blog4aurobindo

When to use interfaces instead of classes

noreply@blogger.com (Aurobindo) — Wed, 10 Nov 2010 13:43:00 +0000

A few years ago, I started seeing developers use interfaces instead of classes in a lot of places. This is a good thing, because it has taken a long time for many developers to really understand object-oriented programming (OOP), and a lot of programmers (myself included) were disguising imperative code with just enough OOP to make things compile. Unfortunately, in many of these scenarios, the technique was being abused or overly used.

Here's a look at some of the situations where it makes sense to use interfaces instead of classes, and where is does not. But first, I'll explain what an interface is at the simplest level.

What exactly is an interface?
An interface defines common functionality across unrelated classes. For example, all sorts of classes that look nothing like each other may have the need to safely get rid of the resources they use.

The IDisposable interface (the name for it in .NET) defines a Dispose() method, which classes then implement. A programmer using those classes knows that, if a class implements the IDisposable interface, the Dispose() method is used to safely release resources.

An interface is a guarantee that certain functionality will work in a standardized way. When properly fashioned, an interface encompasses only the bare minimum for the defined functionality. IEnumerable (which is used to iterate over sequences, lists, sets, etc.), for example, does not provide for a Count property, because it is not concerned with "how many?" it is only worried about "the next one in the sequence".

APIs
I believe you get the most advantage from using interfaces as often as possible when you are writing an API. In an API, you want your code to be as loosely coupled as possible in terms of input and output; after all, you have no control over what the consuming application will need.

There may be a time when it is tempting to work with a List; within a piece of code, and then just return the List, for example. The consumers of the API usually do not need all of the functionality of List, and you can output IEnumerable; instead. This way, if the consumer wants a List, they can have it, or they can have an array of T, or whatever else they might need. By using the common denominator interfaces in your API, you free the consumers from being forced to use or convert to/from your class of choice.

Tightly coupled code
In the fantasy land of Computer Science courses and the blogosphere, developers never write tightly coupled code. In reality, tightly coupled code is a fact of life for the average developer.

You aren't going to make an abstract class and implement the Factory pattern to "future proof" yourself against changes when writing a three line of code class will give you a strong type to shuffle data around. Likewise, coding to interfaces is impractical in many situations; a key sign of this is when you find yourself writing classes that look a lot like structures.

If the only or the best way to get something done is to tightly couple code, then trying to abstract some kind of common functionality into an interface is either doomed to fail or merely more effort than it is worth.

Future proofing
Working with interfaces can give you a measure of future proofing when you are on the consuming end of things. If you are using a library that outputs interface instances instead of classes, not recasting those instances as classes can protect you from changes down the road. Along the same lines, if you only need a certain subset of functionality contained within an interface, working against that interface is better than working against the class.

Go back six or seven years before we had generic types--if you had coded everything to take arrays or Hashtables instead of IEnumerable or ICollection, then if the library ever changed to use List or Dictionary you would have a long road ahead of you to convert over.

Code clarity
Coding with interfaces can improve code readability. How? Because there are fewer "moving parts" for the reader to keep in mind. When you work with an interface, it is more clear what your intentions are and what the capabilities will be. Code is more self-documenting when working with interfaces for this reason.

Sometimes an interface just won't do
Some folks take the use of interfaces to an unworkable extreme. Avoid this at all costs. There will be times when you simply cannot boil down the essence of a variable or a method parameter (or whatever) to an interface. In fact, this is more likely than not. Don't try to force the issue; it's better to just use a class and move on with your life than to try to make things work with an interface.

Blue 2009 Bollywood Movie

noreply@blogger.com (Auros Blog) — Wed, 23 Sep 2009 10:12:00 +0000

A treasure lays buried deep at the bottom of an ocean. There are many people who want to get there by risking life, be it theirs or someone else’s.

‘Blue’ is touted as Bollywood’s first underwater, action adventure thriller. Directed by Anthony D’Souza , the movie is inspired from Hollywood flicks like ‘The Deep’ or ‘Jaws’, but it is not a copy.

The film is about a lost treasure, which three friends try to find undersea. Akshay Kumar , Sanjay Dutt and Zayed Khan play the respective roles.

But in this hunt for the treasure, there’s deceit and betrayal by someone in the group.

