Linux Voice [Issue 31]

Authors Linux Voice

Plaintext

PROUDLY INDEPENDENT SINCE 2013
Banish Twitter!
Build your own
social network
to share daily
October 2016 www.linuxvoice.com blatherings
Why you need to try…
BOINC: HELP
SCIENTISTS DO
SCIENCE BETTER
P72

The best performance
The newest technologies
The most passionate community

GAMES EMULATION

RetroPie
Enjoy the glory days of
gaming all over again –
on a humble Raspberry Pi

FRUGALWARE

Hardware
Put old hardware to
good use with Linux
and Free Software FOSSPICKS –
THE BEST FREE
SOFTWARE FOR
LINUX P64
BURSTING
WITH AWESOME
SOLR Build a searchable archives of your chaotic PDFs
PHOTOGRAPHY Advanced tricks for image processing TUTORIALS!
VERACRYPT Keep your top-secret cat videos safe from The Man

MARTIN WIMPRESS GAMES DEVELOPMENT
O c tob e r 2016 £5.9 9 Pr inte d in the UK

MR MATE LUMO
Why we have this Take an exclusive look
man’s family to thank inside the creation of a
for Ubuntu Mate minor masterpiece

STELLARIUM › AFTERSHOT › OPENVR & MORE!
The only Linux magazine available
as DRM-free PDFs and ePub

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ISSUE 31 WELCOME

FREE SOFTWARE AHEAD
The October issue What’s hot in LV#031
ANDREW GREGORY
I’m pretty sure that computer
games reached their peak on the
SNES. I’m going to give up on
new games and take Mike’s
advice on retro gaming with the
Raspberry Pi and RetroPie.
BEN EVERARD p22
Long-term Linux user and
best-selling author Ben is GRAHAM MORRISON
usually found knee-deep in I’ve never liked Facebook, but I do
either Python code or a want to keep in touch with
tangle of wires. people. I’ve decided to run my
own social network, so I’ve been

T
reading Mayank’s group test to
his month I’ve been thinking a lot about what makes a find the right platform.
distribution great, as I’ve taken a close up look at Fedora for p56
the cover feature and interviewed Ubuntu Mate’s Martin
Wimpress. I’d love to say that I’ve come up with some deep insight MIKE SAUNDERS
that we can use to make all distributions perfect, but I haven’t. There Networks have always been a bit
are lots of trade-offs to make… of a mystery to me. Usually
Some distros do a great job of packaging lots of latest upstream everything just works, but when it
software. Others do a great job of curating software so only the best doesn’t, I’m stuck. Valentine’s
in class in each area is available. Some are constantly changing, Core Tech this month has helped
while others guarantee a stable base for a long period of time. me understand what’s going on.
p94
Rather than try to work out what is objectively the best distro, you
should think about what’s important to you so you can find a distro
that shares your values.

Ben Everard
Editor, Linux Voice

Linux Voice is different.
THE LINUX VOICE TEAM
Linux Voice is special. SUBSCRIBE
Editor Ben Everard
ben@linuxvoice.com Here’s why… ON PAGE 62
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
Editor in hiding Graham Morrison organisations that support free
graham@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, Simon Phipps, 3 We’re a small company, so we don’t
Les Pounder, Mayank Sharma, have a board of directors or a bunch of
Nate Drake, Alexander Tolstoy and shareholders in the City of London to
Valentine Sinitsyn keep happy. The only people that matter
to us are the readers.

www.linuxvoice.com 3
CONTENTS ISSUE 31 OCTOBER 2016

Contents
Make your computer great again!

Regulars Cover Feature
News 06
Debian and Firefox are now doing more to
protect users’ privacy, Skype is coming back 14
to Linux, and the government of Bulgaria
embraces open source.

Distrohopper 08
Automotive Grade Linux for your car
and Clear Linux (thanks to Intel) for your
enterprise-grade Linux containers, plus the
latest goings-on in BSD land.

Speak your brains 10
Suggestions, praise, and a vote of thanks

FEDORA.NEXT
for Linux Mint from a man after our own
heart who just wants the machine to do as
it’s told.

Subscribe! 12/62
Never miss another issue of your favourite
magazine in the whole wide world. You’ll
save money compared with buying it in the
Server, cloud or desktop – Fedora can do it all. Discover the cutting-edge
shops too! features that the other distros won’t have until next year.
FOSSPicks 64
Graham plays a tune on his pipes and the Interview Feature
Free Software applications follows him into
the shire, where he studies them before
releasing them back into the wild.
40 22
Linux Inside 98
The cheekily named Robonaut R2: proficient
in zero forms of communication, but quite
handy to have around on board the ISS.

Martin Wimpress RetroPie
SUBSCRIBE The man behind Ubuntu Mate on being an Easy-peasy retro games emulation for your Raspberry Pi,
ON PAGE 62 unpaid family tech support person. wrapped in a single distro install. Let’s play!

FAQ Group Test
OSVR 38 Social Networks 56
The mad rush for a virtual reality Build your own network for work,
standard has many contenders – school, or just to keep idiots out
could Open Source win here? of your life.

SECRETS OF PiTVi
TURN TO PAGE 26
4 www.linuxvoice.com
ISSUE 31 OCTOBER 2016 CONTENTS

Feature Tutorials

Boinc 72
Contribute a few spare CPU cycles to help
scientists solve climate change, synthesize
proteins and more.

Diary of a developer Veracrypt
Protect files, folders and partitions with
74

Inside the creation of this isometric puzzle fest. serious encryption. Keep your cat videos
secret, keep them safe…

Reviews Raspberry Pi 78
Take your first steps into physical
computing with a Raspberry Pi, a couple of

AfterShot Pro 48 LEDs and a smattering of Python.

Take photographs, Photography 82
then make your images Processing and editing tricks to improve
better than you could your holiday snaps and fix those grainy old
have imagined with this photos scanned from old film.
feature-packed RAW
image editor. Coding

LibreOffice 5.2 43 Stellarium 50
Yet again, the flagship office suite gains Look outside: if it’s daytime, or cloudy, or you
more features and more polish, this time live in a built-up area, you uprobably can’t see
with a focus on collaboration. the stars. That’s why Stellarium is here!

Solr 86
Build a search index for your PDF archive.
Perfect for magazine back issues!

Gaming on Linux 46 Books 48
Go back to the future with the 8-bit charm of Once the forests have gone, we’ll need clever people Packaging 90
Undertale plus a refreshed version of an all-time to repair the broken environment. So read more – Understand the magic that goes into
classic: Day of The Tentacle. expand your mind while you still can! packaging an app with Flatpak.

www.linuxvoice.com 5
NEWS ANALYSIS

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

Public software
Developers don’t need to mess about with legal stuff – we can do that for you.

Simon Phipps founders has led to a serious conflict that there’s also the Software Freedom
is ex-president of the can have an unfair outcome based on who Conservancy, which provides a broader
Open Source Initiative
accidentally ended up as the holder of the range of services, and now hosts a number
and a board member
of the Open Rights assets. If that asset holder is the employer of important projects. Both have a US focus,
Group and of Open of one of the participants, things can get as well as being very much in demand.
Source for America. even more ugly. That’s why it seems a good idea to start
an umbrella entity for Europe. We chose to
Don’t go it alone… start it in the UK where the Community
It’s a natural instinct for makers to try to fix Interest Company legal structure seemed
their own problems directly, so it’s not perfect for open source projects. Thus

B
ack in the January issue, I talked surprising to find so many developers Public Software CIC was created!
about thse proliferation of expecting the next step for their collection of “Public Software” refers to software that
Foundations for open source co-developers is to start a non-profit members of the general public can use
projects. All the most important freedoms association of some sort – a “foundation” without restriction, improve as they wish and
– to use the software for any purpose, study – to host their project. But experience share with anyone. By using the name
and improve it and share with anyone – are shows that making a new legal entity is “Public Software” we are alluding to the
secured by using an OSI-approved licence. often as poor a solution to the problem as name of the key free software and open
But open source projects that develop remaining unincorporated. Running a source licence, the GNU General Public
beyond the first commits do end up needing not-for-profit entity takes time, experience Licence (GPL) — a copyright licence for the
a set of capabilities, including: and administrative attention. Moreover, once benefit of the general public. Public Software
An “Asset Lock”, guaranteeing that the activity scales, all of those are needed in CIC exists to promote software freedom
community assets can only be used in amounts that distract from development. delivered under any copyright licences, both
ways the community approves (including For some projects, that’s a price worth approved by the Open Source Initiative as
domain names, trademarks and paying. The Document Foundation was conforming to the Open Source Definition
copyrights). created in just such circumstances, based and recognised by the Free Software
A “bank”, handling donations, paying staff on the expectation that many people would Foundation as “free software licences”.
and fulfilling tax-reporting obligations. be willing to share the funding and running Public software means more than just
An impartiality guarantor, anchoring the of a large, independent legal entity. But not the essential of an acceptable copyright
representation of its community and every project is like that, least of all on day licence. Our projects also allow participation
ensuring decisions are made in the way one. For most projects, the best choice is to by anyone and reserve project governance
that the community wants independently move into the shelter of an “umbrella” to those actually participating. We are
of any one participant. Foundation, until the project grows to the convinced that code and community
An infrastructure provider, hosting code, point that an independent entity is feasible. created together in public are the best recipe
mailing lists, forums and bug trackers and In the USA, there are a few of these for software freedom. We expect some
also hosting events. “umbrella” entities that provide shelter for projects to move on to their own CIC or
Without a seperate legal entity to look after assets and governance. Software in the charity once they are established, but hope
these things, there are plenty of examples of Public Interest was set up many years ago many will stay to form a critical mass of
projects where a disagreement between the to host the Debian project’s assets, and shared resources for the benefit of all.
It’s early days for Public Software CIC but
It’s natural for makers to try to fix their own projects are already exploring membership. I
hope this will become a force for good
problems, so it’s not surprising so many through software freedom in the UK and
Europe. You’ll find us at
developers… start a non-profit association https://PublicSoftware.eu.

6 www.linuxvoice.com
ANALYSIS NEWS

LibreOffice 5.3 • Skype • Bulgarians • Firefox encryption • Let’s Encrypt •Lumina

CATCHUP Summarised: the biggest news
stories from the last month

Debian sites now Linux comes to the LibreOffice 5.2 released
1 available as privacy- 2 Microsoft Surface 3 tablet 3 Sporting new document
friendly onion services Many of us in the GNU/ classification features,
Hidden onion services on the Linux world aren’t big fans of Microsoft OOXML signature import and a bunch
Tor anonymity network are often software (to put it mildly), but some of user interface improvements,
associated with dodgy shenanigans, of the company’s hardware isn’t too LibreOffice 5.2 is a decent upgrade and
but there are legitimate uses for them shabby. If you’ve picked up or been keeps moving way ahead of the mostly
as well. Now the Debian GNU/Linux given a Surface 3 tablet but want abandoned Apache OpenOffice. See our
distribution has set up many of its to move away from Windows, you review on page 49 for the full lowdown
websites as hidden services, so you can may soon be in luck – Linux kernel on what’s changed in this version.
access them completely anonymously. 4.8 will add hardware support for
The full list is available at https://onion. the machine. The biggest change in
debian.org – including news, blogs and that kernel release is support for the
security updates. Anything that protects tablet’s touchscreen, arguably the most
our online privacy is welcome. important driver.

Bulgarian government Skype for Linux returns – Firefox 50 will trust Let’s
4 goes pro open source 5 well, sort of 6 Encrypt by default
Another win for free software! Ever since Microsoft bought Let’s Encrypt is awesome:
The government of Bulgaria has Skype, questions have been raised it’s a free SSL/TLS Certificate Authority
enacted its Electronic Governance Act, about the software’s long term future (CA) which makes it possible for many
which includes the following clause: on Linux and other non-Windows websites to enable HTTPS (secure
“computer programs must meet the platforms. Indeed, it looked like the browsing) without having to shell out
criteria for open source software”. Linux client was dead not so long lots of money. Until now, Let’s Encrypt
So anything written for use inside ago. But now it’s back: Microsoft has has piggybacked on another CA, but
the government must be FOSS and announced Skype for Linux Alpha, a wants to ultimately become completely
accessible via a public repository. Not “not fully functioning Skype client” that’s independent. When Firefox 50 is
only could this save Bulgaria money available in Deb and RPM formats. released in November, it will support
in the long run, but it’s an important Helpful to Skype users, then, but we Let’s Encrypt by default – and hopefully
step towards transparency and open much prefer open and standardised other browsers will follow suit in time.
standards for the country as well. communication protocols. Your move, Google, Microsoft, Apple…

Lumina Desktop 1.0 Mozilla awards $585,000
7 released 8 to nine open source
You could argue that we have projects
enough desktop environments already, The Mozilla Open Source Support
but Lumina is worth keeping an eye on Initiative has channelled funding
nonetheless. It originally came to life in into various FOSS projects that
PC-BSD, a desktop-oriented flavour of “meaningfully advance the Mozilla
the FreeBSD operating system. Now it’s mission”, giving them a development
available on other Unix-like OSes as well, boost. Some of these are related to
including various Linux distributions, infrastructure that Mozilla uses; others
and is relatively memory-friendly are for security software. For the full
when compared to the mighty Gnome details, see http://tinyurl.com/z6t9rl5
and KDE. For more information and – you can even put your own Free
screenshots galore, see the website: Software project forward for a funding
https://lumina-desktop.org. request there too.

www.linuxvoice.com 7
DISTROHOPPER LINUX DISTROS

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

Clear Linux
Intel’s container-based distro.

I
ntel has quietly been working away on a
cloud computing distro for some time
now with relatively minimal publicity in
one of those rare cases where a big
company develops its own Linux distro and
actually retains the Linux name. The aim of
the project is “not to provide yet another
general-purpose Linux distribution”, but
rather a very fast container-based distro
much like CoreOS, using what it calls “Clear
Containers” while using “the isolation of
virtual machine technology”. The distro does
not ship with a GUI by default, instead
offering separate “bundles” offering a range
of things, among them being a full Xfce Clear Linux does away with a lot of legacy baggage, which also boosts performance.
desktop, enabling the user to pick and
choose and keeping the distro light. particularly in the realm of integrated Installation is not that straightforward and
Clear Linux is a rolling release and updates graphics, providing significant performance is comparable to an Arch install in that
constantly with over 20 builds per week. boosts over conventional Linux distros. you’re greeted with a command line and the
Recent updates include performance Clear Linux’s “bundles” are based upon RPM, aforementioned bundles must be installed
improvements, Mesa 3D 12.0 and kernel but use swupd built atop bsdiff and are to add further functionality. ClearOS is
4.6.4. Being a distro developed by Intel, it conceptually different to conventional meant as a showcase to demonstrate just
doesn’t play nice with AMD hardware and packages. There are a number of images what Intel’s hardware is capable of under the
doesn’t package Radeon drivers. The flipside available, including KVM-based images, live right conditions, though it could be put to
is that it is extremely well optimised, images and cloud deployment images. good use in a data centre.

Automotive Grade Linux
Linux under the hood

O
K, so you might not want to install approach, in which the vast majority of the
this on your PC unless it has wheels system is provided, while the automotive
and an engine, but Automotive manufacturer tweaks and adds the rest
Grade Linux (AGL) is a fascinating project based on the features they want, also adding
supported by the Linux Foundation that their own branding. Some of the partners The current release drives the entertainment
aims to power the car of the future and its include Toyota, Honda, Mazda, Ford and system; future releases will also drive the car.
entertainment system. Nissan, as well as sound system suppliers
The foundation has clearly recognised the like Panasonic. lot of sense given how much cars have
potential and widespread use of open Version 1.0 was showcased at the lagged behind, often using slow and clunky
source operating systems and software in Consumer Electronics Show (CES) in systems. Although Apple CarPlay and
an era where the days of companies building January 2016 and made quite a splash, and Android Auto already exist, AGL has some
their own software from scratch is mostly the first cars running the distribution should big advantages in being fully open source
behind us. Instead, AGL takes an 80/20 be hitting the streets by 2018. This makes a and having so many industry backers.

8 www.linuxvoice.com
LINUX DISTROS DISTROHOPPER

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

I
n the OpenBSD world, version 5.9 of
LibertyBSD has been released.
LibertyBSD aims to remove all non-free
elements from OpenBSD in a “deblobbed”
version of the OS – an approach not often
seen in the BSD realm, which has
traditionally differed from the puritanical
approach of the Free Software Foundation.
The biggest change in version 5.9 is that
support for i386 has been added, where
previously only amd64 was supported, while
other changes include additional
“deblobbing”. On OpenBSD itself, usermount
is being removed, thus removing the ability
for non-root users to mount filesystems,
citing security concerns as a result of a
number of bugs relating to it, which have
been described as “the tip of the iceberg”.
On the FreeBSD side of things, work is
going on to bring AMD’s newer graphics
binaries to the system and porting amdgpu
from Linux 4.6. This is close to being
completed and when finished will mean that
FreeBSD users will have access to much LibertyBSD takes a hard-line approach to non-free binary blobs comparable to that taken by the
newer AMD graphics hardware. Also in Free Software Foundation and distros such as gNewSense and Trisquel.
FreeBSD, it is now getting to the point where
replacing OpenSSL with LibreSSL is has also entered beta at the time of writing seen a new release with a number of
becoming a viable option. This would be a and the final release is expected soon. changes. These changes include the added
big step for web developers looking to close NAS4Free, a FreeBSD 10.3-based ability to set and change UPS monitoring
security vulnerabilities; however, it is far from embedded storage distribution which aims credentials, support for deleting multiple
being standard on a FreeBSD base and to provide the famed BSD reliability and items at once in the snapshots page and
patches are currently required. FreeBSD 11 longevity in lieu of store-bought boxes, has adding a search function to Diagnostics|Log.

AtheOS – discontinued and forgotten
AtheOS is one of those forgotten dead ends that had a relatively
short shelf life of four years from 1997 to 2001, when it was
discontinued. It was originally designed to be a clone of AmigaOS
to provide some continuity given the dire situation Commodore
was in at the time and also making use of the GPL, releasing the
system as free software.
Despite this initial aim, it was soon abandoned in favour of a
general system that aimed to be largely POSIX compliant, but not
a Unix clone. One major departure from Unix-like operating
systems of the time was not using the X Window System, instead
having its own integrated GUI built from scratch. This meant it
was more responsive, at the cost of being able to easily port
readily available applications. Other components, like the kernel,
filesystem and web browser were also created from scratch.
Development had become stagnant on the project by 2002
when the main developer began to dedicate his time to other
things, and another group of developers decided to create a fork
of the OS known as Syllable Desktop. Syllable picked where the
short-lived AtheOS left off, thanks to the GPL-published source,
and is still in reasonably active development and installable on
modern hardware, available at http://web.syllable.org. AtheOS’ ABrowse web browser reminding us what the internet was like in 2000.

www.linuxvoice.com 9
MAIL YOUR LETTERS

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

THANKS!
I know you don’t make Linux, but I thought this was as things just work the way I expect them to do. Using Mint
good a place as any to publicly air my thanks for Linux feels like the first time I picked up an iPod – nobody needs
existing, specifically Linux Mint. to explain it to you, because you can figure it out for
STAR I’ve been working with a new-ish laptop that I bought yourself just by playing with it. That’s truly amazing, and
LETTER last year. Like most people I didn’t pay too much heed to the fact that I didn’t have to pay any money for it is the
the operating system – the term itself was a new one to icing on the cake.
me until recently. What prompted me to learn what an David McKenzie, Sheffield
operating system is was the number of intrusive
messages that Microsoft kept sending me about Andrew says: Cheers David! Linux is indeed ace,
upgrading my version of Windows. I’d put some effort into and we can’t take any credit for it at all. However,
learning how it worked and I didn’t want to have to put that we know someone who can take a little bit of credit
effort in all over again learning a new system. – Martin Wimpress, who we speak to on page 40. If
I mentioned this to a friend who suggested I give Linux you like Linux Mint, you might like Ubuntu Mate. It
Mint a try. I only ever use the machine for email and using was born out of a desire to not reinvent the wheel,
the internet, and he assured me that Linux could do so to speak, so it sounds like just the sort of thing
everything that Windows can, so I gave it a go. In contrast for a chap who has better things to do than re-learn
to Windows, I haven’t had to learn anything new at all – where the Start button is.

AND NOW FOR SOMETHING COMPLETELY DIFFERENT
I know Python is popular with new users, but I’d really like really, is why we stick with a more welcoming
to see some other languages in Linux Voice from time to language (Python) for the entry-level stuff.
time. How about explaining the LAMP stack, with MySQL, I love the idea of a LAMP series of tutorials; we
PHP, Perl and a bit of Apache configuration, for example? I have the knowledge, it’s just a matter of puling
don’t think messing about with LEDs and GPIO pins will it all together, so watch this space. And in the
help my career too much… meantime, if it’s PHP you want it would be remiss
Sean Dwyer, Dublin of us not to direct you to www.hackingwithphp.
com, a brilliant series of tutorials written by our
Andrew says: You can please some of the people former comrade Paul Hudson. He’ll take you from
some of time, but try any more than that and you’re newb to ninja!
asking for trouble. We did run a couple of Perl
tutorials last year, but we ended up getting flak
from Perl programmers for doing it one way when PHP is an old language,
we should have been doing it another way – this, but it works.

10
YOUR LETTERS MAIL

SPACE!
The Apollo 11 guidance code is up on GitHub. Well done
NASA for sharing with us; it’s really made me appreciate
how far I have to go to become a decent programmer, and
how much modern languages do for you. Now back to
playing Elite Dangerous…
James Newsome

Ben says: Indeed so. I wonder how much other
cool stuff is out there mouldering away, lost to the
annals or time? Could MI6 let us have the source to
some of James Bond’s toys, or would that be asking
too much?

Thanks, Margaret Hamilton, for your sterling work.

IT’S ONLY WORDS
Cheers for the Calibre tutorial last issue. I’ve been spending
far too much time down the rabbit hole of online news
what with recent events in UK and US politics, so the
ability to filter my own sources has saved me massive
amounts of time and get my life back. I’ve taken back
control, as it were. Here’s hoping the internet will be safe to
go back to when the US election is all over – I like being
able to check up on the world without becoming obsessed
with it.
Michael Dwyer, London

Graham says: Ah, the internet will never be safe. It’s
full of rubbish, which is why we like the power to
filter off the worst of the nonsense and leave only
the best bits, like old Prince bootlegs and NASA
source code (https://github.com/nasa). Thanks for
the feedback! You decide what’s important, with a Calibre-curated news feed.

www.linuxvoice.com 11
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www.linuxvoice.com 13
FEATURE FEDORA

FEDORA.NEXT
Speed freak Ben Everard dives into Fedora to get the
very latest in Linux technology.

F
edora is a fast-paced Linux distribution that’s distribution to take advantage of the latest trends in
constantly pulling all the latest software from the Linux world. This fell under the moniker Fedora.
around the Free Software world into a solid next. Two years and four releases later, we can now
distribution. The last sentence is as true now as it’s see just how much effect this change has had. It’s
been since the Fedora project released Core 1 back transformed the distro from a great option for the
in 2003, but this doesn’t mean that Fedora is running Linux desktop to one that also perfect for cutting-
the same as it always has. In 2014, the project edge server deployments. Join us as we delve deep
started to look at how to best position the into the heart of Fedora to find out what’s going on.

14 www.linuxvoice.com
FEDORA FEATURE

FEDORA.PAST AND FEDORA.NEXT
Where we’re coming from and where we’re going

Things change quickly, and if you’re a
Fedora user you typically have to
long time. However, since the early
2010s, there’s been a rapid evolution
FEDORA FOR THE AGES
upgrade your OS every year or end up in server technology mostly driven by 25 AUGUST 1991 31 MARCH 2007
on an unsupported version. For most the desire to serve ever more rich user Linus announces the Linux Fedora 7 (Moonshine) released
Kernel on comp.os.linux. without ‘Core’ in the name.
of its life, this means that Fedora has experiences to ever more people on
been more suited to desktop use than internet-connected devices. This push 15 SEPTEMBER 1993 8 NOVEMBER 2007
server. The standard Linux server has led to new databases, web servers First version of Debian (0.01 Fedora 8 (Werewolf) is the first
pre-alpha) released. Linux distro to include
stack – LAMP – was already mature and even paradigms of controlling PulseAudio.
by the time the first release of Fedora access to an operating system kernel 12 NOVEMBER 1994
came out, while the Linux desktop (containers and lightweight VMs). Red Hat version 1 (Mother’s 13 MAY 2008
Day) released. Fedora 9 (Sulphur) brings KDE
environments are still rapidly evolving, With these new technologies coming 4 to users.
so it’s only on the desktop that getting along – and evolving rapidly – the 12 JULY 1998
the latest software (and putting up stable server Linux distros such KDE version 1 released. 25 NOVEMBER 2008
Fedora 10 (Cambridge) brings
with the issues of a as RHEL and CentOS MARCH 1999 support for the ext4 filesystem
changing distro) actually struggled to keep up Gnome version 1 released. and LXDE desktop.
gains you features. with the expectations
2002 9 JUNE 2009
For users wanting a of modern system Fedora Linux starts as a Fedora 11 (Leonidas) includes
more stable If you’re a Fedora administrators. volunteer project to package experimental support for the
extra software for Red Hat. advanced BTRFS filesystem.
environment, the user you typically The Fedora.next
base of the distro, project, launched
once it’s matured
have to upgrade in 2014, aims to
6 MAY 2002
First version of RHEL (2.1)
17 NOVEMBER 2009
Fedora 12 (Constantine)
in the crucible of your operating enable Fedora to released. comes with a preview of
Gnome Shell.
Fedora, goes on to system every year move into this new 31ST MARCH 2003
form the core of technological space last version of Red Hat Linux 25TH MAY 2010
Red Hat Enterprise while still catering to released (version 9 aka shrike). Fedora 13 (Goddard) has a
new Internet install option
Linux (RHEL) and desktop users. The most 5 NOVEMBER 2003
CentOS. These obvious outcome of Fedora.next is First release of Fedora Core 2ND NOVEMBER 2010
distributions take the heart of Fedora that there are now three different (version 1 aka Yarrow). Fedora 14 (Laughlin) is
released concurrently on
and build it into a release that changes versions of Fedora: Desktop, Server 18 MAY 2004 Amazon’s EC2
far more slowly. and Cloud. Each of these is tuned to Fedora Core 2 (Tettnang)
This split between rapidly moving the needs of different users in the introduced SELinux. 24 MAY 2011
Fedora 15 (Lovelock) includes
desktop distributions and slower modern technological landscape. We’ll 20 OCTOBER 2004 the new Gnome 3 desktop.
moving server distributions served look at these over the next few pages First Ubuntu release (4.10 aka
the Fedora community well for a to see how they fit together. Warty Warthog). 8 NOVEMBER 2011
Fedora 16 (Verne) boots using
8 NOVEMBER 2004 Grub 2.
Fedora Core 3 (Heidelburg)
First release to come with 29 MAY 2012
Firefox and switches from Lilo Fedora 17 (Beefy Miracle)
to Grub bootloader. introduces /run/media.

13 JUNE 2005 15 JANUARY 2013
Fedora Core 4 (Stentz) ships Fedora 18 (Spherical Cow)
with OpenOffice 2.0 and Xen. supports Secure Boot, and
offers Mate and Cinnamon.
20 MARCH 2006
Fedora Core 5 (Bordeaux) 2 JULY 2013
drops up2date and rhn-applet in Fedora 19 (Schrödinger’s Cat)
favour of Yum for package replaces MySQL with MariaDB.
management.
17 DECEMBER 2013
24 OCTOBER 2006 Fedora 20 (Heisenberg) has
Fedora Core 6 (Zod) includes ARM as a primary architecture.
AIGLX to GL-accelerate the
desktop. 9 DECEMBER 2014
Fedora 21 is the first release
7 DECEMBER 2006 without a codename
OpenSuse first release (10.2)
3 NOVEMBER 2015
22 JANUARY 2007 Fedora 23 comes with
Fedora users are among the first to get the latest versions of Gnome Shell. Linux Foundation formed. LibreOffice 5.

www.linuxvoice.com 15
FEATURE FEDORA

FEDORA WORKSTATION
Fedora continues to dominate on the desktop

The notifications area in Gnome
Shell makes it easy to keep up
with any important messages
from your system.

The workstation release of Fedora this in the previous issue of this For those of you seeking
boots into a live Gnome Shell (see magazine, but our favourite features the ultimate desktop graphics
boxout for other desktops). Fedora 24 are the improvement to the help performance, Fedora is probably the
brings this bang up to date with system and a more polished interface. distro that best supports Wayland.
version 3.20 of the desktop Also new with Fedora 24 was the Although it’s not yet the default
environment, so you get all the latest Flatpak packaging format, which graphical server, you can enable it. The
features. You can see our full review of makes it easy to ship desktop Wayland experience is getting better
applications packaged into containers with every release, and many users
for security and ease of distribution now use it on their normal system
Spins across multiple distros. without problems.
Spins are Fedora distributions that come with a different
set of default software to the standard Workstation
release. Basically, they’re for people who want a desktop
environment other than Gnome. Here are our favourites:
• KDE There has been competition between Gnome and
KDE for almost as long as there have been Linux desktop
environments. Gnome may be the default on Fedora, but
KDE is the first option on the spins page.
• LXDE Don’t wast computing power on a flashy desktop –
save it for real work instead. LXDE is a perfectly functional
desktop without any of the bells and whistles that waste
CPU cycles, making this spin great for older machines.
• Mate When it comes to the traditional desktop metaphor,
nothing is better than Mate, a desktop forked from the
now defunct Gnome 2. Gnome 3 caused controversy
• SOAS The least familiar of the desktop spins, Sugar On A when it came out, but has
Stick is a desktop designed for children initially used by matured into an easy-to-use
the One Laptop Per Child project. desktop environment.

16 www.linuxvoice.com
FEDORA FEATURE

None of the things we’ve mentioned
so far are exclusive to Fedora, but they
are all technologies that are rapidly
changing, and Fedora users are well
placed to benefit from them before
users on other distros. This adoption
of technologies at the cutting edge is
the real advantage of Fedora rather
than any particular piece of software
that’s unique to the distro.
Fedora is the fastest moving of
the non-rolling release distros. Arch
users have the very latest software
constantly available, but the price
they pay for this is not being able to
easily predict when big updates come. If you prefer a more
traditional desktop
With Fedora, you’ll only ever be a few
experience, the Fedora Mate
months behind Arch, but you can
spin retains the classic
know exactly when things will change. Gnome 2 look and feel.

All aboard
When it comes to picking a distro, the what’s going on with the project, you distros tomorrow. Having a rounded
community behind the project is can browse through the past IRC set of Linux skills means being familiar
important. An active community meetings, as logs are recorded with multiple distros, but if you’re using
means that more software at and posted online at a RHEL-derived distro professionally,
will be packaged and https://meetbot. using Fedora Workstation will help you
bugs are more likely fedoraproject.org. stay ahead of the game.
to be fixed, while an A significant, and There is no perfect desktop distro
open community An active often overlooked, for all people, but Fedora is a great
means that you community advantage option for anyone who wants a
can get involved means that bugs to Fedora for cutting-edge distro with an active
and help shape the sysadmins and community, especially if they want to
are more likely
direction that the other people who use enterprise distros as well.
distro goes in. The to be fixed work in operations is
Fedora community that it’s the upstream
is both active and distribution for RHEL Labs
open with most of and CentOS – the underlying
Labs are collections of software curated for a particular
the activity happening on IRC and system in Fedora today will be the use. To make it easy to get started in a particular area, you
mailing lists. If you want to know underlying system in these server can download Fedora releases with all the software already
installed, or you can add a lab to an existing Fedora install.
• Scientific If you’re a student or otherwise working in the
scientific community, this lab will pull together all the
open source software you need, including iPython, R, Latex
and Gnu Octave. Spend time probing the mysteries of the
universe, not searching through the repositories for the
software you need.
• Security Security is critical to every tech project, and
achieving a good level of security means having a good
range of security tools to hand and knowing how to use
them. Whether you’re just getting started with IT security
or are a seasoned pro, the Fedora Security lab is one of
the easiest ways to get the software you need.
• Games If your machine is more for leisure than work,
this is the lab for you. Packed with the best open source
games (no Steam here), you’re ready to play as soon as
you start up. With the live version, you can introduce
others to the joys of free software gaming.
• Design Suite Free Software has close ties with the design
world, and slowly but surely, many designers are reaching
for open source as a replacement for the Adobe Creative
Suite that has been the industry standard for years. The
Fedora Design Lab brings all the software you need –
whatever your creative medium – into your distro.
The Gnome Software tool makes it easy to find and install whatever software you need.

www.linuxvoice.com 17
FEATURE FEDORA

FEDORA SERVER
Cutting edge software to help your business run smoothly

You can get an overview of how
your machine’s performing from
your web browser with Cockpit.

