An outdated distro for showing the I2P network.
censored. It creates a distributed data IRC client. You can then interact with
store that houses information accessible other members on the forums and
by all members. Freenet also publishes even create your own website. Besides
several tools for anonymous publishing creating a secret identity, you can browse 6th Lightweight Portable Security
and communication. all kinds of websites on Freenet. The
You can install Freenet on all desktop network maintains a list of Freenet
Killer feature: Encryption wizard
operating systems. Once it’s installed websites with the most recently updated
www.spi.dod.mil/lipose.htm
follow its guide to create an anonymous ones at the top. Since the content on
Doesn’t offer anything uniquely different that’s not available
identity using the WebOfTrust plugin. Freenet isn’t filtered, be prepared to
After creating an identity you can set up encounter offensive and illegal content.
elsewhere.

www.linuxvoice.com 55
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www.linuxvoice.com 57
FOSSPICKS

FOSSpicks Sparkling gems and new
releases from the world of
Free and Open Source Software

Raised by endangered Tasmanian wolves, Ben Everard sniffs the air
and howls at the latest and greatest Free Software releases.
Video player

MPlayer 1.3
V
ersion 1.3 of this veteran alternative front-ends for MPlayer.
video player came out This tells us two things about
alongside the FFmpeg 3.0 MPlayer: that it’s well used and that
codecs, and the two work hand-in- it’s default interface is rubbish.
hand. Because of this, the biggest While MPlayer does have a GUI,
update in MPlayer 1.3 is that it now it’s more commonly used as a
plays an even greater range of video command line program. Its
MPlayer is the ultimate
files. FFmpeg handles the low-level popularity comes from a lead to it being a little confusing to
video Swiss Army Knife,
details of what a particular phenomenal range of options that but the command line use – hence the range of alternative
file-format means, and MPlayer enable it to not only play just about options can be hard to front-ends.
turns this into a useful player. any piece of video known to man, fathom.
PROJECT WEBSITE
A quick grep through the MPlayer but also manipulate the video in
www.mplayerhq.hu
website tells us that there are 292 any way you wish. This power does

Process monitor

htop 2.0
L
inux is just a kernel – the this through an ncurses terminal
heart of the OS on top of interface, which both looks good,
which everything else sits. and works well over SSH.
The kernel has its own special place htop is the first program we turn
in memory and controls access to to when investigating performance
the CPU and other resources. Every on our Linux boxes – desktops and
other program that you run is a servers. It doesn’t always have all
process, and it all starts with the information we need, but it does
process 1, which initialises your give a great overview of what’s
system. Every server you run, every going on, and shows you where to
Everything you need to know about your running processes in a
command you execute, every drill down further.
colour-coded terminal screen.
desktop application you open: If you’re still using the bog-
they’re all processes. standard command top (the default
Process viewers help you keep process viewer on many Linux overview of what’s going on, better
an eye on all the different processes distros), then it’s time to switch to sorting of processes, and a tree
running on your machine, and htop htop and be amazed by the neater view to give a better view of
is one of the best. The main job of interface and mouse controls. htop multi-process programs. With
htop is to give you an overview of has colours to provide a quick version 2.0, htop works on Linux,
what’s going on inside your OS X and many BSDs, so you can
machine: which processes are
using the CPU, which are eating up
It’s time to switch to htop now enjoy the same interface on all
your Unix-y boxes.
the memory, and how many free and be amazed by the neater
resources are there. It manages all PROJECT WEBSITE
interface and mouse controls http://hisham.hm/htop

58 www.linuxvoice.com
FOSSPICKS

Windows-like OS

ReactOS 0.4
V
ersion 0.3 of this Windows made it to an impressive $48,000,
clone came out in 2006, but since then the project seems to
and 10 years has brought a have died. It’s a shame, because
lot of improvements, but ReactOS confusion over licensing is holding
seems to us to still be stuck in Windows back in the cloud, so an
no-man’s land. It’s more advanced open source project that could
than most hobbyist OSes, but it’s eradicate this problem while still
not yet advanced enough to be being accessible to people who
useful as a main operating system know the Windows environment
just yet. In order to make the jump, could be very popular.
it needs to offer something tangible ReactOS offers better support for
that Windows doesn’t. old software than modern versions
This may seem like a tough ask of Windows. This has improved in
Relive the glory days of Minesweeper with ReactOS.
for something that’s a clone, but version 0.4 with the NT Virtual DOS
there are two areas where ReactOS Machine (NTVDM) which enables
potentially could develop into a old 16-bit applications to run on gamers, the general support for
serious offering: simplifying cloud modern processors. While this is older Windows software could also
licensing and resurrecting dead likely to be most useful to retro find mainstream use. It could be
software. In the cloud, ReactOS easier to keep a program written for
seems to be struggling to gain
interest. In 2014, the Thorium
ReactOS offers better support Windows XP running on ReactOS
than port it to Windows 10.
project tried to raise $120,000 to for old software than modern
fund development of a cloud PROJECT WEBSITE

desktop based on ReactOS. They versions of Windows https://www.reactos.org

Thought organiser

Cherry Tree
O
h to have a brain like a schema, because the simple truth
computer. Wouldn’t it be is that our wet, soggy brains can’t
wonderful be able to handle this level of data processing.
allocate memory and have it remain Since the mushy data inside our
in one place, always retrievable? heads isn’t formatted in anything
You could create an array of dates approaching a normalised schema,
called birthdays, and just append if we want some way to store our
new elements every time you met thoughts digitally, it needs to be
someone new. able to adapt the chaos in our
Perhaps it would be easier to set minds. Cherry Tree is a hierarchical
your head up like a database and note-taking application that tries to
create a table of people. This table apply just enough order to allow our
could have columns for birthdays, thoughts to be transferred to a
favourite food and other key facts. digital medium and be usable. You
Properly referenced keys could then can create a tree structure of text
Unload your brain into
refer to partners, children and other notes, which nicely fits the flow of restore some order and make sure
your computer and
relationships… actually, we’d have to human thought. One branch leads never forget anything your greatest ideas don’t
be a little careful with normalisation to shopping lists, another goes to again. accidentally get recycled at the
– it would probably be better to your projects, another holds plans bottom of a pile of old notes.
have a tables for families and to take over the world.
households and reference those. If your desk is under a sea of
Alas, it’s useless designing the post-it notes and scribbled on bits PROJECT WEBSITE
www.giuspen.com/cherrytree
perfect Boyce-Codd normal form of paper, Cherry Tree can help you

www.linuxvoice.com 59
FOSSPICKS

Instant messenger

Kadu
T
he world of instant can chat with people on any other
messaging may now be server).
dominated by huge Kadu supports all the usual
multinational companies that features you’d expect from an
produce closed source software instant messenger, such as the
with closed protocols designed to ability to manage multiple
lock users into their platforms, but accounts, buddy lists and file
we’re not yet ready to give up on the transfers, and some more
idea of free and open advanced features such as Off The
communications. Kadu is an XMPP/ Record (OTR) encryption for added
Jabber client that enables you to security. Perhaps the biggest
connect to any chat server that feature of Kadu is support for the
supports these protocols. Once Gadu-Gadu chat protocol, which is
French readers with poor spelling can enjoy this instant
upon a time that included Facebook particularly popular in Poland.
messenger client.
chat, but alas, that is no longer
possible thanks to the social Jak się masz to people looking for a Qt chat client
network dropping support for chat The Qt 5 interface looks good, and that doesn’t require the KDE
software other than its own. works well. Kadu is most attractive framework to be installed. The
If you don’t already have a chat small set of dependencies make it a
account that supports an open
protocol, you can find a wide range
Kadu is most attractive to great option for lightweight
desktops.
of public XMPP servers at people looking for a Qt chat PROJECT WEBSITE
https://xmpp.net/directory.php
(with an account at one server, you client that doesn’t need KDE www.kadu.im

Download manager

uGet
I
t seems to be a truth universally your house is streaming a video
acknowledged that our internet when you suddenly come across a
connection is always slightly new distro that you want to
slower than we want it to be. Back download. You could just download
in the mid 90s, 28.8Kbps was the video and not worry about their
alright, but we would have loved an video buffering, or you could try to
extra 10Kbps. Then, when ADSL remember to download the distro
came out, we always wanted later. With uGet, you can add it to
another 1Mbps. In 2016, we’re your download queue, and set it to
eyeing up BT fibre internet, but no start downloading in the middle of
doubt, next year we’ll want the night. You don’t even need to
something even faster. worry about wasting electricity,
Given that the internet is always, because you can set uGet to shut Mastering your downloads (and your anarchic downloads folder)
and will always be, too slow, we down your machine when it’s is key to getting the most out of your internet connection.
need software to help us make the finished doing its work.
most of our connection. As a Download managers like uGet are We’ll never be satisfied with our
download manager, uGet gives you for voracious data hogs like us. internet connection because the
lots of control over how you get faster we can surf, the faster we
large files over the internet. It won’t
automatically speed up your
The internet is too slow… we can find more things we want to
download.
internet, but it will help you use your need software to help make
connection more intelligently. For PROJECT WEBSITE

example, imagine someone else in the most of our connection http://ugetdm.com

60 www.linuxvoice.com
FOSSPICKS

Terminal image viewer

Termpix
I
f you think really hard, it’s does is interesting even if it’s
possible to come up with a use completely pointless. Essentially,
for an image viewer that runs in the program is really a converter
the terminal. Perhaps you might between images (of any format
need one if you’re ever SSHed into a supported by the Rust image
server and need to check what library), and strings of ANSI text
pictures are available without containing the characters for
downloading them. However, if this half-block colours. This test is then
situation were to arise, installing a printed on the screen to reveal a
new bit of software would probably low-resolution version of the
be more hassle than just SCPing original image.
the pictures to your local machine The end result is something akin
– especially if you have to install the to the charming graphics from 8-bit
dependencies (Rust) on the server. computers. Maybe that’s a use for it
Or maybe you’re the developer of after all: creating graphics for retro
an operating system written entirely games. Be on the lookout for a Coming next issue [maybe]: Linux Voice in glorious ANSI-text-
in assembly language that has no 80s-style adventure game about a rendered technicolour!
graphics system and can only renegade group of Linux journalists fighting against the forces of
handle text, and you need a method proprietary software. It’ll be called
of converting images so they can
be displayed in this environment.
Termpix caught our eye Linux Vice.

Whether or not Termpix has any because what it does PROJECT WEBSITE
real use is a little irrelevant to us. It https://github.com/hopey-dishwasher/

caught our eye because what it completely pointless termpix

Screen reader

Orca
F
or most people, interacting having text as well as icons make a
with a computer means big difference with Orca.
looking at a screen, tapping As it is, Orca works well for people
away at a keyboard and wiggling a with some vision who need a little
mouse. However, humans don’t all help. It could also be useful for fully
come from the same mould, and blind people if used with carefully
not everyone has the same set of selected software that’s been set
senses. The Orca screen reader up with Orca in mind. Perhaps the
converts the text on screen to most useful application for Orca,
spoken words so that people who though, is for developers.
struggle to read a screen can still Remember that not all of your
get the information off it. users have the same physical
Orca sounds fairly robotic, but the attributes as you, so while
You can change the
aim isn’t to produce perfectly designing an interface, try using it does someone who doesn’t know
default Orca setup by
human voice, but to make with Orca and see how it fares. If pressing Insert + the software already have? A few
computers usable for people with you can’t use your application with Keypad Insert + Space. simple changes can make a huge
poor sight. Orca works well, but a screen reader, then what hope difference to some users – all it
ultimately, not many applications takes some thought.
are usable for someone without any
sight, because most user interfaces The Orca screen reader
aren’t designed with visually converts the text on screen PROJECT WEBSITE
https://help.gnome.org/users/orca/
impaired users in mind. Things like
the Tab order, keyboard control and to spoken words stable

www.linuxvoice.com 61
FOSSPICKS

Display server

Wayland
2
016 is slated to be the year range of desktop shells on top of
that the X windows graphical Wayland including Weston, KDE and
display server gets replaced. one called Hawaii.
Actually, 2014 was supposed to be
the year X got replaced, then 2015 Crouching server
was, so we aren’t holding our The difference between Wayland
breath. So far, the only distribution and X is almost entirely behind the
to fully switch to a different display scenes, and this is especially true
server is RebeccaBlackOS. when using a desktop that runs on
For those of you not familiar with both display servers, such as KDE.
the starlet after whom this distro is In theory, the version of KDE
named, she hit a small amount of running on Wayland should be
We ran KDE on Wayland without problems, but heavy users may
fame in 2011 with the song Friday. identical to the version running on X
still find it unstable.
This was followed two years later except that it should perform better.
by the unimaginatively titled This performance will be playing video on it. Ideally, you
Saturday. Fortunately, particularly noticeable in areas that should see no screen tearing and
RebeccaBlackOS (RBOS) has are tricky for a display server, such lower memory and CPU load. We
almost nothing to do with Miss as scrolling a web page with a found Wayland performed well on
Black other than the default our machine, but until it’s used
username of beccaholic.
As the only distro that’s ditched X
The difference between more widely, it’s hard to know how it
will perform in the wild.
for Wayland, RBOS is far more Wayland and X is almost PROJECT WEBSITE
noteworthy for its display server
than its name. You can try out a entirely behind the scenes https://wayland.freedesktop.org

Linux installer

Calamares
I
f you’ve been using Linux for a any distribution, but that any
while, you probably don’t give distribution can adapt it for their
too much thought to the distro own needs rather than building their
installers. Once you’ve installed own from scratch.
your favourite distribution a few By sharing the same installer,
times, you can probably do it distributions can also share the
without even thinking. However, we effort needed to create and
should probably spare a thought for maintain the installer, which should
the first time Linux users as it can mean a higher-quality installer for
be a stressful time when you first everyone while at the same time,
put a new OS on your computer. leaving distro developers with more
The popular KDE distribution NetRunner uses Calamares rather
There are a lot of options, and time to focus on what makes their than building its own installer from scratch.
they’re not always well laid out. Part distro great rather than messing
of this problem comes from the around with an installer.
fact that most major distros build Quite a few Linux distributions Sabayon. Even Fedora is currently
their own installers, despite the fact are already using Calamares, evaluating its usefulness for future
that they all do the same basic job. including NetRunner, Manjaro and KDE remix versions. Keep an eye
Each installer works slightly out and you might come across
differently, and the work on each is Calamares on a distro near you in
duplicated. Most major distros build the near future.
Calamares is a project to build a their own installers, despite PROJECT WEBSITE
distro-independent installer. This
doesn’t mean that you can use it on them doing the same job https://calamares.io

62 www.linuxvoice.com
FOSSPICKS

FOSSPICKS Brain relaxers
https://launchpad.net/pybik/
Real-time action game

OpenClonk
C
lonks are members of a of commercial games that began in
humanoid race who seem 1994. This series ran for an
to be in need of a little impressive 20 years and nine
help. You can guide your clonks different versions. These closed
though a 2D world on various source games are still available as
missions as they build, mine and freeware (not open source) from
fight. Alternatively, you can play www.clonk.de. After the lead
against other users to see who is developer left the project, the
the mightiest Clonk controller. company behind the game
Dig, mine and fight your way to primitive humanoid supremacy
Gameplay is a bit like a more (Redshift) decided to discontinue
as the ultimate Clonk leader.
involved version of the arcade the series. However, it released the
classic Worms. Your Clonks can source code for the game engine language. The enables you to do
collect different bits of under an open source licence, so everything from building your
equipment, and you have to the spirit lives on in OpenClonk. own levels to creating entirely
direct them to use it. The As well as being a game in its new games. If you want to get
missions, though, are more own right, OpenClonk is an stuck into creating your own
complex and require more work interpreter for the C4Script Clonk world, you can find
to complete. Don’t worry if this all everything you need at http://
sounds a bit confusing, there’s a
full set of tutorials to help you get
You can do everything from wiki.openclonk.org/w/C4Script_
Documentation.
started. building your own levels to
OpenClonk is a direct PROJECT WEBSITE

continuation of the Clonk series creating entirely new games www.openclonk.org

Real-time strategy game

Megaglest
M
egaglest is a 3D British, Crusaders – and of course,
real-time strategy what open source game would be
game in which you complete without the ability to play
build and train your army, then as Penguins?
enter battle against one or more The graphics look a little dated,
enemies. As the name suggests, but we don’t believe that game
Megaglest is built upon Glest, an graphics correlate in any way with
earlier open source game that is the enjoyability of computer games.
no longer developed. It doesn’t matter if you can
Although there have been ray-trace in real time, if the
improvements across the board, gameplay isn’t fun then the game
from the player’s perspective, the isn’t fun and conversely, horrendous
The range of different
biggest improvement in graphics with great gameplay still elaborate ways to downgrade the
factions and scenarios
Megaglest over Glest is the make an enjoyable game. We’re means that there’s graphics to regain the lost
increased amount of gameplay. pretty sure that gaming reached a plenty to keep even the feelings of youth, there’s an online
As well as the official game peak with 8-bit CPUs, and if most ardent engaged in community of players, and there’s
which includes six different anything, Megaglest is a little too Megaglest for some usually a game on somewhere
factions to play as (Tech, Magic, realistic. Perhaps we could route time. for you to join.
Egypt, Indians, Norsemen, the graphical output through
Persian or Romans), there are a Termpix for a retro experience. PROJECT WEBSITE
wide range of user-contributed If you’d rather spend your time https://megaglest.org

expansions including Japanese, being sociable than working out

www.linuxvoice.com 63
INTRO TUTORIALS

TUTORIALS
Warning: excessive Linux knowledge may lead to fun and more efficient computing.

