jump to navigation

Google Ads : Under Testing :) August 29, 2008

Posted by xk0der (aka Amit Singh) in : Amusing/Funny Stuff, Random musings , 1 comment so far

While testing my mail server, by sending a mail to my GMail account, I noticed something peculiar at GMail. I sent a mail using Thunderbird to my GMail account, then checked the mail on the GMail’s web interface and found a rather amusing ad under the “sponsered links” section. Click on the image below for full size. The ad is marked with a red circle (ellipse? :) )

Apparently the Google engineers were (are) testing their ad engine or something related when I happen to view my “Test” mail with GMail’s web interface. The Mail I sent had the subject set to “Test” and the body contained just one word “Again”. Probably the subject line triggered their test ad to appear.

The URL displayed in the browser’s status bar is the link to the google’s test ad. Clicking on it takes you to a page at google.com throwing an error “This page does not exist”.

No big deal! I just found this to be amusing, that’s it :)

Like this post?

Git Tutorial : Starting with git using just 10 commands August 13, 2008

Posted by xk0der (aka Amit Singh) in : Programming and software development, Tips and tricks , 7comments

Git is marvelous piece of tool every programmer must have. Git is a distributed version control system developed by Linus and others. Yes you guessed it, it is used heavily by the Linux (kernel) developers apart from many other projects.

How will Git help you and what this post covers.

Scope of this post : This post will deal with the usage of Git by an individual developer only.

Why use version control : Version control gives you a great deal of flexibility while coding. You can make changes without having to worry about breaking things, as you can always move back to previous version(s) of your code. Version control also allows you to compare changes as you move ahead, helping in bug-fixing apart from other benefits.

Why use Git : There are a number of other version control systems available, some centralized systems some distributed systems. Amongst them, Git is one of the fastest version control system, very simple and easy to use, and has lot of helpful features packed in very a small package. Check my other post to know more reasons.

Prerequisite

1) You need a computer :) with preferably Linux (any flavor) installed on it. (This post does not deal with Windows, though you may use the commands given here without any modifications (probably!)).

2) You need Git.

on Fedora distribution, you may install git using the following command

$ sudo yum install git

On Ubuntu distribution, you may install git using the following command

$ sudo apt-get install git
$ sudo apt-get install git-core

(Edit: 21/Oct/2008 - Thanks to robo47 for pointing out the mistake)

For other methods and building from source check out this page.

3) You need some project which you are developing (or would be developing) :) . The project’s language could be anything .. C, C++, D, Python, Perl, HTML, JavaScript, plain text files … you got the idea right? :)

Let the show begin

Command 1 : Initializing an empty git repository.

Befor you can start using the power of git you need to create an empty repository and tell git which files to track. The first command that I’m presenting initializes an empty git repository.

Before executing the command you need to be at base folder of you project. For example if you have all the source code for you project stored here /home/xk0der/SourceCode/myProject, (We’ll call this folder as the base folder for ease of discussion), move there first. Now execute the following command once you are in the base folder.

$ git init

This will create an empty repository in the current directory (the base folder).

For every project that you want to track using git, go to its base folder and issue this command first and then the next 2 commands presented below.

Command 2 : Adding files to git repository.

The next step is to add files to your git repository, essentially telling git that these are the files we want to keep track of. Execute the following command from the base folder.

$ git add .

This will add all the files from the current folder and sub-folders recursively to the git repository.

Command 3 : The commit command.

This is one command you’ll be using quite often.

the above command adds the files but does not commit the changes to the git repository. So you need to issue the following command to make the changes final.

$ git commit -a

This will open a text editor (probably vi) where you can add some comments about this commit. If you prefer not to use the text editor, you can specify the commit message from the command line it self, just use the following format instead of the above one.

$ git commit -a -m "Initial import"

The -m switch is used to specify the commit message. In our case the commit message is “Initial import”. You can put anything between the quotes for your message.