Let’s be honest, if you’re looking for a making the distro reliable under heavy repeat the same tasks to get your
server distro, Fedora probably doesn’t loads, and workable through upgrades, servers running that thousands of
spring immediately to mind. The there’s been work put into making the other people did: you had to install the
though of having just a year or so’s distro easier to set up and manage. software you needed, configure it to
support is enough to make most While a standard Linux distribution behave as you wanted, then configure
sysadmins' toes curl. is a very flexible thing that can be any system-level components (such
Since the creation of Fedora Server turned to almost any computational as firewalls) as necessary. This gave
(in version 21 of the distro), the project tasks, there are a few things that you complete control, but could be a
have thought about what makes a servers are very commonly used to do. little complex, especially for people
great Linux server, and how to apply Despite these common tasks, Linux only managing a couple of servers
that to a fast moving distro. As well system management has traditionally who aren’t full-time system admins,
as all the usual back-end work on been a little disjointed. You had to or Windows sysadmins who don’t

What can I do for Fedora?
On of the great aspects of Fedora is the community.
Although it’s sponsored by Red Hat, Fedora is really created
by volunteers coming together to work on a great distro.
These volunteers come from all walks of life and have a
huge range of skills – and they could include you. If you
like the idea of helping make the next version of this OS a
little more awesome, the Fedora project would love to hear
from you. They’re so keen to get more people on board that
they’ve made a simple tool to help you find the area within
the project where your talents are best put to use. Head to
http://whatcanidoforfedora.org/en to find out more. You
don’t have to be a coder or sysadmin to help (though if
you are, that’s great) – the project is in need of designers,
translators and writers. There’s something for everyone!
The Cockpit interface provides an easy way to manage Docker containers on Fedora.

18 www.linuxvoice.com
FEDORA FEATURE

If you’re interested in helping make
Fedora even more awesome, head
to http://whatcanidoforfedora.org to
find out what you can contribute.

yet know their way around the Linux ability to tweak your system from your runs on the latest code from upstream
system. web browser. You can control system projects. There are a few new server
Fedora has created roles that enable services, configure the network, projects that are currently iterating
you to very quickly set up a launch containers, update your really quickly, such as Docker and
server to a particular task. system and more with just Kubernetes. If you’re using one of these
For example, with just a few clicks of the on a more traditional Linux server
a single line of code, mouse. If you’re a distro, you may find that you have to
you can transform seasoned system manually keep the software up to date.
your fresh Fedora
If you're coming administrator, this Fedora Server might seem like a great
instance into a to a Linux server probably won’t solution here, but the Fedora project
running database for the first time, make things easier has singled this area out for its own
server that’s set Fedora will help for you as can do version of the distro – Fedora Cloud.
up with best all this from the
practices.
you get started command line just as
An alternative route to Fedora on the server
quickly, but if you’re
You may be reading this section on Fedora for the server
In the driving seat coming to a Linux server
and thinking that having cutting-edge software on a server
Not everyone running for the first time, it will help you would be great, but you don’t want to have the underlying
a server is comfortable using the get started. distro change every six months. It turns out that the Fedora
command line. This might sound like We’ll be honest, Fedora Server isn’t project themselves had this want with the infrastructure
heresy in a Linux magazine, but it’s for everyone. If you’ve already got a they use to run the project.
Their solution was to get the latest version of common
true. The terminal interface is hugely swarm of servers running, and are
server software and package it for RHEL. This way, they
powerful and with practice can reduce happy with the process of managing got the benefits of the stable base of RHEL, but also the
complex tasks to a single line, but it them, it’s unlikely that there’s anything benefits of faster-moving packages. Seeing that other
can take a long time to learn to use in the plain Fedora Server distribution people wanted this solution, the Fedora project grouped
well. It’s a little excessive to expect to tempt you away from your current these new packages into a repository called Extra Packages
for Enterprise Linux (EPEL). Although these repositories
someone to become familiar with setup. However, if you’re new to Linux
are maintained by Fedora, they’re for installation on RHEL,
Bash just to keep a single server servers, some of the new features CentOS, Scientific Linux and Oracle Linux.
running. Fedora has built Cockpit – a could make it a lot more accessible. This is something that we at Linux Voice appreciate,
web-based management interface So far, we haven’t mentioned the because our servers run on CentOS with EPEL additions.
– to make life easy for system software. Fedora is well known for Like many others, we find the balance between stability
in the core OS and having up-to-date software in the
administrators. You can install it with bringing the latest software to the
repositories the best solution for our needs.
a single command and then have the desktop, and the server version also

www.linuxvoice.com 19
FEATURE FEDORA

FEDORA CLOUD
Master your containers for easy deployment and scalability.

Had an update go wrong? If you’re
using Fedora Cloud this isn’t a problem,
as you can roll back the upgrade either
from the terminal or the web browser.

Before we delve too far into the Fedora a software platform available over
Fedora Cloud images Cloud images, let’s stop for a moment the cloud is a Platform as a Service
Fedora Cloud comes as image files that can be put directly to work out what we mean by Cloud. (PAAS); whereas a provider of online
on to virtual machines rather than ISO files that need to It’s been a computing buzzword for virtual machines is Infrastructure as a
be installed. The obvious problem with missing the install over 10 years, but it’s still used by Service (IAAS).
step is that it doesn’t catch the useful information that different people to mean different
users typically entersuch as such as login credentials
and any necessary network details. You can pass all this
things. At its heart, cloud computing is What is the cloud?
information to the Fedora Cloud instance using an init. any computing that can easily be done Cloud computing is when you contract
iso image. This is a CD image that contains two text files on different remote machines. This out a specific part of your computing
detailing the data that Fedora needs. The most basic setup can be true on a variety of levels. At needs to a third party. This can have
is the following. A text file called user-data containing: the top level, it’s about applications huge organisational and cost saving
#cloud-config
that can run anywhere. Take, for advantages because it means that
password: fedora
chpasswd: { expire: False } example, a cloud office suite such as one company can specialise in one
ssh_pwauth: True Google Docs – this runs in your web thing (such as running online office
and a file called meta-data containing: browser but the back end could be suites) and do so highly efficiently,
instance-id: iid-LV02; anywhere; it doesn’t matter to you as while another can focus on its core
local-hostname: LV01;
long as you can access it through business rather than try to keep their
With these files in place, you can create the ISO image with
the following (run in the same directory as the above files): https://docs.google.com. office suites running and updated.
genisoimage -output init.iso -volid cidata -joliet A level lower, you can access a The biggest problem with this view
-rock user-data meta-data software platform that could be an of the cloud is that it requires you
You’ll now need to download either the Base or the operating system or a programming to hand over much of your data to
Atomic Host image. Whichever you pick will come as a
language environment. The lowest the third party. If they go bust or get
QCOW file that can be booted up in Qemu (or KVM), but we
ran ours in VirtualBox as it makes it more straightforward to level is providing virtual computing hacked, you’re in trouble. In order to
sort out networking. Before you can use VirtualBox though, power (such as virtual machines) solve this problem, large organisations
you need to convert the image into a VDI file with: though the cloud. run a private cloud where the IT
qemu-img convert -f qcow2 <downloaded- The essential part of all this is that department provides some facilities to
filename>.qcow2 -O vdi <output-filename>.vdi
the user pays for a specific service the rest of the organisation in a cloud-
You can now create a virtual machine with the VDI
image as the hard drive and the ISO file in the CD drive. We they want rather than a specific like manner. Typically this is a Platform
used Bridge networking (in Settings > Network > Bridged piece of hardware or software. The as a service (PAAS) or Infrastructure
Adapter) to simulate the virtual machine as being on a new abbreviations of cloud software often as a service (IAAS).
network interface. Starting the machine will take you to a end in AAS (As A Service) to denote Phew! That’s quite a lot of detail to
login prompt where you can log in with fedora/fedora.
this. For example, an online office get through before we even look at
suite is Software as a Service (SAAS); what the cloud release of Fedora does.

20 www.linuxvoice.com
FEDORA FEATURE

The Project Atomic website
is the best place to get
information about how to use
Fedora Atomic Host.

Firstly, let’s just discard Software as images. This reflects the way they’re roll back to any previous state. With
a Service – it has its place, but it’s not designed to be used. Rather than this roll-back option, keeping up with a
the sort of cloud we’re talking about. installed onto a machine through fast-moving distro poses fewer risks.
This distro is really about working with the traditional install process, they’re Fedora Cloud offers a radically
a PAAS or IAAS system. imaged in a state ready to run. different server management paradigm
You could use a Fedora Cloud It’s the Atomic Host version of that aims to make it easy to manage
image to control containers running Fedora Cloud that is really bringing servers and scale applications. Much
on Docker that are hosted on someone next-generation system administration of the technology behind this approach
else’s PAAS; you could build your own to the Linux world. It’s part of Project is new and evolving quickly, and
private PAAS using Fedora Cloud as Atomic (which also spans CentOS Fedora is ideal for making make the
the host OS; or you could and RHEL) and aims to create most of this new approach.
use Fedora Cloud on an a platform that makes it
IAAS. There are three as easy as possible
versions of Fedora to build and deploy Kubernetes, Docker & LXC
Cloud that suit The Atomic containerised The new technologies that Fedora Cloud is built on can be a
different uses applications little baffling even to people who have been using Linux for
cases:
Host version of across a pool a while. Let’s take a quick look at these three:
Base A minimal Fedora Cloud is of computing
• Linux Containers (aka LXC) is the name given to a group
of technologies that isolate a set of system resources
Fedora release for bringing next-gen resources. running on top of a Linux kernel. This effectively gives
creating virtual Sysadmin to Linux The underlying you the ability to run two or more Linux systems on a
machines on IAAS. technology for this is single CPU. Only a single kernel runs, but the two systems
Atomic Host A Linux Containers, Docker are so well isolated that the two systems appear to be
completely separate from each other.
Fedora build and Kubernetes, but Project
• Docker Using a system of images, users can design
specifically for running Atomic hides as much of this as containers using Dockerfiles that define what distribution
containerised applications with Docker possible behind a single interface (the the container should be based on and how it should be
and Kubernetes. atomic command and the nulecule configured. These images and Dockerfiles can be shared
Docker This release is purely for container specification) that makes it through a Docker registry that makes it really easy to
create, modify and share containers for almost any need.
running inside Docker, and you easier to manage.
• Kubernetes controls groups of Docker containers to
shouldn’t usually download it directly. With all your applications in make it easy to build systems running across multiple
Instead you can get it through Docker containers, the base system should machines. Take, for example, a situation where you
either directly or by creating a Docker always be small and easy to manage. had 10 physical machines and wanted to deploy a web
file that builds from it. The base system is upgraded using app that required a web server and a database. Using
Kubernetes, you could define Docker containers for the
Whichever you choose, you’ll find the rpm-ostree command, which
web and database server, then spin up instances of these
that they don’t come as ISO DVD keeps track of all previous system containers across your 10 machines and load-balance the
images as is normal for Linux distros, states so that if you encounter a system to keep everything running smoothly.
but as virtual machine hard drive problem with the upgrade, you can

www.linuxvoice.com 21
FEATURE BACK TO THE FUTURE

Turn a spare Raspberry Pi into an awesome retro gaming station.
Mike Saunders gets misty eyed reliving the classics.

W
e often hear from readers that and play”. With the right software on the SD and having a bulky PC under your TV (or a
many of you now own multiple card and a HDMI cable, you can plug it into laptop that can’t be used for another job at
Raspberry Pis. As they’re so almost any TV made in the last five years the same time) isn’t idea.
cheap, it’s not the end of the world if one and it just works. So the Raspberry Pi is perfect for this: low-
spends the next few years sitting in a power, silent, plug-and-play as mentioned,
cupboard, but we always have this nagging Now you’re playing with power and with a couple of USB ports for joypads.
feeling that any working technology should And this is especially useful for emulating Over the next few pages we’ll show you
be doing something useful. classic video games consoles and how to set up a spare Pi using the very, very
Now, there are obviously a million and computers. You can do this on a desktop cool RetroPie distribution, so that you can
one things you can do with a Pi, from home PC or laptop of course; Linux has a wealth play old games from the 1980s and 1990s
servers through to robotics, but one thing we of first-rate emulators for pretty much every with minimum fuss. Sure, there are some
like about it – especially thanks to its HDMI platform under the sun. But setting up excellent modern games, but very little
output port – is that it’s very much “plug emulators on a typical distro can be fiddly, compares to multiplayer Super Bomberman…

22 www.linuxvoice.com
BACK TO THE FUTURE FEATURE

Install RetroPie and prepare to beat your old high-scores.
The first thing you need, of course, is a
Raspberry Pi. Excellently, all models of the Pi
can be used with RetroPie, so you’re not just
limited to the latest versions – but there is
an impact on performance. In our
experience, the earlier models (and Pi Zero)
do a decent job of emulating the 8- and
16-bit classic consoles such as the Atari
2600 (VCS), NES, SNES, Master System,
Mega Drive (Genesis), Game Boy and Game
Gear. If you want to try emulating more
advanced machines, like the Sega Saturn or
Sony PlayStation, a Raspberry Pi 3 is highly
recommended – and even then, you’ll get
mixed results. We recommend RetroPie
mainly for 8-bit and 16-bit emulation.
Next, you’ll need the usual bits and pieces
to get a Pi running and connect it to a TV:
a power cable, a HDMI cable, and an SD
card (8GB minimum recommended). Then
you’ll need a USB joypad (or two) to actually
play the games – you can pick up SNES
knock-offs from Amazon for a few pounds/ Every Pi model works well with RetroPie, but for the best performance (eg for PlayStation
dollars/euros. Finally, if you want to do some emulation) we’d recommend the beefed-up version 3.
tweaking of your RetroPie installation, it’s a
good idea to have a USB keyboard around Next, enter df -h, which shows a list of you have any doubts or need more help, see
that you can plug in. You don’t need it to disks (or SD cards) currently in use on your the official Raspberry Pi SD card installation
play games, but you’ll need to use it to gain Linux distribution, along with how much documentation at www.raspberrypi.org/
access to certain advanced features. space they have. Now plug in the SD card documentation/installation/installing-
So once you have all your equipment, you want to use for RetroPie, and run df images/linux.md.
head over to the RetroPie download page -h again. This second time of running the Anyway, the above command could take
at https://retropie.org.uk/download. You’ll command, you’ll see the difference from anything from a few seconds to several
see that there are two download options: the first output, showing which card you’ve minutes depending of the speed of your SD
one for older Pis (models Zero and 1), and added. Note the SD card name in the list – card, so go off and make a cuppa. When it
another for the Pi 2 and 3. Choose which is eg /dev/sdd1. We want to access the SD has finished, enter sync at the command
appropriate for your device, and after a few card directly, and not via a file manager, so line, then remove the SD card and plug it into
minutes of downloading you’ll end up with a unmount it like so: your Pi. You’re ready to go!
.img.gz file containing the filename. This is a sudo umount /dev/sdd1
compressed Raspbian image, much like the (Change the device name accordingly.) If Play it loud!
normal ones you install on a Pi, but highly the output of df -h before showed multiple Now connect your Pi to the TV, plug in your
customised for retro gaming. partitions on your SD card, you’ll need to USB joypad(s), and RetroPie will boot for the
unmount those as well. first time. It will expand the Raspbian
Play your cards right Now we need to directly write the installation to completely fill the SD card,
Next you need to write it to your SD card. Raspbian image to the SD card. To do so, we
Move the file to your home directory (eg use the name we had before (eg /dev/sdd1),
/home/mike), then open up a Terminal but this time removing the number, as we
(command line) window and use gunzip to don’t want to access any specific partition
extract the compressed image like so: but rather the whole device. So:
gunzip retropie-v3.8.1-rpi1_zero.img.gz sudo dd bs=4M if= retropie-v3.8.1-rpi1_zero.img
Note that the filename may be different of=/dev/sdd
in your case – and remember you can hit Be very careful with this command – if
Tab after typing the first few characters of a you put /dev/sda or something else, you
filename to auto-complete it! could end up overwriting your main drive! If

www.linuxvoice.com 23
FEATURE BACK TO THE FUTURE

assigned to Start and Select simultaneously.
This will return you to the RetroPie front-end,
where you can navigate to other emulators
and games. (Press A to go into an emulator,
and B to switch back out.) If your joypad
wasn’t configured correctly, press Start in
the main RetroPie screen to open a menu,
go to Configure Input, and then go through
the process again.

Adding ROMs
Now you’ll want to add some ROMs (see the
“Thorny issue of ROMs” box for more
information on these). If you’re savvy with
the command line, you can plug a USB
keyboard into your Pi, hit F4 to switch to the
command line, and then cd into the /home/
pi/RetroPie/roms directory. There you’ll see
subdirectories for various consoles – most
of the names are obvious, but note that gb is
for Game Boy, gbc for Game Boy Colour and
gba for Game Boy Advance.
You can now copy ROMs into these
A Raspberry Pi running RetroPie, playing Sonic 1, but with a SNES pad connected via a Retrode.
directories, eg from a USB key. If you’re not
What kind of black magic is this?
so au fait with the command line, press
Ctrl+D to return to RetroPie, and then shut
then reboot and you’ll see a shiny splash search for a SNES joypad to get an idea it down by hitting the Start button and then
screen. Once the emulator front-end has of the standard layout). If your joypad has Quit in the menu. Once your Pi has fully shut
loaded, you’ll be prompted to press and hold fewer buttons or you don’t want to assign a down, remove the SD card and insert it into
a button on your joypads to configure them. physical one to an emulated one, just press your computer.
RetroPie will ask you to assign each and hold any button when prompted. In your file manager, navigate to the
button on your USB joypad to a button in the Once the joypad(s) are configured, retropie partition of the SD card, and go into
emulators (eg A, B, X, Y – do a web image RetroPie will display a list of emulated /home/pi/RetroPie/roms. Here you can add
consoles and computers – use the left and ROMs into the appropriate directories as
right buttons on your joypad to navigate mentioned previously. When you’re finished,
between them. As you have no ROMs unmount the SD card, pop it back into your
installed at this stage, you won’t have much Pi, reboot and enjoy playing the classics!
to play, but you can test your installation RetroPie has many advanced features
by going to the Ports option and choosing including the ability to scan for ROMS,
Doom. If all goes well, you’ll be able to play so visit https://retropie.org.uk for
a bit of classic Doom and ensure that your documentation and forums where you can
joypad is set up correctly. get help and share ideas. And if you discover
To exit out of Doom – and indeed any an absolute gem from the 80s or 90s that
emulator – press the buttons you have everyone should play, drop us a line!

An emulator isn’t much fun without any Now, the internet is awash with ROMs, – look at Nintendo with its new NES Classic
games to play on it. But where do you get but their legality is dubious. Some people Edition.
them? If you’re new to emulation, it’s argue that downloading a ROM for a game So play it carefully. If in doubt, buy a
important to understand what the term you already own is fine – after all, you have machine to directly extract ROMs from
“ROM” (read-only memory) means. In this a right to own a backup copy in case your cartridges you own (eg a Retrode). Or play
context, it’s a file that represents the game breaks. Others say it’s still a copyright the many home-brew ROMs created more
contents of a video game cartridge (or infringement. Many people would argue recently by fans of classic consoles – most
floppy disk or CD-ROM). It essentially “Ah, these games are so old, it’s not like the of those games are released for free and
contains the very same bits and bytes of the original vendors are losing any money.” But their developers actively encourage copying
original game. some companies are still selling old games and distribution.

24 www.linuxvoice.com
BACK TO THE FUTURE FEATURE

Mike’s selection of relatively obscure but unmissable retro games.

1 2

4 5

1 Umihara Kawase (SNES) From the outside, this looks like a traditional huge challenge for a machine that had character-cell graphics – 3D images have
jump-and-run platformer, but it has a twist: your character welds a fishing rod, and to be mapped onto sprites. But it works well, with a clever joypad-based input
you can fire its hook onto other platforms to swing around, Spiderman-style. It system and top-notch battles.
makes you think about level structure in a wholly different way, and there’s some 4 Kaeru no Tame ni Kane wa Naru (Game Boy) This was only ever released in
corking music to accompany your antics too. Japan, but the ROM has been translated by hardcore fans and is playable in
2 Unirally (SNES) Known as Uniracers in the States, and created by DMA Design English. It’s based on the engine used in Zelda: Links Awakening, and it’s also an
(of Lemmings and later Grand Theft Auto) fame, Unirally is a side-scrolling racing great role-playing game (although very tough in places).
romp in which you perform stunts on a unicycle at breakneck speeds. It’s shallow, 5 Dragon’s Revenge (Mega Drive/Genesis) Most pinball games tend to be shallow
but tremendous fun to play – especially in split-screen two-player mode. affairs with pretty sounds and shiny graphical effects, but not much else to keep
3 Elite (NES) We’ve talked about Elite (and Frontier) plenty of times in Linux Voice, you glued to the joypad. Dragon’s Revenge is way better: a fantasy world, boss
but you may not be aware that it was ported to Nintendo’s mighty NES. This was a levels, bonus balls and other tricks make it one of the superior pinballers.

www.linuxvoice.com 25
SECRETS PITIVI

SECRETS OF
PITIVI
Get the most out of your motion pictures with open source video editing

F
ast internet speeds and the proliferation of smartphones some serious competition, this is our favourite of the open source
mean that we’re creating and sharing more video than ever video editing options. Pitivi is a powerful and rapidly developing piece
before. As a result of this, video editing software is becoming of software that has really started to shine in the last couple of
more popular for stitching together GoPro camera footage of sports, releases. The stability problems that plagued it for years have now
mobile phone footage of current events and, of course, videos of mostly been consigned to the past, and the new-look GTK 3 interface
cute cats. makes it a pleasure to use.
This month, we’re taking a close-up look at one of the most We’ve been using Pitivi for a few years – here are our eight
popular open source video editing options, Pitivi. Although there is favourite features.

01 02

help you with these, but it does provide
vast numbers of options that are easy
to add to your movie. There are over 70
transitions and over a hundred effects
for you to play with – this is more than

01
Flatpak supports this format. We were able to enough to add a professional look to
Installing software in Linux is download and install the software on your projects – just don’t add all of
easy, provided your distro’s Ubuntu with just two commands, them at once.
repository has the version you want. If which makes it just as easy as apt-get.

03
you’re after the very latest version Nanoseconds

02
though, things can get complicated. Transitions and filters There are a lot of
The Pitivi developers have packaged the Good use of graphical components to a video
latest version up with Flatpak to make it effects requires an eye for – multiple tracks, effects and audio are
easy to install on any distro that style and plenty of creativity. Pitivi can’t all pulled together to make the final
video and these all have to happen at

Pitivi has over 70 transitions and over a hundred the same time to get the right result. If
this synchronisation is off by just a
effects for you to play with – more than enough small amount, the result is a video that
looks amateur. Just how accurate does
to add a professional look to your projects this timing have to be? Well, precision to

26 www.linuxvoice.com
PITIVI SECRETS

03 04

06
05

07
the nanosecond is more than most edits that end up not looking as good
people need, but it’s better to have too as we thought they would. Pitivi has a
much precision than not enough. full undo and redo system so that you
can scroll backwards and forwards

04
Background processing through the changes you made to get
Video processing takes a the project back to the exact state you
lot of processor power. This want it in before you start to make
can mean delays as you wait for things more edits.
to run through. Pitivi does as much as

07
possible in the background, which Render to profiles
means that it enables you to continue There are hundreds of ways
to work on your project while the CPU is to watch a video – just a

08
churning through your data. This few of the most common are: on a
means that the heavy processing television in your living room, (in both
demands don’t slow you down. normal and HDTV flavours), on a phone
on the train on the way to work, on

05
Keyframes YouTube and in a desktop media player.
When linking effects to a All of these have different attributes and
section of video, you need a show differently rendered videos best.
way to place events at a particular point Pitivi can render to different profiles so
in time. Using keyframes you can tag you can output your project so that it’ll
moments in the video and use these to be at its best on different devices.
inform the effect or transition. These

08
keyframes enable you to precisely Scripting
control the way things like fades, The Pitivi project has
movements, pans and cuts happen, developed both the
and this stays the same if you move the front-end user interface and a video
video to another point in the project. editing core called Gstreamer Editing editing power of Pitivi. By building their
Services (GES). This back-end is software in this way, the Pitivi project

06
Full undo/redo independent of the user interface and has vastly reduced the difficulty of
We all make mistakes, and enables technical users to build scripts incorporating non-linear video editing
we also make intentional and software that can access the huge into other projects.

www.linuxvoice.com 27
FEATURE THE BIRTH OF LUMO

THE
BIRTH
OF

Discover games development with the
secret diary of Gareth Noyce, creator of
the superlative isometric platformer, Lumo.

W
e loved the game Lumo Lumo, it’s mostly the product of a
when we reviewed it a single developer: Gareth Noyce. And
couple of issues ago – it’s a following in the footsteps of 80s
tough isometric puzzler with 21st bedroom programmers like Andrew
century graphics and the soul of a Braybrook and Jeff Minter in
game that should take 15 minutes to magazines like Zzap!64, we thought
load off a cassette. What’s even more we’d ask Gareth if he’d consider writing
remarkable is that, like many of the a diary of his development process.
1980s games that helped to inspire And remarkably, he agreed…

Gareth who?
Gareth Noyce started his career with Climax Studios Solent,
first as QA and then as a designer on the Xbox RPG, Sudeki.
He moved to Climax Studios London as a producer before he
partnered with Gary Liddon (yes, Zzap!64) as a co-founder
of Xen Services, and spent several years as a contracted
producer, working on Crackdown, Too Human, PGR3, Fable
2, Space Giraffe and the Xbox 360 visualiser, Neon. In April
2008, Gareth, Gaz Liddon and Billy Thomson (ex DMA Design
& Realtime Worlds) formed Ruffian Games in Dundee, where
Gareth worked as development director.
Over the course of the next five years Ruffian would ship
another five titles for MS: Crackdown 2, Nike+ Kinect Fitness,
Kinect Sesame Street, Season 2, Kinect Star Wars & Kinect
Playfit, and was heavily involved in Crytek’s Ryse during
pre-production, as well as several unannounced and canned
projects.
In April 2013 Gareth moved to Finland and began
teaching game design, Unity3D programming and business
& production courses at TAMK Univeristy. Lumo was born
toward the end of 2013 and is the first project to come out
via Triple Eh? Ltd. In addition he provided a music track for
the Llamasoft Playstation Vita hit TxK, as well as music for an
unannounced PS4 VR game.

28 www.linuxvoice.com
THE BIRTH OF LUMO FEATURE

Lumo’s play mechanic and graphical style was set very early, as
these shots from the first couple of days of development show.

29 April 2013 this is it. I show my girlfriend and make a quick video What is Steam
I arrived in Finland to start up a new dev-studio, to share (https://www.youtube.com/watch?v=uRh_ Greenlight?
the idea being to make mobile games and learn yDp3XF4) with Ste, who both make encouraging Steam is a digital distribution
from the vibrant development community that had noises. Arse Over Tit is born, and I have my project! service for games,
applications and even movies
sprung up around companies such as Rovio and
that you’re probably familiar
Supercell. That didn’t quite go to plan. In fact, I December, 2013 with through its support for
ended up doing something completely different and I’m nearly full-time on Arse Over Tit. The university Linux via SteamOS. Originally
going it alone. Lumo, my first independent game, was where I teach is nearing its winter break and the created as a means for Valve
the result; a modern take on the classic ‘Isometric short consultancy job I’d picked up has finished. The to distribute its own games,
it slowly opened up to third-
Arcade Adventure’ genre (Head Over Heels, Amaurote, design ideas have settled very quickly. I know that
party games after the release
Knightlore etc) that was a mainstay of the 1980s I want to ape the kind of world that Head Over Heels of Rag Doll Kung Fu. Rather
gaming scene. Development took around 2.5 years, presented, so I’ve settled on the location being a big, than act as a gatekeeper,
part-time, and the final result was released in May scary castle, with two or three distinct zones, each Valve sought to open up the
2016. This is, roughly, how it happened. with their own art style and set of toys for the player process of accepting third-
party titles to its community
to discover. I want the player to feel a little protective
of users, and Greenlight
November, 2013 of the character and I want them to feel like they’re was born. In principal the
For the last three months I’ve been working on an lost, so making the player character small, almost process is simple: games in
RTS prototype – think Advance Wars, and you’d childlike, should help both of those feelings. It’ll also the Greenlight process are
be close – aimed at the tablet market. Something subtly magnify the environmental dangers. publicly displayed and anyone
who uses Steam is able to
about it seems like a great fit between game and The prototype was quite bright and I want more
vote ‘Yes’ or ‘No’ to express
form-factor, but it’s becoming increasingly clear that of a ‘Scooby Doo’ feel, so I buy in some textures their interest. In reality, what
I’m not going to be able to finish it and release it as from Gametextures.com and remove all the ambient happens behind the scenes as
a free-to-play game. I’ve not got the money for user lighting, settling instead on wall-based torches that Valve process this information
acquisition (marketing by another name) and I’m light each room while casting long, dark shadows. and allows games to be
distributed is a little murky,
not sure I can support it with enough content after This immediately feels better, so I create a room
often causing controversy
release. It’s depressing and my constant mooching where the player spawns in with a big particle effect as games either avoid the
about is getting on my girlfriend’s nerves: “Why don’t and link it to another room with musical floor tiles process entirely, or languish
you just make something you want to do, and forget that you have to hit in sequence (stolen from the Billy in ‘Greenlight hell’ for years
about the mobile stuff?!” I think she has a point, but Jean music video, natch). Even the act of moving at a time.
I’m still not sure what I can do on my own that I can between rooms makes it feel like a proper game…
finish to a high enough quality. I think I’ll aim for it to be a similar size to Head Over
I’m at a party, a little worse for wear, idly chatting Heels – so roughly 150 rooms. My notepad has a list
to Ste Pickford over Twitter. He’s one of the Pickford of the types of mechanics I’d like to build, so the job
brothers, responsible for many classic games, and of creating rooms begins in earnest.
we’re watching speed-runs of people playing Equinox, But there’s another problem. My girlfriend hates
when it hits me… I’ve always wanted to make a the name Arse Over Tit. I’ve tried explaining that it’s
game like Head Over Heels. It was the first game that just a pun on Head Over Heels, but it’s not washing,
I actually owned, so there’s a nice circularity to it. so I need to come up with something better. It seems
They’re reasonably small and I could probably do the apt to pick a Finnish name given that I’ve just moved
whole thing on my own. Eureka! here, so I fire up Google translator and start putting
When the hangover subsides I get up and start in words: Magic, Spell, Charm, Enchantment… Bang!
work on a quick prototype. It instantly clicks. I think There it is: Lumo.

www.linuxvoice.com 29
FEATURE THE BIRTH OF LUMO

jumping, so there’s plenty of footage. The inner DJ in
Some of the neat gaming elements, me has taken over. I’ve ended up syncing everything
such as blocks merging and floating to the music. Er, don’t do that. If I’m honest, I don’t
away, needed to be carefully slotted into
have a plan on how to promote the Greenlight, I’ll just
the level design so as to not break the
immersive qualities of the game. see what happens.
I push the ‘Go’ button on 12 March and Lumo
stays on the front page of the Steam Greenlight
Community for ~5 days before dropping off, along
with most of my traffic. I’ve posted to every related
Facebook group that I can think of, along with G+,
but, predictably, this isn’t making much of a mark.
I’m a bit worried that I’ll be stuck in the process for a
couple of years as I’ve heard some horror-stories…
And then there’s a bit of luck. Rob Fearon
championed the game in his monthly roundup and
the day after dome.fi – a Finnish game and movie
news site – picks it up. There’s a noticeable spike in
Linux software traffic and I make it to the Top 100.
Because Unity3D’s editor January – March, 2014 I’m there for a week when Valve greenlights a
didn’t support Linux when I’ve been having a bit of fun by sneaking in the new a batch games, so not being included is a
the project started, most of odd reference to old developers. I doubt anyone blow and I have no idea when the next batch will be
Lumo’s development was done
will notice these but they make me chuckle. Some pushed through. I decide to send out some emails
under Windows. But Free
Software – running on Linux crates have “A.C. & G. Ltd” on them, as a nod to to gaming websites in the hope of getting some
– played an important and Ashby Computers & Graphics Ltd which, it was news pieces, but I hear absolutely nothing back. The
crucial part. All of the audio, pointed out to me, became Ultimate Play The Game, traffic to the Greenlight page starts trending down
from the spot effects to music, before later turning into Rare. Carpets and curtains sharply so I begin posting to Reddit and joining the
passed through Audacity.
have borders that mimic the box art of early Ultimate #screenshotsaturday posts on Twitter. I continue
Krita and Blender were
ever-present. ImageMagik games (Knightlore and Mire Mare) and there’s a bit this pattern, every Friday and Saturday, for a month,
was used to bulk-process of graffiti on the wall saying “JR (John Ritman) & but I need a new screenshot of the game each week.
textures. The C# classes BD (Bernie Drummond) Woz Ere” above two little It puts the pressure on being productive!
containing foreign language skulls. Head Over Heels made it into the game! I’ve There’s no obvious end in sight so I try another
strings were generated by a
also taken part in the first, unofficial, Twitter ‘Googly push with the gaming websites, but this time I
Python script, which parsed a
Libre Office Calc spreadsheet. Eye Challenge’ after Rob Fearon suggested that my include a mini CV of the AAA games I’ve made in
The company website and boxes weren’t ‘Rare’ enough. They’re now walking the past and a story about how I’ve left the previous
blog is hosted on Ubuntu. around with eyes that follow the player. Very cute. studio I was a co-founder of. Within an hour I hear
Git was used for source Lighting is still in constant flux, but I’m liking the back from Kotaku, which posts the news to its site
control. Without FOSS Lumo
dark and spooky feel that the castle has, even if I the same day. The day after, Eurogamer picks it up,
simply couldn’t exist, which
is why my other machine is a do keep changing the colour palette. The ambient and then Rock Paper Shotgun. I’m elated and wait
Thinkpad running Linux Mint audio bed I’ve put in – consisting of little creaks and for the inevitable bump in traffic to the Greenlight
Cinnamon edition. groans – seems to be working well and there’s a page. Which never comes. Uh.
distinct vibe forming. It’s coming together.
So, I’m going to need to make the game public
(rather than just my Twitter feed), and the quick way
to do that is probably the Steam Greenlight process.
I’m going to need to distribute via Steam anyway,
but in order for this to happen I need to have some
screenshots and a gameplay trailer. The latter is a
problem. I’ll need at least a minute, preferably two,
of gameplay and it’s going to need to show more
than just running and jumping. It’s time to make an
instance of each of the game mechanics that I’ve
scribbled down in my notepad and see if I can chain
them together into something that looks like a game!