In this issue . . .
66 68

Ben Everard
Can be beaten by the Go AI on a particularly
sluggish Commodore 64
Schedule your work to Put your office suite in
keep RSI at bay the cloud, but stay private

O
Ben Everard sometimes has sore hands, so he You don’t have to hand over your data when you
ne of the big milestones in takes regular breaks from work to ease the strain. put your office suite online. Valentine Sinitsyn
artificial intelligence fell this Workrave makes sure that he doesn’t forget. uses OnlyOffice to build his own cloud.
month. A computer beat a
world champion in Go, a board game
with simple rules but very complex
tactics. While this is an impressive feat
of computing, it’s always felt a little
hollow to me to attach the tag
intelligence to this sort of computing.
Intelligence isn’t the ability to be taught
how to strategise by analysing millions
of scenarios in a contrived environment, Terminal velocity 72 OpenStack 76 Let there be light 80
it’s the ability to thrive in new situations Les Pounder introduces the Not content with one computer, The ever-illuminating
and apply novel approaches to solve awesome power of the Linux Graham Morrision runs 10 on a Mark Crutch finishes his series
old problems. command line interface. single CPU. on light control with Linux.
AlphaGo (the computer that won the
match) could only be considered to be
intelligent if it could take the lessons
learned from Go and apply them in
Coding
other areas: chess perhaps, or business
strategy. Reprogramming the machine
to work in another area isn’t sufficient; it
has to be able to adapt by itself and
transfer the skills of one area to another
just as humans do every day.
If computing’s going to really move
forward, we need to stop focussing all
our efforts on artificial intelligence and
start trying to develop actual Ready, steady ... Go! 84 Languages of the future 90
intelligence. Trendsetter Amit Saha discovers a new language Juliet Kemp enters her virtual tardis and sets forth
ben@linuxvoice.com from Google and likes what he finds. to find the programming languages of tomorrow.

www.linuxvoice.com 65
TUTORIAL WORKRAVE

EASE FINGER STRAIN
WITH WORKRAVE
Stay healthy and pain-free by taking breaks from work.

BEN EVERARD
K
eyboards, mice and monitors are the link for as many years as possible (or at least until we get
between people and computers – the a more robust human-computer interface such as a
meat-space equivalent of a USB cable. Just USB port directly in our cranium).
WHY DO THIS? like a USB cable, this interface can wear out if it's used There are many aspects to taking proper care
• Keep eye- and wrist strain too much or not looked after properly. We may be able of our body, and in this tutorial we're going to look
at bay to get new parts for our computers when they wear at one: timing. All communications protocols have
• Go outside, smell the out, but getting new hands and eyes if our bodies start optimal timings, and the human-computer interface
flowers, feel the rain and to wear out is much more difficult. It's important, then, is no different. The best option isn't just to blast the
the sun on your vitamin
D-deprived face. to take the best possible care of our meaty interfaces information across as quickly as possible, but to work
• Bear the lead-heavy so that we can keep communicating with computers in a way that minimises the strain on our joints.
haunches of the toad and
work more lightly
STEP BY STEP: LOOK AFTER YOURSELF
1
Install Workrave 2
Take a Microbreak
Workrave is an activity monitor that's designed to Microbreaks are the smallest counter on Workrave. By
interrupt your computer use to remind you to take default, every three minutes, Workrave will prompt you
frequent breaks – these breaks are important for the to take a 30-second rest. First, you'll see a popup
health of your hands and eyes. You might find it in prompting you to take a break, and this will then
your distro's package manager, but if you don't you monitor your keyboard use. If you stop using the
can download a tarball from the project's website keyboard, Workrave will start a 30-second countdown,
(www.workrave.org). Installation is via the standard during which you won't be able to access anything on
method of unpacking the tarball then running your computer. The three minutes between
./configure, make and finally sudo make install in the microbreaks only counts time you're actually using
unpacked directory.. your computer. If you stop using the mouse and
If you're unfortunate enough to have to run keyboard, then the countdown will pause.
Windows, you'll also find an install file on the The key aspect of these short breaks is to briefly
project website. There's not currently a version of rest the parts of you interacting with the computer,
Workrave for Apple's OS X, though there are some that is, your hands and eyes. While your hands will
similar applications such as 20 Cubed (https:// automatically rest when not using the keyboard, your
chrome.google.com/webstore/detail/20-cubed/ eyes will only rest if you look away from your screen.
geghmabifcdlkmpnkapfefbbfaonhcef) and Awareness Ideally, you should find something much further away
(http://iamfutureproof.com/tools/awareness). from you than your screen to give your eyes a break.

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WORKRAVE TUTORIAL

3
Take a rest break 4
Finish for the day
Rest breaks are 10-minute breaks that come about No matter how many breaks you take, there's a limit to
every 45 minutes. During these, you should take the how much computer use you do in a day before you'll
opportunity to stand up and get away from your start run the risk of serious problems. Workrave
computer. By doing this, you'll stimulate the muscles recommends four hours per day of actual computer
in your back and arms in ways that will relieve the use (typing or mouse control). Again, this only counts
tensions that can build up while sitting at a desk. We active computer use rather than all the time that your
like to use some of our rest breaks to do finger computer is switched on. You can postpone this three
exercises that help to strengthen our hands and times if you're just coming to the end of a critical piece
minimise the damage caused by typing. of work.
You don't have to take your breaks exactly when Finishing for the day means finishing computer
Workrave suggests: sometimes, you might need just use. Depending on your job, there may be several
a few more minutes to finish working on something things that you can do without using a computer.
while you still have the train of thought in your head. For example, we like to proofread printouts, plan
For this, there's a Postpone button that enables you projects on pen and paper and take care of anything
to delay the break in the same way a snooze button that needs to happen in the real world. By limiting the
delays an alarm clock. You can't just delay indefinitely amount of time you spend at the computer each day,
though, because you're only allowed three postpones you can dramatically reduce the amount of strain on
per break before it becomes mandatory. your body.

5
Configure Workrave 6
Other options
In truth, we're only just starting to understand the Workrave isn't a complete solution to staying healthy
effect that long-term computer work has on the body. while using a computer, it's just one tool to help in one
While most experts agree that taking rest breaks is area. To ensure you have many years of productive
essential to ensuring your long-term health as a heavy computer use a head, you need to ensure that you
computer user, there's no clear consensus on the best properly take every possible precaution against
way to schedule your breaks. Workrave doesn't computer-related injuries. The most basic is proper
mandate the periods of each break, and allows you to desk setup where you ensure that you have your seat,
configure most how long to rest for and how desk and monitor all at the appropriate height. Further
frequently to rest. You can enter the preferences precautions include using ergonomic keyboards and
window by right-clicking on the Workrave window and mice, and considering alternative desk setups such as
selecting preferences. If you're already suffering from standing desks. There isn't a standard setup that's
RSI or some other strain, you may need to break right for everyone, so you'll have to do some research
longer or more frequently. Alternatively, you might feel to find out what works for you.
it more appropriate for your work to break less often. Above all, the most important part of staying safe
If you use multiple computers in the course of your when using a computer is not ignoring any warning
work, you can also configure Workrave in network signs. If you get any tingling, numbness or pain when
mode so that it takes into consideration your work on working, you should immediately look to mitigate the
all your machines. problem and ideally seek medical advice.

www.linuxvoice.com 67
TUTORIAL ONLYOFFICE

ONLYOFFICE: HOST AN
OFFICE IN THE CLOUD
Get all the power of online office suites without having to trust a third party.

VALENTINE SINITSYN
M
arketing guys say we live in a "cloud first"
era, and they are probably right. Many of us
rely on web-based, remotely hosted apps
WHY DO THIS? for daily tasks, like reading email, writing texts or
• Enhance privacy – your working with spreadsheets. Having all your data in a
data is yours. single place accessible from everywhere is good for
• Work from almost any productivity, but bad for privacy. And if you are into
device, anywhere. Free Software, you probably care about privacy.
• Explore free office suites Is there a way to bring together the best of both
beyond LibreOffice.
worlds? The answer is yes – to a certain extent – The OnlyOffice Document Editor displaying SAI
and is often called self-hosting. You still use web specification from Microsoft et al. Despite being free
applications, but run them on your own servers. Your (Apache v2), it comes in OO XML rather than PDF format.
files are under your control, and you only need a web
browser to access them wherever you are. SaaS first. The project's website is at https://www.
OnlyOffice is a hosted alternative to online office onlyoffice.org.
suits like Google Docs, Microsoft Office Online or Zoho OnlyOffice is actually an umbrella term for several
Documents. It's also available in the cloud, if you wish, interconnected products. At its core is the Document
and best of all, it's free (as in speech). We reviewed it Server, which is a family of online document editors.
in LV017, and in this tutorial, we'll show you what is it Document Server provides a word processor,
capable of, and how to deploy it on your network with spreadsheets and presentations, and that's it. To
minimal efforts. manage your documents, you'll need Community
Server, which also brings calendaring, CRM and
Getting your feet wet project management features. Put simply, Document
OnlyOffice started in 2009 as Teamlab, a proprietary Server is your traditional desktop office suite brought
Windows-based product. Five years later it was to a browser; Community Server is a collaboration/
renamed, released under AGPLv3, and brought to groupware tool built on top of it. Communications
Linux, thanks to Mono. Today, OnlyOffice comes in are supported via the Mail Server add-on, and
three main flavours: Free, Enterprise and SaaS. We are OnlyOffice Talk, an XMMP/Jabber service built into the
The OnlyOffice Spreadsheet
Editor showing a sample going to cover the first; Enterprise is a commercially Community Server itself.
document with London hosted solution, and SaaS is a cloud version (both free There are several ways to deploy OnlyOffice;
2012 Summer Olympics and paid-for plans are available). They aren't identical, we'd use Docker. Note that OnlyOffice has known
stats. as new features often appear in the Enterprise or incompatibilities with older Linux kernels. If you run
an LTS distribution, it's better to upgrade to the latest
kernel first. A system with dual-core 2GHz CPU
and 4GB RAM is recommended to run OnlyOffice in
production. For evaluation and testing, half of these
specs should probably suffice.
Ensure you have Docker 1.4.1 or later installed. If
not, either use your package manager or get it directly
from www.docker.com. Document Server official
images are on Docker Hub, so you can get it running
with a single command:
$ sudo docker run -i -t -d -p 80:80 onlyoffice/
documentserver
Depending on how your host is configured, you
may not need the initial sudo. Document Server will

68 www.linuxvoice.com
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listen on port 80; change the first number in -p if you
want anything else. Now, open your web browser and
navigate to http://your-host-name-or-IP-address.
You could use localhost or 127.0.0.1 for now, but
Community Server gets confused with them. So, better
use a real (resolvable) hostname or the host's IP
address, like 192.168.1.x.

Meet the editors
By itself, the Document Server is really bare bones. You
can upload a file from a local PC, edit it and download
back – that's it. You can't create new documents,
Before you can use the
delete them, or manage files in any way. There is at least for now. Comments and changes tracking
Community Portal, some
also no access control. To make long story short, are also not in the Free edition yet, which is a pity. things need to be tweaked.
Document Server is more of a technology demo than The equation editor may feel inconvenient, if you're Make sure to enter a real
an online office suite. You'd want Community Server for used to LibreOffice Math or Latex. Finally, automatic email address.
any real deployment. tables of contents aren't supported. This means
The native document format for OnlyOffice editors that OnlyOfficeis hardly suitable for editing large
is OO XML. This matches OnlyOffice to Microsoft's documents, like books or reports.
offerings but makes Richard Stallman sad. You can Two other OnlyOffice components hide no surprises.
upload documents in almost any format, including Even the ribbon stays almost the same. Formulas
OpenDocument, or legacy DOC, XLS and PPT. Behind in spreadsheets work, and various slide layouts and
the scenes, OnlyOffice calls LibreOffice to convert themes are available for your presentations. OnlyOffice
anything you throw at it to OO XML. It is also possible Free doesn't seem to support macros, which is
to download your documents as OpenDocument files. understandable, yet may disappoint some business
OnlyOffice will even try to open PDFs for you, although
it never succeeded in our quick tests. Yet it handled
a complex DOCX file that LibreOffice failed to render
At the core of OnlyOffice is the
properly – your mileage may vary. Document Server, which is a family
OnlyOffice has most of the features you'd expect
from an online office suite. You have all the usual text of online document editors
formatting options on the first three ribbon palettes.
It is possible to insert images (either from a file or users. It also turns out that the spreadsheet editor
URL), tables and charts and create autoshapes and doesn't play well with Firefox's "Find as you type"
hyperlinks. A useful option is "Insert text", which feature. When it is on, the search box appears at every
creates a text frame, as in desktop publishing keystroke, seizing the focus. You'd want to disable this
software. There is also a quite sophisticated feature during your OnlyOffice sessions.
equations editor, and some styling tools. For instance,
you can change the document's colour scheme Create a portal
(which affects charts, autoshapes and tables), or Community Server builds on the Document Server to
create a heading with one mouse click. add portal features like document management,
Sometimes, OnlyOffice feels rather counter-intuitive. access control, and third-party file hosting support.
To create a new style, you format some text the It also comes with extra tools, including a calendar, a
way you want, then save it as a style, not the other project management solution, a CRM and OnlyOffice
way around. And it doesn't work in OnlyOffice Free, Talk, albeit we won't cover them in this tutorial.

Your office, your way
It is possible to embed OnlyOffice editors in your own enough to view a document in any supported format. To save
software. So, if you like the editors but dislike the Community it, you should also provide some back-end, namely a callback
Server, there's nothing to stop you from making your own handler that runs when the document is saved. The idea is
one that works exactly the way you want. That's what we like that you implement a document storage service component,
about Free Software. which makes documents available to Document Server
To embed the editors, you must have the Document Server (subject to permissions check), and also downloads them
up and running. The client builds on JavaScript (naturally) and from the Document Server when anything changes.
the HTML 5 Canvas element. The later is somewhat close to OnlyOffice provides a rich API to customise the editors' look
how desktop apps work, and sets OnlyOffice editors apart from and feel, and also exposes an API for file format conversions
many cloud office suits. (this really calls into LibreOffice, you know). You will find a
To embed OnlyOffice, you include a JavaScript library and detailed reference documentation along with usage examples
wrap a placeholder <div> element. Surprisingly, this is already at http://api.onlyoffice.com.

www.linuxvoice.com 69
TUTORIAL ONLYOFFICE

The Documents module is
where you'll spend most of
your time. You can make
it a default start page for
that reason

Official manuals suggest running Community Server If you agree to stick to official images, the process
in a separate Docker container linked to Document could be much simpler. First, you may use Docker
Server and Mail Server containers. We'll do it this way, Compose to run all three containers (Document Server,
albeit without the Mail Server. In a nutshell, Mail Server Community Server and Mail Server) with one command.
is just iRedMail plus Postfix, Dovecot, SpamAssasin Second, you don't have to type any commands at all:
and ClamAV wrapped as OnlyOffice add-on. It's really you can use the OnlyOffice One Click Install (https://
optional, as Community Server should integrate well one-click-install.onlyoffice.com) automated service.
with your existing email infrastructure. We haven't tried this path ourselves; if you do, we
Stop and remove the existing Document Server first, strongly suggest you change the password or SSH
then recreate it with the explicit name and no ports key you posted to One Click as soon as the installation
exposed: completes.
$ sudo docker run -i -t -d --name onlyoffice-document- In a similar vein, we don't recommend that you
server onlyoffice/documentserver access OnlyOffice via HTTP in production. Setting up
The official Community Server image at Docker Hub HTTPS is simple; see the Community Server's README
is outdated (8.5 vs 8.7), and it didn't work well for us. for details. Note that you should mount the Data/certs
So, we recreated it locally from the latest packages: volume, not plain Data as the README suggests.
$ git clone https://github.com/ONLYOFFICE/Docker- Otherwise, Community Server won't be able to find its
CommunityServer static files (scripts and stylesheets).
$ cd Docker-CommunityServer
$ docker build -t communityserver:8.7 Make yourself at home
This takes some time. When the process finishes, Now, open https://your-host-name-or-IP (remember
run the Community Server container with: not to use localhost!). Community Server takes some
$ sudo docker run -i -t -d -p 80:80 -p 5222:5222 -p 443:443 time to initialise, so if this page doesn't open, wait a
--name onlyoffice-community-server --link onlyoffice- second and try again.
document-server:document_server -v /opt/onlyoffice/ Community Server needs some initial setup. On your
Data/certs:/var/www/onlyoffice/Data/certs first visit, it will ask you for the administrator's email
communityserver:8.7 and password, the language and the timezone. When
Here, we expose ports 80/443 for HTTP/HTTPS you'll get an email from OnlyOffice, follow the link to
access, and port 5222 for OnlyOffice Talk (XMPP). activate the Administrator's account. For testing, you
Mount volumes (-v) are needed to set up HTTPS (see may skip this step, but you won't be able to get portal
below). notifications or change your credentials then.