Lara Dutta is paired with Sanjay Dutt in the film. The actress did not know deep sea diving before signing the film and underwent a rigorous Scuba diving training to prepare for her role.

The movie’s second heroine Katrina Kaif doesn’t have a big role. But director D’Souza says Kat will surprise the audiences with her role. Sunil Shetty also has a brief role in the film.

Most of ‘Blue’ has been shot

in the Bahamas. Akshay, Sanjay and Zayed swam with real sharks while shooting their stunts in the film.

While shooting one such stunt under water, Akshay Kumar had a narrow escape when he accidentally hit his head against the metal of a sunken ship and began bleeding. Blood attracted the sharks, but before any mishap could happen, the actor was safely pulled above water.

To tone up his muscles, Sanjay Dutt hired the services of a special body building trainer from the US – Lawrence Gonsalves, who guided the actor on losing his former beefy body and developing a leaner physique.

Special water-resistant make-up was required for the film’s leading lady Lara Dutta. For that the producers roped in Hollywood make up artist Nikoletta Skarlatos.

‘Blue’ also feature a special appearance by Australian pop sensation Kylie Minogue who has not only sung for the film but also shot a sizzling video with Akshay Kumar.

Oscar winner A R Rahman has composed the tunes of the film’s songs. In fact, Kylie Minogue agreed to sing and dance to her song in the film because she was captivated by Rahman’s composition.

The movie apparently also has an underwater song picturized on the entire cast.

With a budget of over Rs 100 crores, ‘Blue’ is touted as Bollywood’s most expensive film to date. Made under the banner of Shri Ashtavinayak Cinevision, the movie is set to release in May, 2009.

Conficker: Experts from all over the world fail to defeat internet worm

noreply@blogger.com (Auros Blog) — Wed, 23 Sep 2009 09:29:00 +0000

Till now no one can even think that a worm could knock down global internet. Even tech experts have failed to conquer this deadly worm called Conficker, which has already infected five million computers, and may soon crash the internet in all countries.

So dangerous is the threat, that the world’s largest computer security companies have joined together with governments around the world in an unusual alliance to pool their resources and solve the problem. So much so, that a group (Conficker Working Group) to defeat the worm has also been created.

The worm, which was first detected in November, last year, spreads rapidly to computers through a flaw in the Windows operating system. Infected machines are co-opted into a “botnet” army, which can be controlled and used by the hackers to launch unprecedented cyber attacks.

“The general agreement in the security world is that Conficker is the largest threat that global internet is facing from a cyber crime point of view. It has proven to be extremely resilient. It’s almost impossible to remove,” Rodney Joffe, a Director of the Conficker Working Group, told Sydney Morning Herald. “The best minds in the world have not managed to crack the code behind this yet.”

Microsoft has offered a 250,000 dollars reward for information leading to the identification of the individuals – or rogue governments – behind Conficker. But so far international effort to find a solution has yielded few results.

The creators of the worm can do anything they want with the infected machines including stealing users’ banking details or flooding government servers to knock them offline. The worm has a built-in mechanism to prevent people from scanning their computers with anti-virus software, says Joffe. Unfortunately, even for those who wipe their computers clean and start fresh, if they back up any important data on a portable hard drive, the clean machine is re-infected when the drive is connected to the computer.

The worm also spreads automatically between computers on a network and infects machines without the user having to do anything other than switch their computers on. While majority of the botnets can be destroyed by disabling the server used to issue commands to infected machines, but with Conficker the location of this sever changes every day and state-of-the-art cryptography means it’s almost impossible to crack.

Chrome Frame: Google Offering plug-in to convert IE into Chrome

noreply@blogger.com (Auros Blog) — Wed, 23 Sep 2009 09:28:00 +0000

Google has developed a plug-in for Internet Explorer (IE) that will allow Chrome to run in IE. Chrome Frame is a new browser plug-in developed by Google which will give user a chance to feel Chrome browsing experience inside Microsoft’s Internet Explorer.

Many experts have claimed that IE has fairly low web standards and is susceptible to virus attacks and lacks in performance as well. Many users are turning to Mozilla Firefox, Google Chrome or even Apple Safari for safe browsing. But that does not change the fact that IE is still the largest used web browser (as it comes integrated with Microsoft operating system).