You are ‘all’ ready!

Now open your favorite text editor and start coding. When you feel you have accomplished something or you just want to save the current state of your source code issue the git-commit command as described above. The commit command will create a new checkpoint and save the current status of your source code.

Git (like any other version control system) saves all the commits you have done to your source code repository. This enables you to go back and forth between commits and inspect the changes.

Now let’s move forward and learn a few more commands.

Command 4 : Viewing the commit log.

You can view all the commits you have done till now using the following command

$ git log

This command shows the commit history with the

1) Unique commit hash
2) Name and email of the person who performed the commit
3) Date and time of commit
4) The commit message

Of all these, the first item, the unique commit identifier, the SHA1 hash is of importance to us. This hash will be used with some of the commands listed next, and is used with a plethora of other git commands, not listed here :)

Command 5 : Checking the current status.

While coding, you may want to see what all files have changed, before you do a commit to store them in the git repository. This command helps you achieve that.

$ git status

The above command will list all files that have changed since your last commit.

Command 6 : Finding the difference between commits.

Apart from just viewing files that have changed, you may be interested in viewing the actual differences in the source code.

$ git diff

The above command will show a difference ( a diff ) with respect to your last commit and current changes.

The diff command can actually be used to compare difference between any commits

To view difference between a previous commit and current changes.

$ git diff commit_hash

here the commit_hash is the first eight characters (hex digits) of commit hash as shown in the commit log by the git-log command. Yes! you need not specify the full hash, just the first eight digits are good enough.

To view differences between two previous commits.

$ git diff commit_hash_1 commit_hash_2

This command will display differences between the two commits identified by the commit_hash_1 and commit_hash_2.

Command 7 : Creating branches!

Don’t be scared by the word “branching”, specially if you never dealt with them. Branches are easy to play with and are very useful.

Before I show you the command a bit more discussion about branches.

Why use branches?

Suppose you have an almost stable source code and you are to release the product in a month or in a week or two. You also have plans to include another great feature into your code, but are afraid it might break your code and your release plans may go hay-wire.

This is where branches come into picture. Just create an experimental branch from you main stable trunk ( the one you’ve been working on up till now is the main trunk, the master branch). After you have created the experimental branch, you can continue fixing bugs and polishing the code on the main, i.e. the master branch. Meanwhile you can also continue working on the experimental branch without affecting a line of code on the master branch.

In the end, if you find that the experimental feature is working good enough, merge it into the master branch and release your product. If the experimental feature didn’t quite work out, you can still release the product from the master branch. The experimental branch is still there so you can continue working on it till it gets stable.

This is one scenario (and the most often reason, though not the only one), to create branches.

Okay now, back to commands . Issue the following command when you want to create a branch.

Creating a branch

$ git branch branch_name

branch_name could be anything that you wish, for example:

$ git branch experimental_feature

Branching a branch or “I want more branches”.

You can create as many branches from inside any branch you want, creating a very dense tree if you like.

Just move inside (check-out that branch, see command 8 below) and issue the branch creation command.

Command 8 : Moving to a branch and listing all branches

Once you have created the branch move to it by issuing the command listed below. Always Make sure you do a commit before you issue this command or else changes will move across branches. Make this a habit! (OR have a look at git-stash command, not discussed in this post)

$ git checkout branch_name

Here the branch name is the branch where you want to move. Once checked-out, you can view staus, log, diff etc, using the commands presented earlier.

To go back to the master branch (the main trunk) issue the following command. (Again make sure you had issued the commit command)

$ git checkout master

Listing all branches

Issue the following command to see all available branches in the current repository.

$ git branch

Command 9 : Merging two branches

Move to (checkout) the branch with which you want the merge to happen and issue the following command.

$ git merge branch_name

This will merge the branch branch_name with the current branch.

For example if you want to merger the “experimental_feature” branch with the master branch, issue the following commands

$ git checkout master
$ git merge experimental_feature

Git will notify you with any conflicts it cannot resolve automatically (if any). You can then resolve the conflicts manually.