OnlyOffice isn't the only...
At the time of writing, OnlyOffice was arguably the most and the server. Recently, an OwnCloud plugin for LibreOffice
mature free online office suite. But it's certainly not alone. Online was announced.
The first attempts to run LibreOffice in a browser date The Document Foundation also seems to have no plans
back to 2011. The original prototype used a GTK 3 + HTML 5 to build a cloud service on LibreOffice Online, so it is likely
(Broadway) back-end. This approach didn't scale well, and was a "hosted-first", not "cloud-first" solution. Yet you can try
tying clients to the server too much. it yourself, as Collabora provides CODE (Collabora Online
So, in 2015 Collabora teamed up with IceWarp to build the Development Edition) – an OpenSUSE-based VM image
new LibreOffice Online (LOOL). For starters, Writer, Calc and containing the latest developments in the field. It also includes
Impress were included, but this list may expand in future. The OwnCloud, so you can test both pieces of the puzzle together.
project reuses as much from the existing LibreOffice codebase Download links and detailed instructions are on
as possible, and renders your documents for the web the same https://www.collaboraoffice.com/code.
way it does for the desktop. The LibreOffice Online back-end CODE is bleeding-edge, and not everything may work
calls into a thing called LibreOffice Kit, which draws document properly. We got occasional socket errors, and were not able
tiles, much like map services do. These tiles are sent to the to run the VM on IPv6 network. Yet we hope CODE will help
front-end communicating via a WebSocket connection. This you to build a picture of the LOOL's state today. Give it a try,
means better scalability and less coupling between the client file bug reports, send patches and stay tuned for the updates!

70 www.linuxvoice.com
ONLYOFFICE TUTORIAL

When you log in to the portal, it will show you the
module choice page: go to Documents. To make
Community Server start from this page, click on the
gear icon, choose Common > Modules & Tools, and
set Documents as the default start page.
To create a new document or folder, use the
menu just below the OnlyOffice logo. A button next
to it uploads documents from a local hard drive.
Remember that OnlyOffice converts documents you
upload to OO XML, although you may choose to keep
the original as well. My Documents is where you find
your own files, and Common Documents stores files for
all portal users. You can also share your private files
LibreOffice Online brings
with portal and non-portal users, and control access choice here is OwnCloud (www.owncloud.org): it's
the office suite we all
at user or group level. The only file management popular and free. know and love to the web
feature we miss is a Recent Files list. We assume you already have OwnCloud running browser (OwnCloud app
To open a document, click on its name in the list. An on your network. If not, there are numerous manuals included).
editor window will appear, and you can start making available, not to mention an official Docker image.
changes. Documents are saved automatically. When OwnCloud uses WebDAV for integrations, so you don't
you are done with the document, just close the tab or need any API key. Just click on the icon and fill in
click the "Go to Documents" link in the top-right corner. your OwnCloud login and password. The connection
Note that you're working as Administrator now. URL is found under the Settings link in the OwnCloud
To add some unprivileged users, choose People
from the drop-down near the logo. From the People
module, you can add users or groups, and import If you already use an online office suite,
them from your cloud account or CSV file. You can
also simply send email invitations to those you want
you probably want OnlyOffice to access
to collaborate with. your existing documents in the cloud
Add some storage web interface. The name you use to connect to
If you already use some online office suite, you'd OwnCloud should be in OwnCloud's trusted domain
probably want OnlyOffice to access your existing list. Try to open it in your browser, and OwnCloud will
documents in the cloud. Community Server supports guide you through the process. Remember not to use
integration with third-party file-hosting services localhost, unless Community Server and OwnCloud run
like Google Drive, Dropbox, OneDrive, and Box.com uncontainerised on the same physical machine.
(among others). You may have already spotted their Third-party services are essential for collaboration.
icons at the bottom-left of the portal. This being said, Community Server is rather useless
By default, CommunityServer can set up WebDAV- at conflict resolution. It may happily overwrite the
based integrations only, as everything else needs API file you changed outside the portal, or fail to upload
keys. So, navigate to Settings > Integration > Third- your document to Dropbox for no visible reason. The
party Authorisation. You'll see numerous fields for latest OnlyOffice document editors (not available in
authorisation keys related to different services. To OnlyOffice Free yet) bring real-time collaboration, so
get the required credentials, you'll need to register a these issues should go away some day. Until them,
developer's account with the service of your choice. it'd be better to keep them in mind.
This is usually free yet is a somewhat tricky process.
Luckily, there are step-by-step guides available A bit of summary
at http://helpcenter.onlyoffice.com (search for We hope this tutorial helped you to build an
"Authorisation keys"). understanding of what OnlyOffice is. The technology
When you fill authorisation keys for some service, looks promising, albeit with some glitches that may
a respective icon will appear at the bottom-left of the turn into blockers in specific use-cases. The free
portal. Click on it, and follow the on-screen prompts. self-hosting edition is a real bonus, however it may
Remote services looks like folders at the Community feel more like a teaser for OnlyOffice Enterprise than
Portal, and you have an option to make them a standalone product. We won't replace our good
common for all (or some) portal users. To change this old LibreOffice with it just now, but we'll keep an eye
setting later, you'd have to delete the folder (your data on OnlyOffice's progress. If you already use an online
is not affected) and re-create it from scratch, so think office suite, OnlyOffice Free is a viable alternative.
carefully.
Having a hosted office suite that stores documents Dr Valentine Sinitsyn got addicted to office suites when he
in the cloud doesn't help your privacy much. You'd was the editor of Linux Format Russia. These days, he runs
Vim or Python much more often.
also want a hosted document storage. A natural

www.linuxvoice.com 71
TUTORIAL LINUX FOR LEARNERS

LINUX FOR LEARNERS:
TERMINAL BASICS
Les Pounder takes us on a journey into the Linux command line.

LES POUNDER
W
hen we think of the Raspberry Pi we
initially think of robots, coding and making
cool projects. But what is underneath all of
WHY DO THIS? these projects? Why, it's the humble Raspbian
• Learn Linux. operating system. Raspbian is based upon Debian, a
• Update your Raspberry Pi. solid Linux operating system that has powered
• Navigate the filesystem. everything from PDAs to huge server farms.
• Create files and The easiest way to install Raspbian on a Raspberry
directories. Pi is to use NOOBS (New Out Of the Box Software).
• Copy and move files. For this you will need to download NOOBS on to a PC.
• Rename and delete files. NOOBS comes as a Zip archive, which will need to be
• Add users to the system. extracted to a FAT-formatted SD card with 8GB
• Add users to super user capacity. With NOOBS on your SD card, insert it into
group. your Raspberry Pi and boot up. On first boot you'll be
asked to choose an operating system. Tick the box
next to Raspbian and then click Install. The installation The new Raspberry Pi Configuration tool replaces the old
process can take around 10 minutes, so now is great raspi-config menu and provides an easy to use tool for
TOOLS REQUIRED
time to get a cup of tea. Once completed, the Pi will configuring every aspect of your Pi.
• A Raspberry Pi running
the latest Raspbian reboot and load the Raspbian operating system.
release. be very careful! To temporarily give a normal user
• An internet connection. Expand the SD card super powers we use a command called sudo before
With the Raspberry Pi booted to the desktop we'll now the command that we wish to run with that power, so
perform a little maintenance. It's important that we for example let's open LXTerminal and run the ifconfig
give Raspbian as much disk space as possible. From command with super powers.
the Raspbian desktop you can see the menu in the $ sudo ifconfig
top-left of the screen. Left-click here and navigate to Using ifconfig as an example is quite safe, as the
the Preferences menu. In the new sub menu you can basic command just lists the Wi-Fi and Ethernet
see the Raspberry Pi Configuration application. Click connections for your Pi. We're not interested in the
on it. In the new window, you can see the Filesystem output; this command is just to illustrate how to use
entry; left-click on Expand Filesystem To action. Once sudo with a command. We'll use sudo for real later in
this is done, you will need to reboot for the actions to this tutorial.
take effect.
On a typical Raspbian install there is only one user, Update your Pi
called "pi". This user has a home directory at /home/ It's essential to keep your Raspberry Pi up to date. By
pi. Your work, images, videos etc are all stored in this updating you ensure that your Pi gets the latest
home directory. In this home you can create, edit, software and important security updates. Only a user
delete and move anything without needing any with super powers, sudo, can update the Raspberry Pi,
administrator powers. This is because it is full of your as this is an administrative task that can affect the
files. Each user has their own home and typically can entire system. To update the list of software that your
only work on the files contained in that home. But Raspberry Pi can install we need to check our list of
there is one user who can do what they want, and that software against a remote server. Open LXTerminal
is the "superuser" sometimes known as "root". and type.
The superuser can do anything: configure the $ sudo apt-get update
system, delete any files and create users. But just like You will see lots of text whizzing along the screen;
a Super Hero, with great power comes great this is your Pi talking to a remote server and updating
responsibility, and when using this power you should the software list on your Pi. Now this action does not

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update the software, for that we need to issue another
command, so in the same terminal, and after the The apt-get update
previous command has completed, type the following. command generates a lot
of text – here we can see
sudo apt-get upgrade
the command contacting
After a few moments the screen will update and tell
all of the servers that
you what software requires upgrading. To confirm you contain the Raspbian
are happy with this, press the Y key and then Enter. software. This will update
How long the action will take depends on your internet the list of installable
connection and how many updates are required. software.
A top tip for this task is that you can chain the two
previous commands together. Once the first
command, apt-get update, is completed it is tested to
ensure that it has completed correctly. If that is the
case then the second command, apt-get upgrade, is tilde character "~", this is shorthand for that user's
run. We then add -y to the upgrade command to home directory, and it tells us where we are (by default
automatically upgrade the new software. The we're located in our home directory). Finally we see a
command to do this looks like this. Dollar sign, which tells us that our user has no super
$ sudo apt-get update && sudo apt-get upgrade -y powers.
It's important to keep your Pi up to date and this
action should be done at least once per month. Moving around
Lets try out a command that will tell us where we are.
Basic Linux skills It's called Print Working Directory (pwd), and to use it
There are many commands in Linux, some of which we type.
you'll use every day. So let's open up LXTerminal and $ pwd
try them out. You will now see the absolute file path to your home
First, when we open LXTerminal we will see a directory – think of it as the full address for where you
interface that looks something like this. are.
pi@raspberrypi ~ $ To move around the system we need to know what
So what does that all mean? Well first we can see is around us, and to do this we need to list the
that our user is pi, the default user for a Raspberry Pi. contents of a directory. In a terminal type
Next we can see raspberrypi, which is the name of the $ ls
computer, often called the hostname. Next we see a You'll see lots of text appear on the screen, but what
is important right now is that we can identify files
from directories. You can see Desktop in blue; this is a
Sneaky sysadmin skills directory, so any text in that same colour also denotes
Repeat the last command directories. Let's go into the Desktop directory in a
You can press the Up arrow to reverse search through your terminal type.
commands (pressing Down goes forwards). Once you find $ cd Desktop
the command, press Enter to action it. After pressing Enter we will move into the Desktop
See all of the commands that you have used
The history command records the commands entered in
directory; to verify this, type in pwd and you should
the terminal. You can type history into the terminal but see /home/pi/Desktop. So we're now in the correct
it will whiz along really quickly. So, using a pipe (a tool to directory, take a look around using ls. To go up a level,
redirect the output of one command to become the input of by which we mean to navigate closer to the root of the
another), we can pause the output and press the arrow keys file system, type
to go through the list.
$ cd ..
$ history | less
Use a command from history Now type in pwd –you should be back in your home
When we used the history command you may have noticed directory. Let's try and move into a directory not inside
that the entries were numbered. These numbers can be our home. In a terminal type
used to run a command again, without typing it. All we need $ cd /dev
to do in a terminal is type an exclamation mark followed by
the number of the command, for example.
Now type in pwd and you will see that we are no
$ !22 longer inside our home, we are in the /dev directory.
I forgot to run that command as sudo Take a look around using ls and you will see lots of
We've all been there, we type in that command to change files that represent devices, physical and virtual, that
some aspect of the system, such as adding a new user to are attached to our Pi. This directory is full of stuff and
the system, but we forgot to add sudo to the start of the
command. We pressed Enter and nothing happened. Fear
right now we don't need to know too much about it so
not! To repeat the last command but with super powers all let's return to the safety of our home by typing:
you need to do is type $ cd
sudo !! Now that we're back in our home directory, let's create
a simple text file in the terminal type

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TUTORIAL LINUX FOR LEARNERS

identical copy of a file in the target directory, which in
this case was stuff/. Take a look inside the stuff
directory to verify that the copy has worked. Let's
return to our home directory by typing cd. We shall
create another file but this one shall be blank. To
create a blank file we use the command touch
followed by the name of the file, so in the terminal
type.
$ touch blank.txt
So now we have a file called blank.txt in our home
directory, but we don't want it there, so let's move it
into our stuff directory. Just like the copy command,
the move command is shortened, this time to mv. In
the terminal, type the following.
$ mv blank.txt stuff/
Now change directory to stuff using cd, and then
look inside using ls. Can you see the file? We can also
use mv to rename a file and it works like this. In a
terminal type:
We can use the pwd and ls
$ nano hello.txt $ mv blank.txt renamed.txt
commands to learn where
we are in the file system You will now see a very basic text editor called From the output of the ls command you should see
and what is around us. Nano. We can use Nano to create and edit text files in that there are two files, one of which is called
These are basic building any programming language, and we can edit system renamed.txt.
blocks to our Linux skills. files on our Raspberry Pi. For this example we shall
write a simple Delete files and directories
Hello World! So now we have a directory called stuff which we are
So now let's save our work… but where is the save currently in, and it has two files inside of it. Let's do a
button? At the bottom of the screen you can see six little housekeeping and tidy up the directory. The
columns of text, these comprise our menu. First we command to delete files is called rm, and it should be
need to "WriteOut" our work, so press Ctrl+O to open used with great care. There is no easy undelete or
the save dialog. You will be asked what filename you recycle bin – once it is deleted, consider it gone
want to save the file as; we specified hello.txt. With forever. We'll remove one of the files, renamed.txt, like
our work saved we now need to exit Nano, so press so:
Ctrl+X to exit and return to the terminal. If you type ls $ rm renamed.txt
now you'll see the file that we have just created. Would Now use ls to look in the directory. You should see
you like to take a sneak peek inside the file without only one file now.
using Nano? In the terminal type Let's delete an entire directory. Return to your home
directory and type the following into the terminal.

There is no easy undelete or recycle bin. $ rmdir stuff
What happened? Did you get an error?
Once it is deleted, consider it gone, rmdir: failed to remove 'stuff/': Directory not empty
So what does this mean? Well we can only use the
forever. rmdir command on empty directories, so how can we
delete directories and their contents? Well, the rm
$ less hello.txt
You will now see the contents of the file; to exit,
press Q.
We've created a file, now let's create a directory
called stuff. In the terminal type.
$ mkdir stuff
Type in ls to see the new directory, now try to
change the directory to the new stuff directory using
cd. Once you've finished return to the home directory.