Many corporate houses still run IE. But after the launch of Chrome Frame things will change dramatically. Chrome Frame creates a new frame inside IE and with this frame Google packs all the essential data in a lightweight plug-in to convert IE into Chrome. Chrome Frame also injects the latest versions of Chrome’s Webkit and JavaScript engines into IE. Google claims that its goals are noble and they just want to provide users with better performance browser.

While it is true that running two browsers in one will take more resource from computer but Google says that Chrome is designed to give resources back to the machine when users are not using them with the browser.

Google claims that it won’t be explicitly advertise Google frame in IE but will use subtle methods to alert users of its existence. For example, if users browse to a Google app in Internet Explorer that may render better in Chrome, Google might have a message on the page informing about the plug-in.

Chrome Frame is still in testing stage and will work with IE6, IE7, and IE8 on any Windows-based machine. Microsoft has still not made any comment on this but there are chances that Microsoft will ban Google Frame.

How to Run PHP 5.x with Apache Tomcat 4.x or Apache Tomcat 5.x

noreply@blogger.com (Aurobindo) — Tue, 28 Jul 2009 08:27:00 +0000

I am going to discuss here few steps to run php 5.x on Tomcat 4.x or Tomcat 5.x. We can enable php only in one web application as well as run globally for all applications under tomcat. I assume here, you have Apache Tomcat 4.x or 5.x already installed and running in your machine.

Steps:
1. Download latest php 5.x zip file. I used php 5.0.2. You can download it from here: http://museum.php.net/php5/php-5.0.2-Win32.zip
2. Download latest pecl modules 5.x zip file. I used pecl 5.0.2. You can download it from here: http://museum.php.net/php5/pecl-5.0.2-Win32.zip

Note: PHP version and PECL versions should be same. If you want to try with some other version get from here: http://museum.php.net/php5/

3. Unzip php zip in C: drive(I used C: for my installation, you are open to try new things)
4. Copy php.ini-dist, in c:\php, as php.ini in c: drive
5. Uncomment the line (remove semi-colon at the beginning) in php.ini:
;extension=php_java.dll
6. Extract php5servlet.dll from pecl zip file to c:\php. Ensure that the file is actually present in c:\php (maybe you can't see the php5servlet.dll file in pecl archive, it means you are trying this with newer versions of php)
7. Now create a directory under webapps in your Apache Tomcat installation. Lets say it is named test.
8. Create WEB-INF directory under test
9. Create lib directory under WEB-INF
10. Create web.xml under WEB-INF with the following contents:

<?xml version="1.0" encoding="ISO-8859-1"?> <!DOCTYPE web-app PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN" "http://java.sun.com/dtd/web-app_2_3.dtd"> <web-app> <servlet> <servlet-name>php</servlet-name> <servlet-class>net.php.servlet</servlet-class> </servlet> <servlet> <servlet-name>php-formatter</servlet-name> <servlet-class>net.php.formatter</servlet-class> </servlet> <servlet-mapping> <servlet-name>php</servlet-name> <url-pattern>*.php</url-pattern> </servlet-mapping> <servlet-mapping> <servlet-name>php-formatter</servlet-name> <url-pattern>*.phps</url-pattern> </servlet-mapping> </web-app>

11. Extract php5srvlt.jar from pecl zip archive and extract or unjar (jar -xvf c:\php5srvlt.jar ) it under c:\
12. Modify both the files reflect.properties and servlet.properties to change the line library=phpsrvlt to library=php5servlet and save them. This indicates the file name of the dll file which is loaded by the Java application to serve the requests.
N.B.: This has no connection with the name of the jar file which can be anything. you may get this error “java.lang.UnsatisfiedLinkError: no php5servlet in java.library.path” for any mistake in this step. Please check the two properties file, whether there are any blank spaces. There should be only one line, and no blank spaces.

