Friday, 30 September 2011

Re-start Linux X-Server without Rebooting

In normal operation, the Ctrl+Alt+Delete key combination brings up a menu to shut down, restart, suspend or hibernate your machine. Then there are the times when the X-Server, that software stack that handles the windowing graphics display breaks down and things appear to freeze, the mouse cursor won't move and Ctrl+Alt+Delete doesn't respond either.

There are alternatives; the shortcut keys Alt+PrintScreen+K also quits X-windows to go out to the log-in screen without a reboot.

Wednesday, 28 September 2011

How-to: Linux XKill Terminates Programs

Xkill is an installed component of the X11 Utilities package present in many Linux distributions including Ubuntu and Linux Mint.

It's a tool for terminating badly behaved X clients or unresponsive programs which just stop. Sometimes the only thing to do is kill them!

You can run it in several ways.

Monday, 26 September 2011

Review: Barefoot into Cyberspace by Becky Hogge

Barefoot into Cyberspace book coverBarefoot into Cyberspace - Adventures in Search of Techno Utopia by Becky Hogge

Can we keep the Internet an open, democratic and free tool for the betterment of mankind? Barefoot into Cyberspace tackles this question. Written by a recent guest of ours on the Full Circle Podcast, Becky Hogge is a journalist and former director of the Open Rights Group. In it, Hogge seeks out the radical hackers opposing the old institutions gathering to control the Internet.

Saturday, 24 September 2011

Review: Puppy Linux 5.2.5

Puppy Linux Live CD and installPuppy Linux was designed as one of those small, light-weight Linux distributions, intended primarily for lower specification hardware whilst still providing a full suite of applications and utilities for a usable desktop environment.

Frugal with resources, it was blindingly quick. Lucid Puppy 5.2.5 is not the latest release, dating from April 2, 2011. The download is a 128MB .iso image file which I decided was worth a road-test on an otherwise obsolete AMD chip and main-board combination from 1999...

Puppy Linux 5.2.5 is based primarily on Ubuntu 10.04 LTS “Lucid Lynx,” but there's a mixture of utilities provided using the 'Woof' build system, such as a later version of the e2fsprogs file-system utilities from Ubuntu 11.04 “Natty Narwhal.” Puppy 5.2.5 uses version of the Linux kernel and thanks to that build system, Woof, it can take binaries of other popular distributions and incorporate them into new Puppy releases, among them many components from Ubuntu such as shared libraries and some applications. This may have something to do Puppy rising to no. 9 in the Linux chart on Distrowatch. Compatibility with Ubuntu packages notwithstanding, the spirit of the Puppy remains independent, although I'm slightly concerned that it remains almost a single-handed effort by 'lead' developer Barry Kauler.

Puppy is bootable from just about any media, including LiveCDs, zip disks, USB drives and hard drives. It does a reasonable job of automatically detecting most hardware. However, I found a problem doing a full install in Virtualbox on a partition formatted ext4. Ext4 is not fully supported in Puppy, as the bug lists show.

Puppy's small size makes it a good candidate to install onto USB memory sticks with the ability to save any personalize settings and installed software. At boot-time Puppy loads into RAM, which frees up the boot device for other uses and makes for a very fast system.

Puppy Linux desktop installedPuppy’s diminutive size is one of the distribution’s most attractive characteristics, as is the fact that it loads into RAM, making it very fast. On most systems, in fact, boot time is just 30 to 40 seconds, even on my old P-II clone.

The pragmatic mish-mash of Puppy's interface and tools helps provide the high performance. Puppy uses JWM and OpenBox with FBPanel, all known for their minimum resource requirements. Many of the tools are console-based or have very simple 1990's style low-res control decks. They are easy to use, but it does feel like a step back in time.

Otherwise, Puppy ships with lots of smaller but useful applications for a light-weight but functional desktop. There's the Gnumeric spreadsheet, Osmo personal organizer, HomeBank money management, Abiword and a selection of applications for photo and image management, text editors and media player. Slypheed is the default mail client and Dillo the browser. See what I mean? Step back in time.

Using the JWM Windows Manager, the desktop is a riot of colourful Fischer-Price style icons. The standard start-up sound is a friendly bark. More themes are available and more programs are available through the Puppy Package Manager or using the QuickPet alternative package manager.

If you don't find what you want in the Lucid Puppy repository, the Ubuntu repositories can be used with one tick-box. QuickPet provides a one-click alternative to install programs such as Firefox, Pidgin and LibreOffice, although the performance of these was tardy to say the least. I haven't persuaded Open Office Writer to run at all on my two test beds.

