Tuesday, 30 June 2009

Fix PPA Authentication errors in Linux

When running sudo apt-get update I often get an error similar to this:

GPG error: http://ppa.launchpad.net intrepid Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 0CF459B8DF37ED8B

After a little Google-ing I think I have found the answer. Fire up your terminal and try the following command:

gpg --keyserver subkeys.pgp.net --recv (ERRORKEY)

Replace ERROR KEY with the error code you are getting - it will be something like this - 632D16BB0C713DA6

Next type the following to add that key to your gpg keychain:

gpg --export --armor (ERRORKEY) | sudo apt-key add -

This resolved the errors for me, but I'm not sure it will work 100% of the time!

Saturday, 30 May 2009

Install Adobe Air in Linux

Click Get Adobe Air

cd to your download directory.

Make the file executable by running the following command in a terminal window:

chmod u+x Adobe*

then run the following command in a terminal window

sudo ./AdobeAIRInstaller.bin

and follow the Adobe Air installer instructions!

Once installed you should be able to download and install Adobe Air apps such as TweetDeck or Twhirl!

Thursday, 28 May 2009

DLNA in Ubuntu 9.04

I have recently installed Ubuntu 9.04 on my Macbook (1,1) and was interested to see if I could easily stream media to my new install from my DLNA media server that I use for my PS3 (a Western Digital MyBookWorld NAS). The good news is that this is very simple to do with a plug in for the already installed Totem media player.

The coherence plugin provides DLNA functionality. This can be installed by simply typing 'sudo apt-get install python-coherence' in a terminal window. However, here I experienced a small problem. Opening Totem and going to the plugin menu (under the edit menu) you can see the plugin. However, when trying to activate it you get a popup error message. Luckily this too has a simple solution. Again in the terminal, as root create this file '/usr/share/dbus-1/services/org.Coherence.service' with this contents:

[D-BUS Service]
Name=org.Coherence
Exec=/usr/bin/coherence -o use_dbus:yes -o controlpoint:yes

Close and reopen Totem and the plugin can now be activated. Your DLNA server should now appear under you Totem menu playlist options, enjoy!

It is worth noteing that it does take some time to buffer the video before playback begins.

Links:

Coherence - Here
Guide - Here
Bug report with solution - Here

Saturday, 21 March 2009

Firefox Quick Searches

I guess I have never really explored the full functionality of Firefox, otherwise I would have seen this ages ago! But there you go.

I have a friend at work who is constantly singing the virtues of the Opera web browser to me, trying to get me to adopt it. So far he has failed, but one of the features I do love if the ability to use shortcuts in the address bar for searches. For example if he wants to do a Wikipedia search he heads to the address bar and types in: wiki #whatever which takes him directly to the Wikipedia search results for #whatever. OK so its not so difficult to open a wiki page form your bookmarks and type it in there but it always bugged me that I couldn't find a Firefox extension to do this. That would be because Firefox has this functionality built right in!

Firefox Quick Searches provides exactly this functionality, a way to add custom shortcuts for addresses. That is all very well assuming you know the links for the search shortcut you want to use, fear not. The folks over at Lifehacker have put together their top 15 Quick searches in a handy downloadable (right click and save as) HTML file that you can import straight into your existing Firefox bookmarks.

Unfortunately, they are a bit US centric so I hope they won't mind that I have put together a UK version (right click and save as). The only link that doesn't seem to have liked the move is the Yahoo Local search, but I'll work on that.

Of course the list is totally customizable and its really easy once you know how. Of course with the use of Foxmarks these quick searches will be copied to all the PC's you use Firefox on!

Sunday, 8 March 2009

Reduce Firefoxes Memory Use

When I'm at work I like to use my Portable Firefox to browse the web (on my lunch break obviously!). However, working in a support environment I tend to need to have lots of programs running, documents open and remote sessions active. As such I like to make the memory footprint of my software as small as possible. Here are some tips to minimizing Firefoxes memory usage:

Mozilla Knowledge Base article on reducing memory usage.
Mozilla Knowledge Base article on running in Safe Mode
Trim Firefox memory usage when minimized - Lifehacker article
Clear out browser session history to improve memory usage
Speed up page loading in Firefox

I'm sure there are many other tips and tricks to make Firefox more memory efficient, but I have tried and tested these and found them to provide a real world improvements.