Copy and move files
Now we have a directory called stuff let's copy our
hello.txt file into this new directory. In the terminal
type The /dev directory is full of devices (virtual and physical)
$ cp hello.txt stuff/ that we can use. Only skilled users with super powers
The copy command is shortened to cp and creates an should really do any work in here.

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LINUX FOR LEARNERS TUTORIAL

The adduser command is
Controlling your Raspberry Pi over a rather helpful and asks
us lots of questions in a
Sometimes we cannot be sitting in front of our Raspberry
steady manner.
Pi, either we are working away or we need to remote
control our Pi. Linux comes with SSH, a secure shell, that
enables remote control in a secure manner. The Raspberry
Pi comes with an SSH server ready to go – all we need to
do is connect our Pi to the network and power it on. From
our PC we can then use an SSH client to log in. For Linux
users we have this built in to the terminal, as do Mac users.
But for Windows you will need to download an application
called Putty: http://portableapps.com/apps/internet/
putty\_portable.
For each operating system we need to know the
username (normally pi) and our password (the default is
"raspberry"). provide the details of that user, name, phone number
For Linux and Mac users, open a terminal and type etc. This is not mandatory, so feel free to press Enter
ssh pi@raspberrypi.local to bypass. The last question asks if the information is
For Windows users, install and open Putty. In the new
correct, if so press Y then Enter.
Window you will see "Host Name". Type in:
raspberrypi.local
Our new user, hacker, needs to have super powers,
Windows users should click on Open, and you'll be asked so without any radioactive spillages or elaborate back
for your username, which is "pi". story we shall give them the power they need. It's
For all operating systems you will be asked for your rather easy to add a user to a group; we'll use the
password. Press Enter and you are now in control of your
same command as before but add the group name at
Raspberry Pi, so any command issued in the terminal will
be processed by the Pi and the output sent to your screen. the end of the command. In a terminal type the
following.
$ sudo adduser hacker sudo
So now we can test this user by switching our user
command can be used with directories, so to delete to them. In a terminal type
stuff type the following. $ su hacker
$ rm -rf stuff/ You will need to use the password that we created
The directory stuff and its contents will now earlier. Once this is entered you will see the terminal
disappear. You can use ls to look for it but you will change to reflect that you are now logged in as the
never find it. user hacker. So can hacker use sudo? Let's try by
repeating the ifconfig command that we used earlier.
Create users In a terminal type:
On a typical Raspberry Pi we have one user, pi, but $ sudo ifconfig
what if we shared our Raspberry Pi with another user? You should be able to see the network connections
Do we want them to access our work? Well the on your Pi plus lots of other text, if you see a rather
answer is clearly no, so let's create another user using stern note that you have been reported to root for
the command adduser. In a terminal type trying to use sudo, then repeat the process to add
$ sudo adduser hacker hacker to the sudo group.
Now we used sudo, as creating a new user is a
system-wide activity. This command creates a new What's my IP address?
user called hacker and then proceeds to ask you to Sometimes we need to quickly know the IP address of
create a password for this user. It next asks you to a computer without faffing around with a GUI. We can
use two commands: if you just want the IP address,
type the following into a terminal.
$ hostname -I
But if you really need to know everything about a
connection, for example the IP address for your Wi-Fi
dongle, Ethernet connection and their MAC addresses
then you can use.
$ ifconfig
Congratulations: you have taken your first and
rather important steps with the Linux command line.
Keep these skills sharp and they will help your future
hacks.

Nano looks really basic but it hides a really powerful Les Pounder divides his time between tinkering with
hardware and travelling the United Kingdom training teachers
interface for working with text and files in the terminal.
in the new IT curriculum.
There are other editors such as Vi and Emacs.

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TUTORIAL OPENSTACK AND JUJU

GET STARTED WITH
OPENSTACK AND JUJU
You don’t need a Google-sized data centre to play with the revolution in the cloud.

GRAHAM MORRISON
D
espite the continued hype, ‘cloud computing’ applications themselves don’t exist on a single
isn’t necessarily all that new. It’s very similar at machine either, but rather on an abstraction of those
a hardware level to what has always been resources, effectively an OS for the cloud.
WHY DO THIS? found in data centres: a collection of storage, OpenStack is perhaps the largest of these ‘operating
• Create your own cloud networking and computing resources. The difference systems’. It’s a stack of open source software
• Install Mediawiki (an is in the way those resources are managed and used. designed to control pools of resources, and it’s being
more) with Canonical’s Cloud infrastructure is very elastic – you don’t need used everywhere, from PayPal and eBay, to CERN and
JuJu to hog a single processor, Ethernet connection or hard NASA. The difficulty has always been finding a way to
drive. Instead, applications in a cloud can typically play and install OpenStack yourself, when you don’t
scale from tiny to huge, and they can scale have gargantuan computing resources at your
dynamically according to demand, whether that’s disposal. Fortunately, if you’ve got a powerful enough
more storage, RAM or computing power. The machine and Ubuntu 14.04, you now can.
TOOLS REQUIRED
• Any PC from the last 5
years
• More than 12GB RAM
STEP BY STEP: INSTALLING AND RUNNING OPENSTACK
• 2–3 hours for the installer
1
Find the hardware 2
Install Ubuntu
The biggest problem when it comes to playing with The method we’re going to use to install OpenStack
OpenStack is having a stack of computers handy. leans heavily on the work of Ubuntu and Canonical.
Fortunately, to test out the technology, all you need is We’re going to use their pre-built packages and
a reasonably powerful single machine that’s capable installers, as well as Canonical service orchestration
of installing Ubuntu. You’ll also need a multi-core CPU tool, JuJu. JuJu can be thought of as being a little like
and lots of RAM. For reference, the machine we used a package manager for cloud applications, enabling
has 16GB of RAM and an Intel core i5-2500K CPU you to install (deploy, in cloud terminology) and tie
from 2011. More RAM will help because we’re together services with just a few commands, very
effectively going to create an OpenStack installation much like apt. Of course, there’s a lot more going on in
running across more than 10 Linux Containers (virtual the background, but the end result is that JuJu
machines) on a single PC. Each one of those enables you to easily add services to your own cloud
containers will be asking for several GB of RAM, most after you get it running. JuJu is even used by the
of which they won’t need but your system will still installer to create the OpenStack configuration. All of
grind to a halt while OpenStack works out the RAM which is a long way of saying you’ll need to install
allocation. An SSD could help here, but our system Ubuntu, and it works best if you can give it a fresh new
eventually made it with ordinary spinning storage and installation. We had best compatibility results with
several cups of tea. 14.04 LTS, although 16.04 beta worked too.

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3
Add the packages 4
Start the installation
With Ubuntu installed, we’re going to use the ‘Ubuntu Installing the dependencies is only the first step. The
Openstack Installer’ to grab all the latest packages time-consuming part comes from running the installer
and dependencies. The current focus for these and waiting for it to build a workable environment on
packages is Ubuntu 14.04, because of its long term your system. To begin the process, type the following:
support status. But as 16.04 is also a long-term sudo openstack-install
release, and imminent at the time of writing, it may be The interface to this installer runs via curses on the
a better option. We did try the packages running on a command line. We’re running version 0.99.27 of the
beta of 16.04 and they worked, but we’d still safely installer (March, 2016), so there’s a small chance that
recommend 14.04 unless you’ve got a hardware something may look different in a more recent
requirement only satisfied by a newer release. Open a version, but the process should be identical. The first
terminal and type the following to add the cloud- question you’ll be asked is what type of installation
installer package repository and install the you’d like to perform, and you need to choose the
dependencies we found we needed: ‘Single’ option at the bottom. As the text describes,
sudo apt-add-repository ppa:cloud-installer/stable this is the option for installation on a single machine.
sudo apt-get update
sudo apt-get install python3-pip
sudo pip3 install urwid --upgrade
sudo apt-get install openstack

5
Put the kettle on 6
Make a cup of tea
After being asked for the installation type, you’ll next In total, we waited over an hour for this step to
be asked for a username and password. This complete, although subsequent installations were a
username and password will be used to access the lot quicker. This is the part where new virtual
account and the dashboard, which is the OpenStack machines (containers) are spawned and slotted into
module used to provide a web management interface. the OpenStack ecosystem. Each container is needed
The first stage of the installation will appear as in the to perform a different task or run a different
screenshot, as the installer will download and pack all OpenStack module, and they’ll all end up talking to one
the various tools required. another to create the final configuration. Each will
OpenStack is built with Python (which is why we appear gradually on the terminal and go through a
made sure pip was installed earlier), and a lot of the series of stages after starting off with ‘Pending,’ and
requirements will be for Python packages and the it’s this step that will test your machine’s performance
creation of the first container. After that, you should to the maximum. We’d recommend spending the time
see the ‘Bootstrapping JuJu’ message, which should with a nice cup of tea and reading a little about what
kick off the second stage of the installation. each module does in OpenStack.

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TUTORIAL OPENSTACK AND JUJU

7
Nearing completion 8
Horizon/Dashboard
From top to bottom, the modules that OpenStack On the same machine, enter the login URL. This link
instantiates are Glance, Keystone, MySQL, Neutron/ will be an HTTPS connection, and you’ll need to ask
API, Controller, Compute, Dashboard and RabbitMQ. your browser to make an exception for the self-signed
Briefly, Glance is used to discover and register disk SSL certificate before you can continue. You’ll then be
and server images. Keystone is the identity and asked for the username and password, as shown in
authentication service. Neutron handles the virtual the installer terminal, which is now simply showing
networking. The ‘controller’ orchestrates everything, the output from the openstack-status command. The
the ‘Compute’ module actually runs the instances on dashboard defaults to an overview of the instances,
the hardware and the RabbitMQ server handles the virtual CPUs, RAM units, IP addresses and security
messaging. There’s also the dashboard, which groups being used by your cloud. There’s nothing
provides a web administration interface to the cloud. useful to see because we haven’t added any of our
When the install has finished, the [INFO] text at the own instances, but you can do this by switching to the
bottom will display ‘Status: Deployments complete, ‘Images’ page of the Compute module, which should
Relations complete, Post-processing complete.’ list a single image name. First, we need some security.

9
Set up security 10
Spinning up your own instance
Security is paramount when it comes to the cloud, By default, you should see an image for the Ubuntu
and before you’ll be able to connect to any virtual version you’re running on the Compute > Images
machines you’ll need to create an SSH keypair. This page. New images can be added using the Create
can be done from the command line by typing Image button, but for this example we’re going to spin
ssh-keygen -P "" -b 2048, but don’t let it overwrite up the image already listed. This is as simple as
your current files. Put the new files somewhere safe. clicking on the Launch Instance button. You need to
In the dashboard, go to the Compute > Access & give your instance a name, select a Flavour (start
Security page, click on Key Pairs and use the Import small) and choose your fresh security key from the
Key Pair button to open a panel where you can paste Access & Security tab. When you’re happy with the
the contents of the id_rsa.pub file you just created. options, click on Launch. The instances list will appear
Give the key a name and save it. You now need to with a ‘Spawning’ status in the task field. Your new
enable SSH access through OpenStack’s firewall. Click virtual machine is now being created and within a few
on the Security Groups tab followed by Manage Rules. moments – not an hour this time – 'Spawning' will
Click on Add Rule and select SSH, making sure change to ‘Running’ and your cloud will now be
Remote is set to CIDR. This will allow external SSH hosting your very own instance, just waiting for you to
connects to find a route to your new instance. connect to it and launch a startup business.

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11
Connecting to your new instance 12
Connecting to JuJu
Before we can connect, we need to attach the Building your own applications running on top of your
instance to an IP address accessible outside the own containers is obviously a very powerful step, but
cloud. You can do this by selecting ‘Associate Floating there are other options that cut out manual labour.
IP’ from the drop-down Action menu. After a simple Canonical’s JuJu is one of these, and it’s already being
panel, the floating IP address will appear in the IP used by your system to deploy the various OpenStack
address field, and you should be able to SSH into your modules on your machine. You can see JuJu running
new machine by typing the following, replacing id_rsa by connecting to the container that’s currently
with the path to the private key we generated earlier: orchestrating OpenStack by typing the following:
ssh -i id_rsa ubuntu@floating_ip sudo lxc-attach -n openstack-single-$USER
After accepting the SSH fingerprint, SSH should su ubuntu
automatically connect you to your fully fledged % JUJU_HOME=~/.cloud-install/juju juju status
instance running on your very own cloud, and you can The final command, juju status’ will produce output
install packages and do whatever you need just as very similar to the openstack-status view we used
you would a real machine on a real server. Try during installation, only this time JuJu is the tool doing
installing Apache 2, for example (and don’t forget to all the hard work. Working with JuJu on the command
allow HTTP connections). line is straightforward, but there’s also a wonderful
web interface that can be installed by typing juju
deploy juju-gui followed by juju expose juju-gui.

13
JuJu GUI 14
Installing Mediawiki
You should be able to see from the installation status The JuJu store is like a package repository for cloud
terminal that JuJu GUI has been added as a new applications. Some may need connections to be
service, usually at the bottom of the list where it will made between resources after installation, which you
include a login URL. Enter this into a local browser can do in the GUI, but you can get around this by
with the usual HTTPS caveat and use admin and your installing an all-in-one bundle. To try the installation
password to enter the sandbox. The site that opens is out, search for mediawiki, select it and click on ‘Add
a really impressive graphical overview of your current To Canvas’. You’ll see it appear in the main view
cloud, as orchestrated by JuJu. You can see all the (canvas). It needs to be connected to MySQL by
installed services and how they’re connected. You can dragging from the MySQL icon to Mediawiki and
even drag them around and their elastic connections selecting mysql:db mediawiki:db as the relation. Click
will follow. You can also use the list of services on the ‘Commit Changes’ followed by ‘Deploy.’ Finally, select
left to isolate specific modules and see how they’re Mediawiki and click ‘Expose’ followed by ‘Commit’ to
interconnected. It’s a great way of learning how make the server live. Wait for the initialisation to finish
OpenStack is configured, but the real magic comes and ‘juju status mediawiki’ to check its status and get
from clicking on the ‘Store’ button in the top-right. the IP address after initialisation.

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TUTORIAL CONTROLLING PHILIPS HUE LIGHTS

ILLUMINATE YOUR LIFE
WITH LINUX PART 3
Take your next steps in home automation by using Linux to control your lights.