13. Re-create the jar file with the following command
(jar -cvfm php5srvlt.jar c:\META-INF\MANIFEST.MF -C c:\servlet\ /.), assuming you extracted the php5srvlt.jar in c: drive
14. Copy the jar file to WEB-INF\lib directory created earlier.
N.B: If you want to run PHP for one web application then do step 14 only but if you want to run php globally for all applications under tomcat then copy the php5srvlt.jar into commons/lib directory as well
15. Add c:\php to your System or User Path in Windows environment (Hint: Right-click and select Properties from My Computer -> then go to advanced tab -> click on environment variable)
16. create a new system or user variable PHP_HOME with value c:\php
17. Create a file index.php under test with the following code:

<?php phpinfo(); ?>

18. Restart Tomcat
19. Restart your machine(it is not required but though as we have added system variable so there is no harm doing a restart)
20. Start tomcat server again.
21. Open your browser and go to http://localhost:8080/test/index.php(if you set your port to some other port than 8080 please specify it in the place of 8080)
22. Ensure that there are no errors displayed. Instead you get an informative screen with php version information and whole lot of details.

Hope this helps. Have fun!!!
http://aurosblog.com/?p=481
http://gogetauro.com/blog/?p=143

Modding MOTOROKR E6/E6e/A1200

noreply@blogger.com (Aurobindo) — Sat, 11 Oct 2008 03:46:00 +0000

For the growing interest of how to mod your MOTOROKR E6/E6e/A1200 i have published a article How i moded My MOTORKR E6 edge aka E6e. I have also published Short tutorial for flashing your E6/E6e.

See this and let me know about your progress and never hesitate to post if you face any kindof problem.

Happy modding!!

My MOTORKR E6 edge

noreply@blogger.com (Auros Blog) — Fri, 03 Oct 2008 09:11:00 +0000

Hi Guys!! For since somedays i was busy with my newly bought MOTOROKR E6e aka E6 EDGE. I was too curious to mod it by as you know for modding and installing apps you have to flash your firmware to some firmwares which supprt modding. Like I have 22P firmware installed by default and these firmware is only available in indian phones, as far as i know. So i was eagerly waiting for the 22P firmware to come on internet as i have the alternate way if it doesnt work. After i got the original R535H10_G_11.87.22P aka 22P firmware. Now what should i do. To know more go here.

How to Stop Windows XP from telling you about updates?

noreply@blogger.com (Auros Blog) — Thu, 18 Sep 2008 11:34:00 +0000

Your annoying windows update yellow baloon text will never appear after this. Want to do the trick rite now... more

Current IT Scenario in India

noreply@blogger.com (Auros Blog) — Thu, 18 Sep 2008 11:34:00 +0000

Intel to cut 1,000 managerial jobs worldwide...HP to cut 24,600 jobs following EDS takeover..Satyam Computers to axe 4,500 employees...TCS, Wipro recast hiring plans...Wipro Tech puts 3000 staff under scanner...Where is your skills rated??? The long term trends for the first 10 languages (programming) are........ The other languages in the list of top 50 are....more(aurosblog)

Google Chrome Beta Released!!!

noreply@blogger.com (Aurobindo) — Wed, 03 Sep 2008 08:39:00 +0000

Have you yet heard about Google Chrome (beta) which is a new web browser just released recently? IF you are not, you shall try and see it in action. Some of the greatest features included..... more

How to Hack Windows XP Admin Password or any other password

noreply@blogger.com (Aurobindo) — Sat, 30 Aug 2008 05:31:00 +0000

I recently done this by seeing some youtube video http://in.youtube.com/watch?v=gnYSvs9QzmM. What i knew till now about this net user it is basically a command prompt tool which basically used by Windows Administrators. From this you can add delete users groups and all. To know more.....

Must Have Firefox Extensions

noreply@blogger.com (Aurobindo) — Wed, 27 Aug 2008 13:33:00 +0000

One of the nicest things in firefox is you can add plenty of extensions and add-on as you like. Some do little more than alter the aesthetics. But you’ll find others out there that you can’t browse without. No matter what your purpose in browsing, there is a killer-app extension just waiting for you. Lets take a look at this:

#1: Morning Coffee

This extension allows you to set a group of Web sites that will open (each in its own tab) with the click of a button. I use this extension to open up all the Web-based admin tools for sites I administer. You can even set sites up to open only on certain days (or every day). So news junkies or overworked administrators rejoice: This extension will make your browsing life a little easier.