Deleting a branch

After the merge is done you can delete the experimental branch if you wish by issuing the command

$ git branch -d experimental_branch

The above command will only delete the branch if it is fully merged with the current branch’s HEAD. HEAD is the current position in your branch, the latest commit.

Command 10 : Deleting stuff from the repository.

Issue the following command if you do not want git to keep track of a file or folder (this is the opposite of the git-add command)

$ git rm path/to/the/folder_or_file

That’s it, you’re done!

Before I leave you :) a few more command/features that may interest you, but are not totally necessary as of now.

A graphical repository viewer

To invoke a graphical repository viewer, invoke the following command

$ gitk

Git - Graphical user interface

For those who prefer GUI, you can install a graphical front end to git.

On Fedora

$ yum install git-gui

On Ubuntu

$ apt-get install git-gui

Run the gui by issuing the following command

$ git-gui

Yup, totally done now! :)

That’s all folks. :) I hope this post will help you in getting started with one of the most powerful version control system available around.

Like this post?

JavaScript Associative Arrays Demystified July 10, 2008

Posted by xk0der (aka Amit Singh) in : Programming and software development, Tips and tricks , 3comments

Javascript hides a lot of arsenal beneath its simplicity. In this post I’ve tried to explain normal javascript arrays and associative arrays starting with absolute basics and then presenting the advance concepts that are often overlooked but are simple to understand and are very handy. I’m not a Javascript guru :) . This post is more about what I’ve discovered overtime while coding in Javascript. Hope it helps and saves your time.

Please Note: A single line in the code snippet may wrap or may have been split to fit it into the blog’s page layout. All code snippets are provided for illustration purpose. Though they should work (execute) fine without any modification, I’ve not tested all the snippets presented here.

Normal indexed arrays

I’ll start the discussion with normal indexed arrays. Most of the text in this section would be known to many, but might be useful for Javascript newbies.

In Javascript you can create and use normal arrays as follows:

var myArray = new Array();

Normal arrays uses positive integers numbers (including zero) as index. To store elements to this array. you can use the following syntax.

myArray[0] = 200;
myArray[1] = 300;

Where 200 and 300 are the values stored at the first and the second location in the array, respectively ( index 0 is the first location).

Another way to assign elements is to use the array constructor as follows.

var myArray = new Array(200, 300);

The above code has the same effect as the previous one, storing 200 at the first location (index 0) and 300 at the second location (index 1)

Tip 1 : The array.length property
If you want to add an element at the end of a normal, number indexed array (the one we used above). use the following code.

myArray[myArray.length] = someValue;

For example:

var myArray = new Array();

myArray[myArray.length] = 200;
myArray[myArray.length] = 300;

For the first assignment, myArray.length would be 0, so 200 is stored at the first location (index 0). after the assignment the array length becomes 1 hence 300 is stored at the second location (index 1). At the end if you try to check the length property of myArray, it will contain the value 2. As you would have guessed, you can always find the number of elements in an array by using it length property, as follows

arrayObject.length

Tip 2 : Quick array creation.
You can use the square bracket operator to quickly create an array. This is specially useful when you need to pass array arguments to functions. An example follows.

var myArray = [200, 300];

alert(myArray); // outputs: 200,300
alert(myArray.length); // outputs: 2

The first line in the code, is equivalen to:

var myArray = new Array(200, 300);

Here’s how you can use this trick while passing argument to functions:

function sumAll( arrayArg )
{
    var sum = 0;
    for ( i = 0 ; i < arrayArg.length; i++)
    {
        sum = sum + arrayArg[i];
    }
     alert("Sum is:" + sum);
}

sumAll([100,200,300,400]);
// the alert in sumAll() function should
// display - Sum is: 1000