March – May, 2014
The first week of March is spent editing together
the Greenlight video (https://www.youtube.com/
watch?v=7yQL8UP0TL0). I have just over 30 rooms Steam’s Greenlight process is a nerveracking rollercoaster
to choose from, mainly showing running and of statistics and publicity opportunities.

30 www.linuxvoice.com
THE BIRTH OF LUMO FEATURE

The day after the RPS piece I wake up to people
congratulating me over Twitter – for what I have no
idea – until I check my email and see the email from
Valve confirming that I’ve been Greenlit. Phew!
In the end Lumo was in the Greenlight process
for 35 days. More than 30k people hit the page
and there were 9k Yes votes. It’s the first properly
stressful part of the project, but it’s done.

May–August 2014
I’ve told myself that I’m officially in ‘Production’. Each section in the game
That means doing some of the chores I’ve been has different textures and
putting off, like front-end, sound effects and actually a different feeling, like the
settling some of the outstanding design questions. parts of a large castle.
What powers will the player have? Will the game be
centred around puzzles or skill-based? Should there
be spells? How is the mouse best used?
And then I start getting some interesting emails. church zone, full of cobwebs and spiders! I’ve also
One of the console manufacturers is interested in made great progress with the warp zone. Three of
Lumo appearing on its platform. They’d like to see the mini-games are in and I’ve made some crazy
my design docs and have me present my ideas. little challenge rooms where everything is floating
This is a bit of a problem, because – other than around the player. I’m really happy with how this
some notes scribbled on paper – there is no formal part is shaping up (and the fact that there’s a Bubble
design doc. I’ve purposefully not written one. One Bobble reference in there!)
of the things that’s been so joyous about working I’ve also got the Linux version working. There were
alone is the lack of paperwork associated with a lot of shader issues that needed fixing up, so all the
professional game development. For the most part I hard surface reflective shaders were removed and
just wake up and build whatever is in my head. I put the water replaced. But it’s rock solid, and performs
a presentation together to start the conversation and every so slightly faster than the Mac version on the
hope they don’t need too much, too quickly. same hardware. Happy with that.
Up to now I’ve only been considering Lumo for PC,
so assumed a mouse and keyboard control system December 2014
(with the mouse being used to deploy spells, which I’ve changed the lighting, again. I’ve now got two
I’ve yet to think up). Putting it on console would ‘suns’ in the world, one for each of the back walls.
mean supporting joypad. This could work; in fact, These are different tones (one warm, one cold) so
it might actually suit what I’m doing, as the original everything’s starting to pop a little more. I’m also
8-bit games only had one button. What if I stuck to colour-grading the final image. This is a lovely little
the genre and made Lumo a one-button game? trick that takes the colour of the pixel intended for
By the start of August I have a very rough-and- the screen and pushes it through a look-up table.
ready build with a first pass at the game flow. I take The look-up table enables you to
this to Assembly (a demoscene/LAN party held bake-in adjustments – contrast,
yearly in Helsinki) to show it to a few people and it saturation, brightness, tone etc
immediately becomes clear that no one has played – so gives you fine control over
an isometric game in years. Getting through my the final image, without having
rooms is proving to be too much of a challenge. I to do work to the individual
need to seriously simplify the start of the game. Gah! textures. I remake the
Greenlight video (https://
September–November 2014 www.youtube.com/
I’ve entirely re-worked the flow of the game. There’s watch?v=M7vVXTeCepA)
now a section at the start that focuses on controls, at 60fps to show this off.
followed by another 30 minutes gameplay where
I’m slowly introducing most of the mechanics that’ll January–March 2015
be reused throughout the game. I’m not happy I’ve hit a nice rhythm with
with how linear this has turned out, but I don’t have what I’m building now –
many options, as anything else has proven to be ideas are coming thick and
overwhelming to new players. fast – but this is the busy
I’ve also added an entirely new zone. My girlfriend part of the year for teaching.
and I stumbled on a lovely old church in the country I’m only getting a couple of
so I snapped a few photos of its walls and made days work done in between
some textures out of them. I now have my own little the commuting. I still have a

www.linuxvoice.com 31
FEATURE THE BIRTH OF LUMO

to version 5. In some senses this is an improvement.
Many of the game elements and Up to now I’ve had one version of Unity for PC and
minigames pay homage to some of the different versions for every console, each of which
greats, such as the arcade isometric
had its own bugs. With v5 everything should be
classic shooter Zaxxon.
unified in one editor, with plugins to support console.
But there are other changes under the hood. The
code API has changed. Fortunately none of my
code was affected – I tend not to be fancy and was
already doing the things that the API change was
brought in to solve – but the same can’t be said for
code I was using from the Asset Store. I decide to
re-write all of this. I also bin the stuff used to create
the UI in order to use Unity’s new UI tools. This is a
complete re-write of the front-end, in-game and mini-
game UIs. Ugh.
If that wasn’t nasty enough, the lighting model
has changed. I’m reliably informed that the legacy
deferred pass won’t be optimised on console, so
I have to use the new GI/deferred lighting model.
This isn’t a small change. Every single material and
lot of conversations happening in the background shader in the game needs to be re-done. Every room
about how to release the game, which is eating up needs to be re-lit. I no longer have the old fog model.
time. Progress is slow, I’m low on cash and starting Kill me.
to sweat a little.
The book model is done, I can animate pages, and May–August 2015
I can render stuff to each of the pages, but this was This is, by far, the most productive I’ve been on the
far more difficult than I expected. And it’s had some game. The missing mini-games are written, all the
nasty side-effects, the biggest of which is pausing cut scenes are done. I’ve made well over 100 rooms
the game. Up to now I was just freezing time, so during the summer break. The game moves through
everything in the world was locked, but I can’t do the tutorial section, before slowly opening up into
that and have animations and particle effects play the final hub zone, and I think it’s starting to feel
reliably as the book moves through the world, so in- good. The re-factoring for Unity 5 has stabilised and
game objects now have to detect they’re paused. I’ll the three main skus are all running well and in sync.
be chasing little bugs around this forever, I know it. I’ve no major platform-specific bugs.
I’ve got a Vita version working, albeit slowly, which Everything I’ve thought up has worked first time
shows some potential, but I don’t really have time to and I feel like I’m working like a well oiled machine.
optimise it. I drop this for now. More importantly, I’m finally making the stuff I
envisaged at the start of the project.
April 2015 I’ve also signed a publishing deal. This is a much-
Unity – the game engine I’m using – has bounced up needed injection of cash and support, so for once I’m
not stressing about that side of things.

September 2015
The publisher is taking Lumo to the EGX Rezzed
show in London. This will be the first time the game’s
been in other people’s hands since Assembly, a year
ago. I’m nervous as all hell. I also need to make a
specific build for the show and a new promotional
video (www.youtube.com/watch?v=fdK-HlHavM4).
Fortunately the reaction from the show is
amazing. Several people are calling it the game of
the show, which is extremely flattering. Eurogamer
do a video on it and suddenly Lumo’s in the spotlight.
I’m quietly recovering from the palpitations I’ve been
having all month.

October–December, 2015
I’ve agreed to hit content complete by January so
that Just Add Water Developments can begin on the
console ports. I’ve got one section of the game left

32 www.linuxvoice.com
THE BIRTH OF LUMO FEATURE

to do, about 30 rooms, then Steam integration, save
game, map, stuff like that. Seems fine. Of course, it
doesn’t work out like that.
Most of November is knocked out with travel
to the UK for meetings, bits of PR and teaching. I
get all the rooms done, just, but I need to balance
the game and do all the integration stuff I’ve been
putting off. December becomes an almighty crunch
to get everything done. I’m working every waking
minute and starting to stress a little. The situation’s
not helped by constant bugs in the Unity engine.
Animations are breaking, the particle systems are
not firing, or flicking randomly about the world. UI
rendering picks up random garbage occasionally.
Reflections are dropping the frame rate to Even Lumo’s cover design is reminiscent of computer game adverts from the 1980s.
unacceptable levels and I have a crash on Linux that
I can’t debug. I roll back to an earlier Unity version
and things are stable enough to get to content change to the serialisation order of components. I Rendering
complete, but I’ve just had a glimpse of life over the hack around this and I’m back to where I started. As GPUs have evolved, so has
next four months. It’s not been a good upgrade, but things get worse. the way we program them. In
the early days hardware was
The specular lighting value in the rendering engine
‘fixed function’ – geometry
January–March 2016 has changed. Every single specular material, in- and materials were passed
This should just be a bugfixing phase, but it doesn’t game, is broken. I could actually cry at this point. through the pipeline and
work out like that. I find out there’s a problem with I fight through the process of re-doing the lighting processed in a pre-defined
Unity on Xbox One that requires me to pull out all the and checking the materials in every room of the way – but that restriction was
quickly lifted so programmers
audio using Unity’s in-built system and integrate it game. It’s a rush job, because I have artists jumping
were able to write bespoke
into FMOD. There are thousands of audio instances up and down at Just Add Water who need the code (shaders) to define these
spread around the game and after December’s scenes for the console builds. I get things close, and operations themselves. This
antics I’m in full ‘Hulk Smash’ mode. throw the build over the fence. Looking back I didn’t allowed for differing ways
I’m also struggling to find a version of Unity that’s do a great job at this – some of the rooms don’t look to handle light in the world.
In the fixed-function days
stable across Linux, Mac and PC. Each has different anywhere near as good as in previous builds and the
lighting was inflexible, but
bugs and I have crashes on Mac and Linux. In the intro scene ends up being flat and lacking contrast. with the advent of shaders
end I run with three different patch releases of Unity, None of the metals look good. I’m probably the only it was possible to process
one for each platform, and I do hacks on my side to person that’ll notice, but it’s annoying nonetheless. all the geometry before
get over individual platform bugs. Some of it’s filth. I head to San Francisco for a PR trip, tired and calculating the lighting
(deferred), reducing the cost
Because of this I also have to move off Unity 5.2.x worried about how the US press will take the game…
and increasing the number
and go to 5.3.x. Another API change has been made, of lights you could have in a
which affects a fair amount of my code. All the April–June 2016 scene (with some caveats).
particles need fixing, again, and the scene loading is We’re due out on the 24 April but we’re not going to Due to the quest for more
different. This introduces a weird race condition into hit the date. Unity bugs blocked one of the console photo-realism, many game
engines have moved beyond
the start-up of the game that turns out to be a subtle versions right from the start and we’re stuck in cert
rendering how direct light
with another. For everyone’s sanity the date gets affects objects to include
pushed back a month and I’m in limbo. indirect lighting, or ‘light
In the end we hit the 24 May date with four of the bounces’, as well. This is
skus. Xbox one and Vita follow behind. I receive an called ‘global illumination’, but
because of the constraints
email from Eurogamer to let me know that they loved
of having to render a scene
the game, and finally I get a decent night’s sleep. in real time, this is often a
The rest of the month is a blur of interviews, cheat and may only include
podcasts, 4am Twitch streams and fixing some ‘ambient’ light, often taken
small bugs I notice as people are playing. I also start from something like the sky
that surrounds the world.
on the Director’s Commentary series for YouTube.
It’s been a rollercoaster getting to this point, but
I’ve done what I set out to achieve. Lumo’s a niche
game, admittedly, but watching the first speed-run of
the game on YouTube and hearing that people have
already rinsed it for the achievements is a fantastic
feeling. Turns out there were quite a few people –
The subtle lighting in the game caused a real problem like me – who loved those old isometric games.
when a Unity update changed everything as the game I’m hoping someone else picks it up from here and
neared completion. makes some more.

www.linuxvoice.com 33
FEATURE OLD HARDWARE

OLD
HARDWARE

NEW
GNU/LINUX
Andrew Conway never throws anything away –
not when he can install Linux on it!

W
hat's the oldest bit of from overseas. Sadly, it was sick. I and Gmail duties more capably than
hardware you still have in assumed some hardware had finally ever before.
active service? A few failed and I would have to say Us Linux users are loath to
weeks ago, a laptop I'd given to a farewell. But no, it turned out that abandon older hardware because
relative came back to me. But this the old version of Firefox shipped we know that the right distro can
wasn't any old laptop: I'd bought it with the ancient version of Linux breathe life back into it. Here's the
over a decade ago and it was the Mint wasn't able to cope with Gmail. story of a few devices over the last
very first laptop on which I installed I installed a more recent distro on it decade and their journeys from
Linux myself. Call me sentimental, and it was soon back at my Windows through various Linux
but it was like an old friend returning relative's house doing its light web distros.

MEET THE FAMILY My laptop family
and other Linux
Here's the family photo. Apologies EasyNote's granddaughter, Dot U, devices
for it being somewhat dusty but also of the clan Packard Bell, has
they're having to pose down the benefited from a battery transplant
back of the TV because old Auntie some years ago. Although her
Eee PC cannot leave her wired hardware is in good nick, she's a
connection as she's gone a bit deaf little flimsy and developed a nasty
in the old Wi-Fi department and is crack at the laptop hinge. The
busy doing essential server jobs. whippersnapper, young master Dell
The handwritten Mattel label was XPS 13, is fast, elegant and well
affixed by a jealous MacBook user. built. Although he had a troubled
Grandpa EasyNote is the oldest on childhood which involved major
show and despite being 11 years motherboard surgery and some
old is in rude health except for his temporary kernel hackery, he's been
dead battery and a mysterious a sturdy workhorse for three years,
scorch mark near his LEDs. and is helping me write this article.

34 www.linuxvoice.com
OLD HARDWARE FEATURE

PACKARD BELL EASYNOTE
Shipped OS: Windows XP; My OS: Slackware 11,12&14 , Mint 11 ; AMD Sempron
3100+ 800GHz; 45GB HDD; 512MB upgraded to 1.5GB RAM; 3kg; 15.4” screen

In 2005 I spilled a mug of coffee conundrum to my Dad, Packard Bell Easy
over my laptop and it died. I had who reached into a pile Note R0422
urgent work to finish, so I rushed of DVDs and handed
out to the nearest high street store me one that had
and bought the cheapest new Slackware 11 written
laptop I could find: a Packard Bell on it. I took the DVD
EasyNote for £299. It was only home, stuck it in my
meant to tide me over for a few desktop machine
days, and then become the office and, after reading
spare. But to my surprise it had a some instructions,
good screen, sturdy keyboard and managed to get
ran smoothly enough. Under it installed, dual-
Windows XP, I used Outlook for booting alongside
email, NetBeans for Java coding, Windows 2000.
Microsoft Office for documents and Installing Linux on
Internet Explorer for the web. the EasyNote was much
less straightforward.
Enter, Linux! The first issue was that X
Then over lunch one day soon after, windows wouldn't start. After
a friend of mine recommended I some random fumblings, I found X
read The Cathedral and the Bazaar by windows worked if launched by the
Eric S Raymond. I did, and after root user, and some web research
reading further afield I found that told me the problem could be fixed first issue was that Slackware 11's
Linux was still alive and kicking. You with a permissions option in a file 2.4 kernel didn't have a driver for it,
see, I'd used Linux on my desktop called xorg.conf. This was the first but there was an option to switch to
PC from 1995 to 1999 and for of many occasions where I'd find the 2.6 kernel. Doing this provided
scientific data analysis in the a driver, but still no network device.
following years, but by 2004 I'd After much searching I found
ended up in Microsoft-land because After a bit of some source code for an updated
I'd left academia and was working in kernel module released by the
reading around I
a more traditional office manufacturer. When perusing
environment. Despite my history of
decided to switch to the various files that came with
Linux use I was quite ignorant about Linux –Debian – but it, I found some very handy notes
GNU/Linux's free software I got confused by the made by a chap called Alan Flavel.
underpinnings. various Debian ISOs By some great coincidence, Alan
My first step was to replace shared an office with my Dad many
Outlook with Thunderbird and years before at Glasgow University,
Internet Explorer with Firefox. Next but the touching aspect to receiving
up was replacing Microsoft Office myself rummaging around inside his virtual help was that he had died
with OpenOffice (no LibreOffice back xorg.conf's innards: sometimes the year before. Thanks Alan.
then). After a bit of reading around I just to get X to work, other times Once I'd got Linux set up, it was
decided to switch to Linux – Debian to exploit X's flexibility in getting simply a matter of importing emails
– but I got rather confused by the unusual display configurations and bookmarks from Thunderbird
fact there were various different working. These days xorg.conf gets and Firefox on windows over to
Debian ISOs to download. The automatically generated on the fly Linux. Also, as NetBeans runs on
prospect of installing an operating and I've not had to edit it in years. Java, it was easy to get my Java
system was daunting enough for But the battle with the X server development environment up and
me without the added confusion of was minor compared to the beast running. OpenOffice worked fine too,
understanding what the different that was the Wi-Fi driver. The and so I switched to working under
distro editions were for. The matter EasyNote's Ralink RT2500 chipset Linux full time and I've never looked
was settled when I mentioned my was still quite new back then. The back.

www.linuxvoice.com 35
FEATURE OLD HARDWARE

FROM NETBOOK TO SERVER
Shipped OS: Xandros; My OS: Slackware 13, Tiny Core, CentOS 6 ; Intel Atom it suffered from hard drive clicking.
1.6GHz, single core; 160GB HDD; 1GB DDR2 RAM; 1.45kg; 10" screen; £349
This was caused by its head parking
every eight seconds or so, and as
The main problem with the year-old son from school. A the design lifetime is typically for
EasyNote was its weight. At over message to developers: software 300,000 parks, this means that if
3kg it became a literal pain in the bugs can lead to tears! run 24/7, it would reach its design
upper arse (lower back) especially limit in a month or so. The solution
as I found myself travelling a lot Time to upgrade is to issue this command:
more for work. For this reason, and The Eee PC solution served me well hdparm -B 255 /dev/sda
because I now understood how to for some time but eventually the This tells the first hard drive (sda)
get the most out of fairly modest Intel Atom single-core processor to run without any power saving
hardware with Linux, I bought a and 1GB of RAM proved too limited optimisations and you can ensure
netbook: the ASUS Eee PC 1000H. for certain tasks (in particular it runs on every boot by placing it in
When on my desk it had a separate virtualisation). I replaced the Eee the file /etc/rc.local.
keyboard, mouse and an external PC with the Packard Bell Dot U for Encouraged by this success
monitor. It got a lot of use on the daily use and turned the Eee PC into I installed tt-rss (tiny tiny RSS)
Glasgow to London train and with a server. which manages my RSS feeds,
battery upgrade it was easily and OwnCloud, which I use mainly
capable of lasting a five-hour to manage files. OwnCloud worked
journey, but working on a 10-inch The EeePC draws well at first but in time problems
screen presented problems even emerged with the desktop sync
with KDE in netbook mode.
about 12W, which is client. It'd report the server giving
I experimented with a tiling not much above a mysterious 500 HTTP errors and
window manager – dwm with Raspberry Pi with a conflicts were flagged for files
dmenu – as having each window separately powered which definitely were not conflicted,
using the whole screen made a lot USB hard drive ie the local and server files were
of sense. Alas, although dwm was identical. This was annoying but
stunningly fast and worked well for seemed to be harmless and after
most things, NetBeans refused to checking carefully a few times I
work on it, so I went back to KDE. I installed a minimal CentOS 6 got into the habit of deleting the
KDE 4 was still a little buggy at that on the Eee PC, diverted incoming pointless conflict files.
time and it let me down badly one traffic through my home router to it But this was a bad idea. It finally
day when the KDE taskbar crashed on port 80 and some others (I don't came to a head when I lost a chunk
and froze the clock, which made use 22 for SSH, nor 443 for HTTPS) of a book I was writing because the
me late for picking up my six- and got Apache running. Next, OwnCloud sync client replaced a
with the help of some Dynamic IP freshly edited text file with one from
services (dyn.com and later noip. the week before. What's worse is
com) I set up the DNS for various that I'd deleted the conflict file with
domains that I owned so that the rm command and the OwnCloud
their websites could run on directory only got included in my
the Eee PC. weekly, not daily backups. A week's
The EeePC draws work gone. The problem turned out
about 12W, which is to be that I'd set SQLite as the back-
not much above a end database rather than MySQL.
Raspberry Pi server The OwnCloud team recommend
with a separately you don't use SQLite on a production
powered external server and I'd just found out why. It's
USB hard drive probably OK for a small set of files,
attached. The but mine had grown to thousands
160GB internal drive of files and GB of data over the
is fine for its server years. Fortunately the OwnCloud occ
duties, but I noticed tool made short work of the SQLite
to MySQL conversion, thus solving
Asus EeePC 1000H. the problem.

36 www.linuxvoice.com
OLD HARDWARE FEATURE

THE YOUNGSTERS
PACKARD BELL DOT U Shipped OS: Windows 7; My OS: Slackware 13;
Intel US5400 1.2GHz, dual core; 250GB HDD; 3GB DDR3 RAM; 11.9"
screen; 1.3kg; £450
DELL XPS 13 DEVELOPER EDITION Shipped OS: Ubuntu 12.04LTS;
My OS: Slackware 14.1; Intel i7, 2GHz, dual core, 4 threads; 256GB
SSD; 8GB DDR3L RAM; 13.3" screen; 1.36kg; £1,100

The Eee PC's replacement, the screen and lesser
Packard Bell Dot U, didn't feel that weight made it more
much faster, but the slightly larger convenient for use on the
move. The extra 2GB of Packard Bell Dot U.
RAM over the netbook was
also welcome, especially for
running virtual machines, but to
my dismay the Intel U5400 CPU
lacked virtualisation extensions.
This made a big difference in
some cases; for example,
Qemu fell back on emulation My current laptop is the Dell XPS
and so ran like a slug on a 13 Developer Edition, which came
marijuana plant, but pre-installed with Ubuntu 12.04LTS
thankfully VirtualBox but currently runs Slackware 14.1,
performance wasn't too bad and will soon go to 14.2. I can safely
(for reasons I never quite say that after three years of daily
understood!). Although I didn't use – once a few teething problems
choose this laptop for its Linux were resolved (see my articles on
Dell XPS 13 developer compatibility, it was so easy to Slackware in LV006 and Kernel
edition (2013). install Slackware that it was Parameters in LV009) – the XPS 13
almost boring. Everything worked is the best laptop I've ever owned.
out the box. It's also the most expensive!

EMORTALITY
What will bring these devices to the updates will end in November 2020. service as a server, following an
end of their lives? A failed hard drive Well before that time, the third- SSD drive transplant, or else use a
is probably most likely, but this is party repositories such as EPEL Raspberry Pi 3 running Raspbian
not terminal, as hard drives are might not provide recent enough with an external USB SSD drive. My
reasonably easy to replace, even in versions of PHP for OwnCloud and preference though is to keep my
laptops. In fact, I'm expecting this other key software. There will be no old hardware in use for as along
for my Eee PC, and my plan is to upgrading the Eee PC to CentOS 7, as possible with the proviso that it
replace its aging spinning hard drive because it is only available for 64-bit is not too power-hungry relative to
with a fast SSD one. The bigger architectures and the Eee PC's Intel more modern technology. I'd like
worry is failure of bearings inside Atom is 32-bit. to say it's because I'm conscious
the fan – if it stops spinning then that we live on a planet with limited
the overheated CPU may well suffer This mortal coil resources, which is true, but if
terminal damage. No server lasts forever of course, I'm honest it's also because I've a
But there's another issue. CentOS so at some point in the next two certain, sentimental attachment to
6 will stop getting full updates years I expect I will either press my aging devices especially if Linux
by June 2017, and maintenance my 64-bit Packard Bell Dot U into can make them useful.

www.linuxvoice.com 37
FAQ OSVR

OSVR
MICHEL LOUBET JAMBERT
The new standard in Virtual Reality could be open source.

So what does OSVR stand for
controllers. However, there are a few
caveats, the most striking of which is
that it isn’t available on Linux yet,
will be a number of hardware
manufacturers, the theory goes that
“market logic” will determine which
and who’s behind it? despite it having being designed to standard drives that hardware. History
Really? Open Source Virtual complement the Linux-powered Steam shows though that, it’s not always the
Reality… Seemed kind of obvious, Machines also developed by Valve. best one that wins, nor is it logic that
though I guess it could have been Support is expected to arrive at some determines the winner in many cases.
Operating System Virtual Reality, but point, but who knows when. The name Some advances are being made on
that doesn’t make much sense. As for is also somewhat misinterpretable the fragmentation side of things
who’s behind it, it’s an open project with since, though the source code is though, and Valve has already
a bunch of industry backers, ranging available to look at, gratis, modifiable announced that it will be collaborating
from big-name video game industry and redistributable, it is more restrictive with OSVR. This could mean any
companies to lesser known in the sense that it must retain the number of things so there’s not much
manufacturers, as well as a few Valve copyright. point in being too speculative, but it
academic institutions interested in the does show that Valve isn’t intent on
educational and technological aspects Fair enough, but with Oculus putting up a fight and possibly willing to
of VR over its gaming uses. If you’re Rift, OpenVR and a few others, let the best standard win. However, if I
familiar with game developers, then isn’t VR already fragmented enough had to put money on it, I would say that
some well known names are Ubisoft, considering it hasn’t really reached some sort of open (or semi-open)
Techland and Gearbox, the latter two of the mass market in any significant standard will come out on top,
which have games out on Linux already. way yet? considering that on the development
That’s a good point, but then this and OEM side of things, people will
That’s great, but isn’t OpenVR often happens when a new want to look at the source code and
already a thing? technology comes out and a standard make changes to suit their software or
True. OpenVR is the VR gets established. Remember VHS vs hardware, based on how successful
ecosystem developed by Valve Betamax or Blu-ray vs HD DVD? This is Android has been in the mobile space.
and HTC for their Vive VR headset and kind of the same thing, and while there
So what sets this technology
apart from the rest?
It’s an open project with a bunch of backers, Well, as I alluded to before, there’s
the Linux support and the whole
ranging from big-name video game industry free software licensing thing – more
specifically, OSVR uses the Apache
companies to lesser known manufacturers Licence. There’s also the hardware, with

38 www.linuxvoice.com
OSVR FAQ

each manufacturer having developed
their own standard to go with it, but
OSVR leaving the door open for anyone
to grab it and sell their own hardware.
Like Valve’s policy of sending advances
of prospective sales to developers,
OSVR also has its own financial
incentive in the form of a $5 million
fund which developers can apply for if
choosing the VR ecosystem, which
could be more attractive since it isn’t
necessarily based on sales.

What’s the hardware like for
OSVR then? The Razer HDK2 uses the
The current offering is a lot OSVR standard .
(photo: OSVR).
cheaper than the Oculus Rift and
the HTC Vive, that’s for sure. The
second generation HDK2 (Hacker to get you started as well as guides on With OSVR, there’s potential for console
Development Kit 2) from Razer sells for how to use OSVR on some different manufacturers to use the standard with
around $399, compared to $499 for the game engines. Speaking of which, it their own headsets rather than
Rift and $799 for the Vive, so it’s would also be a good idea to get developing their own from scratch,
certainly the more accessible option. yourself a game engine installed to which is a lot more likely than some
Most reviews do claim it to be not quite develop on. Currently supported sort of partnership with the other big
up to standards with the other two in engines include the Unreal Engine, companies behind the other standards,
terms of visuals, but then VR as a Unity, CryEngine and Blender, so there’s many of which are competitors. This
whole is far from perfect right now, so already a good mix of gratis and libre logic also applies to other uses for VR,
that should be taken with a grain of salt. Linux-supported engines with which to such as research or more adventurous
In specific terms, the HDK2 has a build games and other things, and even companies looking to create new forms
2160x1200 OLED display refreshing at create commercial-grade games of entertainment. Likewise, the
90hz, an IR camera for position tracking considering these are among the most cross-platform nature of an open
and decent user adjustment options. widely-used out there. If you’re new to standard such as this one is a huge
On the controller side of things, the game development, something like advantage in gaming specifically, since
HDK2 doesn’t have its own, unlike the Unity would be a good bet, since it’s developers want to sell as many copies
Vive. However, it has the advantage of user-friendly and there are plenty of of a game as possible and being locked
supporting a multitude of different tutorials and free assets available out of certain platforms, or having to
devices, ranging from XBox controllers online, though Blender Game Engine is incur extra costs of porting to them, is a
to WiiMotes and competing devices, a great option if you want to stick with huge drawback.
showing off some of the advantages of FOSS only. Then again, with that logic, DirectX
an open model and leaving things open shouldn’t really be as pervasive as it is,
for OEMs to create their own How do you see the chances of which goes back to these things not
peripherals. All things considered, it success for OSVR as a virtual always being defined by logic. One
might well be the most appealing reality standard? thing that is certain though is that it will
device out there in terms of cost- It’s too early to say with certainty. come down to a mix of adoption by
performance ratio, and the only device The cooperation with Valve is a both consumers and developers, since
usable with Linux. However, given the good start since, although VR could people will want the platform with the
small amount of VR titles available as a have many potential applications, most games and developers will want
whole and even less using OSVR, none gaming is likely to be the area in which the platform with the biggest user base.
of these devices are that appealing right the teething stages of the technology Success is also largely tied to the
now to those who aren’t either gaming are carried out, considering there’s a success of VR as a whole, since if it
enthusiasts, tinkerers or developers market for it already, and having the turns out to be niche, there’s only a
looking to take their first steps into VR. standard supported by the biggest small pie for the OSVR standard to take
vendor of PC games in one way or a slice of.
So where do I sign up to get another is a very good start. On the flipside, if the VR market turns
developing with this thing? Being an open standard also has a lot out to be larger, then an open project
A good start would be to order a of benefits, not just from an ideological which doesn’t require vast amounts of
set first – it’s called the Hacker point of view, but more that it keeps money being pumped into it has its
Development Kit for a reason. You doors open for third parties to make clear advantages. Check back in a year
should also head over to osvr.github.io their own hardware and adapt it to their or two for more clarity, but OSVR has a
for some resources and documentation needs, as we’ve seen with other cases. fighting chance in the meantime.

www.linuxvoice.com 39
INTERVIEW MARTIN WIMPRESS

“
Maintaining lots of Arch
Linux machines from afar
meant that my Christmases
and Easters and family
holidays were basically me
doing tech support for
everybody in the family

MARTIN
WIMPRESS The man who’s everyone’s Mate

A
s well as being one quarter of Ubuntu Mate. It may be new, but it’s already on the Raspberry Pi, thanks in large part to
the Ubuntu UK podcast, Martin made a name for itself as a blend of new the massive efforts that Martin puts into it.
Wimpress is also responsible for technologies with a classic interface. It’s We caught up with Martin to find out what
the youngest official Ubuntu flavour – also the first of the desktop Ubuntus to run to expect in coming versions of the distro.