#2: NoScript

This is one of the best tools for making sure your browsing experience is secure. With NoScript, you can disable active content from any site you don’t trust. Unless you configure it to allow JaveaScript, Java, and other executable scripting to run from a site, NoScript will completely block the script, keeping you browser safe from known and unknown exploits. And don’t think because you are using FireFox in Linux that you’re perfectly safe! Use this extension regardless of platform.

#3: ColorfulTabs

If you’re like me, you generally have a LOT of tabs open in Firefox. Sometimes this isn’t a problem. But there are times when the tabs can get a bit overwhelming and need a bit of organization. To help with this, ColorfulTabs gives each open tab a different color, making it easier to distinguish between them. With this simple extension, you can color-code tabs either randomly or according to URL. You can also set tabs to fade. Another fun feature is that you can set a background image for tabs.

#4: BBCode

This helpful extension adds BBCode, HTML, and XHTML symbols and formatting to the context menu. BBCode also allows you to add up to 10 custom tags to your menu. This extension shows itself when you’re in a forum and you right-click a text area where you can select the tag you want to add from the menu. This extension will make your forum work quite a bit easier, as well as faster.

#5: Buggybar

This extension is invaluable to Bugzilla power users. With this extension, you will have a Bugzilla Chrome sidebar available which will readily show all bugs that relate to a bug list you have created. As of version 0.2, Buggybar works with all instances of Bugzilla.

#6: Clear Cache Button

I don’t know about you, but I always set up my browsers to clear their cache at exit. But what about those times you want to clear the cache but not exit the browser? Instead of navigating through the menu structure, you can add this simple extension. It provides a button that gives you complete cache clearing with a single click.

#7: TimeTracker

Okay, this is not really a tool that will aid or better your browsing experience. In fact, this little extension will remind you how much time you spend browsing. I have found this little gem useful in a number of circumstances. Whether you are in need of a quick five-minute break from number crunching or you just need to know how much time you spend on a specific Web site, TimeTracker will keep track of how long you browse. What is nice about this is that the tool times across sessions. So when you close the browser, the timer stops, and when you open the browser back up, the timer starts again. You can reset the timer by right-clicking the status bar timer and selecting Reset.

#8: iMacros

This extension automates pretty much anything you do in Firefox. From opening up sites to filling out forms and even administration work — you can automate it with iMacros. The iMacros extension has a sidebar that shows favorite macros. It also has a record feature that allows you to create macros by simply clicking Record, going through the motions of the macro to be created, and clicking Save. These macros can be as complex as you need them to be. When you want to run them, you simply navigate to the macro in the iMacros sidebar and click the Play button. The only downfall I have found with this tool is that you can’t assign key combinations to run macros. Other than that, this extension is a must-have for power browsers.

#9: Fasterfox

This extension does one thing: It makes Firefox load pages faster. Speed of page loading can be increased by allowing simultaneous connections and prefetching. This extension is currently in the experimental stage because of the release of Firefox 3. To install it, you have to log into a Firefox account to download. The extension is worth the hassle. The speed increase is noticeable.

#10: BlogRovR

We all read blogs. From my aurosblog, aurolive, GoGetAuro or your loved one Blog4aurobindo to the countless other blogs available, we all read them daily. And this takes time. Instead of wasting time going to the blogs, let this handy extension fetch them for you. You do have to sign up for an account using this extension (they promise they won’t spam you.) and you will be asked to install another sidebar (Stickies), which is not necessary. Once you have this installed, you just enter the blog URL, and BlogRovR will begin fetching the information for you. Warning: If you have NoScript installed, you have to allow the BlogRovR page to run scripts or it won’t be able to fetch pages for you.

11: BugZilla

If you are into web development then this is one thing you can like the most. With this you can do amazing things like editing, debugging, and monitoring CSS, HTML, and JavaScript of your live websites. Isn't it amazing!!!

With this i also use S3Fox for my Amazon S3(Simple Storage Service) account to access my data and Google Gears to offline editing my files.

Share your experience what are the extensions you are using.

Mistakes to Avoid while installing softwares in your Linux distros

noreply@blogger.com (Auros Blog) — Tue, 26 Aug 2008 09:55:00 +0000

Installing software in Linux is nothing like it used to be, but there are still some pitfalls to watch out for. If you follow this little guide, your Linux life will be made simpler and safer.