Tip 3 : Javascript array elements can be heterogeneous
I’m only storing numbers in all the above examples but Javascript arrays can store a string, an object and for that matter another array itself (as an array is nothing but an object). And one important thing to remember is that unlike many other programming language, all elements need not be of the same type. You can store numbers and strings in an array at the same time as illustrated below.

var mixArray = new Array();

mixArray[0] = "Hello World";
mixArray[1] = 100;

var anotherMixArray = new Array(200,
                                300,
                                "Hello Again",
                                500);

var moreMixArray = new Array();

moreMixArray[0] = 600;
moreMixArray[1] = mixArray;

moreMixArray[2] = new Array(700,
                            anotherMixArray);

moreMixArray[3] = "Incredible!";

The above code may look like madness at first glance, but is perfectly valid and provides a great bit of flexibility to the programmer. if you cannot figure out what’s going in that piece of code, draw it out and things will make sense, look at the figure below. :)

Array Madness Explained

Array Madness Explained

Sparsely populated Array

In Javascript arrays can be sparsely populated, that is, you need not fill-up each and every location in an array. Consider the following example.

var myArray = new Array();

myArray[0] = 200;
myArray[5] = 300;

alert(myArray);

// the alert dialog box shows 200.
alert(myArray[0]);

// 300 will be shown in the alert box.
alert(myArray[5]);

// this shows 'undefined'
alert(myArray[2]);

// this will show '6' in the alert box.
alert(myArray.length);

The above code creates a sparsely populated array, courtesy the statement myArray[5] = 300; All intermediate locations from index 1 to index 2 are created but nothing is stored there, essentially they are not-defined. Note that though the number of elements stored is two the array length is shown as 6. This is because, though the elements may be empty (technically undefined) they are part of the array.

An examples that uses the techniques shown above.

// Store Fibonacci series in an array

// Disclaimer: the code snippet here
// just serves the purpose of
// illustrating usage of array and by
// no means is an efficient or
// elegant solution (even if it is one ;) )
// to calculate or find Fibonacci series/numbers.

var myArray = new Array;
var maxNum = 100;

var a = 0;
var b = 0;
var c = 1;

while(c < maxNum)
{
    myArray[myArray.length] = c;
    a = b;
    b = c;
    c = a + b;
}

// displays
// Fibonacci Series : 1,1,2,3,5,8,13,21,34,55,89
alert("Fibonacci Series :" +  myArray);

// display - Array Length : 11
alert("Array Length :" + myArray.length);

Associative Arrays or something else!

Before we explain the “something else!” part in the heading, some definitions and examples.

Associative Array: In simple words associative arrays use Strings instead of Integer numbers as index. So we can have something like,

new myArray = new Array();

myArray["abc"] = 200;
myArray["xyz"] = 300;

Here the indexes “abc” and “xyz” are called keys and these keys are mapped to the values 200 and 300. So we say that the key “abc” maps to ‘200′ and similarly the key “xyz” maps to ‘200′. It’s that simple!

Where to use associative arrays?
I’m presenting few example here, where associative arrays may be helpful.

Databases: Consider a table with following columns and types, in the format COLUMN_NAME as TYPE

NAME as TEXT, MARKS as NUMBER, DOB as DATE.

In your code if you were to find the type of a column, you can create an associative array as follows:

var studentTypes = new Array();

studentTypes["NAME"] = "TEXT";
studentTypes["MARKS"] = "NUMBER";
studentTypes["DOB"] = "DATE";

alert("Type of MARKS is :" +
      studentTypes["MARKS"] );

As with normal arrays we need not remember the index number. Using the column names as keys we can directly get the types from the mapping.

This is a very trivial example, but the associative array concept can greatly simply coding for similar scenarios.

“But what about the ’something else!’ part”, I hear you saying :) read ahead to know the truth about Javascript associative arrays.