Can you tell us a little bit about how she got her first Android phone, and she did that time). This got back what she was
Ubuntu Mate got started? everything on the phone. A couple of years familiar with (because she’d been using
Martin Wimpress: Well, the genesis of the go by and she really hasn’t used her laptop Ubuntu since 6.06) and wedded bliss was
project is really that I got involved in Mate at all, then one evening she decides that it’s restored. She could organise the photos
itself. Very briefly, I was using Ubuntu but the time to sort out baby photos and tries to again because it was all as she expected.
wasn’t happy with the way Unity was going use Gnome 3 – stern words were As I put Mate on, I noticed that there were
in the very early days, so I switched over to exchanged as she wasn’t familiar with this some bugs and rough edges, specifically
Arch. I was using Gnome 3 and I switched new fangled thing. Very hastily, I removed around the packaging for Arch. I was
my wife’s laptop over to Arch, also using Gnome 3 from her Arch laptop and put Mate thinking, “My wife’s happy with this, I need to
Gnome 3 – this is about the same time that on (I wasn’t involved in the project at all at fix these things so I don’t have the next

40 www.linuxvoice.com
MARTIN WIMPRESS INTERVIEW

www.linuxvoice.com 41
INTERVIEW MARTIN WIMPRESS

Like us, Martin’s a podcaster – tune in to
ubuntupodcast.org to hear his measured,
calming tones.

problem and the next problem…” I environment. The genesis of the project in this thing. That’s when I stepped
started contributing fixes to Mate and was Popey making that initial draft. thought that if there’s potential for it to
working on packaging it for Arch. That’s Popey and I then took a day off work be popular, I’m going to go all in – I’d
how I got involved with Arch. Roll on a – we went over to Popey’s house and only got my pride to lose.
couple of years, and most of the family we did a one-day sprint on how this I started to make alpha and beta
(who I had moved over to Ubuntu in the was going to work. We basically fleshed images and the download numbers
6.06 era) are now running Arch with out the goals of the project and set the were constantly growing. There was
Mate on their laptops. That wasn’t wheels in motion on that day. The
working particularly well for them
because Arch Linux is an attention
purpose was to recreate that
experience that my family were familiar
The core team that
whore and maintaining lots of Arch with, because they’re not technical contribute regularly is
Linux machines from afar meant that – they don’t want to re-learn how to use
my Christmases and Easters and their computers, they just want to pick about 7 or 8 people
family holidays and get-togethers were it up and do what they want to do, put it
basically me doing tech support for down and forget about it – they’re not definitely a groundswell of popular
everybody in the family. They weren’t interested in learning anything new. So, opinion, and it’s just grown from that.
happy with that and it wasn’t going that was the origin – making what they
particularly well for me. had before a thing again. It sort of How big’s the team of Ubuntu
Then I did an interview about Mate snowballed from there. Mate?
on the Ubuntu Podcast long before I MW: Well, the core team that
was involved in the Ubuntu Podcast. In When you say that it sort of contribute regularly is about seven or
this interview I pointed out that Mate snowballed, was there a lot of eight people. The lion’s share of the
was completely bust in Ubuntu. Popey pressure from users to keep packaging work is actually done in
[Alan Pope, podcaster and all-round developing it? Debian, so what makes Ubuntu Mate,
nice guy] was just outraged that this MW: When I started on it, I thought “I nine tenths of that actually happened in
was the case – this was off the air. A need people to test it so I don’t give Debian directly and it just syncs into
couple of weeks later he sent me a link something to my family that’s Ubuntu because that’s the relationship
to an ISO image that he’d made that completely broken. If I give it to people we have. I do most of my work in
was Ubuntu 14.04 with the Mate then I’ll get some feedback about it.” I Debian – the only work that happens in
desktop stuck on top. It was very rough, did that just on Google+ initially and it Ubuntu is branding, artwork, and
but I thought, hmm OK, this could solve spread like wildfire. Word got around Ubuntu Mate Welcome, which is our
the problem – it’s a way that I could and within a few weeks I was very centrepiece.
give my family back that familiar aware that there was a substantial Within the Debian team, there are
Ubuntu platform with that familiar number of people who were interested three people (myself and two others),

42 www.linuxvoice.com
MARTIN WIMPRESS INTERVIEW

then a lot of the work is driven through
the Mate desktop team itself – there’s a
core team of about five contributors.
Ubuntu Mate has several
crowdfunding platforms and we try to
push as much of that money as
possible back into development
projects for Mate desktop or Ubuntu.
We draw in money on a monthly basis
and I pay all the hosting and then I work
with the developers and look at the
projects that we’re interested in
developing, and then pay them to work
on specific tasks in a given month. We
pay as close as we can to the market
rate for development time for them to
work on things.
The Mate desktop team has about
five or six people, then we have a pool
of people specifically on Ubuntu Mate
itself. They are not involved in Mate
upstream, they’re not involved in
Debian, they’re working specifically on
Ubuntu Mate projects. That’s two
people in addition to myself. There’s a
cast of thousands that do artwork and
they look after the forums, and just a
Hands up who else does pro bono
ton of stuff that I can’t do. I can’t do
tech support for their family when
anything artistic or creative at all, so I they’d rather be chilling out?
lean on the community for all that stuff.

You mentioned that you small in Mate. Mostly it’s to do with modern Linux operating system, but in
created Ubuntu Mate because bugfixes and tweaks and very small terms of what the user sees and gets, it
you wanted a distro that your family additions, not a wholesale overhaul. hasn’t changes. We’ve removed a
could use because it was familiar The UI is buttoned down, it’s defined, it’s couple of minor things and we’ve added
and unchanging. Is this still how you as it was documented by the Gnome a couple of bits and pieces, but over all,
see the future of Ubuntu Mate? team all those years ago – we’re not it’s just as it used to be, and that’s how
MW: Technologies underneath Ubuntu changing that. What I do in Ubuntu it continues to go.
Mate are changing rapidly and we’re Mate is try and build some tools around
moving with those changes. Ubuntu that to make it a bit more modern and I believe that Ubuntu Mate was
Mate 16.10 is built entirely against GTK make some conveniences that a the first desktop version of
3. That’s an ambition that we’ve been modern desktop should have, but that’s Ubuntu to work on the Raspberry Pi.
pursuing for a few years now, and we’re not changing the fundamental base. MW: Yes, it was.
the first distro to say, “right, we’re going
to jump”. We’ve just had 16.04 – a nice Is this an ongoing commitment Was that something at you
stable LTS [Long Term Support] – now’s to not change the way Mate pushed?
the time to break all the toys and start works – how it is now is how it will MW: Way way back, I made a tool to
again, which is what we’ve done. be in 10 years time? build an Arch Linux installation that
We’ve invested about €3,000 since MW: Yes. How it is now is how it will works on the Raspberry Pi – this is the
16.04 in development projects to drag always be. It’s a very unglamorous original Pi with 512MB of RAM. I never
the GTK 3 support up to snuff. We’ve project to be involved in because if your quite finished that project and I always
got one outstanding issue at the user interface is your shop window, wanted to make a desktop for the
moment that we’ve got somebody that’s unchanging. What’s changing is Raspberry Pi. When the Pi 2 came out,
committed to do the work and the keeping up with the underlying Popey said, “you should totally make a
money set aside for. But the move to technology, so along the way we’ve version that runs on the Raspberry Pi”,
GTK 3 is not a change in the user adopted support for thing for things like and I thought, I’ll do that when I find the
interface or the user experience, it’s just GSettings and tossed out GConf, and time. Someone in the community,
using GTK 3 to recreate that user we’ve adopted support for systemd you Rohith Madhavan, made the initial port
interface that everyone’s familiar with. know – these are all things that you and it was eight tenths of the way there.
The changes, the new features, are very need to do to make a desktop work in a Because so much of the work had been

www.linuxvoice.com 43
INTERVIEW MARTIN WIMPRESS

done, I decided to pick it up and run all of the Python stack and all of the a H5 device [a low-level
with it, and from that point onwards I’ve GPIO and all of the SPI and I2C and communications protocol] but at that
maintained the Raspberry Pi build. Scratch and MineCraft Pi Edition – all time they couldn’t get the H5 mode to
We had a hinkey version for 14.10, of the things that people expect to be work and they butchered it to work in
but the first proper version was 15.04, on the Pi are on the Ubuntu Mate Pi H4 mode with no flow control at all –
and I’ve really focused on that – it’s our version. that then requires that you patch Bluez
most popular version now [about half of The PowerPC port was the same. I quite heavily. It’s an incompatible patch
all Ubuntu Mate downloads are for the didn’t create that. Someone in the set so by building it for the Pi 3 you
Raspberry Pi]. Most people who are community did the legwork and then I effectively break Bluetooth for every
running Ubuntu Mate are running it on was simply able to adopt their work into other device out there as it’s very
a Pi 2 or a Pi 3. We’ve also made root the official build system. All the hardware specific. I now know more
filesystem available for ARMv7 so you’ll architecture ports have come from the about Bluetooth than I’ll ever need to!
find it when you ask for ODroid Ubuntu, community and I’ve adopted them and
it actually comes with a sort of Ubuntu made them official. What can we expect in the
Mate now, and the same on the Banana future of Ubuntu Mate?
Pi, Pine 64 and so and so on. Were the and major technical MW: I’ve been interested in snaps
It’s kind of become this ubiquitous challenges in getting Ubuntu [Canonical’s container-based packaging
Ubuntu thingy that you can run on all of Mate to run on the Raspberry Pi? format] since I first heard about them.
the ARM devices. As a spin-off from MW: Yes – Bluetooth was a complete I’ve been poking people at Canonical
that, I’ve become involved with the pig to get working. I had access to a saying “is now the time to do more with
Raspberry Pi Foundation and I was an guy called Phil Elwell at the Raspberry this?” and for a while it was, “No, this is
insider for the Pi 3. I got a prototype, Pi Foundation over the course of those very fast moving, very experimental,
and I was able to do some work so that four days leading up to the launch and just learn about the concepts, don’t
on launch day for the Pi 3 we had a he was providing me with kernel actually do anything with it”, but around
version of Ubuntu Mate that supported patches, firmware blobs and what- the end of last year, the very beginnings
all of the hardware features that the Pi 3 have-you. The Wi-Fi enablement came of this year, I started poking Will Cook,
had to offer. That’s kind of a pet project up within minutes – I was really the desktop manager at Canonical, and
of mine and one that I’m keen to pleased with that – but getting saying “I’m really interested in doing
continue ticking over. So Ubuntu Mate Bluetooth to work was a protracted more with snaps, what is it you’re
on the Pi is a little different [to the PC experience. There are some planning?” I got involved in the Snappy
version]. It’s the same base but it’s got complications… Bluetooth in the Pi 3 is play pens quite early on – making

“Comparing KDE Plasma, Gnome 3 and Unity
[on the Raspberry Pi], Unity works the best.”
Shocking!

44 www.linuxvoice.com
MARTIN WIMPRESS INTERVIEW

snaps for desktop applications – and
then I’ve been on the Snappy sprint.
Now I’ve got a good understanding of
what that road ahead looks like.
Probably not for 16.10, because
there’s a lot of work to do for that
anyway, but for 17.04 onwards, I would
like to see snaps playing a significant
role in Ubuntu Mate’s future. Our tag
line is “for a retrospective future”: the
retrospective bit is about the classic
desktop environment, but the future is
that there are new technologies and we
have to move with these. We can keep
our traditional paradigm but we have to
move with the new technological
movement – we can’t just be
languishing.
“As a spin off of making Ubuntu Mate for the Raspberry
What we have now is a classic
Pi, I made a build system that can build all of the
Ubuntu system that can install and run Ubuntu flavours for the Raspberry Pi. There’s a website
snaps, but alongside that, I’d like to called ubuntu-pi-flavour-maker.org where you can
work towards having a fully snapped download images for the Ubuntu flavours.”
desktop environment. If we can offer
both, you can choose a classic install or
a snapped install. Where the snap criticisms that snaps are larger than different versions of the same runtime.
installs really come into their own is on they need be because they all carry the Sometimes there’s a version of an
things like the Raspberry Pi where you same stuff over and over again), you application that’s specific to a version
can chain what are called gadget snaps can now say that they need this of Mate and as we lockstep move the
and deliver your kernel, your base platform snap and you don’t have to desktop along, that application that
operating system and your application carry all that common baggage in each hasn’t been updated doesn’t work any
stack all as snaps and have atomic of your snaps. more and it would be nice to still have
updates across the whole thing, those things work – snaps enable us to
particularly on ARM devices where What are the big advantages to that.
you’re targeting a very precise hardware that you get from snaps?
architecture and configuration options. MW: The main one for me is that as It sounds like there are some
Mate upstream, we’re already making quite big releases coming up
In this setup, would the Mate tarballs with build systems in them, so for you with GTK 3 and then snaps.
desktop fit in its own snap? we’re delivering packages, so of course MW: Yeah. we’ve done the big work
MW: Yeah, so this was something we every distribution under the sun then with GTK 3 and the snaps will keep us
has to repackage that. We all sit there, busy for a little while. Western Digital
I’d like to work towards we make these tarballs and test these
tarballs and within the team we’ve got
are talking to us about making an
Ubuntu Mate device a bit like they have
having a fully snapped people from Fedora, Gentoo, Slackware, with OwnCloud (and they’re also talking
Arch, Debian, Ubuntu, Linux Mint and to NextCloud), but that presents some
desktop environment some of the more esoteric things like difficulties with VLC (which we ship by
Vector. We all go off and package this default) as they need to know what
started on at the sprint. A new concept stuff again for all of these different their exposure is with the codecs and
that’s been introduced into snap distributions and it would be good if we licensing that they need to cover from
packaging is platforms – in the as the upstream we could say ‘here is that point of view. VLC is snapped so we
vernacular of Flatpak they talk about Mate desktop’ – whatever version – could stodge that and put the VLC snap
runtimes. Robert Ancell (who’s part of and we’re able to just deliver it lock, in the software boutique and then they
the desktop team at Canonical) has stock and barrel and everybody gets it. don’t have to distribute anything that
started on a GTK 3.20 platform snap We can deliver the upstream vision and does incur any licensing difficulties for
and there’s a new content interface in everyone can have it and we can spend them.
snaps that enable you to do content more time working on the future rather On single-board computers in
sharing, which basically says “in order than us all reimplementing the same general, Snaps are are going to be very
for this application to run, it requires packaging all over again. That’s one key strong indeed, particularly when you
this platform snap.” Instead of having to thing I really want to see solved. look at what OpenWRT has done
duplicate all the common dependencies The other thing is the update and supporting both paradigms– that’s
within every snap (this is one of the rollback, and being able to have multiple where snaps are really going to win.

www.linuxvoice.com 45
MUGS AND T-SHIRTS!

You can drink
coffee, tea or
champagne.
It’s all about
choice.

This mug
respects your
freedom. Look,
it even says
GNU/Linux!

shop.linuxvoice.com
INTRO REVIEWS

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

On test this issue . . .
Aftershot Pro 48
What a time to ba alive for photography
geeks on Linux. This excellent
RAW image editor
is non-free (boo!)
but is chock-full of
incredibly useful
filters and other
effects. Hurrah!

Andrew Gregory
Has added a new machine to the PC graveyard:
his main Linux box. Time for a new one.

H
aving just got into the magical
world of JavaScript
programming, I’ve come
across the Atom text editor. I know I’m
late to the party (especially so given
that we reviewed Atom on these very
pages in issue 18). Its killer feature is LibreOffice 5.2 49 Stellarium 0.15 50
that it’s infinitely customisable via CSS. Now featuring extra collaboration features paid for Many through the ages have gazed at the stars with
And, true to form, I haven’t by the Dutch Ministry of Defence. Dank u wel! wonder. Now you can do so on your laptop!
customised it one bit. The flexibility
built-in means that it has already
passed in front of many more
aesthetically attuned eyes than mine,
so it’s better that I could ever make it. In
Group test and books
contrast, interfaces that can’t be
modified (Windows 10) or that
theoretically can be modified but
practically are just too damn confusing
(KDE) will always look bad. I don’t need
to do anything to make Atom better; it
matters that I am empowered to do so.
Extend this logic to web browsers,
image editors, emissions cheat devices
in Volkswagen cars et al and you reach
the point of why Free Software is
important. I’m never going to learn to
write a desktop interface so that I can Books 54 Group test – Social Networks 56
make it more intuitive – but I appreciate Learn to write software that’ll take control of Twitter is a cesspool of idiot-fuelled hatred. Create
that, in theory at least, I could do. someone’s machine at the OS level, and fix your text your own, better social network with one of these
andrew@linuxvoice.com processing skills in the web-tastic Ruby language. Free Software systems, for a happier life.

www.linuxvoice.com 47
REVIEWS PHOTOGRAPHIC EDITOR

AfterShotPro 3
Graham Morrison avoids years of photography theory by using software.

A
Web www.aftershotpro.com fterShot Pro is a product with its sights on however, these sliders are also intelligently adjusting
Price £69.99 Adobe’s equivalent Lightroom, which is now shadow and mid-tone exposure, cleverly balancing the
close to being an industry standard at processing within the image to keep everything
enabling photographers to manipulate the RAW looking as natural as possible. We’ve found it works
image data output from their digital cameras. Both much better than the equivalent tools in the open
these applications let you make poorly taken source options, and is a genuine rival to similar
photographs, such as those taken in bad light, with facilities in Lightroom. The new blemish removal tool
the wrong white balance, and with huge areas of also works well, and stops you switching applications,
contrast, look awesome, and good photographs look which is almost impossible if you want to keep
spectacular. What AfterShot Pro does better than the working within the RAW domain until the final export.
open source tools we’ve tried is use intelligent This version also promised to be a lot quicker. We
algorithms to make these adjustments easy. needed to install the OpenCL drivers for our graphics
The combination of ‘Back Fill’ with AfterShot Pro’s hardware, but after this, image rendering was snappy
new highlight recovery tools is the perfect example – much quicker than the previous version, and we
because they can solve all kinds of common can imagine better hardware with better OpenCL
problems with just three sliders, from under-exposure acceleration would be very quick indeed. On the
to lack of detail. Unlike adjusting brightness in Gimp, down-side, we didn’t find any options to force the GUI
to adapt to our high-DPI display, which is a promised
feature for other operating systems. If you’re a
professional photographer, it’s likely you need support
and a solid application for managing your library of
photos and processing them for clients. You may even
be tempted to move to Linux after Adobe recently
denied standalone Lightroom users access to updated
features because of ‘SOX and accounting practices’.
For these reasons Aftershot Pro is worth paying for.
The new Blemish tool
A powerful, if non-Free, professional photo
means you don’t need to manipulator.
do any final touch-ups with
Gimp.

48 www.linuxvoice.com
OFFICE SUITE REVIEWS

LibreOffice 5.2
Graham Morrison investigates the new release of the premier FOSS office suite.

L
ike clockwork, LibreOffice 5.2 arrived in early Web www.libreoffice.org
Price Free
August. Whereas the 4.x series of the suite Licence MPL v2.0
focused on cleaning up the code and other
“under the hood” improvements, in 5.x the developers
have paid more attention to the interface, tweaking
menus and toolbars for a smoother user experience.
So what’s to shout about in LibreOffice 5.2? For
In Calc, the status bar can
enterprises, there’s a new document classification now show multiple
system based on standards from TSCP, the functions – useful for
Transglobal Secure Collaboration Program. This lets getting a quick overview of
you mark a document as internal or classified, with an data.
appropriate warning and watermark. It’s worth noting
that development on this feature was supported by added, and a new crash reporter tool (for Windows)
the Dutch Ministry of Defence – LibreOffice is really should help to narrow down bugs. Then there are the
making inroads in government departments. usual updates to file-format compatibility – docs from
other suites should render better in this release.
More than just .txt LibreOffice remains the flagship FOSS office suite,
There’s also support for multiple document signature but it really could do with an online “cloud” version.
descriptions, along with import and export of Progress is being made on this front thanks to
signatures from OOXML files (as used in Microsoft Collabora, and it’s possible to use a limited version of
Office). In terms of user-facing changes, Writer and LibreOffice inside Own/NextCloud, but it’s early days.
Calc now have single toolbar modes, while Calc has Hopefully for the next release of LibreOffice in February
new forecasting functions and the option to enable 2017, it’ll be quick and simple to install on a server and
multiple statistic views in the status bar. Some dialogs access anywhere in a browser.
have been redesigned to be easier to use, and extra
buttons have been added to toolbars (eg a currency Not a world-changing release, but taking a step
drop-down selector in Calc) as well. in the right direction with lots of small
refinements.
Behind the scenes, performance in OpenGL and
OpenCL has been improved, unit tests have been

www.linuxvoice.com 49
REVIEWS ASTRONOMY APP

Stellarium 0.15
Ben Everard lies in the gutter, gazes up at the sky and wonders what he sees.

G
Website www.stellarium.org aze upon the night sky and you’ll see Even in the space age, the importance of the stars
Developer Fabien Chéreau and thousands of specks of light. If you’re lucky cannot be forgotten, as they shine on long after the
contributors enough to have dark skies, and bored enough batteries in an electronic navigation system run flat.
Licence GPL
to spend the night counting, you should be able to see When lightning struck the Apollo 12 spacecraft as it
around 5,000 stars at a time. These stars, with a few launched from Kennedy Space Centre and knocked
The options windows minor alterations, have been the backdrop of history. out the power to the command module, it was the
appear in a dark theme so They’re the same stars that guided Christopher position of the stars that guided the crew safely into
they don’t ruin your night Columbus across the Atlantic, Ernest Shackleton orbit and on to the moon.
vision. across the Antarctic and Vasco da Gama to India.
Feel like some watcher of the skies
The ancients saw in the stars the figures of their gods,
while even now, in more prosaic times when we know
that they’re giant balls of hydrogen gas slowly fusing
into helium, we can’t help but wonder if one of those
pin-pricks of light has orbiting around it a giant rock
with some creature upon it gazing back at us.
Stellarium is an interactive guide to the speckled
blue-black dome that hangs over our nights. Start the
application and you’ll get a full screen view of the sky
in your current position (or as close as Stellarium can
tell) at the current time. Move your mouse to the
bottom half of the left-hand edge of the screen and
you can change the location and time to see what the
sky will look like at any place at any point in time
(either in history or in the future). This makes
Stellarium a great tool for planning your stargazing –
just enter the place and time and you can see what
you’ll be in for in real life. The real advantage is not that

50 www.linuxvoice.com
ASTRONOMY APP REVIEWS

you get a sneak preview, but that you can learn a bit
more about what you’ll see. Move your mouse to the
left-hand side of the bottom of the screen and a menu
will pop up that enables you to select what you want
to display. The first three buttons from the bottom-left-
hand corner are Constellation Lines, Constellation
Names and Constellation Art. With these switched on,
you can get a better understanding of the skies, at
least from an ancient Greek perspective.

It's not all Greek to me
There’s a huge number of things in the night sky, and
only a fraction of them are visible with the naked eye.
If you have a pair of binoculars or a telescope, you can
explore far more than just the constellations. To
change what appears in the sky, press F4 to open the If you zoom right out you
Viewing Options window. In the DSO (Deep Space Plougher and Oxen to the people of Macedonia. There can see the entire sky in a
Objects) tab, you can configure the various items that is no other subject that knits together science and single view.
you want to appear. Check the Labels And Markers folklore quite as well as the night sky, and Stellarium
box and Stellarium will highlight the most visible of the does a great job of catering to both areas of interest.
displayed objects in the sky, and you can click on There is some software that you don’t realise you
these in the main display to get more information even wanted until you try it, and Stellarium falls into
(including the details to position a telescope at that
item). In the Sky tab of the Viewing Options window,
you can change various settings to make the interface
Stellarium is an interactive guide to
a little more captivating. If you increase the twinkle the speckled blue-black dome that
setting and the number of shooting stars, you can
create a backdrop that’s more magical. hangs over our nights
Version 0.15 of Stellarium brings support for remote
controls, which greatly enhances the ability to use the this category. Even if you’ve never thought you wanted
software for planetariums and other displays. It brings to zoom in on the finer points of the stars, we
in more data in the form of support for more DSO recommend you grab this and get better acquainted
catalogues and more folklores. There’s more to with the night sky. Now, please excuse me, it’s getting
constellations than the Greek one, and Stellarium now dark outside and Aquarius should be rising over the
supports 26 cultures' views of the stars. Using this, we back hedge soon.
discovered that the Inuit describe the constellation we
know as the Great Bear (Ursa Major) as the Caribou. It Discover the universe with the best interactive
guide to the night sky.
is, though, apparently just this reviewer who knows it
as the frying pan. Orion, meanwhile, is known as the

The artwork helps you
understand how the
constellations got their
names.

www.linuxvoice.com 51
REVIEWS GAMING

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

TRADE FOLLOWS THE FLAG Undertale
Does the indie smash hit live up to the hype?

Web http://store.steampowered.com/app/391540
Price £6.99

I
t takes about 30 seconds to realise that
Undertale is very weird. That’s probably what
made it such a smash hit with users of
YouTube’s Let’s Play services, which hepled it sell
Michel Loubet-Jambert is our Games
Editor. He hasn’t had a decent night’s close to 2 million copies, a figure which many
sleep since Steam came out on Linux. games with multi-million dollar budgets would
struggle to hit.

B
oth AMD and Nvidia have The game is an 8-bit RPG with a twist, in that
released a new generation of the player can choose to fight or make friends
graphics cards, which have
with enemies. Making friends means that Looks aren’t everything, and Undertale surprises in
huge performance improvements
over the last. Linux was not left out in monsters of the same type can be avoided in the many ways beyond being better than it looks.
the cold by either vendor as the future, but also voids any experience gain, a
updated drivers which support these serious drawback in a situation where there is no to a game where nothing is superfluous. The
cards were pushed out straight away. choice but to fight. Friendship can be established characters encountered in the dungeon are
On the other hand, users of this
through talking to, petting or even flirting with humorous, each with their own personality and
hardware will not see as many
performance gains as Windows users enemies, which is all part of the game’s humour, traits shown through dialogue and during the
given that most games are not as often toying with RPG conventions. game’s odd minigame battle system.
well optimised for OpenGL as they At first glance, Undertale is a very ugly game The game isn’t all perfect though: its
are for DirectX. There are signs of more reminiscent of MS Paint than charming environments can be bland and its puzzles are
this getting better as more
8-bit nostalgia. In most games, this would put a often tedious, but this can be overlooked since it
developers create games with
cross-platform support in mind while lot of people off straight away, but the fact that it keeps on surprising throughout. Undertale is a
using engines that are also manages to keep players interested is testament unique experience that we highly recommend.
constantly improving their OpenGL
and Vulkan support. It’s mostly the
older games created with a Undertale can convey more in a few pixels
Windows-only development mindset than many AAA games can in their entirety.
that have the biggest performance
gaps. On the Intel side of things,
Vulkan support from the Ivy Bridge
architecture onwards has been
pushed out as part of the Mesa 12
release, which also saw OpenGL 4.3
support and other big changes.
Meanwhile, the itch.io game store
has brought out a new version of its
open source store application, with
improved Arch Linux support and
much better stability in what has
become a very mature application.
This is a great alternative to Steam
for those looking at less commercial
games, especially considering the
delays in GOG’s Galaxy application
arriving on Linux. Itch.io has been
making some changes recently,
including the “refinary”, which is
similar to Early Access.

52 www.linuxvoice.com
GAMING REVIEWS

Haven Moon ALSO RELEASED…
A spiritual successor to Myst.
Web http://store.steampowered.com/app/493720 The sense of intrigue is a prominent
Price £10.99
theme, as the player is dropped into a
solitary and mysterious world full of

I
t’s been over 10 years since the last machinery and hidden passages. This
installment of the hugely popular Myst experience is further enhanced by the
series was released, so it seems that story, which begins with the player finding
now is good time to satisfy people with a note from the survivor of a cataclysmic
that particular itch. Even on a purely visual event, wishing to leave behind his life’s
PAC-MAN 256
level Haven Moon gets the nostalgia treasure. Myst fans are sure to enjoy this Pac-Man is officially on Linux! The game has
receptors tingling, though in fantastic game, but it’s also a good game for those held up extremely well over the years so
real-time 3D. It’s a one-man development wanting to delve into the series, but put off younger games shouldn’t dismiss it, more so
effort, and the love for the Myst games by the dated visuals or wrestling with given the fact that the PC version lacks the
really comes through. DOSBox configurations. pay-to-win nonsense of its mobile counterpart.
The 2.5D graphics, power ups and unlockables
give enough new reasons to play while not
sacrificing what made the game great.
http://store.steampowered.com/app/455400

Haven Moon’s graphics manage Kelvin and the Infamous Machine
to take the player back to 1993 After adding some voice acting during a brief
while still looking modern. Early Access period, Kelvin and the Infamous
Machine has been released, offering a solid
point-and-click game revolving around time
travel. In the game, Kelvin zips around history,

Day of the Tentacle Remastered
encountering the likes of Leonardo da Vinci
and Isaac Newton while solving their
dilemmas. The game is short, but has nice
A point-and-click classic brought back to life. visuals and humour typical of the genre.
http://store.steampowered.com/app/376520
Web http://store.steampowered.com/app/388210
Price £10.99

T
he early to mid 1990s is often
seen as a golden era for point-
and-click adventure games, with
Day of the Tentacle being one of its prime
examples. Though this game and others
have been playable up to now thanks to The new visuals are great for those who like
the open source SCUMMVM software, retro games without dated graphics.
this version features completely redrawn The Ship: Remastered
This very eccentric multiplayer game is
high-resolution artwork (no more upscaled back. Unusually though, a hint system has
currently in Early Access, and is mostly
320x200) and remastered audio, bearing not been added, despite it being the norm bug-free. The game throws most of the
in mind the original non-CD versions of in contemporary adventure games. conventions of the multiplayer shooter out of
the game had no voiceovers. A nice touch For those not aware of the story and the window and instead puts players on an old
is the ability to switch between the old premise, Day of the Tentacle is the sequel timey cruise ship in a “whodunnit” situation.
The player must find out who they must murder
and new visuals and audio, to get a more to Maniac Mansion. There’s a lot of time
and track them down, all the while escaping
nostalgic experience or simply compare travel involved and constant gags through from their pursuer. There’s plenty of laughs
old and new to see how much work has the game’s three varied protagonists and and very original gameplay.
been done to the game, similar to the excellent supporting characters, making http://store.steampowered.com/app/383790
Monkey Island remasters some years this a must-have for any fan of the genre.

www.linuxvoice.com 53
REVIEWS BOOKS

Designing BSD Rootkits
Ben Everard uses rootkits to avoid having to remember SSH passwords.
Author Joseph Kong
Publisher No Starch Press
Price £21.50
ISBN 978-1593271428

R
ootkits are bits of software that C programmer with some knowledge of
attackers use to maintain access to assembly language.
a computer after they’ve broken in. The main aim of this book is obviously
Essentially, they’re software kits to maintain to help penetration testers and security
root privileges. A good rootkit has to be researchers understand how to build
invisible to the system administrator yet at rootkits for BSD, a Unix-alike alternative to
the same time have complete control over Linux. There is also a secondary use – in
the machine in question, and the best way order to build a rootkit, you have to have a
to achieve that elusive goal is by running in solid understanding of how the kernel works,
the kernel. and a great way to get this understanding
Designing BSD Rootkits is a book about is to poke it in ways it’s not designed to be
how to control a running BSD kernel to poked. In other words, it makes a good, if
allow you to nefariously manipulate data – highly unorthodox, introduction to the BSD
including core kernel data such as the list kernel (and, indeed, all Posix kernels).
of open ports. This is obviously a massively
complicated subject, and in order to get An unusual and interesting way to start
investigating Unix kernels.
the best out of this book the reader is No Voodoo Beasties were harmed in the making
expected to be a reasonably competent of this book.