The miracle of Puppy is that it resurrected an old Pentium-II era AMD-based machine with only 256Mb of memory. Desktop performance was good, when the equivalent Ubuntu live CD's for 11.04, 10.10 and 10.04 failed to run, much less install locally. The screenshot is of that machine happily running Puppy, much faster than it ran Windows XP.

Where it surprisingly failed is in Virtualbox, where the Puppy Live CD managed to run badly and install to a virtual disk a version which still won't boot despite much remedial work.

Puppy remains a bit of a mixed bag. I certainly wouldn't run it on any current hardware and I'm not sure I'd want to suggest it as an alternative to anyone but a bold tinkerer familiar with Linux distributions; but as a fall-back on old kit, you can do worse than take the Puppy for a walk. Ouch. Sorry. RC

Puppy Linux official home page:
Puppy Linux Wiki site:

Thursday, 22 September 2011

Create an Elevated Nautilus Launcher

In the Ubuntu file system, you can use Nautilus file manager to browse most files but can only write files in your own home folder and sub-folders such as Desktop and Documents. If you have to perform file operations outside of your home folder using the Nautilus file manager, you'll get errors owing to insufficient write permissions. If you've got sudo nautilus in the command buffer of every terminal session it might be time to create a launcher for Nautilus with elevated permissions.

Go to the Gnome Menu > Applications > Preferences > Main Menu

I've chosen to create mine in the "System Tools" menu group in the left panel, highlighting that then selecting "New Item" on the right panel.

Give the launcher a name such as Elevated Nautilus in the "Name" box.

gksu nautilus
in the "Command" box. This will run the file manager as Root.

Select "OK" button and "Close" button.

You can now go to Menu > Applications > System Tools and find the Elevated Nautilus launcher in place. You will need to enter an admin password to activate it.

Be careful with this one, as it runs with root permissions, you can use it to delete or change any files in your filesystem. RC

Wednesday, 21 September 2011

How-to: Remove Old Linux Kernel, Clean Up Boot Menu

Usually when Linux updates to a new Linux kernel version, the old one is left behind and your boot menu gets longer. Once you're sure your new Linux kernel is working and stable, you can safely remove the old kernel versions and clean up the boot menu. 

Do this with care and attention removal of the current running kernel will render your system un-bootable. I know, I've done it!

Run the System Monitor (sysmon) where the system tab will tell you the version number of the current running kernel. In a Terminal session, the command
uname -r
returns the same information; on my Ubuntu machine it's 2.6.38-8-generic.

Next, go to System > Administration > Synaptic
In the lower left panel, choose Status then select 'Installed' from the filter list. This narrows down your candidate list to those installed.
Enter the current kernel version number (e.g. 2.6.38) in the Search box. You wil get a filtered list based on your latest kernel version - mine is 2.6.38-11-generic).
Right-click the items with smaller sub-version number (e.g. 2.6.38-10) for older Linux kernels and select Mark for Complete Removal. The complete set of files to be removed for older kernel versions will most likely include linux-headers-2.6.38-10, linux-headers-2.6.38-10-generic and linux-image-2.6.38-10-generic.
Select Apply from the top panel.
Select Apply again when the confirmation dialog pops-up to confirm removal of the marked packages. The old versions will drop out of the boot menu when it is cleaned up automatically after the old kernel version is removed. RC

Saturday, 17 September 2011

Full Circle Side-Pod Episode Ten: Dancing in Bare Feet

In this episode, interviewing Paul Levy and Becky Hogg.

Just me, Robin Catling hosting things today, but I'm not alone, as we have not one but two guests.

First up is Paul Levy, from Cats3000, Rational Madness and the Critical Incident un-conference, who will be talking about Learning to Dance with Spiders. We'll follow that with an interview I recorded about a month ago (before I got caught up with OGG Camp). Our second guest is Becky Hogg, journalist, activist and author of the book Barefoot into Cyberspace.

The Full Circle Podcast is also a proud member of the Tech Podcasts Network.  