MARK CRUTCH
O
ver the past couple of issues we've been
exploring ways to control Philips Hue and Lux
“smart” bulbs using a Linux box. Last time we
WHY DO THIS? left you with a simple web page that would let you
• Control the colour of your turn a light on and off, change its name and adjust its
lights brightness. This time we're going to add some colour
• Learn about data-* controls for Hue bulbs.
attributes You could base your new code on the brightness
• Mix HTML and SVG slider we used last time, but it's not a simple copy-
and-paste job. The API requires the hue value to be
specified in a range from 0 to 65535. That's easy
enough: just change the min and max attributes
on the new slider. The saturation value runs from 0
(white) to 254 (100% colour), but we prefer to have our
slider running in the opposite direction, so that white
is at the right-hand end of the scale. There are a few
ways that we could flip our scale to accommodate
this requirement, but we chose to just change the min Our first pass at adding colour controls works, but looks
and max to run from -254 to 0, then negate the value a little plain.
as it's passed to our new set_saturation() function.
This is the code we added to our HTML: fetch(sURL, {method: "PUT", body: sPayload});
<div id="div-hue"> }
<label id="label-hue" for="hue">Hue:</label> If you've got a mixture of Hue and Lux bulbs it
<input id="hue" type="range" min="0" max="65535" would be nice to hide the additional UI for those bulbs
onchange="set_hue(this.value);" /> that only support brightness changes. There are a few
</div> steps needed to achieve this: we need a way to show
<div id="div-saturation"> and hide the relevant parts of the interface; we have to
<label id="label-saturation" store some extra information to indicate which bulbs
for="saturation">Saturation:</label> can change colour; and we need a function that fires
<input id="saturation" type="range" min="-254" max="0" whenever the currently selected bulb is changed.
onchange="set_saturation(-this.value);" /> In the HTML page we decided to wrap our new
</div> controls in another <div>. We've given ours an ID
And here's the extra pair of JavaScript functions we of div-colour, and enclosed the div-hue and div-
call when these sliders are moved: saturation sections inside it. This gives us a single
function set_hue(nValue) target to show and hide in order to suppress both
{ controls at once. The <select> element also gets a
var sURL = `${sBaseURL}/lights/${$("lights").value}/ new onchange attribute with a value of check_lamp_
state`; type(); – this will be the name we use for our new
var sPayload = `{"hue":${nValue}}`; function. To hide the new <div> we'll set or remove
fetch(sURL, {method: "PUT", body: sPayload}); a “hidden” class, and create a line in our CSS file that
} tells the browser what to do when the class is present:
function set_saturation(nValue) .hidden { display: none; }
{ We now have the capability to hide the controls, but
var sURL = `${sBaseURL}/lights/${$("lights").value}/ we still don't have any information about which lights
state`; need them shown and which ones don't. It's time to
var sPayload = `{"sat":${nValue}}`; extract a little more information from our initial query

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CONTROLLING PHILIPS HUE LIGHTS TUTORIAL

to the Hue API in order to set a flag for those lights By adding some CSS, our
that support colour. We'll determine this by testing for colour controls actually
the presence of a hue property on the state object in have some colour!
the JSON. Modify the for loop in your main() function
to look like this:
for (var sLightID of Object.keys(oJSON)) {
var oOption = document.createElement("option");
oOption.setAttribute("value", sLightID);
if (oJSON[sLightID].state.hue !== undefined) {
oOption.setAttribute("data-lamp_type", "colour");
}
oOption.innerHTML = oJSON[sLightID].name;
oSelect.appendChild(oOption);
}
The only addition here is that, when we create the
<option> elements inside our popup menu, we're
also adding a data-lamp_type attribute to any bulbs
that have a hue property in the JSON. As we're only these new additions together:
dealing with two possibilities here – colour or not function check_lamp_type() {
colour – we're just using the presence of the attribute var oOption = $("lights").selectedOptions[0];
to distinguish between them. Nevertheless, it makes if (oOption.dataset.lamp_type === "colour") {
sense to give the attribute a sensible value to make $("div-colour").classList.remove("hidden");
the code more readable. } else {
We could simply have called the new attribute $("div-colour").classList.add("hidden");
PRO TIP
lamp_type and browsers would have been perfectly }
Download the example code from www.
happy. But it's possible (though unlikely) that some }
peppertop.com/hue.zip
future revision of HTML could introduce a lamp_type First we get the currently selected
attribute to the standard that conflicts with our own option, then the next line checks the
version. To avoid problems like this, HTML 5 has a state of our new attribute, via the dataset property,
rule whereby you're safe to use your own attribute and adds or removes the class as necessary. Reload
names provided they're prefixed with data-. This your page, and you should now find that the Hue and
becomes a kind of semi-private namespace that the Saturation controls are shown and hidden based on
HTML working group promises never to pollute with the type of bulb. This approach of pulling data from
their own additions. These data-* attributes can be the JSON and storing it in a data-* attribute is one
read and written using the normal getAttribute() and method that could be used to keep the controls in
setAttribute() methods, as we've used in the main() sync with the current state of the selected bulb, if you
code, but they're also accessible via a “dataset” want to create a more sophisticated interface.
property on your element, in which case the data- The colour controls are visible unless we explicitly
prefix is dropped in the JavaScript, making things a hide them, but that only occurs when a new bulb
little more readable. You can see an example of this is chosen from the popup menu. What happens if
in the new check_lamp_type() function that will tie all our first bulb happens to be a Lux bulb? We would

Working with RGB
One omission in the Hue API is the ability to set conversion function requires us to split the string
a colour using RGB values. This requires the if (maxRGB === r) { into its hexadecimal components, then convert
developer to do some additional work to convert h = ((g-b)/c) * 60; those to decimal. Here's a function that you can
an RGB value to hue, saturation and brightness, } else if (maxRGB === g) { hook into the picker's onchange handler that does
though the mapping isn't a simple one. We prefer h = ((b-r)/c + 2) * 60; the hard work for you using a regular expression
to keep the brightness control separate from the } else { and a few parseInt() calls:
hue and saturation, so here is a cut-down function h = ((r-g)/c + 4) * 60; function colour_from_picker(sHexRGB)
for just returning those components for a Hue bulb, } {
when given red, green and blue values in the range h = (h < 0) ? h + 360 : h; var aValues = sHexRGB.match(/^#(..)(..)(..)$/);
0–255: // h is 0-360 degrees; map it to 0-65535 for Hue API var r = parseInt(aValues[1], 16);
function rgb_to_hs(r, g, b) { h = Math.floor(h * 183); var g = parseInt(aValues[2], 16);
var h, s, c; s = Math.floor((maxRGB - minRGB)/maxRGB * 254); var b = parseInt(aValues[3], 16);
r = r/255, g = g/255, b = b/255; return [h, s]; var [h, s] = rgb_to_hs(r, g, b);
var minRGB = Math.min(r,g,b); } set_hue(h);
var maxRGB = Math.max(r,g,b); The HTML 5 colour picker widget (<input set_saturation(s);
c = maxRGB - minRGB; type="color" />), returns its value as a hexadecimal }
if (c === 0) return [0, 0]; number in the form #rrggbb. To use this with our

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TUTORIAL CONTROLLING PHILIPS HUE LIGHTS

be showing the colour UI, even though it's not a first-class citizen in HTML5. This means that you
appropriate. The fix is quite simple: we simply need to can throw a block of SVG code into any HTML5 web
call our new function once we've finished initialising page without having to concern yourself with the
the UI. Just add a line to call check_lamp_type() after complexities of combining two XML languages in
the for loop in the main() function, before the closing a single document. Add the following SVG to your
brackets of the second then() method. HTML file, just before the closing tag of the “div-
colour” section (so that the new code is inside the
Improving the UI <div>, just after the hue and saturation sections):
One issue with our user interface at the moment <svg id="svg" width="100%" height="100%"
is that there's no indication as to what colour any viewBox="0 0 65535 254"
particular value for the hue slider will produce. We preserveAspectRatio="none">
know it's red at either end, green a third of the way <defs>
along, and blue at two thirds, but it would be better to <linearGradient id="gradient-hue">
have a graphical representation of that. It is possible <stop stop-color="red" offset="0%" />
to style HTML sliders, but the syntax is a little different <stop stop-color="orange" offset="14%" />
for each browser; however, we only want to add some <stop stop-color="yellow" offset="28%" />
colour to the “track” of the slider, and only for Firefox <stop stop-color="green" offset="42%" />
and Chrome/Opera, since our JavaScript is too cutting- <stop stop-color="cyan" offset="56%" />
edge for other browsers anyway. This results in a <stop stop-color="blue" offset="71%" />
relatively small amount of code to add to the CSS: <stop stop-color="purple" offset="85%" />
#label-hue { display: none; } <stop stop-color="red" offset="100%" />
#hue::-moz-range-track { </linearGradient>
background: linear-gradient(90deg, <linearGradient id="gradient-saturation"
red,orange,yellow,green,cyan,blue,purple,red); x1="0" y1="0" x2="0" y2="1">
border: 1px solid darkgrey; <stop stop-color="white" stop-opacity="1"
height: 10px; offset="0%" />
border-radius: 5px; <stop stop-color="white" stop-opacity="0"
} offset="100%" />
#hue::-webkit-slider-runnable-track { </linearGradient>
-webkit-appearance: none; </defs>
background: linear-gradient(90deg, <rect x="0" y="0" width="100%" height="100%"
red,orange,yellow,green,cyan,blue,purple,red); fill="url(#gradient-hue)" />
border: 1px solid darkgrey; <rect x="0" y="0" width="100%" height="100%"
height: 22px; fill="url(#gradient-saturation)"
border-radius: 5px; onclick="svg_colour_selected(evt);" />
} </svg>
We also added the same code a second time, but That's a lot of code, but what it does is actually
modified for the saturation control. Just replace every quite simple: it draws two rectangles, one on top of
instance of “hue” with “saturation”, and instead of a the other, each filled with a different linear gradient in
a linear-gradient running through the colours of the order to provide a sweep of colours in one direction
rainbow, it just goes from black to white. and saturation in the other. Let's look at it bit-by-bit to
PRO TIP With both sets of additions in place, our get a better understanding of what's happening.
If you can ssh into your home network, UI is starting to look almost professional: We start with our <svg> container. This tells the
use the -R option to forward port 80 from HTML range inputs are one- browser that we're introducing a block of SVG code
your web server to a port on the local
machine, allowing you to control your
dimensional widgets. They enable you into the page, and that it should take up 100% of the
lights from anywhere in the world. to change a single value by moving a available width and height in its parent container
slider along a fixed track. Another option, (the div-colour block). That lets us adjust the size
when you have two related parameters, of the parent in our CSS file, knowing that the SVG
is a two-dimensional input widget that lets you click will automatically resize to match. Within a block of
anywhere within a plane in order to select a pair of SVG it's possible to introduce a different coordinate
coordinates. system to that used by the main page, using the
There are several different ways to approach this, viewBox attribute. This takes the x and y coordinates
each with their own pros and cons, but we've chosen of the top-left and bottom-right corners of the new
to use SVG to draw the UI for our hue-saturation coordinate system, allowing us to specify that, within
selector. This is an XML-based language for drawing the SVG world, our coordinates run from 0 to 65535
vector graphics, and has been a W3C standard for a in the x-direction and 0 to 254 in the y-direction,
long time. Its take-up has been very slow, largely due regardless of the “real-world” dimensions of the web
to lack of support in Internet Explorer, but the last few page. The preserveAspectRatio attribute ensures that
years have seen a surge in its popularity, resulting not our rectangles will fill the available space, even though
only in IE gaining support, but also in SVG becoming it means ignoring their native aspect ratios.

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Inside the SVG we have a <defs> section to hold Throw in some SVG and
definitions for things we'll need later in the code. There things really start to look
are a pair of linear gradients, each containing <stop> fancy.
elements that define the colour stops. Unfortunately
SVG doesn't automatically space the stops for you,
so you have to specify the offset for each one. The x1,
y1, x2 and y2 values on the saturation gradient ensure
that it runs from top to bottom, rather than the default
of left to right. Notice also that the saturation gradient
runs from white to white, but with the opacity running
from 1 to 0.
Finally we get to the rectangles we're drawing.
They're both positioned at the top-left corner of our
coordinate space, and extend to 100% of it in either
direction. Each is filled with a gradient from the defs
section by a reference to its ID. The “painters model”
that SVG uses means that later objects are drawn
on top of earlier ones, so our second <rect> is placed
on top of the first. Because the saturation gradient
is partially transparent, the hue gradient will show {
through from the rectangle below. As it's on top, the var oPoint = oSVG.createSVGPoint();
second rectangle is also the right place to put our click oPoint.x = x;
handler – the first one never receives any clicks itself. oPoint.y = y;
If you reload the page at this point you'll be var oMatrix = oSVG.getScreenCTM().inverse();
disappointed to see the new selector only appears oPoint = oPoint.matrixTransform(oMatrix);
as a thin strip across the screen. This is because return [Math.floor(oPoint.x), Math.floor(oPoint.y)];
we haven't fixed the height of the parent <div>, so }
the SVG collapses down to the minimal amount of In an ideal world we would be able to pull our
vertical space it can. Let's hide the old sliders and SVG coordinates straight out of the click event. The
give the new control some breathing room with this x-coordinate could be passed straight to
addition to the CSS file: set_hue() and the y-coordinate to set_
PRO TIP
#div-hue { display: none; } saturation(). Unfortunately the browser
Another approach to laying out the web UI
#div-saturation { display: none; } only gives us the values transformed is to use the new CSS flexible box model,
html { height: 95%; } into the HTML coordinate system. The which makes it easy to create widgets that
body { height: 100%; } transformation takes place through a grow and shrink as the page size changes.
#svg { border: 1px solid darkgrey; } matrix multiplication, and it's possible
#div-colour { to query the <svg> element for the
height: 50%; specific coordinate transformation matrix that was
margin: 0; used via the getScreenCTM() method. The returned
} matrix has an inverse() method that gives us a matrix
By setting the <html> to 95% we allow the page to for transforming values in the opposite direction. By
fill most of the window, but not enough to cause scroll creating an SVG point, setting its coordinates to the x
bars to appear. The <body> is set to use all that space, and y values from the click event, then performing an
allowing plenty of room for our div-colour to fill. We've inverse matrix multiplication, we can get the original
set that to a percentage height, allowing it to grow and SVG coordinates back once more.
shrink as the window size changes. With our SVG-powered colour selector working,
The last step is to add some JavaScript to handle that concludes our short foray into the world of
clicks within the new control. The onclick handler on smartbulbs. But we've only just scratched the
the second rectangle passes the click event to svg_ surface. The web interface has plenty of scope for
colour_selected() so let's add that, and another helper improvements or new features, and the Bash and
function, to the JS file: Python examples from part one offer a wealth of
function svg_colour_selected(e) possibilities for hooking the lights up to other data
{ sources. As an unobtrusive notification system, your
var oSVG = e.target.nearestViewportElement; own house lights are hard to beat, so let us know on
var [h,s] = convert_coordinates(oSVG, e.clientX, e. the forums if you come up with any particularly good
clientY); ways to use these devices.
set_hue(h);
set_saturation(s); Mark Crutch now has his Hue lights flashing around a
} spinning office chair, to recreate his childhood dream of
becoming Joe 90.
function convert_coordinates(oSVG, x, y)

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TUTORIAL GO

WRITE AN IMAGE CROPPING
PROGRAM WITH GO
Learn the ropes of Google's excellent Go programming language.

AMIT SAHA
G
o (or Golang) is attractive because of its C-like
syntax, static typing (but with a feel of being
dynamic typed) and its rich standard library. In
WHY DO THIS? this article, our aim is to introduce you to some of the
• Get to grips with one features of Go. We do not assume that you know Go,
of the languages of the but assume familiarity with another programming
moment. language. By the end of this article, you will have
written a command line program that can crop Illustration of the program we will write by the end of this
images to your desired height and width. More article. (The Go gopher was designed by Renee French.
importantly, you will have had a very short (http://reneefrench.blogspot.com).
introduction to the language and how to use
packages from the standard library as well as environment variable to point to the workspace
third-party packages. This will hopefully inspire you to directory, so set the following to your
go ahead and learn more about it. Let’s get started! .bashrc or the file relevant to your shell, so that it is
Before we can write our first program, we will need always set when you start a new terminal session
to install the Go tools, which includes the Go compiler (Replace <user> with your username):
and other useful bits and bobs. On Fedora 23, we can export GOPATH=/home/<user>/golang
install Go 1.5 using the distro's package manager: Once you have set the above, start a new terminal
$ sudo dnf -y install golang session and type in
On other Linux distros, please download the Linux $ go env GOPATH
binary and follow the instructions on the install page /home/<user>/golang
at https://golang.org/doc/install. Once the If you see your GOPATH printed correctly similar to
installation steps are completed, open your favourite above, we're all set to perform one final step before
terminal emulator and type go version and it should our first program.
print a message similar to below: Execute the command mkdir -p github.com/
$ go version linuxvoice/helloworld while in the src sub-directory
go version go1.5.2 linux/amd64 we created above. The directory tree should look like
this:
Functions in Golang are created using `-- src
`-- github.com
the func keyword, followed by the `-- linuxvoice

function name and a list of arguments
`-- helloworld
The reason we do this is that since all the Go code
you write (or that of the third-party packages we use)
Now, we are ready to set up our workspace. Create will live in the same src sub-directory, it is important
a sub-directory called golang in your home directory we have distinct sub-directories where they live. It is
(/home/<user>) and a sub-directory, src, inside it. All customary for the top-level sub-directory to be of the
the source code for Go programs will live in the src same name as your code hosting site (here, github.
sub-directory. This includes the programs we write as com), the next sub-directory to be the username (here
well as the third-party packages we will use (more on linuxvoice), and finally the sub-directory for our code
this later). itself (helloworld).
The directory tree for your workspace should look
as follows: Hello World
golang/ The program below will print the customary "Hello
`-- src World" message when run. Type in the following
The go compiler and other tools expects the GOPATH program to a file hello.go and place it in the