Text Processing With Ruby
Ben Everard starts work on a magazine editing robot in the hope of retiring. One day!
Author Rob Miller
Publisher Pragmatic Bookshelf
Price £25.50
ISBN 978-1680500707

T
ext processing is one of the most at acquiring text including reading from
useful skills to have in programming. files, getting standard input and scraping
Whether it’s pulling data out of log websites. The second looks at transforming
files, scraping websites or analysing the text, which comes down to regular
sentiment in millions of Twitter posts, the expressions, parsers and natural language
ability to condense a large amount of ASCII processing. The final chapters explore
(or Unicode) into a useful form is vital. writing text to files and standard output.
Text’s importance comes from the fact that This book is thorough, informative but
it is the bridge between computers and a little unexciting. There are plenty of
humans – it’s the only format that both can examples to help the reader understand
easily understand. It’s sometimes called what’s going on, but they’re all a little
the universal format and shows no sign of contrived. More meaty examples would
becoming less popular despite being one of help keep us more engaged and help us see
the earliest forms of data representation. exactly how everything came together.
Text Processing With Ruby does a good
job of covering the whole area of modern A thoroughly useful book for new Ruby programmers,
but it lacks pizzazz.
text processing by splitting the subject into If you only learn one programming skill, learn
three parts. The first part of the book looks text processing.

54 www.linuxvoice.com
GROUP TEST CREATE YOUR OWN SOCIAL NETWORK

GROUP TEST
A serial online socialiser, Mayank Sharma would do anything to avoid real work – even test a
bunch of web apps to deploy his own social network.

On test Create your own social network

A
BuddyPress n online social network social network into your existing
URL https://buddypress.org operates pretty much like its online infrastructure.
Licence GNU GPL v2 physical offline counterpart: The web apps in this group
Latest release 2.6.1.1 you meet people, establish test help you create focused
Is this the WordPress for social networks? connections, keep up with the social networks as a means of
contacts, and continue the connecting people. You can deploy
relationship. But social networking them to bring together students
Community Builder on the internet has one major
benefit over offline ones – it enables
and equip them with the means
of collaborating on projects,
URL www.joomlapolis.com/community-
you to find like-minded people exchanging class notes and even
builder
beyond your physical network, even advertising the availability of dorm
Licence GNU GPL v2
Latest release 2.0.14+ across time zones. Also thanks to rooms. For businesses, a custom
We know what it does, but is it any good? the power of keywords and search social network can be an ideal
fields, you can skim through the extension of a bulletin board or a
noise and find like-minded groups company intranet. It also helps

Elgg from the comfort of your armchair.
But why should you go through
bring together physically separated
people who are connected through
URL www.elgg.org the pains of hosting and managing a strong common thread, like the
Licence GNU GPL v2
your own social network when you various campuses of a university, or
Latest release 2.1.2
can join one instantly for free? For regional offices of a multinational
Will I let my familiarity with the software
cloud my judgement? starters, hosting your own social corporation. Similarly, a corporation
network gives you the option to could deploy such a social network
customise and brand it as per your on its intranet as a virtual water
whims and wishes. This is also cooler for its employees and a
Mahara helpful if you want to integrate the means for them to exchange notes.
URL www.mahara.org
Licence GNU GPL v3
Latest release 16.04 Hosting your own social network
Can it bid Sayonara to the rest?
gives you the option to customise
and brand it as per your wishes
Oxwall
URL http://developers.oxwall.com Deploy a server
Licence Common Public Attribution Unlike standalone desktop apps, the out a web server, the exact procedure
Licence web apps tested over the next few pages depends on the Linux distribution that’ll
Latest release 1.8.3 are designed to reside on a web server power it.
Will it make the rest drive up the wall? that you’ll have to set up before you can Most web apps will work atop the
fiddle around with any of these apps. LAMP platform; some might even allow
LAMP is the most common platform you to swap out components for other
for rolling out server software. It uses a alternatives. All apps have detailed
Trident Linux distribution as base that has the installation instructions. The installation
URL www.online.me Apache web server together with the document will also list the exact libraries
Licence Creative Commons Public Licence MySQL database, along with support for that they require and should be one of
displaying apps written in PHP or Perl. the first documents you read if you want
Latest release 8.0
While it doesn’t take much effort to roll to try out one of these web apps.
Can it poke the competition?

56 www.linuxvoice.com
CREATE YOUR OWN SOCIAL NETWORK GROUP TEST

What makes a social network?
Tools of the trade.
A social networking website is a Web 2.0 service. Furthermore, there are certain elements, without aspect of an online social network. To facilitate the
The term Web 2.0, coined by O’Reilly Media in 2004, which social networking on the web wouldn’t be discovery of shared information, the network should
isn’t a technology update to the internet, but rather possible. User profiles play an important part in have the provision to assign keywords or tags to
refers to the so-called second generation of web- helping you find like-minded people. Once you’ve them. In fact, tags are so popular that they’ve paved
based services that encourages reader participation. found the people you want to be connected to, the the way for Folksonomy or collaborative tagging. By
A social network is made up of several such network should enable you to connect with them and transferring indexing control to users, Folksonomy
communication tools and services, including blogs add them as friends. After connecting with friends, websites incite people to share. To keep its members
for sharing content and forum boards for fostering you’d want to share information, ideas, pictures, or updated, the network should also have some form of
discussions. documents with them, which is another important feed syndication.

Oxwall
Your own Facebook.
Oxwall ships with all the essential
components you need to get users to
interact. Users can blog, share pictures and
videos, discuss via forums, share with wikis,
comment, tag, and rate all types of content,
and a lot more. The core software and the
essential plugins are available gratis, while
additional plugins can be bought for a
one-time fee. Oxwall relies on a simple
step-by-step installation process. At the last
step the installer displays a list of plugins
that you can enable. These can be activated You can easily monitor active users and maintain decorum by suspending abusive users.
or disabled later from the administration
console. which offers fine control over the CSS style plugins that you have selected. You can
Oxwall’s admin interface is pretty well laid of the theme. rearrange the pages and menus by dragging
out and divided into various sections. While and dropping with the mouse. You can also
you edit your network, ensure it’s not visible Broaden the horizon edit each item to either make them visible
to anyone by disabling the site and putting In addition to customising the network to everyone, to guests, or to every logged-in
up a maintenance page with a personalised visually you can also make dramatic member. You can enable users to customise
message. If you are running a closed changes by activating plugins. their own page components, but you can
network, or a very specialised one, you might Some plugins, such as the Activity “freeze” certain elements to prevent them
want to make the casual visitor pause and Notifications and Friends plugins, are from being edited or moved by the users.
read about the network they are about to pretty straightforward and require no
enter by putting up a splash screen. configuration. But plugins such as the Control your users
Forum plugin and the Contact Importer offer Managing users is one of the strong points
Make it your own some additional controls. For example, to of Oxwall. Before you throw open your
The most convenient way to personalise import contacts from Google or Facebook, network, you should create custom account
your network is to alter the default theme. you need to equip Oxwall with your Google types and edit profile questions for each. For
Oxwall ships with a bunch of themes, and Client ID, and Facebook App ID. example, if you’re setting up a network for an
you can grab some more from its website Besides the additional plugins that ship educational institute you can have different
(http://www.oxwall.org/store/list/theme/ with the app, you can fetch additional ones registration questions depending on
latest). from the Oxwall store (http://www.oxwall. whether the user is a teacher or a student.
You can tweak various aspects of the org/store/list/plugin/featured). Some If this all sounds a little daunting, head to
theme right from within Oxwall’s admin plugins are only available for a fee, such demo.oxwall.com to get to grips with the
interface. Depending on the theme, it might as the PayPal Billing plugin, which lets administration of the network.
also take several images, such as for a you accept payments from users of your
Helps roll out a feature rich network that
background and logos, and you can replace network via PayPal. can be customised to the hilt.
them by uploading custom graphics. The Oxwall also lets you rearrange the default
theme customiser also includes a CSS tab, layout of the dashboard depending on the

www.linuxvoice.com 57
GROUP TEST CREATE YOUR OWN SOCIAL NETWORK

Mahara
The LinkedIN for education.
Unlike the other social networking which can hold everything that can be
software in this group test, Mahara stored digitally. These components are
caters to a particular demographic. It’s individually known as artefacts. Multiple
designed to allow users to demonstrate artifacts are collated into pages and
their skills and work by creating digital you can have as many pages as you
portfolios. Additionally you can also use like, either with a different number of
the platform as a social networking artefacts, or different purposes and
system to enable users to interact with audience. For example, you can have
their friends and create their own online a page for your family that includes
communities. Mahara includes tools holiday photos. Similarly, you can
and services such as blogs, custom create a page to showcase your work You can export your portfolios as HTML sites or in a
pages, a resume builder, and can also and a resume to potential employers. format that can be imported into another Mahara install.
be hooked with the Moodle learning If you want people to see your page
platform. Mahara is a popular tool you can add them as individuals or as hang of the administration interface.
among universities all over the world a member of a group, and pages can You can choose the layout of the page
that use it to record achievements and even be made publicly available. and drag and drop everything from
assist with personal career blocks of plaintext to recent forum
development of their pupils. Admin panel posts, PDF files, images and a lot more.
While installing, Mahara shouldn’t Besides the Dashboard, Mahara’s Mahara hosts a demo (http://demo.
throw any unexpected issues, don’t administration interface includes tabs mahara.org) to tinker with its back end.
make the mistake of using the software for uploading and editing content,
Helpful for creating a network that shows
without first spending some time arranging them into portfolios, and off the user’s achievements.
with its documentation to grasp its defining groups. Creating a portfolio is a
true potential: Mahara ePortfolios, fairly intuitive process once you get the

Trident
A good beginning.
Trident bills itself as a social CMS, and extensions (both free and paid-for) from
had its first stable release late last year Trident’s marketplace. The software
after half a decade of development. It is made up of two main components.
offers several unique features, such as There’s a content management
the ability to create multiple profiles for interface for managing the installation,
a user’s different personas. Trident has which can be handled by appointed
the usual slew of social networking admins and moderators. Then there’s
features, such as the ability to make the Studio, which helps you design and
friends, communicate with them, share extend Trident’s functionality.
and like content, and more. To the
admin it offers tools such as custom Initial minimalism You can use the pages module to customise the content,
page builders, navigation menu There aren’t many components inside visibility settings and layout of a page.
builders, permissions control and Studio on a fresh installation. You get
several other common content a tour of the default core components their visibility for different members.
management functions. The developers and can start building your network by Then there’s the designer, which helps
boast of testing the app on all form customising them, such as your profile, you change the site’s logo, design
factors and claim that its typography, the site’s homepage and other pages. and manage the cover image as well.
link targets and navigation are all You can then download more apps Once you get familiar with Trident, you
optimised for touch devices. from the marketplace, which lists free can use the forms tool to customise
Before you install Trident, you’ll need and paid-for apps. Trident’s database and forms.
to register for a free account with its Studio makes it straightforward to
One of the easiest networks to configure,
commercial developer BoonEx and customise your Trident installation. but it ships with a limited set of functions.
grab a set of keys. You’ll need these For example, you can build a page by
to download additional apps and picking the right blocks and configuring

58 www.linuxvoice.com
CREATE YOUR OWN SOCIAL NETWORK GROUP TEST

Elgg Diaspora:
Old but still going strong.
the distributed
social network
Unity in diversity.
Diaspora is a unique social network. It works and
behaves like the popular ones and lets you add friends
and follow hashtags and displays updates in your
stream. As a social network, Diaspora is very capable
and some even credit its Aspects feature as the
inspiration for Google+’s circle.
However, the biggest advantage of Diaspora is that
it’s open source and federated, which liberates it from
the control of any one organisation. The Diaspora social
network is made up of a number of servers called pods
that connect to each other. The pods are independently
operated, and anyone can set one up and connect
it to the Diaspora network. Pods can be private to a
Elgg users can also use the built-in messaging capabilities to send messages to other particular group, or open and allow anyone to join – so
registered users on the network. to join the Diaspora you can get an account with a
publically listed pod. Alternatively, you can also set up a
Diaspora pod for your organisation.
Elgg is one of the most versatile pieces of to revamp the front page, enable the Front
A couple of years after crowdfunding the
software that offers almost everything you Page Demo plugin. Elgg ships with over 30 development, the Diaspora developers passed on
need to start a social networking site such plugins, such as blog, bookmarks, pages, the development baton to the community under the
as a blog, filesharing features and a notifications, etc. Some of the plugins guidance of the Free Software Support Network. But
Twitter-like service. Setting it up is a pretty that you might want to activate includes this had no effect on the hosting of the network, since
the actual hosting of the pods is done by individuals
standard affair. Site Pages, which lets you create simple
around the world. To join Diaspora you can sign up with
The administrator dashboard divides web pages, and Tag Cloud for displaying any of the public pods listed at http://podupti.me. For
the settings under two major heads, all tags. Furthermore, Elgg has an active more information about Diaspora, read our FAQ on this
namely Administer and Configure. The plugin community that churns out plugins social network from Issue 8 (https://www.linuxvoice.
options under the Administer category by the hundreds. In the Elgg world, themes com/faq-diaspora).
give you various statistics about the are also treated as plugins. Some of the
server, lets you view online users, add new popular third-party plugins include Profile
users and put the network in maintenance Manager for creating custom profile fields,
mode while you’re setting it up. The Tidypics photo gallery plugin, and the
Configure category houses quite a lot Chat plugin for adding instant messaging
of functionality. The Settings section in functionality.
particular is useful for altering options that All users on Elgg get a profile page and
affect the entire Elgg deployment. From a landing page, known as the dashboard.
here you can change the name of your Both areas can be populated with widgets
social network that you specified in the that pull data from various sources to
wizard while deploying Elgg. show the user’s activity. You, as the
administrator, can set up a default layout
Customisation galore for all users that the individual users can
The default Elgg-fuelled network is very then rearrange as per their preferences
barebones. You can start by customising and requirements. Users can write blogs,
the order of the menu items displayed at create and participate in groups, and can
the top and can also add custom menu also host their own pages, upload all kinds
items. You can also modify the default of multimedia content and link them along
profile fields. If the existing items in the with the text content. Elgg also has an
profile don’t work, you can easily replace impressive access permission system
them with something that suits your that lets you define parameters for
requirements, and can even create your accessing a particular type of content. Follow the detailed installation guide
own custom fields. on Diaspora’s website (https://wiki.
Create a simple-to-administer network with
For more flexibility in designing a all the features you’d need. diasporafoundation.org/Installation) to easily set
custom profile page you can use the up your own pod.
popular Profile Manager plugin. If you wish

www.linuxvoice.com 59
GROUP TEST CREATE YOUR OWN SOCIAL NETWORK

BuddyPress vs Community Builder
Battle of the extensions.
WordPress and Joomla are two very
popular content management systems.
Both have elaborate extensions
mechanisms for fleshing out the base
installation. BuddyPress and Community
Builder are two different plugins that
equip social networking features to
WordPress and Joomla respectively.
BuddyPress is developed by
Automattic, which makes it the
official extension to turn a simple
BuddyPress blog into a social network.
The extension adds core networking
functionality such as the ability to
create profiles, add friends, create
groups and message people.
BuddyPress’s configuration options
are housed under the Settings section
in the WordPress administration BuddyPress is designed to be modular. So while it includes the core networking features, for other social
panel. Several configuration options functionality, you’ll have to install other plugins such as bbPress for forums.
for BuddyPress also extend existing
WordPress configuration settings: for the website to communicate among Community Builder menu in the Joomla
example, the Users settings in the themselves. There’s also a useful components menu. The plugin draws a
WordPress administration screen gets notifications system for everything handful of its own menus that can be
a new section called profile fields that from friend requests to whenever controlled from under the existing
you can use to let users share all types someone tags you. Joomla menus section.
of information on their profiles. On the front-end you get a CB login
The plugin also associates certain Foster a community form in addition to the Joomla login
WordPress pages with BuddyPress If your website is powered by Joomla, form. Unlike BuddyPress however, which
pages. This enables you to create you can use the Community Builder takes over the registration process
custom registration and activation plugin to create a social network for from WordPress after installation, you’ll
pages. If you’re installing it on a live your users. Installation is again pretty have to manually turn off the Joomla
WordPress website with registered straightforward, and once activated the registration form else your website will
users you’ll appreciate the fact that the plugin shows up as an additional have two registration boxes.
plugin automatically syncs WordPress drop-down menu in the Joomla CB lets you customise the look and
user profiles with BuddyPress profiles. administration panel. Some settings are feel of the user’s profiles through fields,
BuddyPress enables members on also available from under the tabs, add-ons, and more. The plugin
make things easier to find by organising
multiple profile data fields into tabs.
You can also create custom profile
fields that can be of any of the 23 built-
in field types including text, checkbox,
image, video, file, etc. There’s also a tool
that’ll sync the Joomla user table with
the CB user table. You can get more
community features via plugins.

BuddyPress
The official mechanism for helping users
socialise on a wordpress website.

Community Builder
The BuddyPress alternative for Joomla-
powered installations.
Head to http://demo.cbdemosites.com to get to grips with the administration of a
Community Builder-infused Joomla installation.

60 www.linuxvoice.com
CREATE YOUR OWN SOCIAL NETWORK GROUP TEST

OUR VERDICT
Create your own social network
Community Builder and BuddyPress software. Despite being available for
aren’t standalone options for creating no cost, the software isn’t of much use
social networks. Rather they are both if you don’t use the keys handed out
designed to extend networking features freely by its corporate overlord. If you Oxwall lets you customise all aspects of your social
to members on their respective base don’t have any issues with this, you’ll network including the layout and appearance without
dabbling with HTML or PHP.
websites without setting another one find Trident easy to customise and
up from scratch. Both fit snugly into the flesh out. The Dashboard is very user-
back-end of their respective content friendly and the Studio offers a unique
management system. installation of mechanism to shape the look and feel 1 Oxwall
both is simple, so if you’ve got a of the installation. Killer feature Easy to administer
WordPress or a Joomla website setup, URL http://developers.oxwall.com
you don’t really need to consider any of Our winner Create a social network that’s intuitive to
the other solutions on offer. This leaves us with Elgg and Oxwall, administrate and flesh out.
The other four solutions are both of which trump the others for
standalone options and can be better offering the most functions and
compared to each other. Of these,
Mahara will appeal to the least number
flexibility. They both ship with a good 2 Elgg
number of plugins and offer many
of users since it’s designed with a very more, including several paid ones, on Killer feature Twitter-like service
URL www.elgg.org
particular use case in mind. Mahara their respective websites. Straight out
Useful for creating a user-centric social
excels at creating a network that of the box, Oxwall has a more appealing network.
enables your users to showcase their admin interface, which pips it over
achievements and engage with others Elgg, which by default creates a rather
based on this. Forums and groups are uninteresting-looking landing page.
Mahara’s two main networking tools. Elgg has a Twitter-like service and 3 Trident
Its administrative interface is logically you can control its character-limitation. Killer feature Studio
divided into tabs, and you can have it up Oxwall, on the other hand, lets you edit URL: www.online.me
and running in no time. its interface for mobile devices as well. Offers a unique network editor but is too
Then there’s Trident, which is young Once you’ve set up an Oxwall-powered dependant on its corporate sponsor.
in terms of stable releases but comes website you can either open it up to
from developers who have a strong public, or restrict access to it behind a
pedigree of creating social networking walled garden.
4 Mahara
Elgg and Oxwall both ship with a good Killer feature Digital portfolios
URL www.mahara.org
number of plugins, and offer many more Show off your work by creating a merit-based
network.
on their respective websites

Ready to deploy 5 BuddyPress
Once you’ve decided to roll out your custom appliances are self-contained systems that Killer feature Impressive profiles
social network it’ll be a good idea to leverage run atop Just enough Operating System URL https://buddypress.org
the expertise of others. Depending on the (JeOS) components that are required to The best mechanism to add social networking
scale and size of your network you can power that particular app. The project
function to a WordPress blog.
deploy them with ready-made appliances currently produces such an appliance for
as well as on specially-tuned web hosts. Elgg. Bitnami on the other hand produces
Virtually all projects including Elgg, Oxwall self-contained applications that include
and BuddyPress collaborate with multiple all the libraries and runtimes. While the
web hosting providers and offer quick project currently supports none of the social 6 Community Builder
deployment and assistance. networking platforms covered in this group
Killer feature Plugins
Another deployment option is in the test, Elgg and Oxwall are in its upcoming list.
URL www.joomlapolis.com/community-
form of prefabricated appliances. The Furthermore, you can use its LAMP stack as
Turnkey Linux and Bitnami projects are the base on top of which you can roll out all
builder
two popular examples of these. Turnkey of the mentioned web apps.
An extensive plugin to transform a Joomla
installation into a social network.

www.linuxvoice.com 61
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www.linuxvoice.com 63
FOSSPICKS

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

Our benevolent editorial overlord Graham Morrison tears himself away
from updating Arch Linux to search for the best new free software.
Software planetarium

Stellarium 0.15.0
S
tellarium has always been our window, which means if it’s you’ll even see the objects move as
favourite Free Software daytime, the only stellar objects you watch, including phases of the
astronomy application. It’s you’ll see are the sun and moon. moon, the angles of planets, solar
also hugely successful, available for Press Alt and ‘+’ on your keyboard eclipses and even shooting stars.
Windows, OS X and even Android. to advance time an hour and watch
But the thing that really grips you how the horizon darkens through Distant stars
about Stellarium, and what we’d twilight and the encumbrance of This releases uses Qt 5.6, which ran
argue has made it so popular, is the heavens present themselves. faultlessly even on our modest Intel
that even from the first screen you Press + alone, and the view will GPU. This is important because
see, it always looks gorgeous. The skip ahead 24 hours – a brilliant almost every element within the
default view launches full-screen way of watching the phases of the main user interface is accelerated
(press F11 for windowed mode) moon, or the orbits of Venus and through your graphics hardware,
and places you in the middle of a Mercury playing with the sun. Click often generating 60 frames per
photorealistic meadow. The on any object to see detailed second even when updating the
ambient light within this scene will real-time statistics on your details on stellar bodies in real time.
be similar to the light outside your selection, and zoom in enough The quality is good enough for
projection in planetariums, and a
new addition is a plugin for remote
control use like this, where a guide
4 can take an audience on a virtual
1
tour. Our second favourite feature is
2
the additional sky cultures, now
including sky art for Macedonian,
3
Ojibwe and Dakota/Lakota/Nakota
constellations, projected into the
sky. But behind this graphical
stardust, Stellarium is also a serious
6 tool capable of helping study and
5 observations. There’s initial support
for the Washington Double Star
Catalog, for example, and you can
now create bookmarks for places,
8 plus there are new functions in the
wonderful scripting engine and
7 additions to the powerful AstroCalc
utility, brilliant for planning an
outside viewing session. Plus, the
1 Object details When an object is selected, real-time in-depth statistics and details appear here. User Guide has been completely
2 Sky art The constellation art of lots of different cultures are embedded within Stellarium. overhauled. Stellarium is one of
3 Shooting stars Stars twinkle, deep space objects are newly textured, and both atmospheric fog and light pollution help
those brilliant examples of what
render either a realistic or a Spielberg-esque view of the sky. 4 Ocular views Limit your view to that of your telescope or open source can do. It’s great.
camera, for accurate predictions. 5 Backgrounds Import your own garden, or enable one of the new 3D environments for
terrestrial viewing. 6 Starlore Alongside the excellent User Guide, there’s also excellent background info on sky art
cultures and other viewable elements. 7 Toolbox Easily turn on and off viewable elements, include satellites and labels. Project website
8 Configuration Place your viewer anywhere on the globe, or even in space, at any time. www.stellarium.org

64 www.linuxvoice.com
FOSSPICKS

Filesystem

ciopfs
We’re used to the idea that if you The same files’ or folders’
don’t know what you’re doing, you destination can be addressed as
shouldn’t play with the filesystem. games/SystemShock2, GAMES/
But there’s one exception to this, SYSTEMSHOCK2 or games/
and it’s thanks to the wonderful systemshock2, for example. And
FUSE (filesystem(s) in userspace). we’ve just given a great big hint at
FUSE lets you – an ordinary user how this can be used: cheap Wine/ IF CAPITAL LETTERS IN FILE PATHS CAUSE YOU PROBLEMS
– create, mount and play with Windows games conversions, INSTALL CIOPFS.
filesystems on your own, without where the case of paths within the
messing up the integrity of the executable are wrong and yet to use. With both FUSE and Ciopfs
Linux system you’re running on. hard-coded. installed, type ciopfs source
FUSE is great for mounting destination, just like mounting any
experimental write-enabled Apple or An easy fix for lazy paths other filesystem, and you’ll be able
NTFS partitions, for instance, as Pointing Wine at a game installed to freely navigation within the
well as experimental or within a Ciopfs mount point will destination mount point either
development filesystems. Which is avoid any conflict, as both types of lowercase paths, uppercase paths,
definitely the category that ciopfs file paths will work. It’s a brilliantly or a mixture of both. You can then
falls in to. Ciopfs is old (the last simple idea, and almost as simple supply this path to any problematic
update was from 2011), but we’ve application having trouble with its
already found a great use for it. It’s
a FUSE filesystem that mounts
FUSE is great for mounting capitalisation.

your own filesystem within itself, experimental filesystems – Project website
only the files and folders within
ciopfs are no longer case-sensitive. such as Ciopfs http://www.brain-dump.org/projects/ciopfs

CLI status bar

Monky 2.0
Tmux, the tool that enables you to requirement, but with similarly
run multiple consoles alongside complex configuration potential.
one another, has become the What makes Monky particularly
standard way we interact with most powerful is that it uses Haskell for
of our Linux systems, and one of its its configuration file, effectively
best features is the plugin system. turning what are normally static
This enables you to easily install parameters into dynamic functions
modifications to your environment you can embed into your own
without even restarting Tmux, status display. Fortunately, there
adding the ability to suspend and are plenty of examples and enough Monky is a little like
resume, for example. modules to play with that you don’t Conky without the update has changed most
One of the best plugins turns the have to understand too much dependency on X.org. modules, and as such, older
bottom line of your console into a Haskell, but getting a decent It’s also difficult to get examples will need some
status bar, where you can add any configuration is still a challenge, running. modification to work, or you can
details you choose with other even when a little copy and paste start afresh. But using the modules
plugins, such as Git branches, the and a few parameter edits are to display details on disk usage,
date or unread emails, and if you usually all that are required. This network usage, wifi strength and
have the skill, building your own CPU usage to build your perfect
plugins to display and do exactly
what you need is one of of the most
What makes Monky so status utility is a project worthy of
any elite hacker’s time.
unexpedidly powerful aspects of powerful is that it uses
Tmux. Monky does a similar job,
only without the Tmux and console Haskell for its config file Project website
https://github.com/monky-hs/monky

www.linuxvoice.com 65
FOSSPICKS

RSS reader

FeedReader 1.6 beta
Like many, we’re still mourning the interface from the comfort of your
loss of Google Reader, despite it own desktop. Its web-centric
being three years since its demise. interface links to popular services
Google Reader was one of Google’s like Feedly, and even OwnCloud,
best web apps, pooling whatever and presents your stories in the
RSS feeds you subscribed to into a mixed hierarchy of your own
single place, and it’s almost categories and sub-categories just
impossible to write anything about like Google Reader.
RSS aggregation without The application is great for
mentioning it. It was the best way in-place readability, but we really like Thanks to its web-based UI, FeedReader gets very close to
of keeping abreast of 100s of its ability to push stories you’re approximating the functionality of ye olde Google Reader.
stories, and nothing has come interested in to Pocket, perhaps for
along to replace it. later reading on the train journey you of their status. This is
While a few services, like Feedly, home, as well as Instapaper and something the web apps can’t do
have started to compete, nothing Readability for non-web formatting. well, and helps if you’re serious
really gets close to that old There’s also a daemon that runs about your news feeds. We typically
functionality. Offline applications silently in the background, updating navigate 600 stories a day, and we
were always an important part of stories and occasionally notifying found FeedReader more than
the same ecosystem, and since capable of helping us navigate the
Google Reader, many seem to have
gone cold.
FeedReader's interface links mess of updates (mess should be
the collective noun for news).
FeedReader is an exception to popular services like
though, and is one of the best tools
for recreating a good online Feedly and even OwnCloud Project website
http://jangernert.github.io/FeedReader

RSS reader

QuiteRSS 0.18.5
And still RSS won’t die. Despite the exported OPML file spat out by our
social networking revolutions web client, and QuiteRSS read this,
supposedly replacing the need for updated stories and populated the
syndicated content from boring old various categories quicker than the
websites, many of us depend on online equivalent, without any
RSS to get updates on sites we noticeable hit on system
trust, outside of their own need to performance.
‘push content’. This is what makes
FeedReader (above) so interesting, This is the news
and why there are still other Reading quality didn’t suffer either,
applications being developed, such as the stories themselves are Penguins, the Olympic games and Donald Trump – all will be old
as QuiteRSS. rendered using an embedded news by the time you read this.
Almost at the opposite end of the WebKit core browser, with layout
scale to FeedReader, QuiteRSS is a identical to the online versions. any catch your interest. You can
great little utility recommended to Adblock is even included. It’s also quickly disable images, which is
us by podcast listener zmoylan. It quick and easy to filter and search useful if you’re tethered to your
features no background daemon, or through your stories, and we liked phone’s data allocation, and stories,
integration with cloud services, and the way you can switch the story feeds and categories can all be
it can’t push news stories back to view into ‘newspaper’ mode. opened in separate tabs, like a
Pocket. But it’s very fast (not just Each story in your selected finely tuned web browser.
‘quite’ fast as its name implies), and category is listed in a single page
does everything you need perfectly. one after the other, so you can Project website
We imported our feed list from an scroll through them quickly to see if https://quiterss.org