File Sizes:
  • OGG 27.8Mb
  • mp3 23.6Mb
Running Time: 1hr 12minutes 18 seconds  

Feeds for both MP3 and OGG:
RSS feed, MP3:
RSS feed, OGG:

Your Host: Robin Catling (blog at, twitter @robincatling) Additional audio by Victoria Pritchard 

Show Notes  

00:59 | WELCOME and INTRO  

02:26 | Interview: Paul Levy Discussing:
  • Cats3000 and Rational Madness
  • Texts theatrical performance
  • Critical Incident unconference
  • which together lead to Learning to Dance with Spiders: "Led by Paul Levy. Paul will share some experiments from his forthcoming book about living consciously with your mobile phone and staying intact in the world of social media. Truly ground-breaking, uncomfortable, and usable."
Also discussed:
Paul Levy's site combines Cats3000 and Rational Madness at, where you will also find the e-book The Collusion of Mediocrity. It's a little early for the Critical Incident un-Conference for 2012, but take a look over the conference notes for last year and this year over at Critical Incident website,  

26:48 | Interview: Becky Hogge Becky Hogge Barefoot into Cyberspace: Adventures in Search of Techno UtopiaAuthor of Barefoot into Cyberspace - Adventures in Search of Techno Utopia Through activism and journalism covering hacker counter-culture, from Stallman and Lessig, the Chaos Club to WikiLeaks Julian Assange and Rop Gonggrijp, quote:

"I think most of what were fighting still today in the world is incompetence. Most of what we’re fighting is stupidity, and maybe a little bit of opportunism. There is also the ominous, control-seeking large corporate interests."

"We come in peace. We’re not called Chaos Computer Club because we cause chaos. If anything, a lot of our collective work has actually prevented chaos by pointing out that maybe we should lay some decent virtual foundations before we build any more virtual skyscrapers."

Barefoot into Cyberspace: Adventures in Search of Techno-Utopia by Becky Hogge, illustrated by Christopher Scally

ISBN 978-1-906110-50-5 (print) | 978-1-906110-51-2 (Kindle)

1.10:49 | FEEDBACK: How to get in touch with us  

1.11:10 | WRAP and OUTRO

Friday, 16 September 2011

How-to: Sharing in now with Google Plus One sharing now with Google Plus OneYou can now hang out with the cool cats by adding Google Plus One sharing to your blog. At the bottom of each post and page you can now include Google Plus One sharing buttons for your readers to share your content across the full range of social networks/services. took a little while to catch up with Google Plus. There was a code generator for putting the Google Plus One button into a widget, but now Google Plus is included in the standard sharing options.

It is all encapsulated in the Sharing options to make it as easy as all the other services. From the Wordpress Dashboard, go to Settings, then Share Button.

Here you can customise which sharing services you want hooked into your blog. The common services - Facebook, Twitter, Digg, Stumblupon, LinkdIn and the rest have now been joined by a Google Plus One button. Email and Print are also standard buttons.

You can easily enable services by simple drag and drop of the buttons from the Available Services section down to the Enabled Services section. You can drag the buttons to the desired order and see how that looks in the Live Preview section.

You get to choose the button style and what pages on which Sharing will appear - this sets the granularity or level of sharing; that is, only on posts, on media within posts, on your homepage and static pages and so on. sharing now with Google Plus OneCustomising Sharing Services
By default, these are simply links to the sharing service, but you can also display Twitter, LinkedIn, StumbleUpon, Reddit and Digg in “Official” mode, hooking into the specific API's in order to display the number of shares in real-time on your blog post pages, as reported by each Official service - including the counter in Google Plus One.  

Hidden Drag and Drop services
If you want to save real-estate or minimise the amount of clutter on your post footers, you can also drag any of the services into the Hidden Services section. This places your enabled sharing services behind a single Share button, to be revealed as a little sharing dashboard when you mouse-over the parent button.

Adding Your Own Service Sharing 
Services outside of the standard set can be added as custom links, you just need to add it using the Add a New Service link in the Available Services section; you have to provide Service name, the Sharing URL and the Icon URL for the button (for example

The Sharing URL is the URL address to the sharing service. Quite flexible, this field accepts wildcards, for example %post_title%, %post_url% (short URL), %post_full_url% and %post_excerpt% in the URL. The example Wordpress gives is

Verify that the target service responds to the use of these wildcards (or variables) before you enable it on your live blog - so you don't look like a chump. You will be able to review your Sharing stats in the Dashboard.

It is possbile to turn off sharing for individual posts using the check-box in the Edit Post panel.

Code Master
As documented at the Google Webmasters page, you can get the code snippet for a standard Google Plus One button and do-it-yourself on Wordpress or any other website.