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helloworld sub-directory we created above:
// This is a simple program which prints Hello World
package main
import "fmt"
func main() {
fmt.Println("Hello World!")
}
Your src directory should look as follows:
`-- src
`-- github.com
`-- linuxvoice
`-- helloworld
`-- hello.go
Since Go is a compiled language, we first have to
compile it. To do so, we will use the build sub-
command of the go tool from the src/github.com/
linuxvoice/helloworld directory:
$ go build hello.go
You should now see that a hello executable has
been created, which we can execute as follows:
$ ./hello
Hello World!
Congratulations – you have successfully run your
first program. Let's now understand the program we
wrote above. The first line in the program above is a
comment, indicated by the beginning //. In the next
line, we declare a package for our program. Every
program in Go must declare a package to which it
belongs. The package main is special – it tells the Go Flowchart showing the key
compiler that this is an executable program. The other steps performed by the
kind of program we can write in Go is a package, or in cropper() function
other words, a library which we use from another
executable program. The next line (import "fmt") }
imports the fmt package from Go's standard library. It Every variable declaration in Golang must specify a
implements the formatted Input/Output functions. type, indicating the data type of the values that we
Next, we write our main() function – this is where will store in it. The statement, var shortMessage
the execution begins when you run a program in Go. string declares a variable, shortMessage, which will
Functions in Golang are created using the func store a string. Here we assign the string "Hello World"
keyword, followed by the function name and list of to this variable. We then call the fmt.Println() function
arguments it accepts in parenthesis, and then the with this variable. Go supports a short-hand form of
return values. The main() function is special, as it variable declaration inside functions using the :=
neither accepts any arguments nor does it return operator. Using that our above variable declaration
anything. Next, we start the function body with an would become shortMessage := "Hello
opening curly brace and have a single statement in World". This is however only valid when PRO TIP
the body – fmt.Println("Hello World"). This line calls we also specify the initial value of the Using go run, we can combine the building
the Println() function in the fmt package passing the variable. and running steps into one. For example,
string "Hello World!" to it. Besides the built-in data types such as we can build and run fact.go as go run
fact.go and you should see the output as
The Println() function just prints the string followed integers and floating point numbers, above.
by a new line. programs can define a new data type
The closing brace ends the function body. using struct. For example, let's say that
We will now rewrite the program so that we can in our image cropping program, we want to define a
change what message we print by having the data type that will store the image path, desired height
message stored in a variable: and width that we want the image to be cropped into.
// This is a simple program which prints a string We would create a new data type as follows:
package main type Config struct{
import "fmt" path string
func main() { height int
var shortMessage string = "Hello World" width int
fmt.Println(shortMessage) }

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TUTORIAL GO

we return the value in fact using the return statement.
The program execution begins at main(), where we
declare a variable num initialised with 10, then call the
factorial() function with this variable as an argument.
The return value is stored in fact. Then, we print the
factorial using the Printf() function in the fmt
package. The Printf() function is used here because
we want to substitute the values of variables num and
fact string. Unlike Println(), Printf() doesn't
automatically add a new line at the end of the output,
so we have to do it ourselves.
Create a sub-directory fact in the sub-directory src/
The passed-in desired height and width creates a "crop github.com/linuxvoice and type in the above program
box" on the image starting at the top-left position. into a file fact.go. The linuxvoice sub-directory
structure should now look like as follows:
The above code creates a new data type – Config linuxvoice/
– which has three fields: path, which is a string, height fact
and width, both of type integers. We then create a fact.go
variable of this type as follows: helloworld
image := Config{path:"/var/cat1.jpg", height:10, width:10} hello.go
Note that we used the := operator here as well to Let's build and run the program from the fact
create a variable of Config type. We can refer to each sub-directory:
of the fields with the . (dot) operator. That is image. $ go build fact.go
path, and so on. In our image cropping program, we $ ./fact
will not be defining any new new type, but we will be Factorial of 10 is 3628800
using variables of struct type.
Writing the image cropping program
Writing your own functions Now that we have seen the absolute basics, we'll get
Except for the very rare cases, our program will on to the image-cropping program. You can find the
usually be composed of functions other than the entire source in the file, crop.go in the repository
main() function. The final program we write by the https://github.com/amitsaha/linux_voice_1. Since
end of this article is a more practical example, but this is a relatively long program, I will present and
here's a simple demonstration. The program below discuss the source code referring to snippets of the
calculates the factorial of an integer (10): program from top to bottom.
package main The program starts with a block comment:
import "fmt" /* Simple command line program to crop images
func factorial(num int) int { Usage:
fact := 1 $ go run crop.go --height=5000 --width=7000 <path to>/
for i := 1; i <= num; i++ { cat1.jpg <path to>cat2.png
fact = fact * i The cropped images will be placed in the same directory
} as the
return fact original images with the file names being
} cropped_<original_file_name>.<original_extension>
func main() { */
num := 10 When you have comments over multiple lines, you
fact := factorial(num) can have them as a block comment instead of
fmt.Printf("Factorial of %d is %d\n", num, fact) prefixing each line with a // as we saw in our first
} program. The /* indicates the beginning of a block
We start by declaring the package and importing comment and */ indicates the end.
the fmt package. The function factorial() accepts an Similar to all our programs so far, our image-
integer parameter and returns an integer. It starts by cropping program will be an executable program, so
creating a variable, fact, and initialising it to 1. Then we we specify the package to be main and then import a
have a for loop. If you are familiar with C, C++ or Java, number of packages from the standard library as well
this should seem familiar, but without the as the third-party package github.com/oliamb/cutter.
parentheses. The loop variable, i, is initialised with a When you try to import a package that's not in the
value of 1 and continues until its value is greater than standard library, Go will look for it in the src/ sub-
the number, incrementing by 1 in every step. The ++ directory we created in the beginning. Thus, in this
operator in Go is used to increment the value in i by 1 case, the cutter package should exist in src/github.
in place. In the body of the for loop, we have the com/oliamb/cutter. We will see how we can do so
statement that actually calculates the factorial. Finally before we run our program.

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package main
import (
"bufio"
"bytes"
"flag"
"fmt"
"github.com/oliamb/cutter"
"image"
"image/jpeg" Since we don't care about the index in our final Flags and options
"image/png" program, we use the throwaway variable, _, recognised by our program
"io/ioutil" (underscore) and use the variable t for the actual
"log" element. In the body of the loop, we check if the
"net/http" incoming imageType is one of the recognised image
"os" types using the If statement. If a match is found, we
"path/filepath" return true. If we haven't found a match after
) checking both the elements of the slice, we return
Next, we have the first function in the program: false.
func validateImageType(imageType string) bool { The next function in the program is the cropper()
recognizedImageTypes := []string{"image/ function, which performs the core functionality of the
jpeg", "image/png"} program. It accepts three parameters: a string
for _, t := range recognizedImageTypes { containing the path to a image file and two integers
if imageType == t { corresponding to the desired height and width. The
return true function then performs the steps outlined in Figure 2.
} Steps 1,2 and 3 are carried out by the following lines:
} imageData, err := ioutil.ReadFile(inputFilePath)
return false if err != nil {
} log.Fatal(err)
The validateImageType() function accepts a string }
argument, imageType, and returns a Boolean, imageType := http.DetectContentType(imageData)
specified by the bool return type. In the first if ! validateImageType(imageType) {
statement, we create a slice of strings log.Fatal("Cannot handle image of this type")
recognizedImageTypes consisting of the two image }
types that our program will be able to crop. A slice in The first statement uses the ReadFile() function
Go is a data structure used to store a collection of from the ioutil package to read the entire file into
elements of the same type. The position of an memory. The function returns two values: the data as
element in the slice is referred to as the index and bytes and an error value, which are stored in the
starts at 0. It is similar to an array in C. Go also has variables imageData and err
arrays, but we shall not discuss them in this article. respectively. If the value in err is not PRO TIP
Then we go over each element of the equal to nil (a special value indicating an The Fatal() function essentially does two
recognizedImageTypes array using a for loop and the absence of a valid value) or in other things – it prints the message associated
with the error – when it is called with a
range keyword. The range keyword returns the index words, if there was an error when error value, else the string passed to it,
and the element itself for each of the elements in the reading the file, we call the Fatal() and calls the Exit() function from the os
slice. Here is a demonstration of how range works in function from the log package passing package, thus terminating the program.
this case: the error. This will print an error message
// Example of how range works and terminate the program execution.
package main Next, we detect the image type by using the
import "fmt" DetectContentType() function in the http package.
func main() { We call it passing the bytes we just read into
recognizedImageTypes := []string{"image/ imageData as an argument. It returns a string
jpeg", "image/png"} corresponding to the image type of the supplied
for i, t := range recognizedImageTypes { image. Once we have the image type, we call the
fmt.Println(i) validateImageType() function we wrote earlier. If the
fmt.Println(t) function returns false, we call the Fatal() function from
} the log package with a message, and our program will
} exit after printing the message.
The above code will print: If, however, the image is one of the recognised
0 image types, we proceed with Step 4, which is
image/jpeg implemented by the following code:
1 reader := bytes.NewReader(imageData)
image/png img, _, err := image.Decode(reader)

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TUTORIAL GO

if err != nil { croppedFileName := fmt.Sprintf("%scropped_%s",
log.Fatal(err) croppedFileDir, fileName)
} croppedFile, err := os.Create(croppedFileName)
The Decode() function in the image package is if err != nil {
used to decode the bytes in imageData. However, the log.Fatal(err)
Decode() function expects the data as a Reader, and }
hence we use the NewReader() function of the bytes defer croppedFile.Close()
package to create a new Reader that will read from The cropped image will be stored in the same
the bytes in imageData and then pass it to the directory as the original image into a file
Decode() function. This function returns the decoded cropped_<original_filename>.<original_extension>.
image of type Image, the format of the image as a That is, if your original file was in /var/images/cat1.
string and an error value. Since we don't care about jpg, the cropped image will be saved in /var/images/
the format of the image any more (we already know as cropped_cat1.jpg. Hence, we will need to find the
it), we have used the underscore instead of using a directory of the file supplied as well as the filename
variable. If the value of err is not equal to nil, we call (and extension). We can get both using the Split()
the Fatal() function passing err to it, else we proceed function from the path/filepath package. It returns
to the next step. two values: the directory and the filename, which we
The following code implements Step 5 above: store in croppedFileDir and fileName respectively.
The directory name is returned with a trailing /. Now
Our program will support cropping that we have the directory and the filename of the
original image, next we create a string,
multiple images at once and expects croppedFileName, using the Sprintf() function from
the fmt package, whose value will be the location of
the paths to the images as arguments the cropped file. Then, we call the Create() function in
the os package to create the file passing it the value in
croppedImg, err := cutter.Crop(img, cutter.Config{ the variable croppedFileName. It returns two values:
Height: cHeight, the first referring to the opened file, and the second an
Width: cWidth, error value. We check for the value of err to see if there
}) was any error while s the file and call Fatal()
if err != nil { otherwise. The next statement uses the defer
log.Fatal(err) statement to specify that just before the function
} returns, it should close this file using the Close()
We call the Crop() function from the cutter package function.
passing the decoded image and a structure variable Finally, we can implement Step 6 – encode the
of type Config (defined in the cutter package), cropped image and write it to the above file:
indicating the desired height and width (Figure 3). This croppedFileWriter := bufio.NewWriter(croppedFile)
function returns the cropped image and an error if imageType == "image/png" {
value. Once again, we check if the err value returned is err = png.Encode(croppedFileWriter,
not nil and if so, we call Fatal() passing the err value croppedImg)
so that it prints the error and exits. }
Before we can implement Step 6, we have to create if imageType == "image/jpeg" {
a new file where we will store the cropped image: err = jpeg.Encode(croppedFileWriter,
croppedFileDir, fileName := filepath.Split(inputFilePath) croppedImg, &jpeg.Options{100})
}
if err != nil {
log.Fatal(err)
}
croppedFileWriter.Flush()
The first statement creates a new Writer to write to
croppedFile. This is required for the encoding
operation. The encoding function we use will depend
on the image type, and hence we use an if statement
to check the image type and call the appropriate
encoding function. If the image type is image/png, we
call the Encode() function in the image/png package
with two arguments: the writer where we want to
write the cropped image to and the cropped image
Original image (Source: http://scienceblogs. that we want to encode. Similarly, if the image type is
com/gregladen/files/2012/12/Beautifull-cat- "image/jpeg", we call the Encode() function in the
cats-14749885-1600-1200.jpg) "image/jpeg" package. The first two arguments to the

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function are the same in this case, and there is an Cropped image of height
additional argument – a variable of the jpeg.Options and width set to 500 and
struct type indicating the quality of the encoding we 700 pixels respectively.
desire. Here we specify the quality as 100 (the highest
quality).
Both the functions return an error value. Next, we
check if there was an error, calling Fatal if there was
one, else we call the Flush() function so that all the
data is written to disk.
The final function in our program is the main()
function. It does the following things:
1
Set up the flags, which enables us to specify the
input as command line flags and arguments.
2
Check if all the required input has been supplied to The Args() function returns all the command line
the program. arguments that were not flags as a slice. We use the
3
Call the cropper() function above with each of the len() function to find the number of arguments
images specified and the desired crop height and specified, and if it is 0 we terminate the program
width. specifying an error message.
Step 1 above is implemented by the following code: The following code snippet implements Step 3:
cHeight := flag.Int("height", 0, "Crop Height") for _, inputFilePath := range flag.Args() {
cWidth := flag.Int("width", 0, "Crop Width") cropper(inputFilePath, *cWidth, *cHeight)
flag.Parse() }
The flag package is used to specify command line As earlier, we use a for loop and range to go over
flags for our program. We expect both the height and each of the image paths supplied as command line
width to be specified as integers. Hence, we call the arguments. In the body of the loop, we call the
Int() function twice to set up the flags for height and cropper() function with the input file path and the
width storing the returned value in cHeight and cropping width and height.
cWidth respectively. The first argument to the
function is the flag that will be specified, the second Cropping images
argument is the default value if not specified, and the Now that we have gone through the entire program,
third is a short description of what the flag means. it's time to get the code and run it. From your terminal,
The third line above calls the Parse() function, which run the following command:
essentially looks at the command line arguments $ go get github.com/amitsaha/linux_voice_1
supplied to the program when run and stores the You should now see two sub-directories under your
value of the flag in the correct variables above. src/github.com sub-directory, amitsaha and oliamb.
Next, we implement Step 2. The following code Under amitsaha, you will see a linux_voice_1
snippet checks if both the flags were supplied and a package which has our program, crop.go, along with
non-zero integer specified: a few other files. Under oliamb, you will find the cutter
if *cHeight <= 0 { package, which is the package we use to crop the
log.Fatal("Must specify the crop height to be a images. What we saw here is that go get was able to
positive integer") find out that our code in crop.go used a third-party
} package and it downloaded that as well and placed it
if *cWidth <= 0 { in the right location. This is why we need GOPATH to
log.Fatal("Must specify the crop width to be a be set (among other things). Now, cd into the github.
positive integer") com/amitsaha/linux_voice_1 and run the program:
} $go run crop.go --height=500 --width=700 test_images/
Note that we have used *cHeight and *cWidth to cat1.jpg
refer to the values in the two variables instead of just The original image (Figure 5) will be cropped and
cHeight and cWidth. This is because the Int() function the cropped image will be placed in the test_images/
above returns the address of the values. If the value in sub-directory as cropped_cat1.png (Figure 6).
any of the variables is not a positive integer, we We started with the complete basics of Go in this
terminate the program. article, and quickly went on to writing a non-trivial
Our program will support cropping multiple images command line program to crop images. Along the
at once and expects the paths to the images as way, we learned about declaring variables, defining
command line arguments. So we need to check if at data types, writing functions, handling errors and
least one was supplied. The next snippet does that: working with several Go packages.
numImages := len(flag.Args())
if numImages == 0 { Amit Saha is the author of Doing Math with Python (No
log.Fatal("Must specify at least 1 image to crop") Starch Press) and a software engineer. He blogs at https://
echorand.me, and can be reached at amitsaha.in@gmail.com
}

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CODING COMPUTER LANGUAGES

THE FUTURE OF
COMPUTER LANGUAGES
The future is unknowable… but when it comes to coding we can have a good guess.