66 www.linuxvoice.com
FOSSPICKS

Text editor

GhostWriter 1.4.0
We obviously do a fair bit of writing.
And for us, at least, there is no
one-size-fits-all text editor for the 2
various things we do. Some writing 1
is done in Vim, for example,
especially when working with 4
3
GitHub’s Markdown and writing to a
specification. Other writing is done
in FocusWriter, which is currently
our favourite distraction-free editor
for writing more descriptive text.
GhostWriter, as its name implies,
8
is designed more for creative
writing rather than documenting
APIs or writing tutorials, but it still 5

has a unique take on this that
makes it worth a look. What makes 7
GhostWriter different from 6
something like FocusWriter is that it
uses Markdown within the main
editing window so you can add
1 Outline As you write headings and subheadings, they appear in the outline view. 2 Markdown Using the Markdown
things like titles, subheadings and
lists without reverting to menus or syntax (and there’s an included cheat sheet), you can mark which parts of your document are important. 3 Task List Add
things that need to be done within the text, and mark them finished when complete. 4 HTML preview See how your
keyboard shortcuts, and without writing will look after being exported to a web page. 5 Themes Light and dark themes are included, and you have full font
needing a special file format. As control. 6 Hemingway mode Disable the Delete key for writing streams of consciousness. 7 Word count Simple but
we’ve mentioned in previous issues, essential when you write words for print.
Markdown is a simple syntax for
marking bits of your text document Apart from the menu, there are statistics overview for when you
– using # for titles, for instance, three things you can click on in the need more details, and settings for
only without all the hassle of writing window – an icon to make how much or how little of your
opening and closing brackets, as the application full-screen or writing is highlighted.
with HTML or XML. windowed, an icon to highlight only Pandoc, which we looked at last
We really like GhostWriter. While the line you’re writing on and an month, is used for the output, which
we understand the overall ethos of icon to enable Hemingway mode. means everything from HTML to
‘distraction free’ – presenting Hemingway mode? This is a mode PDF looks fantastic. Font and UI
nothing but a typing-and-words we’ve seen in a few distraction-free rendering is excellent too, especially
interface to the writer – our editors over the last few years, and on high DPI displays and a desktop
practical needs outweigh our with Qt 5.6 or higher. This may
creative needs, and it’s good to see seem superficial, but readability and
GhostWriter starting with things like Like Hemingway, the crispness of text is one of our main
the menu being visible, as well as
indicators for editing mode and
features in GhostWriter are reasons for using a high-DPI display
in the first place, and it’s a pleasure
word count. It’s amazing how few but expertly chosen to type things into GhostWriter.
important word count is to most This may also be subjective, but
writers, and yet it’s often almost it disables to the Delete key. This it’s quick too – characters appear
impossible to find an editor that may work for some writers perhaps almost instantly (as they do in
makes this visible all the time too troubled with perfection, but we FocusWriter), which is something
without eating great swathes of find the Delete key useful. you only really notice when you
screen. Even with FinalWriter you Perhaps more like the real type lots of things. The only thing
have to drag the cursor to the Hemingway, the other features in missing from FocusWriter we can
bottom border of the screen, which GhostWriter are few but perfectly think of is the typing sound.
is more of a distraction than the chosen. In particular, there’s an
hopes of being distraction-free by outline window that shows heading Project website
not showing it by default. and subheadings, a document http://wereturtle.github.io/ghostwriter

www.linuxvoice.com 67
FOSSPICKS

PulseAudio mixer

PAmix
There are almost as many software Each application that’s sending
audio mixers as there are audio audio to PulseAudio is listed
subsystems for Linux. There are vertically, and alongside each of
even a few for the command line. these there’s a volume slider. Each
We’ve always relied on alsa-mixer, audio source also has a bouncing
for example, when our machines volume indicator, just like the VU
are making a sound we just can’t meter on an 80s stacking Hi-Fi, and The build pamix executable is a mere 56k in size.
stop any other way. it’s very quick and easy to see
PAmix is an ncurses-based mixer what's responsible for whichever audio issues, and the clarity of the
for PulseAudio that has no sound you want to control. output and control is better than
dependencies (other than ncurses Pressing M will mute or unmute you find in desktops like KDE, for
and PulseAudio) and gives you the audio source, and you can instance, although this has
instant access to the audio output control the volume with the H and I improved drastically over the last
on your hardware. It’s not powerful keys. J and K are used to switch six months. If you ever need more
and it’s very simple in its between inputs and Q to quit. That’s control, there’s always pavucontrol
functionality, but it’s also tiny and almost all there is to this small tool, and even PulseAudio on the
runs instantly. It was quicker to but it’s about all you need 90% of command line, but if you want
build the entire project from its the time when dealing with normal quick visualisation over a remote
source code that waiting for the Raspberry Pi audio client, or you run
graphical pavucontrol mixer for
PulseAudio to load on the desktop,
PAmix provides all you need everything from the terminal, PAmix
is an excellent addition.
for example, and it provides just 90% of the time when
enough functionality for the
majority of users. dealing with audio issues Project website
https://github.com/patroclos/PAmix

Games controller config

SC Controller
Valve’s Steam Controller has now SC Controller is a brilliant utility
been out for almost a year, and the that enables you to create profiles
verdict is still undecided. It does and reconfigure every aspect of the
away with the traditional dual Steam Controller, without ever
analogue sticks, and replaces them having to launch Steam. This is
with circular touchpads and clever particularly useful if you want to
haptic feedback, the intention being use the controller on a computer
that they can act as sticks if you that doesn’t have Steam installed,
want them to, but they can also act or a computer where you don’t Turn your Steam Controller into a keyboard and mouse, all without
more like a mouse, which is want to install Steam. Steam (thanks Ioangogo!).
essential for FPS games, for It supports the redefinition of the
example. We use ours alongside a single analogue stick, the pads and thresholds, analogue output (great
regular controller for playing games the orientation input, as well as for mouse control) and even the
such as Kerbal Space Program – a emulation of other controllers such ability to trigger scripts and
game that otherwise requires a as a real 360 controller, a mouse, a commands. It takes Steam
mouse and keyboard. trackball and a regular keyboard. Controller out of the world of niche
Steam Controllers work with You also have control over pressure gaming and into a world of huge
Valve’s Linux-based Steam Boxes, potential, especially if you can pick
and SteamOS, where the up a Steam Controller in one of
community have created profiles SC Controller enables you Valve’s famous seasonal sales.
for most games, but they’ve also to reconfigure every aspect
been difficult to use outside of
of the Steam Controller
Project website
Valve’s ecosystem. Until now! https://github.com/kozec/sc-controller

68 www.linuxvoice.com
FOSSPICKS

FOSSpicks Brain Relaxers
Space adventure

Oolite 1.84
We’ve of course covered Oolite genuine alternative, although it’s
before. It’s absolutely one of the much more like Elite than Elite
best open source games you can Dangerous, and some players will
play, and has been the best prefer it for this.
interpretation of the 1980s classic,
Elite, for over a decade. Elite, for the Right on, commander!
uninitiated, was a game set in the Updates come few and far between
vastness of space. You could be a – the last one was in May 2015, but
trader, a pirate, a mercenary, or a each one is a signification
mixture of all three. improvement over the previous
The 3D graphics were also version. In particular, the game’s AI
revolutionary, helping pull the player and combat have become a lot If you don’t have the example, has been enhanced to
latest PC (and
into a world that felt infinite. David more satisfying. make it more like the pseudo-
Windows!) for running
Braben, one of the original Version 1.84 makes a few Elite Dangerous, Oolite is random of the original BBC version,
developers of Elite, is now head of important changes, such as putting a brilliant alternative and there are many, many bugfixes
Frontier Developments, a games HUID messages under the console, that's more true to the too. Fundamentally, it’s a brilliant
company that has spent the last and allowing all ships to carry original. game and Oolite is the best version.
couple of years developing Elite multiple lasers, but it’s never lost
Dangerous, though sadly there’s no the attention to detail. Even the Project website
Linux version. This makes Oolite a movement of the tumbling ship, for http://www.oolite.org

2D platformer

ReTux
Despite being completely Free code, or re-distribute it themselves,
Software and proud of it – there aren’t any obvious mirrors
declaring itself as a “100% libre offering the same files.
software and libre culture action
platformer loosely inspired by the La mode classique
Mario games,” this cute old-school On first glance, the game looks a lot
game has taken an unusual like the old Linux platform game
approach to distribution. All SuperTux. But ReTux isn’t a copy.
ReTux may look like
downloads, including source code, The visual similarity is because and the way you navigate the island
SuperTux, but that’s only
are encrypted. ReTux has taken the art assets and because reTux has setting will feel very similar to Super
You need to pay $4.99 USD or used them within its own game borrowed some of the Mario or The Great Giana Sisters, as
more to receive the password that engine, implementing its own same images. will the coin collecting, jumping and
unlocks the files and gain access to gameplay mechanics such as throwing things as you attempt to
either a set of executable binaries, infinite lives, defaulting to running reach the flagpoles at the end of
or the full Git log and source code rather than walking, super-powers each level. It’s now a classic game
from the development repository. that come from special items and a mechanic and it’s obvious a lot of
There isn’t even a demo version you colour palette that is apparently thought and appreciation of the
can try. But we respect the accessible to colourblind people. genre has gone into the game.
developers for trying a different There are 41 levels, plus a level
funding strategy, and while anyone designer, with some puzzle Project website
can presumably ask for the source elements. The way you progress www.nongnu.org/retux

www.linuxvoice.com 69
INTRO TUTORIALS

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

In this issue . . .
72 74

Boinc: Help scientists do Encryption with
Mike Saunders
Finds too many TLAs a PITA. science more betterer Veracrypt
Advance the world of science with Boinc, and Nate Drake checks out the key features of the
become a scientist without even leaving your desk. latest fork of Truecrypt, employing military-level

O
ne of the terms we often use in Ben Everard explains all. encryption for your data.
Linux Voice is FOSS, for “Free
and Open Source Software”. It’s
a useful shorthand way of expressing a 78 82
couple of philosophies in our
community, but it’s also a bit of a
cludge. Can’t we settle on one simple
description? I understand that from the
perspective of GNU founder Richard
Stallman, the “free” highlights freedom
more than low cost or practicality. But it
can be misinterpreted – for instance Raspberry Pi: Physical Photography: image
with dodgy Windows “freeware”.
Indeed, I asked Richard about this a
computing processing
few years ago: whether, looking back, Go back to basics with Les Pounder and discover Apply smart fixing, processing and storing
another word like “libre” may have made physical computing with Python, a Raspberry Pi, techniques to your images. Alexander Tolstoy
more sense. He seemed to agree that and a bunch of LEDs. saves you time, so you can watch more cat videos.
“free” has led to ambiguities, but
hammering home the “free as in
speech, not beer” line has helped to Coding
explain. Personally, I like to use the term
“Free Software” as the freedom is
Get access to ev
incredibly important to me – the ery
Linux Voice tuto
freedom to use, share and modify rial ever
published in ou
software. Freedom from spying r digital
library of back-i
governments and companies. Freedom ssues
available exclus
to keep software and hardware running ively to
subscribers – tu
for as long as its users wish, without rn to
page p56 to join
enforced obsolescence. I’ve nothing Solr 86 Build packages 90 .
against the term “open source”, but I do Add some order to the chaos that Valentine Sinitsyn explains the
share Stallman’s concerns. is the Linux Voice back catalogue tech and tricks behind creating
mike@linuxvoice.com with a search engine. nicely wrapped-up packages.

www.linuxvoice.com 71
TUTORIAL BOINC

ADVANCE THE WORLD OF
SCIENCE WITH BOINC
Ben Everard gets a labcoat and becomes a scientist without ever leaving his desk.

B
BEN EVERARD oinc is a bit of software that lets you pass on power to try to improve the sum of human knowledge.
your spare CPU time to projects that need the There are a huge range of projects on Boinc, including
Why do this? computing power. By dividing a task between analysing data gathered by telescopes, building our
• Help scientists do thousands of Boinc users – each of whom contribute understanding of diseases and investigating the
science some of their spare CPU cycles – research structure of proteins. By working with this software,
• Put spare computing institutions can get a huge amount of computing you’re contributing to these highly worthwhile fields.
power to work
• Save the polar bears

STEP BY STEP: SOLVE CLIMATE CHANGE
1
Install software 2
Select a project – Climateprediction.net
If Boinc isn't in your distro's repositories, you’ll need to There are a huge range of Boinc projects, most run by
grab it from the project’s website: https://boinc. researchers at universities around the world; we’ll use
berkeley.edu. This will download a shell script that the climateprediction.net project, as it runs on Linux
you need to run to create the BOINC directory. Inside and it’s a project that we think is important. Open up
this directory you’ll find two programs called run_ Boinc and go to Tools > Add Project, search for
client and run_manager. Run these with: climateprediction.net, and then press Next. For the
./run_client --daemon first use, we recommend not joining a team or adding
./run_manager extra details, as you can do this later if you choose.
There’s detailed troubleshooting information at
https://boinc.berkeley.edu/wiki/Installing_BOINC.

3
Advanced mode 4
Will it gobble your CPU? Nice!
Boinc's default interface is designed to make it easy All Boinc processes have a nice value of 19. The nice
for non-technical people to join projects, but we prefer value is used to determine what processes to run on
the Advanced View. Go to View > Advanced View (or the CPU at a given time. The higher the nice value, the
press Ctrl+Shift+A) to switch the interface. The less likely the process is to run, and 19 is the
Advanced View gives you a tabbed interface where maximum they can be. In other words, the nicer a
you can see much more about what’s going on process is, the more it lets other processes run first. If
including the specific tasks that are running, the there are any other processes that need to run, the
amount of storage that’s being used and statistics for kernel will select those rather than the Boinc ones, so
how things are running. Different projects run in your machine's performance shouldn’t suffer.
different ways, so it can be interesting to see how they
make use of your computer.

72 www.linuxvoice.com
BOINC TUTORIAL

5
Adding more projects 6
Set up a team
You can add as many projects to Boinc as you like, but Teams in Boinc are used to report where the
since you only have a set amount of computing computing resources have come from. They’re not
power, the more projects you add, the less CPU time important in the grand scheme of things, but enable
each one gets. Boinc will, by default, split your people to show how much computing resources
computing power evenly between all projects you add. they’re contributing as a group. For example, you can
You can control the share of your computing power see the most active teams on Climateprediction.net
that each project gets in the project’s settings. here: http://climateapps2.oerc.ox.ac.uk/cpdnboinc/
Highlight a project in the Projects tab and click Your top_teams.php. You can apply to join a team by
Account. This will open your web browser and take searching for a team, and clicking ‘Join This Team’ on
you to the project’s settings page where you can their webpage. Alternatively, if none of them are a
configure all your settings. Go to the project’s good fit, you can create your own team by going to
Preferences link (eg ClimatePrediction.net the Teams website (for climateprediciton.net, this is
Preferences), and click Edit. You can now increase or http://climateapps2.oerc.ox.ac.uk/cpdnboinc/team.
decrease the share of your CPU that this project gets. php), and clicking Create A Team. Creating a team
The higher the number, the more CPU time it gets. could be a good option if you have several computers
that you contribute from and you want to see how
powerful they are.

7
Settings 8
Boinc mobile
In the default setup, Boinc should stay out of your way Most people have a low-power computer that runs all
and just run in the background when you have spare day every day – their smartphone. Although the
CPU cycles. However, if you do encounter a slow- computing power of a single phone is quite low when
down, there are configuration options that you can compared with a desktop, the combined power of
use to tweak the way the software runs. thousands or millions is still significant. At present, the
Under Options > Computing Options you can set software’s only available for Android, and you can find
limits on the amount of computing power that can be it in the Google Play Store.
allocated to Boinc projects such as a limit on the total The obvious concern with sharing your phone’s
amount of CPU time or CPU cores. The Disk And computing power is that it will drain the battery or use
Memory tab in this options screen is particularly up mobile data. Boinc on Android will only start
useful, as these are often the resources that Boinc can processing if the device is connected to the mains
cause problems with. Another way of limiting Boinc is and fully charges, and it will only transfer data over
getting it to stop when particular software is running Wi-Fi. For most people, this means that it’ll happily
– this is great if you have some software that requires share your phone’s computing power overnight, but
plenty of computing horsepower that you don’t want not run when you’re out during the day.
to slow down.

www.linuxvoice.com 73
TUTORIAL VERACRYPT

ENCRYPT YOUR FILES
WITH VERACRYPT
Explore the features of the latest fork of the Truecrypt safekeeping solution to
employ miltary-level encryption on your data.

T
NATE DRAKE ruecrypt is dead. Long live Veracrypt! On 28 using it to protect your most sensitive personal
May 2014, the developers of the handy information.
Why do this? encryption program Truecrypt suddenly
• Use multiple announced that they would no longer continue Three cheers for cascades
encryption ciphers maintaining the software. Most popular distros of Linux, including Ubuntu and
simultaneously to The mysterious programmers behind the project Linux Mint, now offer system encryption by default as
protect files in case
any one is broken. recommended switching to Bitlocker instead. This well as the option to encrypt your home folder.
• Use plausible came as a bitter blow to those who had previously Gnome’s disk utility has the option to format a drive
deniability to keep used this cross-platform utility. Truecrypt’s popularity with LUKS so it requires a password to access. This
your data safe even if stemmed from the fact that it provided a simple GUI begs the question why there’s any need for additional
you’re forced to hand
over a password. to create encrypted containers of any size wherein encryption software.
• Combine passwords files could be placed. It also enabled users to quickly Aside from the benefits of being cross-platform, the
with keyfiles to and easily encrypt an entire USB stick or hard drive. answer is that Veracrypt employs cascades of ciphers.
strengthen hugely Users of the Windows version also had the option to In addition to the default encryption algorithm used
the protection of
you encrypted encrypt their entire operating system. by LUKS, which is AES, Veracrypt also offers Serpent
information. For Linux users, there were few viable alternatives and Twofish (Twofish was developed by security guru
that allowed such powerful encryption to be employed Bruce Schneier, and is based on Bruce’s previous
so easily, which is perhaps one of the reasons why block cipher Blowfish, which was developed in 1993
French IT security consultant Mounir Idrassi decided but is still very widely used). Most crucially, Veracrypt
to fork the Truecrypt project and create Veracrypt. allows creation of encrypted file containers or drives
Version 1.17 of Veracypt was released in February using any one of these drives or a combination such
2016 and continues to be maintained. Although the as AES-Twofish-Serpent.
GUI is not particularly intuitive (as with Truecrypt) it The degree to which using cascades of ciphers
only takes a matter of minutes to install and start protects your data rather than relying on just one
really can’t be overstated. For instance, if you choose
AES-Twofish-Serpent, each 128-bit block of data is
first encrypted with Serpent, then with Twofish , and
finally with AES. Each of the cascaded ciphers uses its
own key. All encryption keys are mutually independent
so that all three ciphers must be broken without the
correct key to access your data.
There is no need to remember this however, as
the volume creation wizard explains each cipher
when selected in the drop-down menu as well as
how each cascade of ciphers operates. Naturally
employing multiple ciphers will also come at a cost
in processing speed, so it’s best to make use of the
handy ‘benchmark’ button to test the speed of each
algorithm in RAM.
The volume creation wizard also enables you
to choose your own hash algorithim; currently the
options are SHA-256, SHA-512 and Whirlpool. One
of the criticisms of Veracrypt’s predecessor Truecrypt
was that it used the rather dated RIPEMD-160.
The volume creation wizard helpfully explains how each encryption algorithim is applied. Veracrypt can open old Truecrypt volumes using this

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Use entropy from the
mouse to generate random
keyfiles. You can also
randomise their size.

hash, but for security reasons no longer employs it to this also enables multiple people to access the
create new volumes. same encrypted volume. The veracrypt volume
can be created using only a keyfile to open it, and
Keyfiles knowhow each person can then encrypt said keyfile with the
If cascade ciphers and more secure hashes don’t tip password of their choice.
the balance in Veracrypt’s favour, the volume creation Veracrypt has a built-in generator for random
wizard also enables the use of keyfiles in addition to a
password. In simplest terms a keyfile is a file whose
content is combined with a password to open a
Without both the keyfile and the correct
volume. Without both the keyfile (or keyfiles) and the password, the encrypted Veracrypt
correct password, the encrypted Veracrypt volume will
not open. volume will not appear
This provides a huge benefit firstly in that it will
become much harder to ‘brute force’ your password keyfiles, using entropy gained from wiggling your
as the encryption key will be combined with the data mouse within its window. The downside of using
in the file. Secondly, it is more in keeping with the Veracrypt’s own keyfiles is that they are quite obviously
modern standard of two-factor security such as a just random data, so would be easy to detect.
password combined with a security token or smart One way to increase security is to generate a
card. If the keyfile itself is protected by a password, number of keyfiles but only use a certain number

Getting started
Head over to https://veracrypt.codeplex.com/releases/ Veracrypt you’ll need to run the script ‘veracrypt-uninstall.sh’.
view/619351 to download the Linux version of Veracrypt. The If you prefer to download and compile the source code
more security-minded might also wish to verify the download yourself, download it from https://veracrypt.codeplex.com/
via the PGP signature. The user guide can also be downloaded wikipage?title=Downloads extract it and open README.md
from this page. in your favourite text editor. Scroll down to the section titled
Use your favourite archiving program to extract either ‘Instructions for Building VeraCrypt for Linux and Mac OS X’
‘veracrypt-1.17-setup-gui-x64’ or ‘veracrypt-1.17-setup- and follow the steps there.
gui-x86’ depending on your processor architecture. If in doubt, If you’re using a GNOME Desktop Environment, veracrypt
choose the second of the two. should appear right away in your Accessories post-install.
Next in Terminal run Otherwise you can run it from terminal with
chmod a+x sudo veracrypt
code plus the filename to make it executable and run it. Veracrypt needs admin rights to be able to mount an
You’ll be welcomed to the installer. Choose to run ‘Install encrypted volume so may ask for your password if you choose
Veracrypt’ rather than extract the Tar Package and agree to to run without
the terms and conditions. You’ll also be told that to uninstall sudo

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TUTORIAL VERACRYPT

from the Linux command line or the free erasure
software Darik’s Boot and Nuke.
While this may be true theoretically, key disclosure
laws in many jurisdictions place the burden of proof
upon the suspect. An unscrupulous adversary may
also employ ‘rubber hose cryptography’ ie torture
or coercion to obtain a password from a volume
they suspect to be encrypted. Moreover, if you use
Veracrypt to create an encrypted file container rather
than encrypt an entire drive, there is really no plausible
reason for you to have a large block of useless
random data on your computer.
For this reason, Veracrypt has an option to create a
hidden volume inside your main encrypted container
or drive. As the name suggests, the hidden volume
is created within the free space of another Veracrypt
volume (the ‘outer volume’). When the outer volume
is mounted, it is impossible for an adversary to be
certain that there is a hidden volume inside, as any
The hidden volume lies
of them, eg only the last three files of a group of 10. free space is always hidden with seemingly random
inside the outer volume.
Veracrypt will let you know It’s also possible to use any kind of file as a keyfile, data anyway. Even the headers to the hidden volume
the maximum possible size such as an MP3 or JPEG. Provided there are enough are encrypted, so there is no way to determine if they
to avoid overwriting data. picture/music files on your system, an adversary are valid data without the correct password.
would have a much harder time divining which one When using the volume creation wizard, you have
is the keyfile. If you choose to use an ordinary file to the option to create a hidden volume with a separate
do this, however, bear in mind that if even one of the password and/or keyfiles to the outer volume.
Once your outer volume is mounted, copy some
plausible-looking files there and make a note of the
Veracrypt has an option to create a password. This is the password that you would give
hidden volume inside your main up if compelled to provide one, which would lead
your adversary only to the dummy files. The hidden
encrypted container or drive volume would be mounted separately with a different
password, and would contain your truly personal files.
first 1024 kilobytes of your file changes, the key will no When the outer volume alone is mounted, even
longer be valid. Veracrypt cannot determine if a hidden volume exists,
and if you copy data to it, it may overwrite files already
Plausible deniability in your hidden volume. Fortunately Veracrypt has a
Although any file can be a keyfile, it’s not easy to hide
the fact that you are employing encryption in the first
Volume creation
place. Gnome’s disk utility, for instance, makes no
effort to hide the LUKS header if used to encrypt a To create an encrypted volume on Veracrypt, head over to
the Volumes menu then Create New Volume.
drive, so while it may not be possible to access your
You’ll first be asked to choose whether to create a file
data, it may be clear to your adversary that you have container which can be mounted as a virtual drive and have
something to hide and you may run afoul of your files placed inside it, or to encrypt an entire non-system
country’s key disclosure laws. partition such as a USB stick. Choose accordingly and
In the UK for example, the Regulation of then click ‘Next’. Choose your volume type, in this case,
Standard. You’ll next be asked to choose the location
Investigatory Powers Act (2000) requires members of
of your file container, so click on Select File to choose a
the public to provide their passwords when requested location and a name eg myfiles.vc. Clicking Next will let
to the police. Failure to comply can result in up to two you choose your encryption algorithim and hash. If you're
years in prison. In 2010 a 19-year-old in Lancashire stuck, stay with the default options (AES + SHA-512), then
was sentenced to 16 weeks in a young offender’s click on Next.
You’ll be asked to specify the volume size. Veracrypt will
institution for refusing to cooperate with a formal
also state how much free space is available. Click on Next
order to hand over his password. to choose a password and add any keyfiles. Once these
Veracrypt encrypts all volume headers, so by are entered, click Next to choose a filesystem. The default
analysis of a drive alone, it’s not possible from a of FAT is probably best provided you don’t plan on storing
technical perspective to determine that the data on files larger than 4GB. (You can choose Linux formats and
even NTFS if you wish though.) Finally you’ll be asked to
it is encrypted. The data appears to be random and
move your mouse inside the Veracrypt window to gather
could be there as a result of a secure wipe of the drive randomness. The longer you do this, the harder it will be to
by using brute-force your volume password.
dd

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Plausible deniability
Although it can be difficult to convince a shadowy
government organisation that your encrypted files are really
just random data, the first step is to use an external drive,
rather than create a file container. The Veracrypt project
recommends drives that don’t implement wear-levelling
such as SSD’s and USB sticks, as traces of a hidden volume
may remain, so consider using an old-school hard drive with
magnetic storage if available.
Once inserted, head to the Volumes menu on Veracrypt
and Create New Volume. Next choose to ‘Create a volume
within a partition/drive’. Click on Next then on Hidden
Veracrypt Volume. Click Next then Select Device, then the
main partition of your external drive eg /dev/sdb1.
You’ll be asked to choose the outer volume encryption
algorithim and hash. You can then specify an outer volume
password and/or keyfiles. Remember these must be
plausible, so choose a secure password (20+ characters).
Click Next to start generating randomness from your mouse
movements, then Format to begin creating the volume. Any
files already on the volume will be lost.
Once volume creation is complete, you’ll see it’s been
automatically mounted. Click on Open Outer Volume and
copy some plausible-looking files into it. Click on Next
when you're done to begin creation of the hidden volume. Example of a Cold Boot
Choose whatever Cipher and Hash Algorithm you wish, then Many of the updates made to Veracrypt have been
attack. Cooling RAM
click next. You’ll then choose the size of the hidden volume. done to simplify the original Truecrypt code used chips with compressed air
Veracrypt will tell you the maximum possible size. Choose as well as make it easier for users to download, preserves data in virtual
Next and then Format to create the hidden volume. verify and compile the source code themselves as memory, like such as
It’s highly advisable to visit Veracrypt’s wiki and read
any privacy-minded person should. Some of the encryption keys, which can
Security Requirements and Precautions Pertaining to
Hidden Volumes for some help on best practices for improvements made by Veracrypt have resulted in then be harvested with
plausible deniability. longer access times to mount encrypted volumes, specialised pen-testing
although this has been cut in half with the most software.
recent release of the software. Source: https://www.ethicalhacker.
feature named ‘Hidden Volume Protection’ To prevent Mounir was kind enough to take time to speak net/features/root/using-cold-
boot-attacks-forensic-techniques-
this when mounting the outer volume on Veracrypt, to Linux Voice about the Veracrypt project. Of late, penetration-tests
click Mount Options when accessing the outer the main focus has been on developing support
volume and enter the password there to your hidden for Windows UEFI encryption, as he claims that
container. In this way, the data inside your hidden currently there is no open source software available
volume will not be affected. for this. Nevertheless the Linux version is under active
Plausible deniability will naturally only be effective if development, and anyone interested in finding out
the data in the outer volume is something you would more or devoting their time is welcome to contact the
genuinely wish to hide, so placing vintage episodes of project on veracrypt@idrix.fr.
the TV show Blockbusters in there, for example will be Veracrypt also will not protect against so-called “Evil
unlikely to impress an adversary. Maid" or “Cold Boot” attacks, whereby an adversary
has physical access to the machine on which you
Veracrypt viability mount the volumes. This vulnerability isn’t unique to
No security solution is perfect. While accessing an Veracrypt but can be reduced by employing keyfiles
encrypted volume in Veracrypt for instance, the and keeping your machine physically secure.
operating system may write to unencrypted volumes. Finally, given the extensive security features already
The existence of a hidden volume may be revealed by listed, it should be obvious that failure to put in the
analysing an encrypted drive or container at different correct password and provide all the correct and
stages eg if you place it inside a cloud storage service unaltered keyfiles will result in the encrypted volume
like Dropbox. The Veracrypt website recommends failing to open. Either make sure to write these down
storing encrypted data offline and accessing via a live or use a password manager like KeePass.
Linux CD where possible. Some of the wariness of Whether you’re a hardened security guru or a
Veracrypt stems from the Truecrypt project. In April beginner, Veracrypt offers some dazzling security
2015 a full security audit of the 70,000 lines of code in features. As with all security issues, it’s important
Truecrypt was completed by the Open Crypto Alliance to explore these yourself and invent a solution that
Project. The full results of their findings are available works for you.
from the Alliance’s website, but in brief no evidence of
any deliberately coded backdoor was found, nor were Nate Drake is the author of "Locking Down Facebook", a free guide to
any major vulnerabilities. protect your privacy while using the social network.

www.linuxvoice.com 77
TUTORIAL LINUX FOR LEARNERS

PYTHON AND PHYSICAL
COMPUTING
Go back to basics and introduce physical computing using the Raspberry Pi.

T
LES POUNDER aking your first steps into coding and physical
computing can be a little daunting. Even the
Why do this? relatively simple task of turning on an LED can
• Learn electronics fill a new user with dread. But this challenge is
• Learn the basics of immensely rewarding and will unleash a new way of
Python thinking – the way a maker thinks! So to ease you into
the new world of the maker we shall use three
You will need
projects, each of which will build upon the last and
• Any model Raspberry
introduce new programming concepts. The goal of
Pi running the latest
Raspbian release these projects is to get ourselves familiarised with
• A mixture of female hardware components and how we can control them Our project uses one simple circuit built upon a
to male and male to in different, and relatively simple ways. breadboard to demonstrate essential coding concepts
male jumper wire
For all of the projects we shall use one simple and maker skills using Python.
• 3 x LED (red, amber,
green)
circuit. The basic circuit comprises an LED that is
• A breadboard
connected to the GPIO of the Raspberry Pi. The long It encourages the learner to attempt it and rewards
• 3 x 330Ω
leg, the anode, is connected to a specific GPIO pin; this them quickly with a view to further challenges.
resistor (orange, is set in the code for each project later in this tutorial. In this first project we shall flash each of the LEDs
orange,brown) The short leg, the cathode is connected to a ground present on the breadboard. Each LED will flash three
• 3 x momentary rail on our breadboard via a 330Ω resistor. This circuit times in rapid succession before moving on to the
switches (buttons)
is replicated so that there are three occurences on the next. Via this project we shall learn to import libraries
breadboard. A push button is also inserted into the to enhance our code. We also learn about variables
breadboard, so that the legs of the button are across and two types of loops.
the centre channel of the breadboard. The button To get started, open the Python 3 application from
is also connected to a specific GPIO pin, and to the the Programming menu, found in the top-left of the
common ground rail of the breadboard. Raspbian desktop. Once this is open click on File >
Please refer to the diagram at https://github.com/ New to create a new blank document. Now click on
lesp/LV31-Python-Basics/archive/master.zip for a File > Save and call the file Project-1-LED-Flash.py.
detailed overview of the circuit. Subsequent saves will be instant.
Our first two lines of Python will be to import
Project 1 – Flashing an LED 1001 external libraries into our code, namely the GPIO Zero
We start our projects using a simple flashing LED as a and Time libraries. Importing libraries is a way of
means of output. In this era of virtual reality and high- adding extra abilities to your code. For example, by
definition gaming, the humble LED is still seen as the adding the GPIO Zero library we can now interact with
“Hello World” of physical computing. The first project the GPIO pins. There are many libraries for Python and
with hardware and software should always be simple. we go into detail via the boxout in this tutorial.
From the GPIO Zero library we import LED, which
this will enable us to interact with the LEDs. From the
Time library we import sleep, which will enable us to
control the pace of our project.
from gpiozero import LED
from time import sleep
This circuit diagram shows
The next section of code contains four variables.
where every component
needs to be placed. We Variables are containers for information. They can
used Fritzing (http:// store anything that we need to store, from a person's
fritzing.org/home) to draw name to sensor data. A variable is given a name,
the diagram. typically one that reflects the expected content. In

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this project we create four variables:, the first three The Raspberry Pi website
(red, amber and green) are used to store the number has plenty of resources for
of the pin that will be connected to the long leg of our you to investigate at your
LED. We use the GPIO Zero LED function to call and leisure. They cover most
topics and ability ranges.
store the location, which is then neatly wrapped up
www.raspberrypi.org/
in our variable. The fourth variable, flashes, stores an resources.
integer value, a number that has no decimal place.
This integer will control how many times each LED will
flash, hence its name.
red = LED(17)
amber = LED(27)
green = LED(22)
flashes = 3
We now move on to the main loop that will control
our project. To run the code indefinitely we use a
while True loop. This is an infinite loop that will run the sleep(0.5)
code contained therein forever. As you can see in the Once the red LED has finished flashing, the for loop
code, after starting the loop the code underneath is ends and returns to the next line in the main loop. The
indented. Python uses indents to identify where code next line in this example is another for loop that will
belongs. In this case the code belongs in the infinite flash the amber/yellow LED in the exact same fashion
loop. as the red LED. This code is indented in the exact
while True: same manner as the previous red LED sequence.
We now start a new loop inside the main loop. The for i in range(flashes):
new loop, a for loop, will use a range to control how amber.on()
many times it goes round. The range is a number that sleep(0.5)
we want to count to. In this case we use the variable amber.off()
“flashes” to control the number of times that we wish sleep(0.5)
to flash the LED, the default value being three times. We repeat the same code for our green LED,
for i in range(flashes): replacing amber.on() with green.on().
The code now indents a further four spaces as we With this code complete, save your work and
have just created a new for loop and now we need click on Run > Run Module to start the LED flashing
to write the code that will be actioned for a certain sequence. Now watch your LEDs and count how
number of times. This is the code that will flash many times they each flash. An extension activity for
our LED on and off. Earlier we named each variable this project would be to change the number of times
after the colour of LED we wish to use. So we need the LED will flash, and then change the speed at which
to turn on each colour, wait for half a second using it flashes. To stop the code at any time press Ctrl+C
sleep(0.5), then turn off the colour before another
sleep is used. This last sleep is important, otherwise Project 2 – Random choice LED 989
we will not see the flash effect. So here we see the For project 2 we add a random element to our code.
code that will flash the red LED, and this is inside of a In this project we reuse the same circuit as Project 1
for loop that will iterate three times before it exits. but this time we introduce user input in the form of a
red.on() button. Once the button is pressed it triggers the code
sleep(0.5) to choose an LED at random and then flash the LED.
red.off() Click on File > New, to open a new blank document.