Magic and mystery continued…

Try the following code snippet.

var myArray = new Array();

myArray["a"] = 100;
myArray["c"] = 200;

// the alert box will contain nothing,
// it'll be empty!!
alert(myArray);

“What happened here? why did the alert box print nothing? why didn’t it output 100,200?”, don’t be too startled, more mysterious things are about to happen…

Try another piece of code.

var myArray = new Array();

myArray["a"] = 100;
myArray["c"] = 200;

alert(myArray.length); // output: 0

“What? ZERO!” … yes zero, because my friend there is NO such things as associative arrays in Javascript. “WHAT!”, you say, but you read it correct. Read ahead to know what these “key” to “value” mappings are.

Object and Properties and Not Associative Arrays

Javascript allows you to add properties to objects by using the following syntax:

Object.yourProperty = value;

An alternate syntax for the same is:

Object["yourProperty"] = value;

Shoosh!… If you are not getting what’s going on, you may skip to the next section, and I promise, it won’t hurt your usage of the so called associative arrays in Javascript.

Well, back to the discussion. In the code where we say myArray["a"] = 100; What we really are doing is creating a property named “a” for the “myArray” object and storing the value 100 in the property.

try the following code, to make things clearer,

var myArray = new Array();

myArray["a"] = 100;

myArray.b = 200;

alert(myArray.a);
alert(myArray["b"]);

Remember: These are not alternate ways to assign values to an associative arrays, these are alternate ways to assign properties to an object.

The object “myArray” is of the type Array() in our example, courtesy the statement “var myArray = new Array();”. But in theory and in practice you can use any Class’s object to simulate the associative array. Try the following code and you’ll get what I mean by using any Class’s object.

var myArray = new Date();

myArray["a"] = 100;
myArray["b"] = 200;

alert(myArray["b"]); // output: 200.

Got the point? Good! :), but I suggest you use the Array class (for simulating the associative array behavior), as it makes the code more obvious (when read).

Now that the mystery is solved, just to avoid confusion, let’s use the term “associative arrays” for the Object-Property assignment behavior.

Tip 4 - Quick associative array creation

We cannot use the Array() constructor to assign elements to associative arrays as we did with normal (proper) arrays. But we can use the Javascript’s object notation to simulate the square bracket effect. (see tip 2).

Check out the code first:

var myArray = { "abc":200, "xyz": 300};

alert(myArray["abc"]); // output: 200

The curly braces is a quick way to define an object, specifically and unnamed object or an object with no class. Normally we have been creating objects using the new operator, which expects a class name to be present.

The colon separates the property name and the value associated with it. The property name goes to the left of the colon and the value goes to the right. Multiple properties are separated using a comma.

The quotation marks enclosing the property names is optional, but is required if you are going to use property names with spaces.

In the associative array terminology, just replace the term property from the above paragraph with key.

Tip 5 - using for(in) to iterate through an Associative array

You can iterate through an associative array using the for..in loop construct as follows.

var myArray = {abc: 200, "x y z": 300};

for(key in myArray)
{
   alert("key " + key
         + " has value "
         + myArray[key]);
}

The above code snippet will display two alert boxes with the following text “key abc has value 200″ and “key x y z has value 300″ respectively.

Some explanation:
The for loop here iterates through all the properties of the object “myArray”. The variable “key” will contain the property name inside the for block, which can be used with the object to retrieve the property’s value.

In terms of associative array, you can think of the for..in construct to be iterating through all the “keys” in the array one by one, assigning the key’s name to the variable “key”.

Epilogue

I’ve not gone into much details about the Javascript object notation and neither have I dealt too extensively with the associative array concept, but nevertheless I’ve tried to present the concept of associative arrays in as simple a manner possible. I hope the post will help the newcomers to Javascript and experienced programmers alike.

Thank you for reading. :)

Like this post?

Git and Trac - A Love Story. June 26, 2008

Posted by xk0der (aka Amit Singh) in : Miscellaneous, Programming and software development , 1 comment so far

This is a post I’ve written at my Company blog. Here’s a small excerpt and the link to the complete post.