JULIET KEMP
A
fter looking at a few of the many computer mainframes, virtual machines, and cloud computing)
languages that have been invented over the will be used to replicate the old hardware and run the
last 50-odd years, it's time to polish up that same code; that's actually easier, cheaper, and safer
WHY DO THIS? crystal ball and attempt to make some predictions (from a project management point of view) to do than
• Speak expansively on the about the next 50 years… or at least the next 20. Are rewriting the code.
future of programming in the older languages that are still in use today coming C, on the other hand, is actively used in modern
your next job interview. to the end of their useful life? What new languages are development and still underpins large swathes of
• Inform your choice of your coming up that are going to take the world by storm? software. The Linux kernel is, of course, written in
next language to learn.
What are the current big problems that modern C. C is outstandingly good at what it does, and it's
• Learn from the past.
programmers and language designers are trying to hard to imagine its dominance for close-to-the-metal
solve? And how is the practice of programming going development disappearing any time soon.
to change in the future? So would it be surprising if Fortran, C, and COBOL
Looking at languages over the last 30–50 years, it's code is still chugging along happily in particular niches
apparent that there are a bunch of 'old' languages that in another 40 years? Not even slightly.
are still firmly in use. Fortran, COBOL, C, Ada, and The middle-aged languages like Java, JavaScript,
others are still out there and aren't in danger of and Python are all still under active development, and
disappearing any time soon, though some of them are in very heavy use. The way that people are working in
perhaps a little more precarious than others. these languages has changed (see section below); but
Some older languages are in use primarily for the languages themselves are well entrenched and
legacy systems (especially old mainframe software) will more than likely still be around in 20 years time.
and it's possible that those systems might gradually On the other hand, 15 years ago Perl was everywhere,
be ported over to newer languages. Since these whereas now its profile is much lower; however,
languages don't see much new development, if that there's still lots of Perl out there and it remains a
happened they would gradually become obsolete. useful language. (And, of course, Perl 6 will surely
More likely however is that newer hardware (newer arrive at some point and may change the scripting
landscape again.)
Older functional languages like Scala (2001) and
Haskell (1990) have recently risen in popularity.
Facebook and Google both use Haskell for some
of their work; and LinkedIn, Twitter, and Tumblr
all use Scala. This reflects a generally increasing
interest in functional programming, with functional
ideas and features appearing in other mainstream
languages (such as Java 8's introduction of lambdas).
Whether this is the start of functional programming's
forthcoming reign of glory (as functional
programming enthusiasts argue), or whether it's just
a brief flurry of functional ideas being pinched by
other languages, is as yet unclear. Perhaps most likely
is that as more people get to grips with functional
programming, it will become more popular for those
problems that it solves particularly well, but that other
languages and paradigms will continue to be popular
Are mainframes, and the in their own niches. More generally, the trend suggests
software that runs on that the same thing may happen to other languages
them, on their way out? at various times, as their particular features become

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COMPUTER LANGUAGES CODING

suddenly relevant to a modern problem (see the
concurrency section below).
Another area of development hooks new (or
new-ish) things into existing, older, languages. More
and more languages are being written to run on the
Java Virtual Machine – Clojure, Groovy, JRuby and
Jython are the best-known, but there are a couple
of dozen others. Does this suggest a general move
towards a single platform that can be coded in
multiple languages? It's an idea with obvious practical
advantages if it works well; packaging and installation
become potentially easier, while programmers can
work with the higher-level language that best suits
them and their problem domain. It does mean
carrying the overload of an extra virtual machine, but
increasingly virtual machines (of whatever sort) are
part and parcel of how software is run.
Hello World in Erlang. Save
any mutable shared data at all. This means that each the file, then execute it in
Concurrency process has its own private state, and processes the Erlang shell.
Concurrency is possibly the biggest issue facing change state based on their own behaviour or on
modern programmers. It exists when multiple explicit messages from other processes, not on
computations are executing at the same time, and a shared structure that any process can access.
may be interacting with one another. This can be on (Shared structures have the problem that they must
cores within a single chip, in threads on a processor, be locked while being accessed; if a process dies
or on multiple processors/machines. Because the while it has a lock, this can cause issues for other
computations aren't just parallel, but may interact
(and share resources), there are numerous issues to
tackle for the process to be successful, including data
The middle-aged languages like Java,
exchange, memory allocation, and scheduling. JavaScript and Python are still under
Concurrency is increasingly a big deal as it becomes
more common (and cheaper!) to run multiple threads/ active development
cores/processors at the same time.
Various potential solutions or resources to support processes trying to access the same structure.)
solutions are available and/or under experimentation. Erlang is also functional, and its focus is scalability,
Erlang (which dates back to 1986) has grown in high availability, and no downtime. This reflects its
popularity recently, being used for cloud-based high- telecom industry origins; telecoms demand absolutely
performance computing that needs concurrency. minimal downtime. This makes it a good match
Erlang has concurrency 'baked in', with a set of for modern web and communications services
primitives that create processes and handle inter- (WhatsApp uses Erlang). The Erlang VM handles all
process communication; these processes form the the scheduling and load-balancing, meaning that the
basic structure of an Erlang program. Erlang also programmer doesn't have to.
avoids the problem of mutable shared data and lock Another approach to parallelisation is the language
access by only passing messages and not having CUDA (or the open-source OpenCL), which utilises the

A, B, C... D?
C and C++ have been around for a long time and are hugely
successful, as discussed in the previous section. D is
intended as a re-engineering of C++, keeping its good parts
and in particular its performance, while making it more
convenient for programmers, taking inspiration from the
lessons learnt from practical programming experience in
C++. It ditches some C++ features, and adds a bunch of
extra ones, including unit tests, garbage collection, and
various array features. It also adds an inline assembler;
illustrating that, like C/C++, D is intended to allow the
programmer to access low-level processor features as
required. Its creators claim that D is suitable for everything, Compiling D with the gdc compiler. (All those error
from high-performance back-end code to quick-and-dirty messages are just one missing semi-colon.) Note the
scripting. need to specify output file with -o.

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CODING COMPUTER LANGUAGES

Swift was released in mid-2014, is growing very fast
and is now open source. According to Apple, it's all
about "protocol-oriented programming". Protocols, in
Swift, are rather like interfaces; and in Swift, instead of
creating classes and subclasses, you are encouraged
to create protocols and then create types and structs
that use them. Protocols can also be extended with
default behaviours. This makes Swift highly flexible; in
This is a Swift playground
processors in modern graphics cards (GPUs) when particular because a type can have multiple protocols
on OS X, with code on the
left, results on the right, they're not in use for graphics, thus running in parallel. very easily, whereas multiple class inheritance is not
and a pop-up box showing This works really well for certain problems, and is possible in all languages and can be top-heavy where
the result of a particular popular with academics. Effectively, CUDA translates it is possible. Protocols can also be used by more
line. Playgrounds aren't the data into graphical form and then uses the GPU than just class types. It's also easy to extend existing
(yet?) available on Linux, to 'look' at and analyse it, as GPUs are optimised for protocols using the extension keyword, at which point
though the language as a image manipulation. anything that conforms to this protocol now also
whole can be downloaded Perl 6 and Clojure are also being promoted as conforms to your extension.
from swift.org.
suitable languages for solving concurrency problems. Conveniently, Swift co-exists with Objective C in
Clojure (a variation on Lisp) is intended to make it the same app, so developers can move over to it
"simpler to design and implement parallel algorithms", easily. It also includes a lot of interactive development
and compiles down to the JVM. Perl 6 introduces easy technology, in particular the "playground" section
(or easier) concurrency in a dynamic programming of the IDE, which enables the developer to try out
language. However, it's anyone's guess when Perl 6 pieces of code. (This is also explicitly aimed at helping
(or rather, a complete implementation of the Perl 6 people learn to code.) And there's a strong incentive
standard) is actually going to be released. for developers to move over to Swift, because there's
Google's new language Go (unveiled in 2009) is such a huge market for iOS/OS X software, and it has
designed to handle concurrency well, although the such a low barrier to entry. If you're starting out in the
major aim was for Go to be hugely clean and "simple Apple universe, you'd choose Swift over Objective-C,
enough to hold in one programmer's head". Go is and even if you're already an Obj-C coder you might
compiled, statically typed, and aimed at systems well jump ship.
programming. (As of this year, it's also available Swift shows off a few modern coding ideas – high
for mobile device and smartphones, another nod preference for flexibility and speed of development,
to the importance of mobile-first coding.) Go code and a fondness for interactive development
is intended to be concise and readable, and, rather
like Swift (see below), it uses interfaces and type
embedding over virtual or non-virtual inheritance.
Big Data
Flexibility, fast development, and a certain kind of The growing importance of big data means that R (a
statistical language, around since 1997) is becoming much
simplicity are important. See p84 for our tutorial!
more popular, and is used by companies such as Google,
Facebook, and the New York Times. However, it's suggested
Web-first and mobile-first that it can be slow with big data sets and is better used for
The other big current coding issue is web-based and prototyping than for building models. Matlab (a numerical
mobile-based coding. More and more software is run programming language) has always been heavily used in
the scientific community but opinion is divided on whether
in browsers (the ultimate example being ChromeOS),
it is on the way out or not. The big recent improvements in
which makes JavaScript and other web languages Python's maths and statistical libraries may make Python a
increasingly important. more appealing choice for numerical programming. IPython
Currently JSON is the data-object format of choice, and NumPy (designed to make Python competitive with
with libraries in every major language, and web Matlab for numerical computing) are good for scratchpad
use, and Python's data community has many toolkits
services are RESTful; but 10 years ago it was all about
available. Matlab definitely still has its niches though,
XML and SOAP. So in another 10 years will we look despite being an expensive piece of non-free software. Both
back from a similar distance on JSON and REST? Matlab and R have parallelisation packages available.
Web-coding is still moving pretty fast, so this is one of Julia is similar to Python, but runs much faster. It's
the most likely areas for things to change noticably in created specifically with scientific number crunching
in mind, with powerful concurrency and networked
the reasonably near future.
programming facilities, and interfaces available with
The importance of mobile-first coding suggests Fortran and C library routines. With the week-long runtimes
that Java will be around for a while, as Android (a of some scientific computing, the increase in speed that
version of Java) has the majority of the smartphone Julia provides is important (taking 1 second rather than
and tablet market. The other big chunk of that market 4 isn't a big deal; taking a week rather than four weeks
definitely is). Julia is super-fast, potentially more scaleable
belongs, of course, to Apple and to iOS; making Swift,
than Python, and easy to learn; but the community is in the
Apple's new iOS/OSX/watchOS language, which early stages, and currently it just doesn't have the libraries
replaces Objective C, one of the most important and toolkits to compete with Python or R.
languages to watch.

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Automated testing, test-first coding, push-on-green,
The Internet of Things and other similar practices can also make for tighter,
The Internet of Things is the newest buzz-phrase and no more reliable code, if used properly, and thus for less
one quite knows where that's going. Some applications time spent fixing bugs after software deployment.
are straightforwardly nonsense (the classic 'smart fridge', Improvements in version control systems, commit
for example), but the 'internet of things' covers a lot of
hooks to fire off automated tests, and so on, certainly
ground, and other parts of it do make more sense. This
certainly has the feel of something that really could change mean that a programming job looks different now
dramatically in the foreseeable future, and if that happens, from how it did 10 years ago (and still more compared
then changes in coding languages, and perhaps in coding to 30 years ago).
practice, are very likely to follow. Might 3D printing evolve
to the point where we need compilers that compile actual
Farther Future
objects, rather than code? What would that even look like?
Is Moore's Law coming to a slowdown? Does this
suggest that something else will take its place, the
environments and for code automation (the compiler same way that integrated circuits replaced transistors
will make suggestions for you to improve your code). (which in their turn had replaced relays and vacuum
tubes)? Ray Kurzweil argues that this will happen, and
Coding: learning and practice tips nanotubes for the most likely replacement. (He
There's a lot more available for younger coders than also argues that computational capacity will continue
there used to be. Raspberry Pi and Scratch are both to grow exponentially, which leads to a bunch of stuff
supporting different ways of learning to code, and about the Singularity that I am not going to get into.)
learning for quite young children (especially Scratch). Reconfigurable hardware is another idea being thrown
Robots Dash and Dot also aim to introduce the ideas around, and is starting to be implemented in limited
behind coding to young kids, and then support them ways. New hardware often drives new software, and
in learning slightly more complicated ideas and without knowing what exactly what that will look like
algorithms. The focus is on solving problems in a (if it happens), it's nearly impossible to make
coding-type way. A new generation of coders coming predictions about it.
up from this background might tackle programming Looking at the last 40 years, however, hardware has
and languages in a brand new way. changed a fair amount, and software has changed
Coding jobs are also starting to look different. More along with it, but we are still using some of the same
coding in the cloud and easier code-sharing means
that teams might be spread across the world and What's fascinating is the way that new
never or rarely meet one another. Cloud deployment
means that you might not know the sysadmins purposes and new problems will arise,
responsible for deploying and managing the software
you write in the same way that you might have done
and how programmers will solve them
at one time. Then again, there's more scope now
for writing software that is accessed from your own languages that were popular then. By extrapolation,
servers, rather than sending out disks to be installed therefore, we'll still be using some of the languages
on a client's systems. we're using now in another 40 years' time. Coding
Various forms of increased automation give practices have changed, though, and the languages
programmers more time to focus on the important have often changed along with them. Modern Fortran
stuff. Libraries, frameworks, APIs and plugins mean looks a fair bit different to original Fortran; Java 8 is a
that programming can now be more about sticking long way away from Java 1.
existing things together than about writing entirely The fundamental problem is that no single
new things – but that also frees you up to focus on language can possibly have every feature any
the global application logic, and widely-used libraries programmer could ever want, because some of them
and frameworks make for more exhaustive user- are incompatible with one another. So any vision of
testing and thus fewer bugs. Python's recent growth the One True Programming Language is doomed
is partly a reflection of the expansion of its libraries, from the start. (Though many languages compiling
making it easier to stick scripts together quickly. A onto a single virtual machine that then runs on many
problem can be if multiple competing frameworks other machines is more feasible.) We'll always have
exist; knowing which to use may be a challenge, and multiple languages for multiple purposes, and we'll
it reduces some of the advantages of having shared always have multiple programming paradigms for
frameworks in that the user base for each framework multiple purposes. What's fascinating is the way that
will be smaller. new purposes and new problems will arise, and how
IDEs and other code extensions can also generate new programmers will find new ways to solve them,
more code for you, especially in boilerplate-heavy with languages both new and old.
languages. An example is JavaScript, where updates
like CoffeeScript and Less.js are making it easier to Juliet Kemp is fluent in over 6,000,000 forms of
communication, including esoteric languages such as Perl.
write JavaScript and complicated CSS.

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CORETECHNOLOGY

CORE
Valentine Sinitsyn develops
high-loaded services and
teaches students completely
unrelated subjects. He also has
a KDE developer account that
he’s never really used.
TECHNOLOGY
Prise the back off Linux and find out what really makes it tick.

Asynchronous Disk I/O
Spawn tons of disk I/O requests, and do something else while they
are in flight. Just like with sockets, albeit without `epoll()`.