Python libraries
In this tutorial we lightly touched upon Python libraries, in the shell. Once you're done with the help tool press Ctrl+D to
sometimes referred to as modules. Libraries are a great way of exit back to the Python shell.
adding extra functionality to your code, but what libraries are If you need to install a particular library then you'll need to
included as standard? Well if you would like to find out, open open the Linux Terminal, the icon for which is located in the
the Python 3 shell by clicking on Run > Python Shell. In the top-left of the Raspbian desktop. In the new terminal window
shell type this command followed by Enter. type
help() $ sudo pip3 search NAME OF THE LIBRARY
You will now see a helpful message giving instructions on If you don't know the library name just type a keyword, for
how to use the tool. We're interested in the modules, so type example “twitter” to show all the Twitterrelated libraries. Once
modules and press Enter. It may take a few seconds for the you have found a library to install, in the terminal type
list to appear but it will show a complete audit of every Python $ sudo pip3 install NAME OF THE LIBRARY
library installed and ready for use. If you're interested in a This will install the library and further enhance the
particular library then you can learn more by typing its name possibilities of your projects.

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TUTORIAL LINUX FOR LEARNERS

If you are a little baffled We now enter into an infinite loop, while True, which
by the GPIO pins, fear not: is identical to what we created in Project 1.
http://pinout.xyz, Written while True:
by Phil Howard from Our next line of code is a conditional statement, in
Pimoroni, is your single this case it simply asks whether the button has been
resource for all of the pins. pressed, (remember that “button” refers to the variable
we created earlier). When the button is pressed
the GPIO Zero library understands that the button
changes the state of the GPIO pin it is attached to.
When left unpressed the GPIO pin connected to the
Immediately save your work as Project-2-Random- button is pulled high, meaning that it is turned on and
LED.py and remember to save regularly. flowing with current. When we press the button we
We start in the same manner as Project 1, by connect this high pin to the GND, pulling the GPIO pin
importing a series of libraries to add functionality to low and triggering a change of state which GPIO Zero
our code. But in this project we import Button from uses to identify a button press.
GPIO Zero. This will enable us to use any free GPIO if button.is_pressed:
pins that we wish as a button. We also import the We now need to write the code that will be actioned
choice function from the Random library, a function when the button is pressed; as with Project 1, any
that enables us to introduce a random choice element code that belongs to a loop or a conditional is
to the project. indented to identify where it belongs. So when the
from gpiozero import LED, Button button is pressed we create a variable called colour
from time import sleep that will store the answer to a random choice of the
from random import choice LED colours in the LEDS list we created earlier. We
Just as in Project 1 we declare variables to handle then print this to the Python shell for debug purposes.
the locations of our LEDs, which are attached to Remember that printing output to the shell is a great
specific GPIO pins. But in this project we introduce a way to understand how the project works, and it helps
button, sometimes called a momentary switch. This when debugging a problem.
colour = choice(LEDS)

Printing output to the shell is a great print(colour)
Just as in Project 1 we create a for loop that will
way to understand how the project iterate for the number of times stored as an integer

works, and it helps when debugging in the flashes variable. But what's different this time
is that we use the colour variable that we have just
created. The colour variable stores the colour of the
button is attached to pin 2 of the GPIO and so using LED that has been randomly chosen. So rather than
the GPIO Zero library we declare that there is a button explicitly call the LED by its colour we just use the
attached to said pin. Our last variable, flashes, handles colour variable and add on() or off().
how many times the chosen LED will be flashed. for i in range(flashes):
red = LED(17) colour.on()
amber = LED(27) sleep(0.5)
green = LED(22)
button = Button(2)
flashes = 3
Our next line of code requires an introduction.
LEDS is a list, data that is stored as a list of comma
separated values. In other languages a list is
sometimes called an “array”, but they all work in much
the same manner. A list can be used to store lots
of values, in this example we use a list to store the
variable names used for our LEDS. Lists are indexable,
meaning that we can retrieve data from any part of
a list, and we can also add and delete data in a list.
Our list contains three items of data, numbered 0,1,2,
as Python starts counting from zero. So red is 0, and
if we wanted to print that value of red we would use
print(LEDS[0]) and it would print the content of the
variable red. We cover more about Lists in the boxout.
So now we create our LEDS list and use it to store the
LEDs we have attached. Components such as buttons, resistors and LEDs are
LEDS = [red,amber,green] cheap and plentiful.

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colour.off() Once you have mastered
sleep(0.5) this project you are ready
to move on to our Biscuit
And with this last section of code completed we
Security System project
should now save our work, then click on Run > Run
https://www.linuxvoice.
Module to start the code. Now press the button next com/raspberry-pi-simple-
to the red LED to start the random choice. Due to forms-of-input.
the small selection of options you will see the same
colour chosen quite often – it only has a 1 in 3 chance
of being chosen. An extension activity for this project
would be to add more LEDs and create a lightshow
that runs before the colour is chosen to give the
illusion of lots of options being computed.
our LEDS are turned off before we turn any more on.
Project 3 – Conditional LEDs 891 This loop iterates through all the colours in the LEDS
For our final project we shall adapt our code to create list we created, turning each of them off.
a function, a method of running a sequence of code for led in LEDS:
by calling its name. The goal of this project is to press led.off()
a button and have a corresponding LED light up. We next break out of the for loop, but remain inside
Click on File > New to open a new blank document. the function. Our next six lines are a conditional
Immediately save your work as Project-3-Pick-A- statement that will test to see if the argument passed
Colour.py and remember to save regularly. We start to the function is one of the three LED colours that we
our code by importing the libraries that will provide have used. If the colour passed is not red then the test
the GPIO functionality for our LEDs and buttons and is repeated for amber and green. For each condition
control the pace of our project. These are the same as we indent the code to show what will happen if the
in Project 2. condition is true.
from gpiozero import LED, Button if colour == "red":
from time import sleep red.on()
As with our previous projects we create variables to elif colour == "amber":
state the GPIO pin used for our LEDs. amber.on()
red = LED(17) elif colour == "green":
amber = LED(27) green.on()
green = LED(22) The final part of this project is to create an infinite
Next we create three new variables; these are loop that will constantly run a conditional statement
used for our three buttons, which represent each of to check which button has been pressed. When a
the coloured LEDs in our diagram. Each button is button is pressed it triggers the code for that condition
attached to a specific GPIO pin which we now declare. to be executed. In this case it will print the colour of
red_button = Button(2) the LED to be lit (we do this for debugging purposes).
amber_button = Button(3) We then call the lightup function and pass the
green_button = Button(4) argument, being the colour of the LED to be lit.
The list that we created in Project 2 is re-used to if red_button.is_pressed:
contain the names of the LEDs that we have created print("RED")
as variables. lightup("red")
LEDS = [red,amber,green] elif amber_button.is_pressed:
Our next section of code is where we create a print("AMBER")
function. A function is a sequence of code that we lightup("amber")
can execute by calling its name in the main body of elif green_button.is_pressed:
code. Functions come in two forms, a basic function print("GREEN")
that when called will execute the code contained lightup("green")
within. But the most useful is a function that takes an Our last line of code is outside of the conditional
argument, an extra parameter/instruction that it can statements but is still inside the main loop. It simply
act upon. We are going to write a function that will instructs the code to sleep for a tenth of a second
take the colour of the LED that we wish to illuminate between checking the status of the buttons.
as an argument. sleep(0.1)
We start by defining the name of the function, in With the code now complete, ensure that you save
this case lightup. Inside of the brackets we give a your work. Once it's ready, click on Run > Run Module
placeholder name for the argument, which is “colour”. to launch the code and press one of the buttons on
def lightup(colour): the breadboard to trigger the light of your choice.
So now our code is indented to signify that it is
part of the function. Our first two lines of code in the Les Pounder makes things, breaks things, and spends the rest of his
function are a for loop. This loop will ensure that all of time teaching teachers about the new IT curriculum.

www.linuxvoice.com 81
TUTORIAL PHOTOGRAPHY

IMAGE PROCESSING,
FIXING AND STORING
Apply smart fixing, processing and storing techniques to your images.

T
ALEXANDER he days when digital cameras produced
TOLSTOY terrible results with noise, blur and pale
colours – which led us more often than not to
Why do this? Gimp to fix things – are gone. Now when most people
• Perform mundane take point-and-shoot photos with their smartphones,
tasks with batch
processing most of the work is performed automatically –
• Clean up dust and cameras apply smart logic to produce perfect JPEGs
scratches while various cloud services (starting with Google)
• Save space with upload your gallery online. But there are still other use
sensible file formats
cases where manual intrusion is needed – scanning
and restoring old photographs, playing with creative
collages, photo retouching, backing up huge amounts
of graphic data and so on. In this tutorial we'll take a The healing brush in Krita is easy to set up, and it
look at certain techniques that will help you apply an produces great results in retouching skin defects.
action to many images at once, fix specific image
defects and optimise your storage. ratio and angle of the brush right in the clone options.
When it comes to image editing, the undisputed Hardness and shape should be adjusted in the brush
king of the hill is Gimp. Here we can do almost catalogue, which can be invoked also from within the
anything with bitmaps, and we'll start with the clone clone tool options. It's best to press the Edit button
tool. Click its icon on the toolbar (it's depicted as a and adjust all available brush parameters to match
Overlap dust and scratches
with patches of the stamp), then Ctrl+click the source area (which the tool your liking.
'healthy' neighbouring will copy pixels from), move your mouse to the target Cloning lets you fix certain defects, like dust and
pixels – that's the essence area and start painting by clicking and holding the left scratches, but it is also useful for removing undesired
of the new method. mouse button. Gimp lets you adjust the size, aspect objects from a photo. Say, you've got a marvellous
portrait taken on a sea shore, but people on the
background deflect the attention of the viewer. Playing
with the brush settings for the clone tool in Gimp
you can gradually remove strangers by accurately
cloning sand, water and sky parts and make your
photo perfect. By the way, you can do the same in
other Linux software too. For instance, Krita – a part
of the KDE-centric Calligra office suite – has the Edit
Brush Settings button on its top toolbar, where you
can select the clone brush engine and proceed with
stamping exactly the same way you did in Gimp.

Photographer, heal thyself
Krita and Gimp are the most bold and feature-rich
Linux graphics applications; now, let's look at their
healing capabilities. The healing brush is an advanced
version of the standard clone tool. It can be found as a
separate tool at the Gimp toolbar (it looks like a yellow
adhesive bandage), or as an option in Krita's brush
engine settings (Painting Mode > Healing). Either
application you choose, healing is preformed in the
same way as cloning – you set the source area and

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transfer it to the target are – but unlike plain cloning, a
healing brush respects surrounding pixels and lets
you carefully recover texture and colour tone in
damaged areas. When working with skin defects
healing performs noticeably better than cloning and
lets you avoid blurred areas caused by a soft brush.
The next big thing we'll do in this section is
removing dust and scratches – very common defects
that frequently occur in digitised historic pictures.
The problem is that you can hardly automate dust
removing routines, and in most cases you'll need
to diligently remove each spot with dozens (if not
hundreds) of cloning or healing actions. Luckily, there
exists an original technique that greatly reduces the
amount of work. Again, we'll be using the best image
editor for Linux – Gimp.

Logical programming
The idea comes down to the following steps. First
create a copy of the current layer, desaturate it and
increase the brightness and contrast to much higher
Batch processing is easier
levels, so that dust and scratches will turn to exactly routines by hand. Luckily, they need not, and in the
than you might think.
white spots, but midtones will remain at their shades following examples we’ll find out how to automate Don't do so many recurring
of grey – you'll need to play with brightness and bulk actions. actions by hand!
contrast sliders to achieve the best result, as it will be The first common action is resizing. Say, you need
individual for each image. Now choose the Select by to attach 20 images to the email, but the recipient
Colour tool and click anywhere on a dust or scratch. doesn’t need that many megapixels in each photo,
Hold down Shift and click on a lightest grey pixel while the web server would simply reject the very
somewhere nearby to add more area to your big attachment. The easiest way to scale down
selection. You now have a mask of defects, which
includes some undamaged areas as well – don't
worry, we'll deal with it later. Now extend your
We'll remove dust and scratches – very
selection by one pixel (Select > Grow) and soften it by common defects that frequently occur
some more pixels (Select > Feather). You can now
delete the current overburned layer safely – look how in digitised historic pictures
your selection matches dust and scratches of the
original image Now here's where the magic happens. your photos is to install the dedicated plugin for
Select the Move tool and (important!) change its the Nautilus file manager. In Fedora, do it with the
mode to Selection. It means that when you move following command:
anything now, only the selection itself will be moved, $ sudo dnf install nautilus-image-converter
but not image content. Move your selection sideway There's a very similar (yet different) extension in
by few dozen pixels, so that the selection now covers Ubuntu, which you can get this way:
mainly 'healthy' areas to the neighbouring damaged $ sudo apt-get install nautilus-image-manipulator
spots. Do the copy-paste sequence, change the Move Whichever you’ll install, don’t forget to restart
tool mode back to Layer and drag your pasted bits Nautilus (or simply log out and then log back in) in
back to their original position. How do you know when order for the changes to take effect. Once you do
you're back in the right place? Well, change the that, select the scope of images you’d like to resize,
blending mode for the pasted bits from Normal to right-click any of them and select Resize Images.
Difference and let it guide you. When your patches are Both Ubuntu and Fedora-centric Nautilus extensions
in place, use the Eraser tool with a reasonably large provide nearly the same features: they let you specify
soft brush to remove false-triggered patches. Finally the new size in pixels or percent, choose to save new
bring back the Normal blending mode and press the files along with the originals (non-destructive mode)
Anchor icon to merge your patches with the and also apply a prefix to filenames. As the names
background. It all may sound complex, but once you suggest, you can also mass-rotate images in the
do at least one iteration of such 'patching', you'll love same way – just choose the appropriate item from
this method because it really saves you a lot of time. the Nautilus right-click menu.
Sometimes you need to apply an edit or If you need more features for bulk actions, try
transformation to a lot of images, and it makes some Phatch — a photo batch processor for Linux. Phatch
users believe they need to do a huge number of can batch resize, rotate, apply shadows, perspective,

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tags and do image transformation with a few mouse
clicks. Don’t forget to put the Save action at the end
of the queue in order to keep the original images safe
and secure.
In fact, you don’t have to use any desktop
environment in order to process images in Linux: In
cases when you want to escape from a heavyweight
GUI desktop, you can happily deal with images using
command line tools. Once you have ImageMagick
installed on your system, you can manipulate images
however you want. Start with the display command to
view images, like this:
$ display path/to/picture.jpg
Convert images from one format to another using
the following syntax:
$ convert sunrise.tif sunrise.jpg
Explore the depth of the $ convert --help command
and find out how to resize and rotate images as well.
In the following example we’ll convert, resize, rotate
our test image and also apply the charcoal filter to it:
$ convert sunrise.tif -resize 1024x768 -rotate 180
Squeeze extra disk space
rounded corners, duplicate directory hierarchies -charcoal 4 -quality 80 sunrise.jpg
by using the latest next-
gen file storage formats. and much more. Phatch is available in many Linux If you need to perform bulk actions on the
Everything is open source! distributions, including Ubuntu and Fedora, so install command line, feel free to use Bash as a means for
it in a convenient way via apt-get/dnf or from within a applying a command to multiple files. For example,
graphical package manager. Keep in mind that Phatch let’s rotate all images in the current directory while
also has a special Nautilus integration extension called retaining the original files:
nautilus-phatch. Install it as well in order to access $ for file in *.tif; do convert $file -rotate 90 rotated-$file;
extra bulk actions from images’ context menu. done
Or maybe we want to convert files to another
format and resize them within one command:
In real life most photos are stored in $ for i in $( ls *.tif); do convert -resize 50% $i $i.jpg; done

JPEG, whereas screenshots and web Use advanced image formats
graphics look best in PNG There are dozens of graphic file formats, but in real life
most photos are stored in JPEG, whereas screenshots
In Phatch, press the big + sign to add actions to and web graphics look best in PNG. Let's skip other
the queue. The list of actions is quite extensive and specialised file formats such as TIFF or numerous
you can also put several actions in one queue in any RAW flavours from different camera vendors for the
combination. Phatch lets you be more creative with sake of brevity. Historically JPEG compression was
your images and add, say, a watermark, special EXIF developed as an optimal trade-off between higher

Sorting and tagging
There are some great open source applications that can an hierarchy. If you select a tag and create another tag in its
help you store and tag images – it's fairly useful once you context menu, it will be placed inside that parent tag, so that
photo library grows large. The most well-established photo you can create complex trees, like People > Relatives > Family
organizers are Digikam and Shotwell. These are desktop > Brothers, or, say, Places > Vacation > Summer > America. Of
heavyweights and thus are shipped with almost any Linux course, it takes a certain amount of time and diligence to add
distributions. Let’s have a look on how to sort and tag images tags manually, but it is worth it. Tags add extra features to
in Digikam. your library and simplify image searches: you can browse the
When browsing your images in Digikam, select at least convenient list of date-based subdirectories with your images,
one of them, right-click and go to Assign Tag > Add New Tag. but once you need to perform custom searches (eg ‘show me
Enter the name of the new tag and optionally set the keyboard all pictures of my dad’), tags are your best friends.
shortcut, which will let you seamlessly assign/clear that tag Shotwell has a very similar approach to managing tags, and
later on. When you’re done, you tag will appear in the Recently it also has a very useful left-side panel with events, folders
Assigned Tags of an image’s context menu. Sooner or later and tags tree. Anyhow, Shotwell is believed to be a lot simpler
you will have many tags that need to be properly managed than Digikam, while being more suitable for novice users.
and reviewed. You can see the full tags tree either through Shotwell is more user-friendly and robust, while Digikam sports
the context menu at Assign Tag > More Tags, or by clicking on some pretty snazzy features that other photo applications do
the tiny Tags button at the left side panel in Digikam. Initially, not, such as automatic face recognition and grouping photos
tags form a plain list, but in fact they are designed to form by depicted people.

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quality and smaller file size, which used to be a
headache in the days of dial-up internet and small
hard drives. JPEG is lossy, but it delivers very natural-
looking images even with agressive compression
ratios. On the other hand, the PNG (Portable Network
Graphic) gracefully solved the problem of transferring
lossless bitmaps graphics across networks thanks to
its built-in compression.
In modern days the technology has advanced even
further and now we have two projects on GitHub
that outperform the above two formats in terms of
compression efficiency: Lepton and FLIF.

What the flif?
FLIF is a new lossless image format based on
MANIAC compression (Meta-Adaptive Near-zero
Integer Arithmetic Coding), which outperforms PNG,
FFV1, lossless WebP, lossless BPG and lossless
Digikam is versatile image
JPEG2000 in terms of compression ratio. Let's see file smaller. Dropbox published a comprehensive
sorting machine. Provide
how we can use it. Download the code snapshot article that describes how the algorithm works (http:// it with your images and
from the project's website, make sure that you have bit.ly/29VqPnT), pointing out optimisations they get the neat subdirectory
the libpng-dev package (or similar) and then type $ implemented in encoding 8x8 pixel blocks – these are structure with few mouse
make. In a few seconds you'll get the compiled flif used in JPEG compression. clicks.
binary, which acts as an encoder and decoder of FLIF
images. The syntax is very simple: Store images more efficiently
$./flif input.png output.flf Building Lepton from source is very straightforward.
and the traditional ./flif --help for the list of options, Download the sources and execute the well-known
such as interlacing, palette, quality and more. Keep in sequence:
mind that FLIF currently can convert only PNG, PAM $ ./autogen.sh; ./configure; make; make check
and PNM file formats, so it makes sense to compare $ sudo make install
FLIF outputs with the PNG as the most widespread Lepton has a very simple syntax and while you can
format from the above list. In our tests, lossless FLIF enjoy many of its advanced features, you can start
output was smaller than PNG with the highest with this template:
compression ratio and comparable with JPG in terms $ lepton input.jpg output.lep
of file size. The only problem is that you cannot view If your JPEG file uses progressive encoding (eg
.flf files, so right now you can only use the flif binary Gimp does it by default when exporting to JPEG), you’ll
to archive images and recover them later using the need the appropriate extra option:
$ ./flif -d input.flf output.png command. However, it $ lepton -allowprogressive input.jpg output.lep
is possible to view the FLIF-encoded images using the To restore (decompress) your file, use the same
separate tool called UGUI_FLIF (https://github.com/ command but switch the .lep and jpg order. Lepton is
FLIF-hub/UGUI_FLIF), which is based on HTML and quite effective: it can trim down your files by 15–20%
JSON. Once the FLIF file format is finalised there will without losing quality.
be a more appropriate viewer – because files encoded The reason why you might want to use FLIF, Lepton
with an older FLIF binary will not be compatible with a or both is precisely one. Despite the fact that most
newer one. people have at least 1TB of storage in their desktop
Lepton is a compression and decompression machines, the sheer volume of images that have to
algorithm that was open source by the Dropbox be stored is growing even faster than most people
company. This cloud-based storage provider has can reasonably store themselves. Converting some
proprietary code in its core, but otherwise it is very thousands JPEGs to the new Lepton format lets you
friendly to the Linux community. Lepton does with free extra disk space. Lepton files are about 20%
JPEG what FLIF does with PNG, and as long as the smaller than their source JPEGs, so saving can be be
two image formats are completely different, we very noticeable. Both Lepton and FLIF are in an early
cannot compare their performance directly. Perhaps development state, but this only means that we don't
you might want to use PNG for screenshots and have ready-to-use viewers and a desktop integration
JPEG for photos, and now there are finally two open yet. The core feature — encoding and decoding works
source projects for that. Lepton offers a lossless flawlessly, so you may want to use Lepton and FLIF
compression for JPEGs, which resembles convenient as archive tools.
archiving. But unlike putting a JPEG file to a ZIP or
TAR.GZ archive, which makes very little sense in Alexander Tolstoy stores his library of over a hundred thousand cat
saving the disk space, Lepton really makes the output photos on a single floppy disk.

www.linuxvoice.com 85
CODING SOLR

BUILD A SEARCH ENGINE
WITH APACHE SOLR
Add some order to the chaos that is the LV catalogue with a Python search engine.

W
e’re producing vast quantities of data. one on port 7574. We’ll be interacting with them via
BEN EVERARD
Some of this is nicely structured in HTTP, so let’s start with the most usual HTTP client,
spreadsheets and databases, but there’s the web browser. You can see details of the install
Why do this? also lots in less computer-friendly formats such as by going to: http://localhost:8983/solr/#/. We don’t
• Build powerful search PDF and MS Word files. In this code concepts we’re need to change anything here for our purposes, but
tools using the
going to take a look at using the Apache Solr search if you have any problems, you can see the logs in the
technology behind
some of the web’s platform to sift through a trove of PDF files to find Logging tab.
biggest sites exactly what we’re looking for. Solr works with collections. These are groups of
• Obsessively tag, The first step is to grab the software. The version data a little like individual databases in a MySQL
index and organise
in most distros' repositories is out of date, so the best instance. Data is added to a particular collection, and
all your things
option is to download the latest version from http:// queries are run on collections rather than all the data
• Use Python to access
RESTful JSON APIs lucene.apache.org/solr. Click on the Download Binary in the instance. By default, there’s a single collection
over the internet link and you should be presented with a list of mirrors. called gettingstarted. We’ll use this for our project.
The file you need should be called solr-6.1.0.tgz (or Now we have our server and our collection, the only
possibly a newer version). As the filename suggests, thing we need is data. Solr is designed to work with a
this is a tarball, so save it to your machine and diversity of datatypes including PDF files, so for our
decompress it. project, we’re going to work with Linux Voice PDF
When you start Solr, you
You can start Solr without installing it fully by files. We release these both for the full issue and for
also get a web interface
running the following command in the directory you individual articles. We’re going to use the individual
where you can see how
everything’s running. Point created by unzipping the download: article files from issue one of Linux Voice, which you
your web browser to http:// bin/solr start -e cloud -noprompt can download from https://www.linuxvoice.com/
localhost:8983/solr/#/ to This command will start two instances of Solr (it’s download-linux-voice-issue-1-with-audio/. You’ll
get started. designed to be run as a cluster), one on port 8983 and need to download these and save them to a directory
that only contains these files. The following command
will enter them into the Solr data store:
bin/post -c gettingstarted <directory containing the
files>
You can check that everything’s worked by querying
the search engine via curl. The following code should
return all the articles that contain the word Linux:
curl "http://localhost:8983/solr/gettingstarted/select?wt=
json&indent=true&q=linux"
This should output a lot of data formatted in a way
that makes it hard to read. In order to make our search
engine useful, we need to create a human-useable
interface for it, and we’ll do this with a Python script.
The primary interface for Solr is a RESTful API
that serves JSON over HTTP. Let’s just go back
to that previous sentence and pick apart the
acronyms before going any further. REST stands
for Representational State Transfer, which in itself
doesn’t tell us much, but it’s a style of Application
Programming Interface (API) based on the way the
world wide web works. Perhaps the most important
thing to understand about RESTful APIs is that the
server is stateless – that means that all the details

86 www.linuxvoice.com
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needed for the request are in the request itself
(including any login or session information).
The request is served over HTTP, which is the same
protocol that web browsers use to get data from web
servers, so we can use exactly the same tools. In the
first example, we used Curl, but we can also use a web
browser. Most programming languages have a library
for getting things via HTTP (in Python it’s urllib), and
you should be able to use any of them if Python isn’t
your thing.
JavaScript Object Notation (JSON) is a way of
structuring data in key-value pairs in plain text that
looks remarkably similar to Python’s dictionary
format – so similar in fact that we can use a module
called simplejson to convert the text returned by the
RESTful API directly into a Python dictionary.
Using this RESTful API, we can build a really simple
Solr is designed to be
query interface with Python: Python code above you can see that we print out two
scalable to huge instances
import urllib2 items that are returned in JSON: the resourcename so it runs with shards
import urllib and the xmptpg_npages – the name of the file and by default. In the basic
import simplejson the number of pages. Rather than just searching setup, two shards run on
through the text of the article, we can focus our the same machine, but
base_url ="http://localhost:8983/solr/gettingstarted/ search on one particular attribute. For example, if you in production there could
select?wt=json&q=" enter the following query when running the Python be multiple shards across
program above, you will get only the articles with two many data centres.
while True: pages:
query = raw_input("Query:") Query: xmptpg_npages:2
result = urllib2.urlopen(base_url+urllib. You can chain parts of your queries together by
quote(query)) separating different search terms with spaces. By
result_openned = rsp = simplejson.load(result) default, Solr will return results that match any one of
for doc in result_openned["response"]["docs"]:
print "file" + doc["resourcename"][0]
+ " pages " + str(doc["xmptpg_npages"])
Solr is a search engine that works
This builds a HTTP request using input from the with text documents, but it can handle
user, then formats the returned JSON data nicely for
printing out. a wide range of different bits of data
So far, we’ve used the query to search through
the article text and find things related to our search the search terms. So the following query will match
term, but we can do more than this. Solr is a general anything that is about either LUGs or FOSDEM:
search engine that works with text documents (like Query: lugs fosdem
the PDFs we’re using here), but it can handle a wide Adding a plus sign to the start of a search term
range of different bits of data. Each different type of tells Solr that you only want results that include that
data contains different attributes. For example, in the particular term. If you want only those articles that are
two pages long and about FOSDEM, you can use the
following query:
Apache Lucene and Solr
Query: +fosdem +xmptpg_npages:2
If you’re just after a text search library to add to your
By default, Solr will see how well each document
project, you can use Apache Lucene, which powers the
search in Solr. Although it’s written in Java, there are matches the search query and return the results
Lucene bindings for other languages including Python that based on their relevance. We can find out just how
enable you to bring in just the searching power to your good a match each document is by getting Solr
project. The advantage of Solr is that you get the full server to return the value for score with the fl (field list)
– with the ability to run in a distributed manner – to store
parameter to our request. We want all the fields that
your data and handle queries.
Solr itself started as an internal project by CNET exist (which we get with the * wildcard), and the score
Networks, which donated the code to the Apache Software pseudofield. In your Python program, change the
Foundation in 2006. Under Apache the software has base_url line to the following:
developed significantly particularly in its ability to handle base_url ="http://localhost:8983/solr/gettingstarted/
huge numbers of queries very efficiently. It’s proved itself
select?wt=json&fl=*,score&q="
on some of the internet’s biggest sites including the
Internet Archive (archive.org), DuckDuckGo and Netflix. You can now include the score in the final print line
of the script:

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CODING SOLR

Total score of each distro in issue one of Linux Voice

LV Prattle Factor

Fedora was the most
print "file: " + doc["resourcename"][0] + " pages " + base_url ="http://localhost:8983/solr/gettingstarted/
relevant distro to issue 1 of
Linux Voice. str(doc["xmptpg_npages"][0]) + " relevance " + select?wt=json&fl=*,score&q="
str(doc["score"]) while True:
This is a useful way to find out just how good a lv_prattle_factor = 0
match a particular page is, and it can also be useful query = raw_input("Query:")
in determining how predominant a particular word print base_url+urllib.quote(query)
or phrase is in your collection. If we add up the score result = urllib2.urlopen(base_url+urllib.
from every document returned by Solr, this will give quote(query))
us an idea just how dominant that word was in issue result_openned = rsp = simplejson.load(result)
one of Linux Voice. We’ll call this the LV Prattle Factor for doc in result_openned["response"]["docs"]:
because it says how much we prattle on about it. The print "file: " + doc["resourcename"][0]

The Solr web interface code to add this feature is: + " pages " + str(doc["xmptpg_npages"][0]) + " relavence "
includes a query builder to import urllib2 + str(doc["score"])
help discover the various import urllib lv_prattle_factor += doc["score"]
options to the HTTP API. import simplejson print "Linux Voice Prattle Factor: " + str(lv_
prattle_factor)
We can now use this to work out one of the age-old
questions: just which distros get the most coverage
in Linux Voice? You can see the results of this in the
graph above – and Fedora was the most talked about
distro for us back in February 2014.
Hopefully, you’ve now got an idea of how to start
working with Solr, but it can do far more than we’ve
had a chance to look at here. As well as searching,
you can look at aggregate data, and perform more
complex inquiries using more specialised data, such
as location tagging. If you need a customisable
search engine, Solr is a great place to start.

Ben Everard, Linux Voice's editorial overlord, is probably breeding an
out-of-control slug plague as you read this.

88 www.linuxvoice.com
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www.linuxvoice.com 89
CODING PACKAGING

FLATPAK: BUILD A CROSS-
DISTRO PACKAGE
Why rely on a distro's package maintainers when you can package software yourself?

