Restore Ubuntu panels

It seems a common (or more frequent) issue with Ubuntu? I've been using Ubuntu for few months (in addition to other LINUX based OSes I've been using) and came across this issue in my Ubuntu 10.10 (Maverick Meerkat). At the start up it gives you some error messages saying "unable to load blah blah... " (on some desktop applets etc...).

It's relatively easy to restore them back to their original(default) settings though. Just run the below and the panels will be restored.

$ gconftool --recursive-unset /apps/panel
$ rm -rf .gconf/apps/panel
$ pkill gnome-panel

How to recover deleted files in Eclipse

Well, this happened to me, file was not in a version control either and I was desperate to recover it.  Luckily there's a feature in eclipse to restore files from the context menu ("Restore from Local History...") of the relevant component (src folder, package folder etc...) where you deleted it from.
You can even get any other previously saved version of it from the dialog as shown below...

My experience with Stanford AI-Class

Well, it all started around 3 months ago, Introduction to AI (Artificial Intelligence) was offered free (ai-class) for anyone from around the world in partnership with the Stanford Engineering. Initially more than 160, 000 students signed-up for the course. But the participation seemed to degrade a bit as the course progresses. But fairly a big number of students were involved throughout the course. We are almost at the end of the course now. So thought of putting a summary about the course...


Organization of the course:

First of all, kudos to the whole team for such an exciting experiment. The lectures, assignments and the exams are all well organized and easy to get started to anyone familiar with basic computing and web. The tools/forums provided for collaboration are adequate as far as the course is concerned and they've all been well handled and moderated.


Course content:

It's not just fun learning in the spare time but also gives a lot more freedom as students to get clarified and improve upon while learning. I'd like to highlight the fact that it gives the opportunity to listen (and see) the original lecture any number of times when we need as this might not be possible in a real class.

I really liked all the topics and learned quite a lot within a short time. And my favorite was the topics related to robotics. It's really a privilege to learn all these basics with some real world examples as a proof for their applications.


Thanks:

A big thanks to both Prof. Peter Norvig & Prof. Sebastian Thrun for putting their valuable time in to this and make it a reality. And a special thanks should go to the technical team for handling the huge amount of traffic well with minimum down time.


Next step:

I hope this experiment will have a big impact on how the education should be delivered & modeled in the future. And I personally am proud to be part of this experiment.

Work with Mercurial in GUI mode (Fedora 14)

Recently I had to work with Mercurial repositories which involved some of my project work and while I'm at it just went on to see how to use it with the help of a GUI tool if any. Then I found out that Tortoise has a GUI support for this which is named TortoiseHG. (Note that one can always use hg which is part of the  standard Mercurial installation which works fine with the command line for the same).

So, how to use TortoiseHG?

Installation:

For the fedora it's available in the Fedora's update repository. You can easily install it using yum. 
     Note: You need to have Mercurial installed before proceed. If you don't then it'll be installed as a dependency. So no        
                 worries :)

yum list tortoisehg <Check whether its available>

<Login as root>

yum install tortoisehg <Install>

Usage: You use hgtk to work with GUI mode.


Example: Simple repository init with it look like this:

You can use most of other commands similar to this. Go figure... :)

Google+ account settings

There seems to be some changes in account settings of the Gmail account with the new features including Google+. Of course the settings are much more related to and aligned with Google+. And some options available previously seems to be gone. I'm not sure whether they will later appear in a different form. But as of now there's a link for the old settings page in bottom of the new settings page saying "Looking for older account options and your Google Products?" which brings the same old "settings page". (Note: Of course there are other ways to access these pages by the means of direct URLs etc...)

This might be useful specially if you used to access different products like blogger, App Engine from within your Google account settings.

Installing Inkscape on Fedora.

I was looking for a good diagramming tool for fedora (#14 specifically) then found out that Inkscape is a good one for the job (I'm not that expert on the tool yet).

I was interested in installing it from the source (just for fun :)). I know that you can use yum (or any package management tool) to do all of this very easily but I haven't tried that path. So I cannot comment on how it works there.

Here are key things you should be aware of if you are going to do the same:

There are quite a few dependencies that you should resolve before installing inkscape including a garbage collector (GC) for C/C++ which I had some trouble getting installed. So I thought of mentioning it here for anyone trying the same.

Install the GC:

1. Get the source from here (I used gc-7.1) and extract it to your preferred location.
2. Change to the folder you extracted the source and run ./configure --disable-shared --enable-static
3. If all seems fine (with no Errors reported) then run make.
4. If everything is fine then it's time to install, run install (as the root).

This should have the GC installed in your machine.

And for the rest of the Inkscape compilation and installation you'll find almost everything you need here.

How to create JMS resources from CLI in GlassfishV3

We'll look at how JMS resources specifically Queues (PTP model) & Topics (Pub-Sub model) can be created by the asadmin tool.

There is always this admin console (GUI mode) in Glsssfish which you can use to create all the resource types you need in applications. But the CLI tool (i.e.: asadmin) provided with the distribution also can be very handy if you need to create the resources for quick testing. We'll see how we can use this to create JMS resources specifically Queues and Topics:

Queue:

[Vijitha@localhost bin]$ ./asadmin create-jms-resource --restype=javax.jms.Queue --description="PTP Test queue" jms/MyPTPQueue 
Authentication failed with password from login store: /home/Vijitha/.asadminpass
Enter admin password for user "admin"> 
Administered object jms/MyPTPQueue created.
Command create-jms-resource executed successfully.

You may verify this either by CLI or the admin GUI console.

1. CLI:

[Vijitha@localhost bin]$ ./asadmin list-jms-resources
Authentication failed with password from login store: /home/Vijitha/.asadminpass
Enter admin password for user "admin">
jms/MyPTPQueue
Command list-jms-resources executed successfully.

2. Admin GUI console: Resources -> JMS Resources -> Destination Resources

Topic:

[Vijitha@localhost bin]$ ./asadmin create-jms-resource --restype=javax.jms.Topic --description="Pub/Sub test topic" jms/MyTopic
Authentication failed with password from login store: 
/home/Vijitha/.asadminpass
Enter admin password for user "admin">
Administered object jms/MyTopic created.
Command create-jms-resource executed successfully.

You may verify this either by CLI or the admin GUI console.

1. CLI:

[Vijitha@localhost bin]$ ./asadmin list-jms-resources
Authentication failed with password from login store: /home/Vijitha/.asadminpass
Enter admin password for user "admin">
jms/MyTopic
Command list-jms-resources executed successfully 

2. Admin GUI console: Resources -> JMS Resources -> Destination Resources