Git and Trac - A Love Story

Git and Trac, both got married very recently (at our setup ) ), and the newlywed couple are quite a charm to work with. It all started with the search for a version control tool which could be used now, with just four of us using it, and that would scale beautifully to hundreds and thousands of users. The version control system would be the groom. Meanwhile we were also in search for a perfect partner (the bride), an issue tracking system, that would gel with our choice of version control seamlessly.

To begin with, we all (at Hidden Reflex) were leaning towards a central repository setup ….. more

Like this post?

x86 Emulator in Java - Cool! June 26, 2008

Posted by xk0der (aka Amit Singh) in : Programming and software development, Random musings , add a comment

Before I write anything about it, here’s the link to the JPC project

http://www-jpc.physics.ox.ac.uk/index.html

It’s a nice feat these guys have achieved by creating an emulator for Intel x86 architecture in Java. I’m not sure how useful this project would be, but it’s a cool peice of software :) . Hats off to the JPC developers.

Some of the demos with DOS games are nice. Got nostalgic playing the old DOS games; Prince, mario, keen, invaders :)
What more, it can run Linux! .. I’m yet to try their Linux demo though, but the DOS one’s were very fast.

And to top it all, they have release the source code, I’ve just downloaded it and ‘am going to have a look at how they have done it. Meanwhile you can visit their demo pages and enjoy some of the good ol’ DOS games.

Like this post?

Setting up Linksys WiFi router with Airtel Broadband June 4, 2008

Posted by xk0der (aka Amit Singh) in : Tips and tricks , 9comments

I bought a Linksys WiFi router last weekend. I had a little bit of trouble configuring it, although the problem was trivial, it took me some time to figure it out. I’m jotting down some notes here about what I did to resolve the problem. ( I’ve have some tips at the end of this post which you may find usefull for use with linksys (and probably other) routers and with most DSL modems.)

The Problem
The beetel DSL modem installed by Airtel has the IP address set to 192.168.1.1. The Linksys router (and probably other routers as well) use the same IP address (192.168.1.1) as their default IP address for accessing their configuration page. This causes an IP address conflict and hence the router wouldn’t be able to forward IP packets to the modem.

The Solution
1) Insert the installation CD/DVD provided with the wifi router and follow the instruction for installing the router. During the installation (Probably at the final step) the router will fail to detect Internet connectivity. That’s fine, as this is the problem we are resolving. Leave the setup window open and proceed to next step.
2) Open your favourite web-browser and enter the following address in the URL bar : 192.168.1.1
3) The above step should open the Linksys configuration page. If you are prompted for a username and password, enter admin for both the fields. If you had set a router password in step 1 enter username as admin and the password you had set in step 1. Before the username and password is asked you might be displayed a page with 3~4 icons, labeled WAN, LAN etc. select the WAN Icon, enter the username and password as described above, if prompted for.
4) On the page displayed select Setup tab (most likely the first tab) and under that select Basic setup (The exact name/text might vary but would most probably be something similar). Scroll down and locate the field Local IP address. The default value for this field would be 192.168.1.1, change it to 192.168.0.1.
5) Scroll further down the page and click on Save Settings. Reset your router and DSL modem (Power them OFF, wait for 10~15 seconds and power back ON). Wait for around 1~2 minutes (So that the Router and DSL modem have properly rebooted).
6) Complete Installation of the router (Click ‘Try Again/Re-try’ in the setup window we left open in step 1)

You should now be able to browser Internet properly on the wired (directly connected) computer. Setup your Laptop and Desktops with WiFi Ethernet card/adaptors to connect to the WiFi router. After that you should be able to access Internet through them.

Tips

I hope this post was of some help to all the Bharti-Airtel broadband users. Thanks for reading. :)

Like this post?