L
VALENTINE inux is diverse, and so are its packaging
SINITSYN technologies. We aren't going to cover all of
Deb, RPM, Pacman, Flatpak, Snap etc in this
Why do this? tutorial. It wasn't planned as a definitive guide to these
• Understand the technologies either. Instead, we'll focus on typical
twisted logic behind
approaches and concepts, using two popular
dependency hell
implementations. A package is essentially an archive
• Make it easier for
users to get hold of (often a tarball) containing binary and data files which
your software constitute an application, along with some metadata.
Metadata carries essential information about
a package. For instance, it tells us the package
name, author, and version. Using these, package
management tools (such as rpm, dpkg/apt or
pacman) can tell if there is a newer version available
in the distribution repositories. If you're downgrading
a package, the system also understands it and acts
accordingly. Metadata can also tell us to which From time to time, package managers grab remote
category the package belongs, much like a "Shelve repositories listings, and check if there's anything new.
into" hint on a book back cover, and what the package
priority is. But most importantly, metadata conveys install all the dependencies, of course. This is tedious
dependency information. and error-prone, so most distributions and even third-
The software you write (or use) doesn't exist in party vendors such as Atlassian or Dropbox build
a void. If it's compiled, it often relies on libraries. If package repositories, which are generally reachable
not, it obviously wants an interpreter. For example, over the internet.
you'll need a web server, a database and PHP 5.4 or Official repositories are usually self-contained; that
better to run OwnCloud. Exiv2 and an LDAP server is, they provide all dependencies for any package
aren't strictly necessary, yet they add some features hosted. From time to time, your Linux system grabs
(namely, Exif and centralised authorisation support). the list of packages from every repository you have
Metadata encodes all this information in a configured and suggests that you install updated
machine-readable way. The OwnCloud package will ones. You may also want to refresh package lists
depend on the PHP package (exact names differ manually, for instance, if you configured a new
per distribution) with the version not less than repository. This is what happens when you type apt-
5.4. Both Apache and Nginx can run OwnCloud, so get update on a Debian-based system.
the web server dependency may come through a
metapackage. This is a virtual package (think alias) Debian way
that many real ones may choose to provide. Both Perhaps that's enough theory for now, and it's time to
Exiv2 and the LDAP server may come as optional (or get your feet wet. Though I'm reluctant to offend the
suggested) dependencies. When you instruct your Red Hat users, I'd still say that Debian's packaging
package manager to install OwnCloud, it pulls in PHP, format (Deb) is predominant in Linux landscape at the
a database, and whatever web server you choose moment. So, let's spend a minute learning how you
automatically. This is not the case with optional package your code for Debian and its derivatives.
packages; the tool would normally list them for you Before we proceed with our experiments, we need
after installing OwnCloud, and if you'd like any of them, an application to package. Recently I stumbled upon
issue a separate command. QOwnNotes (www.qownnotes.org). If you ever tried
It is fully possible to download a package file and to use Evernote in Linux, you'd probably agree that
install it manually. It implies you'll also download and the experience could be better. Evernote forces you

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PACKAGING CODING

to store documents in the cloud, with all the usual
concerns about privacy. And it has no native Linux
client. QOwnNotes may have fewer features, but it's
free (as in speech), it runs on Linux, and it plays well
with OwnCloud. If something doesn't work for you,
you can just go and fix it rather then grumble on the
Evernote forums. In other words, it's not a drop-in
replacement for Evernote, but it looks promising.
Moreover, QOwnNotes is already packaged for
many Linux flavours, including Debian. We'll study this
Debianisation and discuss alternative ways where
appropriate. I also suggest you look in QOwnNotes/
build-systems at its GiHub page (https://github.com/
pbek/QOwnNotes) to check how the same concepts
are applied across different packaging tools.
Not an Evernote, or a clone,
Grab the latest sources as described on QOwnNotes' supports (any means it should compile on any host).
but it still looks interesting
installation page (http://www.qownnotes.org/ In rare cases when the program is hardware-specific, to try. Or, at minimum, to
installation). Debianisation lives under debian/, which you should provide an architecture string like amd64 package.
contains a handful of files. or arm here. Architecture-independent packages such
Let's start with debian/control. It can be rather long as your Python code can use all instead.
and describe multiple packages, but for QOwnNotes, it Depends lists runtime dependencies. Note
spans only 18 lines. A blank line splits this file into two there are no -dev packages here anymore. Version
paragraphs referring to the source package and the requirements come in parenthesis: foo (>=1.0) pulls
only binary package it creates. foo 1.0 or higher. Optional dependencies may use
Source: qownnotes Suggests or Recommends. Add Provides if you
Priority: optional provide some virtual package (aka metapackage).
Maintainer: Patrizio Bekerle <patrizio@bekerle.com> ${} is the control file syntax for substitutions.
Section: editors shlib:Depends runs the dh_shlibdeps tool to calculate
Build-Depends: debhelper (>= 9), cdbs, qt5-qmake, shared libraries' dependencies of your application.
qtbase5-dev, libqt5svg5-dev, qtdeclarative5-dev You'd want to include it unless you build a static
Source and Maintainer define the package and the executable. In a similar vein, misc:Depends accounts
maintainer names. Both are mandatory. You also see for the additional packages that debhelper may have
qownnotes is an optional package that belongs to the decided to pull behind the curtains.
editors category. Other priority levels include required debian/control is perhaps the most important
(absolutely necessary) or important (expected on any piece of package metadata, but not the only one. Did
self-respecting Unix system). you notice it doesn't tell the package version? This
Build-Depends lists packages that are required comes through debian/changelog. This file follows
to build QOwnNotes. They aren't necessary in the a strict format described in the Debian Policy Manual
the same you need to run it. Remember that Debian
puts header files and alike into -dev packages. A Debian source package is just a
Neither qmake nor the Qt headers are essential for
QOwnNotes to run, but they are required for the build
tarball or two along with a .dsc file
process. If you wonder what on Earth debhelper is, storing the metadata
we'll get on it shortly.
A Debian source package is just a tarball (or two) 4.4 (https://www.debian.org/doc/debian-policy/ch-
along with a .dsc file storing the metadata. The exact source.html#s-dpkgchangelog). Usually, you update
format is usually set via debian/source/format. the changelog with dch tool to avoid pitfalls. Last but
QOwnNotes uses 3.0 (quilt). It was designed for not least, each package must contain a copyright
official packages which separate upstream sources notice – this is stored in debian/copyright, which is
and local Debian changes. For us, it's not the best both machine and human-readable, like Markdown.
choice, so set the format to 3.0 (native) now.
A binary package paragraph looks very similar: Building binaries
Package: qownnotes Now, your package wants a recipe to build the code.
Architecture: any The main build script for a Debian package resides in
Depends: ${shlibs:Depends}, ${misc:Depends}, debian/rules. In a nutshell, it's just a Makefile, which is
libqt5core5a, libqt5gui5, ... the de-facto standard to convey build instructions in
... Linux. Here, it's executable and carries a #!/usr/bin/
Package is the binary package name. Architecture make -f shebang. Packaging tools expect you provide
tells us what hardware architecture the package some predefined targets in this file, such as build to

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CODING PACKAGING

QOwnNotes comes through Building the package is just a matter of typing
Flatpak; everything else is dpkg-buildpackage -us -uc. The switches ask not
from native packages. Can to sign anything with GnuPG. Recall that the code
you tell the difference? compiles against the libraries (and architecture) you
have on your build system. That's how the package
is built for the particular distribution, and that's why
it's important to have a clean reference environment.
Tools like Pbuilder or sbuild do so via chroots.
Baking Debs is quite easy, but creating proper
Debian packages could be tricky. Be sure to read the
Debian New Maintainers' Guide (www.debian.org/
doc/manuals/maint-guide), if you're seriously into it.

All in one
You might call traditional packaging dependency-
centric. The idea is to have all the required bits only
once per system. This sounds reasonable: why do you
want multiple copies of the same library consuming
disk space? What if the library appears vulnerable?
prepare and compile the sources, or binary to create a Keeping track of these multiple copies and updating
binary package. The Debian Policy Manual, 4.9 has a them is tedious, at best.
complete list. The coin is double-sided, though. In the real world,
Thanks to Autotools, CMake and friends, most Linux libraries have bugs, and different minor versions aren't
applications build in standard ways. This means necessarily interchangeable. Imagine you have AppA,
nearly identical debian/rules, each taking time to which wants libfoo=1.0.2, and AppB, which pulls
author and debug. Reinventing the wheel is hardly libfoo=1.0.1. This is a famous dependency hell, a rare
an option, so Debian introduces debhelper tool to situation which is nevertheless hard to resolve.
automate standard bits. Debhelper comes with many Storage is cheap these days, and isolation
dh_* commands to wrap up the process. You just mechanisms in recent Linux kernels limit potential
need to call them from your debian/rules. damages in case of vulnerability exploitation (but see
In the case of QOwnNotes, this file is even simpler: the boxout). This gave rise to technologies that build
#!/usr/bin/make -f self-contained, distribution-neutral packages.
#export DH_VERBOSE = 1 Flatpak (http://flatpak.org), formerly xdg-app, is a
DPKG_EXPORT_BUILDFLAGS = 1 good example. Flatpak aims at desktop applications
include /usr/share/dpkg/default.mk and uses much the same sandboxing mechanisms
export QT_SELECT=qt5 as in container virtualisation.
include /usr/share/cdbs/1/rules/debhelper.mk The self-contained application model could be
include /usr/share/cdbs/1/class/makefile.mk interesting to proprietary software vendors, but also
include /usr/share/cdbs/1/class/qmake.mk to complex open source projects such as LibreOffice
Basically, this just includes the CDBS (Common (https://www.libreoffice.org/download/flatpak).
Debian Build System) components needed to build a We've introduced Flatpak back in LV030, and this time,
QMake-based application. CDBS is a Makefile "library" we'll walk through the package building process.
which complements debhelper. Qt 5 is selected if
there is more than one version of the library installed. Pack with Flatpak
DPKG_EXPORT_BUILDFLAGS tells us to export Before we proceed, make sure you have Flatpak
CFLAGS, CPPFLAGS and alike. Uncomment the DH_ installed. (Traditional) packages are already available
VERBOSE line to make debhelper more chatty. for some distributions. We'll stick to Arch, which has
From time to time, backwards-incompatible Flatpak in the official repositories. If you use Fedora or
changes are made to debhelper (and most other Debian, the differences would be minimal.
software as well). So packages should tell which Flatpak runs applications on top of shared runtimes
debhelper "compatibility level" they expect. It comes and uses SDKs to build packages. There is an official
through debian/compat, and packages set it to 9. Gnome runtime, but QOwnNotes is a Qt application.
Some parts of your package may not come The experimental Qt 5/KDE Frameworks 5 runtime
as a build process artefact. Imagine you want and SDKs are available at https://community.kde.
some custom config file or an icon: you can use org/Flatpak. Follow the instructions on the page to
debian/install, or its per-package equivalent, install them: it's easy. Remember, Flatpak sandboxes
debian/<package name>.install, to put arbitrary files everything, so it doesn't matter if you have KDE or not.
into the package. Similar mechanisms exist to create There are two approaches to Flatpak packaging.
empty directories, install init or cron scripts, and so on. Large real-world applications use flatpak-build and

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JSON manifests to automate the process. QOwnNotes
is not that big, so we'll do everything manually with
flatpak build. First, create a directory where you'll
build the package. Then, untar QOwnNotes' sources
and initialise the build process with flatpak build-init:
$ flatpak build-init qownnotes org.qownnotes.
QOwnNotes org.kde.Sdk org.kde.Platform
This will create the qownnotes staging directory
for package files. Each Flatpak application must
have a unique name consisting of three or more
dot-separated alphanumerics. Otherwise, it could
be anything, yet "reversed DNS" notation is most
common. Then we specify an SDK and the runtime
It's sooo cuuute… and
the application will use. Confusing their order leads to system:
steals your passwords (red
cryptic error messages, so be careful. $ flatpak build-finish ../qownnotes --socket=x11 line) even if running in a
Now you can start a build process. Issue --share=ipc --share=network --filesystem=home sandbox. Thank you, X11.
commands you'll normally need to build the --command=QOwnNotes
application, but prefix them with flatpak build <path QOwnNotes draws windows over the X11 protocol,
to the staging directory>: thus the first two switches. Besides, it will need
$ cd qownnotes-X.Y.Z network access for OwnCloud integration, and you'll
$ flatpak build ../qownnotes qmake PREFIX=/app want to store notes in your home directory as well.
QOwnNotes.pro The final switch tells Flatpak which command
$ flatpak build ../qownnotes make it should execute in the sandbox. Flatpak stores
$ flatpak build ../qownnotes make install packages in OSTree repositories, which are in turn
QOwnNotes employs a QMake-based process. Note modelled after Git. The next command creates one
we instruct it to install the application under /app under repo and commits the application:
inside the sandbox. This is a requirement. $ cd .. && flatpak build-export repo qownnotes
Some changes are due before you can wrap up the If you receive complaints about desktop file
build. Certain files, such as desktop entries or icons, contents, just do the changes as requested. It's
are exported to the host filesystem for integration. possible to wrap the repository into a single-file bundle
Flatpak expects them to begin with an application (see flatpak build-bundle). We don't want to do this,
name to ensure uniqueness. flatpak-builder handles as we can get QOwnNotes directly from the repository:
the renaming for you, but we're on our own: $ flatpak --user remote-add --no-gpg-verify --if-not-
$ find ../qownnotes/files/share/{applications,icons} -type exists qownnotes repo
f | perl-rename 's/QOwnNotes\./org.qownnotes. $ flatpak --user install qownnotes org.qownnotes.
QOwnNotes./' QOwnNotes
perl-rename may come as rename, if you are not We configure `repo` "remote" repository under the
on Arch. You'd also want to adjust the icon name qownnotes name and install the application from it.
inside the desktop file. Then you'll need to decide --user tells Flatpak this should be done for the current
which resources the sandbox will share with the host user, not system-wide.
That's it! You can now run QOwnNotes with flatpak
run org.qownnotes.QOwnNotes. It should also be
In security, there is no silver bullet available in your desktop application menu.
Shortly after Ubuntu 16.04 LTS, featuring the Snap package Universal packages may help vendors to reach
manager, was released, a proof of concept exploit was wider audiences. Opponents argue that they make
published: a cute teddy bear silently grabs your keystrokes
pushing adware or other malware to users easier.
in an X11 environment. If it were real, an attacker could use
it to steal your passwords or credit card numbers, not to Moreover, Linux distributions are diverse for a reason.
mention personal messages. They target different users, and maintainers oversee
With a few tweaks, you can run the same exploit under this process. Maintainers help to keep software in
Flatpak (see the screenshot). It doesn't play well with distributions consistent. And they mediate between
Chromium-based browsers though – you always patch
users and developers. This is a social role that a
Linux viruses to make them work for you, you know. But it's
just a proof of concept, after all. technology is hardly able to take.
The problem isn't in Snap (or Flatpak). The vulnerability Perhaps the best thing universal and traditional
is in X11 itself, which officially allows any application packaging can do is to complement, not to substitute
to receive keystrokes or inject events into any other each other. And now you have some grounds to put
application. So, the exploit would work in a traditional
both in your arsenal.
package as well, yet such package would hardly get past
the "maintainer barrier". The bottom line: nothing protects
you, if you don't protect yourself. Valentine Sinitsyn is a university professor, Mandriva contributor,
physicist and Linux systems developer.

www.linuxvoice.com 93
CORETECHNOLOGY EXTENDED ATTRIBUTES

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.

Network Addresses Assignment
V
irtually all PCs (and some toasters) seem to OUI Lookup Tool found at https://www.wireshark.org/
have an IP address today. Computing devices tools/oui-lookup.html.
aren't born with an IP address (neither v6 nor MAC addresses aren't what you use on the internet,
v4). Before they connect to the outside world, they though. They naturally depend on the underlying
need this address configured somehow. In the technology, and would be a pain to use in the diverse
simplest case, you assign it manually. This isn't very world that is the internet. Another abstraction layer
convenient from the end-user perspective, however. (IP) is needed. MAC addresses are good to deliver
When we connect to a Wi-Fi hotspot, we expect to data to their ultimate destination in local networks.
start browsing and chatting, not changing settings. This suggests there should be some means to
Assigning an address can be a convoluted process, convert between IP and MAC addresses.
and this is what we'll speak about today. Address Resolution Protocol, or ARP (RFC 826)
serves these purposes. Hosts learn IP addresses
Prehistoric RARP of their neighbours via broadcasting. An everyday
Now, have a look at your home router's back cover, equivalent of this would be a delivery boy shouting
flip your laptop or take the lid off your smartphone. "Who is Joe Doe here?" in a crowded open space
Chances are, you'll see a sticker with the device's MAC room. This procedure happens regularly on any
(Media Access Control) address. Usually, it looks like network, as tcpdump may show you:
six colon-separated octets: `70:5a:b6:59:c4:5d`. Both $ sudo tcpdump -n arp
Ethernet and 802.11 (Wi-Fi) devices have it. The first ...
three octets tell you the manufacturer; for example, 14:32:23.852185 ARP, Request who-has 192.168.101.149 tell
`00:05:5d` is D-Link. These octets are often called 192.168.101.44, length 28
the OUI, or Organizationally Unique Identifier. The 14:32:23.853860 ARP, Reply 192.168.101.149 is-at
manufacturer further assigns the remaining three 74:d4:35:56:7d:ed, length 46
octets, so that each device on the planet gets its own ...
unique MAC. Even virtual network adapters have their Remember not to run network sniffers on corporate or
own MAC addresses: public networks – this could be deemed illegal.
$ ip -o link show dev docker0 When a reply is received, the requesting host
6: docker0: ... link/ether 02:42:11:c8:7c:c4 ... remembers it in a cache. This helps to avoid
Here the `02:` prefix designates a locally administered broadcasts for known addresses, thus saving you
With Wireshark's OUI
Lookup Tool, you can address, which doesn't constitute an OUI. some bandwidth.
check the manufacturer of There are many services that let you look up the What's in that cache on your local system? The
any network card straight manufacturer for OUI straight in your browser. Being a arp command knows, and it can also manage the
from the browser. Free Software proponent, I recommend the Wireshark cache (which is rarely needed). By default, arp prints
hostnames. If you want the raw IP addresses, add -n
to the command line:
$ arp -n
Address HWtype HWaddress Flags Mask Iface
192.168.101.44 ether 90:4c:e5:c7:89:69 C enp1s0
192.168.101.1 ether 04:8d:38:c2:88:b3 C enp1s0
Any user can list ARP cache entries, as they are
no secret. You'll need root permissions to set (-s)
or delete (-d) them, however. Try it. You'll notice
that some entries, such as the one for your default

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gateway, aren't easy to remove. This is because your
PC communicates with these hosts quite often. So, it
learns the address back before you type arp, making
an entry re-appear.
ARP maps IP addresses (which are configurable)
to MAC addresses (which are built-in). What if we
look at this from another angle? Can't you build an
inverse of this mapping to obtain IP addresses by the
given MAC? Reverse ARP (RFC 903) was historically
first to implement this idea. If you think about it for a
moment, you'd agree this protocol already handles
automatic IP address assignment. An administrator
may configure reverse ARP mapping on the router,
and network hosts will be able to learn their IP
addresses via RARP requests. This works, and early
Sun workstations happily followed this approach. Yet
it wasn't very flexible. In plain RARP, you can't learn
anything but your own IP address: no hostname, no
routes, no other settings. Moreover, it's IPv4-only and
low-level. For a diskless workstation, knowing the
IP address alone won't be sufficient to boot it: you'd
The "DHCP Offer" message
also want a path to the boot image. A more advanced it sets its own address to zero and the server IP
provides a client with a
protocol was due to solve these issues. address to 255.255.255.255. The latter is a special range of IP settings the
address that all hosts respond to. Of course, if the server can assign him.
Medieval BOOTP client has its server IP address pre-configured, it may
One of the first attempts to build such a protocol was use it instead. The server won't be able to resolve the
BOOTP (RFC 951). BOOTP is a simple client–server client IP address via ARP unless the client already
protocol that builds on UDP as a transport. Clients use knows it. However, the server knows the client's MAC
UDP port 68, whereas servers listens on port 67. address, so it can add a corresponding entry to the
As the name suggests, BOOTP was conceived to ARP table "manually". Broadcasting is also an option.
facilitate bootstrapping. It defines two message types Clients also use randomly assigned identifiers to
(or opcodes): BOOTREQUEST for client requests and match responses to requests. When a client receives
BOOTREPLY for server responses. Both are using BOOTREPLY, it installs the IP address it contains and
the same package format. In the request, the client continues as normal.
says what its hardware address is. In the reply, the
server tells the client what IP address it should use. Modern DHCP
The server also specifies the boot image that the BOOTP already handles centralized IP address
client can download via TFTP. Moreover, the packet management, yet it is rather static. The assumption is
structure allows for optional extension fields, which hardware addresses map to IP addresses 1:1. This is
may carry additional bits of data. not enforced, and the server is free to take addresses
The client can also build a request the way it will out of some pool. However, the protocol provides no
be handled by the specific server. BOOTP messages way to tell the server that the client is not interested in
carry the server's name, and if the server accepts a his address anymore. So, sooner or later this pool will
packet with a name different from its own, it silently be exhausted.
discards it. This adds some flexibility, but it is another In other words, a dynamic address assignment
bit of data that must be pre-configured on the client. protocol should only "lend" IP addresses for a limited
In a similar fashion, BOOTP supports clients which time. When it elapses, the client must renew its lease.
already know their IP addresses. This may sound Otherwise, the address is considered free. Of course,
ridiculous, but remember that it's a bootstrapping, a client may terminate his lease prematurely – this
not an address assignment protocol. Dispatching is useful if the system is going to shut down, for
boot images is another task it tackles, and IP address instance. The procedure is in principle no different
makes a good key to it. That is, the server can use from what you normally do in a car rental service.
an IP address as an identifier to send different boot The protocol that implements it is called Dynamic
images to different clients. Host Configuration Protocol, or DHCP (RFC 2131). It's
If you think about BOOTP carefully, you'll quickly ubiquitous, and when the network "just works" for you,
come across a "chicken or the egg?" sort of problem: DHCP is what makes it happen. DHCP and BOOTP run
how does a client send a UDP datagram to the on the same UDP ports and use the same message
server if he doesn't know his IP address yet? And layout. You may think of BOOTP as a "stripped-down"
how is it expected to receive the reply? The answer DHCP, for the purposes of bootstrapping only. This
is broadcasting. When a client crafts the request, is like TFTP relates to "full-fledged" FTP. DHCP is an

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Dynamic nature of DHCP doesn't mean the
addresses themselves must be variable. Most DHCP
servers support so-called "static leases", which can
assign a permanent IP address to specific hosts. This
could be useful, say, for your home server or NAS.
A few parameters are usually required to connect
your PC to the internet. Besides an IP address, you
need to know your local network mask. You'd want
the gateway address to route traffic outside the
local network, and at least one DNS server to resolve
domain names (LV024). In some cases, you'd also
need a web proxy or some custom routes.
In BOOTP, this sort of configuration was conveyed
via Vendor Extensions, which become Options in
DHCP. The reason is perhaps they are not vendor-
specific anymore. DHCP Options are standard.
Moreover, one of them is always present and carries
the message type we've just spoken about. IP address
lease time is also a DHCP Option.
The "DHCP Ack" message
extension to BOOTP, and most DHCP servers are You can distinguish DHCP Options by their
is an acknowledgement
that the server has compatible with BOOTP clients. numbers. Say, Option 1 sets a subnet mask, while
committed IP settings for DHCP introduces several new message types. Option 3 stores the list of routers, in order of
the client. When a client wants to allocate an IP address, it preference. DHCP Option 6 is for the DNS server.
broadcasts the DHCPDISCOVER message to discover Web Proxy Auto Discovery (WPAD) works via DHCP
DHCP servers nearby. Each server receiving this Option 252, which contains a URL of the Proxy Auto
message replies with DHCPOFFER, containing an Configuration (PAC) script.
IP address along with other IP settings. At this point, DHCP Options look nice and convenient, but
the address isn't assigned yet. The client may receive remember that clients may ignore settings that you
multiple DHCP offers. It chooses one and replies push to them this way. For tricky stuff, like WPAD,
with a DHCPREQUEST message to the originating this is rather possible. Better treat DHCP Options
server. This way, all other servers know their offer was as recommendations. If you need these settings
rejected. enforced, you want something else.
Now the server commits the configuration and Now, look at two Wireshark screenshots we have
replies with DHCPACK. If things don't go well, a here. They capture a DHCP client address assignment
negative response (DHCPNACK) is sent, and the procedure I triggered with dhcpcd (see below). All
procedure restarts. Upon receiving DHCPACK, the messages share a Transaction ID because they
client also does its final checks and replies with belong to a single session. Unsurprisingly, everything
DHCPDECLINE if it detects any problems. starts with the "DHCP Discover" message sent to
Otherwise, the address is considered assigned. 255.255.255.255, an IPv4 broadcast address. The
The lease time is sent along with other DHCP options server replies with "DHCP Offer" sent to yet-unknown
(see below) in DHCPACK. When this time is about to to the client unicast address, 192.168.101.37. This
elapse, the client sends another DHCPREQUEST to works, as the server already knows the client's
renew the lease. If the client decides to relinquish the hardware address, and no ARP request is needed.
lease, a DHCPRELEASE message is sent instead. The lease time is two hours. The client responds with

IP configuration, the DIY way
Just because you can have your IP address assigned It is up to you to ensure that the IP address you've chosen
automatically doesn't mean you need to. Good old static is not conflicting with anything else on your network. You may
network configuration still works in 2016. also notice a CIDR notation, addr/mask. It allows you to assign
Linux provides several approaches to manual network both the IP address and the netmask in a single command.
configuration. The one is via ifconfig and route. Another is mask is the number of bits set in the network mask, so /24 is
using the single ip tool, which is more versatile. equivalent to `255.255.255.0` in ifconfig's parlance.
The roadmap is as follows. You bring the device online, Next step is adding the default route:
assign it an IP address, then add some routes (at least, # ip route add default via 192.168.1.1
the default one) and configure DNS. Imagine you want to Any valid destination (host or network) is acceptable where
configure the network on eth0 device. Then start with the default is. You need to substitute 192.168.1.1 with your
following (as root): gateway address, which needs to be on the same subnet as
# ip link set up dev eth0 you are. Your final step is to tell Linux the DNS server to use:
This brings the device "up", that is, to the active state. Now, # echo 'nameserver 8.8.8.8' > /etc/resolv.conf
assign it an IPv4 address with: Things are trickier if your system uses resolvconf or similar
# ip addr add 192.168.1.5/24 dev eth0 management framework. In this case, refer to the man pages.

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"DHCP Request", asking the server to commit the
suggested configuration. "DHCP Ack" completes the
sequence.

Server side
There are many good DHCP servers available for
Linux. A de-facto standard is dhcpd from the Internet
Systems Consortium (ISC). For smaller networks,
there is often a simpler alternative called dnsmasq
(http://www.thekelleys.org.uk/dnsmasq/doc.html).
You may already run dnsmasq without being aware: it
comes pre-loaded on many home wireless routers.
Strictly speaking, dnsmasq isn't a DHCP server. It is
an all-in-one solution, providing caching DNS server,
DHCP, network booting and everything else you may You'll often find dnsmasq
want for you home or small office network. Of course, dhcp-host=bert,192.168.0.70,infinite (or dhcpd) running behind
it's free, and you'll probably find it in your distribution's This also shows you may use client-supplied names the facades of modern web
package manager. dnsmasq uses a single as identifiers instead of their hardware addresses. browsers.
configuration file. Typically, it's /etc/dnsmasq.conf, It is also completely possible to set the DHCP
and it comes with a lot of comments. The parameters options you want. dnsmasq already fills some of
we are interested in start with the dhcp-range= line. them with sane defaults. For instance, the daemon
This enables the DHCP server and supplies it with a assumes that the default gateway and DNS servers
pool to assign addresses from. Optionally, you may are on the same machine as itself. If it's not the case,
also specify the lease time here: the following should help:
dhcp-range=192.168.0.50,192.168.0.150,12h dhcp-option=3,192.168.0.254
That's it – now your clients will get dynamic dhcp-option=6,8.8.8.8
addresses from the supplied range. Of course, you An alternative syntax uses symbolic names, like so:
can do some fine-tuning, if you want to. Say, this is dhcp-option=option:router,192.168.0.254
how you assign a given client a static IP address dhcp-option=option:dns-server,8.8.8.8
along with the hostname: Now, run dnsmasq with an init script, systemd unit
dhcp-host=11:22:33:44:55:66,fred,192.168.0.60 or whatever else your Linux uses, and start serving
Again, you may append a comma-separated your clients. Note that it is generally not a good idea
lease time. It makes sense to set it higher than for to run two DHCP servers on the same subnet if
ordinary clients, as there is no point in re-acquiring the they have their address pools intersecting. As you
same IP address every few minutes. dnsmasq even likely already have DHCP enabled on your router,
supports `infinite` lease time, if you want to make the experiment carefully. In any case, if your network
assignment permanent: starts to misbehave, just tear down dnsmasq.

Command of the month: dhcpcd
ISC's dhcpd is a de-facto standard DHCP server. forked to background, child pid 2069
No wonder its counterpart, dhclient, is the de-facto ...
standard DHCP client. But Linux is all about choice, dhcpcd is quite chatty by default, at it tells you
and there is one other thing: dhcpcd. which offers it got and what it decided to do about
Personally, I tend to use dhcpcd whenever I want to them. When the process finishes, the command forks
initiate a DHCP procedure manually. It's simple: you into the background and keeps running silently to
just type dcpcd and tell it which interface you want to renew the lease when the time comes. The command
configure: also accepts numerous arguments. For instance, you
# sudo dhcpcd wlan0 can send arbitrary DHCP options with -v. When you
DUID 00:01:00:01:1f:13:91:56:90:4c:e5:c7:89:69 decide you no longer want to use your address, run
wlan0: IAID e5:c7:89:69 dhcpcd -k to relinquish the lease.
wlan0: soliciting a DHCP lease Tools like dhcpcd are rarely useful in modern
wlan0: offered 192.168.101.44 from 192.168.101.1 desktop environments with their graphical network
wlan0: ignoring offer of 192.168.101.44 from 192.168.101.1 setup tools. However, they may come handy in
... disaster recovery systems, or otherwise less user-
wlan0: leased 192.168.101.44 for 7200 seconds friendly Linux distributions. It's good to be aware of
wlan0: adding route to 192.168.101.0/24 them just in case you'll need to negotiate a DHCP
wlan0: adding default route via 192.168.101.1 server manually someday.

www.linuxvoice.com 97
LINUX INSIDE

LINUX INSIDE:
ROBONAUT R2
Robonaut R2 is a humanoid robot that lives this form-factor is that it can interact with either on earth or in space can operate
on the International Space Station. Initially parts of the space craft that have been Robonaught by wearing a visor, vest and
designed as an earth-based prototype, R2 designed to be used by humans. pressure-sensitive gloves.
proved so capable that it was launched into The brains of the machine are actually Initially, R2 was just a torso, but legs
space on 24 February 2011 on what was located where its stomach would be if it have been added to enable it to move more
the Space Shuttle Discovery’s final had one. 38 Power PC processors easily and NASA even hope that in the
mission. It is, at the time of writing, the only controlled by a Linux kernel control the future it will be able to perform space walks
humanoid robot in space. The advantage of movement and communications. Users more effectively that human astronauts.

Nick Veitch
proper tools, resulted in a lot of writing be resilient to reboots (which happened
was the original editor
of Linux Format, a things out by hand, converting instructions frequently in some missions) and the
role he played until he into numbers and writing a Basic program to software implemented a very basic form of
got bored and went ‘Poke’ the values into memory. multitasking so that important things (firing
to work at Canonical It was a tiresome and error-prone process. the engines) always happened on time
instead. Splitter!
I always remember thinking “they said this irrespective of what other processes were
computer was more powerful than the ones running. The available storage memory
used in the US space program, I bet they (actually, wire-wound ferrite core storage)
didn’t write their code like this”. Well… was so small that many spaces had to be

I
learnt to program on the ZX80. I don’t Recently great chunks of the original code used for multiple variables depending on the
remember how long it took to give up on for many of the Apollo missions systems phase of the mission – some slots were
ZX Basic – do remember trying to has been uploaded to GitHub (https://goo. used for up to seven different variables.
convert listings printed for other computers gl/p5pccF). Aside from just the curiosity of It is a remarkable achievement (and if you
to ZX Basic, but ultimately, it wasn’t enough leafing through the annotated source, it is are curious you can also find online
space to realistically do much in Basic, So I amazing to see how tightly coupled this emulators for the different computers and
eventually had to work out how to use Z80 code was with the hardware – every cycle the DSKEY interface used by astronauts
assembly, which with no room for any needed to be accounted for, and needed to (www.ibiblio.org/apollo).

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