B
ack in LV016, we dealt with asynchronous read(fd, buf, sizeof(buf));
networking I/O. This way, network services Here, read() won't return until it puts some data in
serve one request while waiting for a database buf, or an error occurs. Sequential execution is easy to
to supply data for another. Asynchronous I/O greatly reason about. The downside is this code can't do
improves the service's capacity. No wonder it is a anything useful while it waits for read() to complete,
workhorse behind many popular web frameworks, like and it can take time on a busy disk.
JavaScript's Node.js or Python's Tornado. One can also set fd to non-blocking mode:
But network services rarely exist in the void. The int fd = open("somefile.txt", O_RDONLY | O_NONBLOCK);
data they serve ultimately comes from some storage, Or, via fcntl() system call:
often a file. If access to this file is blocked, it stops the fcntl(fd, F_SETFL, O_NONBLOCK);
entire event loop. This hurts performance and is In non-blocking mode, if read() can't complete
something we'd rather avoid. Is there a way to treat a immediately, it returns (-1) and sets errno to
file asynchronously, like a socket? Meet a rather EWOULDBLOCK, or EAGAIN if fd is a socket. It is quite
obscure and often misunderstood Linux feature: common to check for both:
asynchronous disk I/O! res = read(fd, buf, sizeof(buf));
Blocking vs Asynchronous
I/O time diagram. The Traditional file access is blocking. This doesn't scale if (res < 0 &&
latter interleaves I/O and very well, yet it makes code more straightforward: (errno == EAGAIN || errno == EWOULDBLOCK)) {
processing, resulting in char buf[1024]; /* handle gracefully */
better capacity. int fd = open("somefile.txt", O_RDONLY); }
Of course, you can busy yourself waiting for the
descriptor until read() succeeds, but it would be rather
inefficient. You may think about feeding fd to epoll()
Blocking I/O Asynchronous I/O or similar (LV016) – it worked for sockets, didn't it?
Bad news everyone: this time, it won't. With epoll(),
you'll simply get an EPERM error. poll() and select()
will run, but immediately report fd readable regardless
read () #1 of whether the read would block or not.

read () processing Using threads
Perhaps a more traditional (and more popular) way to
read () #2 non-blocking file I/O is via threads. Threads are worth
a Core Tech of their own (please drop us a line if you
handle read #1 are interested in this subject), but in a nutshell the idea
is simple. When you want to read data from a file, you
handle read () spawn a new thread. This thread issues a blocking
handle read #2
read() and waits for it to complete, while the event
loop continues normally in the original thread. When
read() returns, the main thread gets some notification.
Threads execute in parallel, so this is much like the
behaviour we are after. No wonder many applications

94 www.linuxvoice.com
CORETECHNOLOGY

and frameworks take this route. Say, Node.js (or, more
precisely, libuv) behaves exactly this way.
Threads have their own issues and arguably make
your code harder to debug, but it's only part of the
story. The real problem is that threads are a rather
costly abstraction to create and maintain. The latter is
usually mitigated with so called "thread pools": your
create a number of threads (say, 32) in advance and let
them idle. To defer something to a thread, one posts a
message to shared queue to which all threads "listen".
The first thread to "hear" the request handles it. If a
thread remains idle for some time, the application may
decide to kill it. Similarly, if the application detects that
Our samples print hash
threads in the pool are mostly busy, it may spawn (which is recommended) at the beginning of main():
marks to show you they
additional ones to increase the capacity. struct aiocb request = { 0 };
can do something while
request.aio_fildes = fd; data loads from the disk.
POSIX AIO request.aio_offset = 0;
Asynchronous file I/O (AIO) APIs in Linux come in two request.aio_buf = buf;
flavours. Both provide a way to issue (or enqueue) an request.aio_nbytes = LARGE_CHUNK;
I/O operation, to retrieve its status as it finishes, and request.aio_sigevent.sigev_notify = SIGEV_THREAD;
to cancel the operation you are no longer interested request.aio_sigevent.sigev_notify_function = &handle_
in. Both have some notification mechanisms to read;
tell your application the operation has completed request.aio_sigevent.sigev_value.sival_ptr = &request;
(that's the main idea). The difference is in design, Here, we set the descriptor (aio_fildes), the buffer to
implementation, and (naturally) interfaces (function receive data (aio_buf), and the number of bytes to
names, structures and so forth). read (aio_nbytes), as in ordinary read(). aio_offset is
The first API we are going to cover is POSIX AIO. As file offset, as in pread(), but it's not optional here.
the name suggests, it's part of the POSIX standard Asynchronous requests can complete in any order, so
and is available across many Unixes (which is good). "current file position" doesn't make sense. There are
Note that POSIX dictates interfaces, not some additional fields you may want to fill; consult
implementations: we'll revisit this point later. On Linux, aio(7) for details.
the POSIX AIO comes in librt (a part of Glibc) with request.aio_sigevent.sigev_notify = SIGEV_THREAD;
other fancy stuff like POSIX message queues and request.aio_sigevent.sigev_notify_function = &handle_
process timers. Most POSIX AIO calls have the aio_ read;
prefix, and they are declared in aio.h. request.aio_sigevent.sigev_value.sival_ptr = &request;
POSIX AIO has two main notification means: a Then comes the callback. Here, we opted for thread
signal, and a threaded callback. Neither are notify (SIGEV_THREAD), and send it a pointer to the
particularly convenient for applications built around request (sival_ptr). Generally you shouldn't let pointers
event loops, albeit signalfd may help you a bit (see to stack-allocated values leave the function, but for
boxout). Notifications are configured per I/O request. this simple example, it will work fine.
For a signal, you choose a number (usually SIGUSRx). Finally, we kick off the operation with:
For thread notifications, you supply a function which aio_read(&request);
executes "as if" it were an entry point for some thread. The callback (handle_read) runs when it completes:
Either case, you may choose a value to pass to the static void handle_read(union sigval sigval)
callback. It could be an arbitrary integer or void *. The {
latter is commonly used to send a pointer to some struct aiocb *request = sigval.sival_ptr;
application-specific structure. It is much like the this int res;
pointer in an object-oriented languages like C++. res = aio_error(request);
Let's dissect a simple POSIX AIO example. It reads if (res < 0) {
some (presumably large) file and prints a hash mark /* Request is still in progress or cancelled */
simultaneously, to prove the operation is really } else if (res > 0) {
asynchronous. You'll find the complete sources on the printf("\nError: %s\n", strerror(res));
LV website. } else {
int fd = open(argv[1], O_RDONLY); printf("\n%ld bytes read\n", aio_return(request));
First, we open a file. Note that ordinary blocking /* Use request->aio_buf to read the data */
mode is used, as asynchronous I/O and non-blocking }
I/O are different things. Then, we prepare the request. done = 1;
POSIX AIO represents requests with struct aiocb, }
which is the same for reads, writes and sync First, it checks if the request completed
operations. We allocate one statically and zero-fill it successfully. If this is not the case, aio_error() returns

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CORETECHNOLOGY

Linux AIO is generic API, but it was likely designed
with databases in mind. As such, it expects your code
to meet some requirements, which may look strange
unless you write a DBMS. You must open files with the
O_DIRECT flag to disable caching at kernel level. O_
DIRECT expects that userspace buffers, their sizes and
file offsets are aligned on a 512-bytes boundary. All of
this sounds like Linux AIO is better suited for
accessing raw devices (say, /dev/sda1) than
filesystem data. If you miss O_DIRECT, the code would
still compile and run, but may eventually resort to
blocking I/O. These requirements are not a problem for
a database engine, which usually works on pages
rather than bytes, implements custom caching
MySQL (and its clones)
a positive integer which is the same as errno for strategies, and often operates on raw disk partitions.
implements Linux AIO
support through the libaio synchronous requests. Next, we print the number of POSIX AIO doesn't dictate buffering rules though, so
wrapper. bytes read. aio_return() yields what would be the one can't implement it on top of Linux AIO. Linux AIO
return value of synchronous read() or write(). Finally, provides asynchronous equivalents of fsync()/
the callback sets the flag that tells main() to stop: fdatasync(), and vectored read/write operations. Other
/* Simulate event loop */ syscalls, like fallocate(), are not part of AIO.
while (!done) { Linux AIO has two notification channels. When an
fprintf(stdout, "#"); operation completes, the kernel can send your
fflush(stdout); process a signal, as in POSIX AIO, or deliver the event
usleep(LOOP_TIMEOUT_USEC); via eventfd. The latter is a Linux-specific mechanism,
} which plays well with epoll() and friends. This means
Note that we ignored all possible threading issues it's easy to plug eventfd into an existing event loop. As
for simplicity's sake. The aio(7) man page provides a you may guess, this makes eventfd a preferred way to
much longer and more elaborate example. It uses get Linux AIO notifications in your code.
signal notifications, and also shows how to cancel the Let's rewrite our example using native Linux AIO. At
request. the beginning, we create the "context" with io_setup():
Frankly speaking, POSIX AIO is rather unpopular in #include <libaio.h>
Linux, and you'll hardly meet it in the wild. One #define NR_EVENTS 32
exception is the lighttpd web server (www.lighttpd. int main(int argc, char **argv)
net), which proudly introduced AIO support in version {
1.5. However, lighttpd 1.5 was a preview release which io_context_t ctx = { 0 };
dated back to 2009 and never became stable.
One reason is that many applications don't really
When everything is a file
need asynchronous disk I/O. Database management
systems or similar software that juggles gigabytes of If you want something to integrate nicely with event loops,
data under heavy load can benefit from it. For the rest it should be available as a pollable file descriptor. That's
why Linux wraps many traditional concepts, like signals,
of us, the game is often not worth the candle. Another, into file descriptors.
and perhaps more compelling reason, is that Linux We briefly touched this topic in LV016. Now, let's focus
provides no kernel support for POSIX AIO. Under the on two mechanisms: eventfd and signalfd. Both can be
hood, Glibc implements this API entirely in user space used together with Linux AIO (albeit eventfd is preferred);
via threads, so all the usual limitations apply. Leave signalfd may also be helpful in POSIX AIO. Note these
mechanisms are Linux-specific, and you can't use them in
POSIX AIO for using in portable code (if at all); Linux portable code.
has something else to offer. Eventfd is a generic event notification tool. It maintains
a counter, which write() increases or sets, depending on its
Native AIO mode. read() either decrements the counter or resets it, and
Linux has introduced "native" AIO in version 2.6. This blocks if the counter is zero. epoll() and friends report the
eventfd descriptor readable if it has an event pending. For
is true kernel space implementation, yet unsuitable more details, see eventfd(2).
as a backbone for POSIX AIO, as we'll learn shortly. Signalfd works in a similar fashion. You create it with
Linux AIO is also missing from Glibc, leaving you signalfd() and specify which signals you want to receive
with two options. First, you may use syscall() to run through the descriptor. Usually, you also block "normal"
Arch-specific system calls directly by their numbers. delivery of these signals with sigprocmask(). The descriptor
becomes readable if there are any of these signals pending,
Or, there is the libaio library (https://git.fedorahosted. and read() yields one or more struct signalfd_siginfo
org/cgit/libaio.git), which wraps everything for you. instances. The latter is mostly analogous to siginfo_t a
The wrapper is in fact rather thin, so many developers "normal" signal handler receives. Again, refer to signalfd(2)
prefer the former. Our example will use libaio though, for details.
to hide some small yet unnecessary details.

96 www.linuxvoice.com
CORETECHNOLOGY

char *buf = NULL; iotop gives quick and
int fd; accurate answers to many
io_setup(NR_EVENTS, &ctx); questions regarding disk
I/O in your system.
fd = open(argv[1], O_RDONLY | O_DIRECT);
posix_memalign((void **)&buf, 512, LARGE_CHUNK)
NR_EVENTS is how many concurrent AIO
operations we want the context to support. libaio
uses io_context_t as the context type, but native
syscalls use aio_context_t. You must zero-fill either
one, or io_setup() will complain. We also open the file
and allocate a properly aligned memory buffer with
posix_memalign(). if (n_events > 0) {
Next step is to prepare the request. Linux AIO cb = (io_callback_t)event->data;
represents requests with struct iocb. Conceptually, it's iocb = event->obj;
the same as struct aiocb, but libaio provides helper cb(ctx, iocb, event->res, event->res2);
functions to fill it: }
io_prep_pread(&request, fd, buf, LARGE_CHUNK, 0); }
io_set_callback(&request, handle_pread); }
res_fd = eventfd(0, EFD_NONBLOCK); }
io_set_eventfd(&request, res_fd); We wait for eventfd to trigger, and resume pending
io_submit(ctx, 1, &request_ptr); events as soon as it can to let it trigger again. Then,
We also create a non-blocking eventfd and io_getevents() is called. It can block if no I/O events
associate it with the request. are pending in the context, but as eventfd has fired, we
Finally, io_submit() is called to submit the request. know there is something in. io_getevents() accepts
The second argument is the number of requests to the context, and a minimum and maximum number of
submit, so one can enqueue them in batches. A tricky events to grab. It returns the number of events stored
part is that io_submit() can also block for various in the array that the events argument points to. If it's
reasons, like allocating something in the kernel. In this non-zero, we execute the callback. event->data comes
toy program, it's not an issue, but in real code you'd from request.data, which io_set_callback() filled with
probably call it inside the event loop. Another nuance a pointer to the handle_pread() function. As before,
is that you should never fork() with asynchronous handle_pread() checks for errors and prints the
operation in flight if you allocate buffers from the heap. number of bytes read. Refer to the sources for details.
The only thing left is to start the event loop. With At the end of the program, we call io_destroy() to
most of the epoll() machinery omitted (LV016 has all deallocate resources the context owns.
details), it may look like this: Several open-source projects implement Linux AIO
while (!done) { support in their software. MySQL does this via libaio
n_ready = epoll_wait(epoll_fd, &epoll_event, 1, LOOP_ for the InnoDB storage engine. Rspamd (www.rspamd.
TIMEOUT_MSEC); com) builds on the raw Linux AIO syscall interface. It
if (n_ready > 0) { doesn't actually use AIO anywhere in the code now,
if (epoll_event.events & EPOLLIN) { but has the test suite providing nice usage examples.
read(res_fd, eventfd_buf, sizeof(eventfd_buf)); Database heavyweights like Oracle support Linux AIO
n_events = io_getevents(ctx, 0, 1, &io_event, NULL); as well, albeit they won't let you learn from them.

Command of the month: iotop
You probably know the top utility, which builds nice how much time the process or thread slept waiting for
stats on CPU usage. iotop does the same, but for disk blocking I/O to complete. SWAPIN is the same, but for
I/O. You must run iotop as root for security reasons. swap. Use arrow keys to change the sorting column
The main screen shows the overall system stats and (the current one is marked with >), and R key to
the list of processes. TOTAL figures display the reverse sorting order.
amount of data transferred to a kernel block device By default, iotop displays an instant snapshot of the
subsystem. ACTUAL measures the exchange with system's I/O. To show accumulated values instead,
physical storage, and it may not be equal to TOTAL run it as iotop -a or press A. This is useful to see which
because the kernel caches data and reorders I/O task consumed most I/O bandwidth in the long run. It
requests for optimum performance. is also possible to run iotop in batch (non-interactive)
Below it is per-process statistics. To toggle mode and save its output to log files (LV025). In
processes not doing any I/O now, press O, or run the interactive mode, press I to assign a thread different
tool as iotop --only. The IO column gives a clue on I/O priority. ionice(1) describes the options.

www.linuxvoice.com 97
/DEV/RANDOM/ FINAL THOUGHTS

Final thoughts, musings and reflections
Nick Veitch
was the original editor I’m lucky enough to live by a
of Linux Format, a river and work from a shed right
role he played until he alongside.
got bored and went
I try to keep everything
to work at Canonical else clutter-free.
instead. Splitter!
Yes, it’s a Mac, but
the build quality
and battery life is
exceptional.

S
o, Microsoft has decided to port one
of its flagship products, SQL Server, to
A worn Rubik’s cube,
Linux. By 2017, you could all be
which I’m not great
querying MS’s finest for your WordPress at (2 mins),
blogs if you so wish (and want to stump up
the cash). We are expected to believe this is
part of some “Redmond Spring” where
friendly competition is embraced and not
compared to deadly diseases.
It is perhaps just as likely though that the
not-so-evil empire has realised that for SQL KDE is now running
mostly in tiled mode
Server to compete in future, it really has to with 4 different
run on Linux. All of its main competitors do. desktops.
And where once the argument could be
made that people choose services, not
operating systems, that doesn’t hold true in
the cloud to the same extent. And the cloud
is where everything is.
Linux basically beats everything in the MY LINUX SETUP
cloud (http://goo.gl/FFHpmI), and Linux
images are among the most popular even
on Microsoft’s own cloud platform, Azure.
TOM ORALS
So the decision to port SQL Server to what is Regular reader and full time Linux user who lives by a river!
ultimately the only growing market segment
in which it can’t compete at the moment is a What version of Linux are you It was Mandrake back in the late 90s.
bit of a no brainer. And the competition will currently using? I’ve used KDE ever since.
do everyone good – SQL Server is fast and I’m using Arch Linux. I know it’s
robust (at least on Windows), so no doubt become a little notorious for name What Free Software/open source
Oracle is examining its strategy and code dropping, but I love the package availability can’t you live without?
also. It’s such a good idea, and it’s interesting and git-based AURs. The kernel? Other than that, Bash,
to think of what might follow (Active perhaps.
Directory anyone?). But still, there is a tingle And what desktop are you using at
of that old Ice Fear – the hurrahs over this the moment? What do other people love but you
announcement had barely died down when KDE – although the more I use it the can’t get on with?
MS also revealed it had received its latest less of KDE I’m using. I mostly use it I really don’t like Unity. There’s nothing
dollop of what it likes to euphemistically call to tile windows. visually appealing about the icons or
“IP licensing fees” from another Android- the palette. It looks and feels too clunky for
based tablet manufacturer. Microsoft What was the first Linux setup you me, like a kiddie version of Linux.
certainly loves Linux, all the way to the bank. ever used?

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