Problems with Yahoo Mail June 3, 2008

Posted by xk0der (aka Amit Singh) in : Miscellaneous , 8comments

For the past 3~4 days I’ve been experiencing problems with Yahoo! Mail. I’ve asked few of my friends and relatives and they all seem to be having the same problems. The problem is affecting both Yahoo Mail classic and the new ajaxian Yahoo mail.

Symptoms observed
1) Yahoo! Mail rejects your login credential straight away. You are not able to login, either using just your yahoo ID or the (recently added mechanism) your full yahoo mail address (yourid@yahoo.com).
2) You are able to login, but the page is not rendered properly. Yahoo mail classic displays your mails but clicking on them wouldn’t open them (only mail subject is show, the body is missing). New Yahoo Mail would render only partially, contents of folders (Inbox etc.) are not listed.

I’ve tested the problem on Linux (Fedora, Ubuntu) and Windows XP with variety of browsers. Here’s the complete list of browsers

Windows XP: IE7, Opera, Firefox 2
Linux (Ubuntu): Opera 9.27, Firefox 2, Firefox 3 beta, Epiphany
Linux (Fedora): Opera, Firefox 2, Firefox 3

On Epiphany, Yahoo Mail tends to behave properly most of the times, but on all other browsers it mis-behaves 100% of times. (This is my observation).

I dunno what the guys at Yahoo are doing but this is really p*ss*ng off their users. I am, for sure, really irritated. I use Yahoo Mail heavily and this is causing real inconvenience to me. It is not just a few minutes glitch, its been consistently happening for a long time now. Are there any other people experiencing the same?

Update: 4th June 2008
It seems Yahoo is finally aware of the problem(2) http://www.ymailblog.com/blog/2008/06/external-accounts/

Quoting from the Yahoo Mail Blog

We are still evaluating the reports of inconsistent html rendering, but I do have an update regarding reported issues with the retrieving of POP email from external accounts.

Our engineers have reviewed the issue, identified the root cause, and are already underway rolling out the fix. Some users should see improved performance immediately, while others may not notice it for a few days (as it hits each farm).

We are very sorry for any frustration you guys have experienced, and for not getting updates out to you sooner.

As for the problem (1) I guess it has been resolved. At least I haven’t faced any problems today logging into Yahoo mail.

Update: 10th June 2008
I guess the problems described in this post have been resolved by Yahoo, I haven’t had any problems for more than 24 hours now. A big thanks to Yahoo! team. Hopefully things wouldn’t break down again, and if they do, would be resolved quickly.

Like this post?

Cyber Wars : Revision3 vs MediaDefender May 30, 2008

Posted by xk0der (aka Amit Singh) in : Miscellaneous, Random musings , 1 comment so far

A popular Internet Television network named Revision3 was brought to knees by a cyber attack from a company named MediaDefender, offering services to prevent copyright infringement using P2P distribution method. You can read the complete story here: Revision3 CEO: Blackout caused by MediaDefender attack.

The story seems to be straight out from a Scifi movie. An interesting read, but what’s more interesting are the tactics used by MediaDefender to achieve their goal. The tactics used could well be described as Guerrilla Warfare.

One of their primary tactics is to contaminate the P2P networks with fake and broken files. They create multiple sources for these decoy files and rate them high, so that they show up at the top of a search result, in a P2P client. Other commonly used method is Denial Of Service (DoS) attack.

Apart from this, MediaDefender has been accused of creating multimedia sharing websites to lure people into uploading copyrighted content. MiiVi is(was?) one such website. MiiVi was advertised as a place where you could get full length movies for downloads. MediaDefender, initially denied its involvement with MiiVi, but a major E-Mail leak found MediaDefender guilty. Wikipedia entry for MediaDefender provides more evidence (facts/stories), linking MiiVi to the MediaDefender company.

As the ars technica news entry points out, P2P is also being heavily used for legitimate file sharing. To give an example many of the Linux Distros are available for download over bit-torrent. I once used P2P to transfer (to my project mate) big documents and source-code and related-files of my college project, when you could only send like 1~2 MB of files as e-mail attachment.