Thursday, 5 March 2009

Firefox addons to make the most of the Eee PC screen

After installing Crunchee here are a couple of Firefox extensions I've installed to make the most of the screen real estate.

1) Disable Menu (press alt-m to show or hide the main menu)
2) Hide Nav Bar (press F2 to show / hide the navigation bar)
3) Foxmarks (a great tool for syncing bookmarks between PC's, it includes a nifty work / personal profile facility.)
4) Shareholic (customizable list of options to allow you to share the site you are reading through a variety of mediums like twitter or your tumblr blog.)
5) Better Gmail and Better Greader (obviously)
6) Read it later (a great bookmarking tool when you want to 'read it later')
7) and of course Greasemokey with the following scripts:
- Google Apps sidebar remover (removes the adds from Gmail),
- Google Reader Minimalistic (gives you some hot key options to hide the top panes, w, and the side pane, u.)
- Writing Room 4 Google Documents - allows you to toggle the Google header on or off.

Many of these additions help to make the most of the small screen on the Eee PC 901.

Thursday, 26 February 2009

Cli apps for mobile browsing

Now that I have my mobile working with Crunchee to provide me with Internet access on the move I thought I should investigate some simple, less bandwidth hungry apps that I can use on the go.

Alpine:

Top of the list comes my favorite Email client Alpine. This a a very simple, straight forward command line email client. It is IMHO easier to configure and use than its main rival Mutt. However, if you are interested in learning more about Linux and email system, I thoroughly recommend giving Mutt a try.

If you are planning on using Pine with Gmail or Google Apps then you can follow this guide to get it all set up.

Gcalcli:

If you are a keep Google Apps user another Cli application I would suggest is gcalcli. Gcalcli is a Python application that lets you view your Google or Google Apps calendar from the command line. It's Google code page provides a great How To to get you started.

Note: I had a few problems getting this to work but finally found this solution.

Irssi:

Irssi is a great, customisable and expandable IRC client. That said I almost never use it for IRC. One of the best things about Irssi is its expandability, using this expandability I use Irssi as my Instant Messaging and Twitter client. Installing Bitlbee gives me access to all my IM accounts and using the script provided by Twirssi I have a fully functional Twitter client right inside Irssi.

Note: In an upcoming post I will detail how I use Irssi, Bitlbee and Twirssi to access all my IM account and Twitter from within Irssi.

Cmus:

Cmus is a simple command line music player. It is one of the simplest and easiest to use I have found.

elinks:

elinks is a fully featured command line web browser. I think most people would be surprised how easy and refreshing it is to brows the web via the command line, if for nothing else than the complete lack of advertising! Though I always have Firefox on hand in case!

With the tools listed above you should be able to get almost anything you need to do online done via the command line. The added benefit of this is that it dramatically reduces your data usage which is great if like me you have a measly data allowance on your mobile contract!

Lastly, there are a couple of other great command line apps that I use daily.

MC:

MC or Midnight Commander is a command line file manager with a great many features include the ability to view the contents of RPM package and other common archive formats as if they were simply another directory, and to function as an FTP client.

Vim:

Vim, a command line text editor, includes features such as syntax highlighting. Though Vim is often seen as a tool for programmers, it can be useful as a generic text editor, it even has a plugin for Blogger!


Gnu Screen:

Of all the tools described so far I think the most useful, certainly the most used, is Gnu Screen. It is quite difficult to describe what Screen is, other than it provides an environment in the command line that allows you to run all the above applications and switch easily between them. In addition you can disconnect from your session, leaving all your programs running, and reconnect latter, picking up just where you left off. If you intend to use the command line a lot I thoroughly recommend looking into Gnu Screen.

My .rc or config files for each of these programs are available here if you want something to get you started.

All the software used above is freely available and can be downloaded directly from most Linux distributions repositories. Most of these are developed by individuals or teams in their spare time for the benefit of the Linux community.