The official Google Plus One sharing snippet on the Official Google Plus One website provides for buttons in 4 different sizes as Small(15px), Medium(20px), Standard(24px) and Tall(60px). RC

Wednesday, 14 September 2011

How-to: Act on Gmail Forged Mail Warnings

Keyboard by Andrew* at Flickr under Creative CommonsAre you seeing the error in Gmail: "This message may not have been sent by...." another Gmail user?

You'll see this warning if a sender is claiming to be from Gmail, but the service can't confirm that the email actually originated from a Gmail sender. Like most third party messaging services, all mails sent through Gmail contain authentication data in the message header that can verify that the message was sent through Gmail. 

So if you see this warning, how should you act on it?

Saturday, 10 September 2011

Review: HTML5 Guidelines for Web Developers

HTML5 Guidelines for Web Developers
by Klaus Förster, Bernd Öggl, Addison-Wesley / Safari Books

Whether you are a web developer, hardcore coder or, like me, just somebody who dabbles and tries to keep up with the latest technology, you will find this volume on HTML5 of interest.

"You should definitely have a basic knowledge of HTML, JavaScript, and CSS; a willingness to work with a different browser for a change, not just the one you are used to; and above all, a desire to discover something new."

Written by a couple of enthusiasts from Innsbruck, Austria, it's a good round-up of what's in and out of the emergent HTML5 standard.

There is a companion website in English and German demonstrating the code snippets at

It's good that Förster and Öggl sat down to produce this, as I have struggled this year to find a decent source that encapsulates the proposed HTML5 standard. As Open Source developers and sys admins, they have a good grasp of web technologies.

For the uninitiated, there is the obligatory, but brief, overview of HTML standards in a 'how we got here' introductory passage which begins the valuable list of external references to sites and publications for further reading; this salting of the text continues throughout.

The What's New and What's Obsolete section summarises just that, then it's onto the meat of HTML5, starting with semantics, document structures, punctuated with code samples and highlighting important points of note.

So it goes on; intelligent forms is all about more interactive web pages. Audio and video, importantly, has to cover codecs, containers and players, as this is one of the most eagerly awaited aspects of HTML5. There's a thorough section on Canvas, a programmable picture on which you can draw via a JavaScript API. Scalable Vector Graphics (SVG), Math Mark-up Language and Geo-Location round out the page mark-up components.

Web Storage and Offline Web Applications gets a chapter, for interacting with Cloud services, while Websockets extends the HTTP protocol for broadcast communications between client and server. Web Workers is a new mechanism for background processing and error handling, as far as I understand it: "...scripts running parallel in the browser... in desktop applications these are known as threads; in the browser they are called web workers." See? Some of this is genuinely new to me, I shall have to go back and re-read some of these chapters.

Förster and Öggl have produced an excellent, no-nonsense guide to the HTML standard so far, with prolific examples. It is well written (I suspect their English is better than mine) in a concise style edited for clarity. You know these two have learned from other technical guides and avoided many of the pitfalls. The subject matter may go over your head, the writing doesn't, nor does it talk down or patronise. Developers will like it and the rest of us can get a flavour of what is beginning to emerge. RC

Thursday, 8 September 2011

Review: MakeUseOf Guide - Restoring Old Hardware With Ubuntu

MakeUseOf Guide: Restore Old Hardware with Ubuntu GuideOld Computer New Life: Restoring Old Hardware With Ubuntu [PDF] by Stefan Neagu

This new guide by MakeUseOf author Stefan Neagu does just what it says on the cover. Outlining everything you need to know to get Ubuntu up and running on older computers, all those old (and not so old) machines that don't quite race along with Redmond's finest software, this is a guide to free software in general and an excellent beginners' installation guide to Ubuntu Linux in particular.

Thursday, 1 September 2011

How-to: Change Ubuntu Unity Configuration Settings

The Ubuntu Unity desktop doesn't have a lot in the way of user preferences - unless you know where to find them. You can adjust some of the settings in Unity if you can get to grips with the plugins for the Compiz rendering engine.

You will need the CompizConfig Settings Manager installed as a pre-requisite. You can install it through Software Center by searching for 'CompizConfig Settings'
  • Run the CompizConfig Settings manager then under Preferences you will need to find and add the Unity plugin to the CompizConfig Settings panel. You will need to turn off Automatic sorting to unlock the plugins list to add it to the active panel.
  • In CompizConfig Settings, select the Unity plugin, then choose the 'Experimental' tab.
    There's a stack of settings to adjust for transparency, timings for show/hide, Dash icon animation types, showing of devices in the Dash and blur.
It's not the complete control over settings you get in Gnome Desktop, but then as we know, Unity is not Gnome. RC