Apart from this, what happened to Revision3 could happened to any other business. So where are we heading towards? A supposedly legitimate business is attacking other legitimate business. Crackers/Terror outfits are already using MediaDefender like tactics to attack governments/organisations across the globe. Virtual warfare is gaining momentum. Interesting!

Like this post?

Dying Democracy? April 10, 2008

Posted by xk0der (aka Amit Singh) in : In My Opinion, India and Politics , add a comment

I do not know what to make out of the ruling by Supreme Court (SC) of India with respect to the quota for Other Backward Classes (OBCs) in “IITs, IIMs and other Central educational institutions” the ruling adds that the SC “excluded the creamy layer from the benefit”. Here is the full coverage of the verdict at rediff.com:

http://www.rediff.com/news/2008/apr/10quota.htm

Who decides who belongs to the creamy layer of OBCs? How do they decide who belongs to the creamy layer? and why the hell do we need reservations based on castes/creed/religion/sects and the like?

Quoting from the article: “All judges favoured periodic revision on the implementation of the 27 percent quota.”, remember when the original constitution was drafted and the reservations were to last just for 10 years? What year is it now? 2008!

It is but clear, why after every five years the reservations policy is extended to yet another five year term. And every now and then new categories are added to the beneficiary list.

When will this vote politics end? Never!

What to do about it? Think beyond caste, think beyond they-me, think beyond their state-my region, Think beyond India, think Global, think Humanity!

Like this post?

Overcoming the fear of Python January 16, 2008

Posted by xk0der (aka Amit Singh) in : Programming and software development, Random musings , 5comments

As all C, C++ and Perl devotees, I too looked upon Python with apprehension. Python? What? I asked. The very idea of white-spaces being part of syntax gave me jitters and I convulsed with disgust. Why Python? Perl can do it. OOP? Perl has it … errm .. Kind of.

After reading numerous articles about python by putting the search terms “I hate pyton“, “python will die” and the like, I started getting a grasp of differences and likeness between python and other languages. One thing more I learned was, never be judgmental about a programming language if you have not used it. So after traversing threads at various forums related to “Love Python” and “Hate Python” I started understanding the various mumbo-jubo related to python. And then the thought occured to me, let’s give it a try. I downloaded python on my Windows XP machine at home and Vim for windows. Then jumped right into coding a problem that was asked to me in an interview. It was a design problem actually, but nevertheless a design can be implemented :) .

Within minutes I was automatically indenting code as I used to with C,C++ or Perl (or other free form languages I had used, for that matter). So the frown over mandatory white-spaces soon turned into a smile. And by the time I could realize I was finished creating a four road junction traffic simulator. I did searched the net for some reference, but the best thing was I just looked at the example and understood what it was, no reading what the code does or will do. Other syntax came so naturally that I didn’t even had to look online. That is I guess the beauty of Python.

In around half an hour or so, I had a complete running program in Python, using classes, random number, lists and other subtle features. The code was so readable, I thought, do I need some of those comments I’ve put in there? Some were required. But most of the time the code was itself very much self-explanatory.

Later I booted my laptop (it has FC7 installed) and copied the code on my Lappy. Python comes bundled with FC7 so I straight-away executed the code. Wow! … Its faster than windows .. Ha ha … yes this is what I noticed. Then I tinkered a bit more with the code, optimizing some things and learning new stuff in the process. Overall I enjoyed my first step into Python, very much.

I’m not going to shun C,C++ or Perl for that matter. For quick one-liners Perl is still the best. My domain is embedded systems and Linux Kernel programming so C and C++ are essential. But this discovery about Python has really give me an option. Option to create large and manageable programs in less time. They say in the python community, You spend more time solving the problem as you code and less time worrying about the language and its syntax. I Agree!

Like this post?