#1: Installing from source when your system is primarily an .rpm or .deb system

Many new Linux users don’t understand that both rpm and apt (or dkpg) keep track of everything installed on the system. However, those systems (rpm, apt, and dkpg) can keep track only of packages they install. So when you find that obscure package that comes only in source and you compile it yourself, your package management system will not know what to do with it. Instead, create either an .rpm or .deb file from the source and install the package with the package management system so that system will be aware of everything you have installed.

#2: Neglecting the many graphical front-end package management applications

Most people don’t even realize that there are graphical front ends that take a lot of the guesswork out of installing packages in Linux. For yum (the command-line package management system for rpm), you can use Yumex for yum (installed with yum install yumex); you can use Synaptic or Adept for apt (installed with apt-get install synaptic or apt-get install adept).

#3: Forgetting to update the list of available packages

When using apt-get or yum, make sure you’re updating the list of available packages. Otherwise, your system will not remain updated with the latest releases of installed packages. To update with apt-get, you issue the command apt-get update. To update with yum, issue yum check-update.

#4: Not adding repositories for yum or apt-get

Both yum and apt-get use a listing of repositories that tell them where to locate available packages. But the default repositories (often called “repos”) do not include every Linux package known to Linuxkind. So if you run the command to install an application, and yum (or apt-get) can’t find the package, most likely you’ll have to add a repo to your sources listing. For yum, the sources are in /etc/yum.conf. For apt-get, they are placed in /etc/apt/sources.list. Once you have added a new repo, make sure you run the update so either apt or rpm is made aware of the new source.

5#: Not taking advantage of installing from a browser

Just as with Windows, when your system sees you are attempting to download an installable application, you’ll be asked whether you would like the package management system to attempt to install the file or just save it to disk. In both instances, you will be asked for the root password (so you must have access to said password for this to even work). One thing I’ve always like about this method (be it in a yum-based or dpkg-based system) is that it has almost always been good about locating and adding dependencies.

Naturally, this method works only when you are downloading a file that’s applicable to your system. If you attempt to download an rpm file on a Debian-based system, you won’t have the option of installing the file.

You can take this one step further and select the Always Do This… check box in the Firefox popup so that every time you download a file associated with your package management system, it will automatically prompt you for your root password and continue to install the package. This streamlines the process quite a bit.

#6: Forgetting the command line

Let’s say you’ve installed a headless server using Ubuntu or Debian (a common setup for Linux servers) and haven’t installed any of the graphical interfaces or desktops. To do any maintenance, you have to log in via ssh (because no admin would log in via telnet) and are limited to the command line only. Even so, your ability to keep your system updated or install new applications is not limited. You can still use yum or apt-get to manage your packages.

With a Debian-based system, you have another option: Aptitude. From the command line, issue the command aptitude and you will be greeted with a nice curses-based interface for apt. This system is easy to use and gives you an outstanding option for maintaining a gui-less server without losing functionality. Aptitude lists Security Updates, Upgradeable Packages, New Packages, Not Installed Packages, Obsolete Packages, Virtual Packages, and Tasks. As you scroll through the list, you will not only get the installed vs. the new package release numbers but also a description of the package. After using Aptitude, you will quickly see how simple updating Linux packages can be, even from the command line.

#7: Blindly unpacking tar files

I can’t tell you how many times I have downloaded a source package and without thinking, untarred the package not knowing its contents. Most times this works out fine. But there are a few times when the package creator/maintainer has failed to mention that the entire contents of the package are not housed in a parent directory. So instead of having a newly created directory housing the contents of the tar file (which can contain hundreds of files/directories), those files are blown up into the directory you unpacked them into.

To avoid this, I always create a temporary directory and move the tar file into it. Then, when I unpack the tar file, it doesn’t matter if the contents are contained within their own directory or not. Using this method will save you a LOT of cleanup in those cases where the creator didn’t pack everything in its own neat directory.

#8: Deleting those make files

When you’re installing from source, you’ll probably run make clean to get rid of all of those unneeded source files. But if you get rid of the Makefile, uninstalling will be a hassle. If you keep it, you can usually uninstall the program simply by issuing make uninstall from the directory housing the Makefile. A word of warning: Don’t dump all your Makefiles into one directory. First rename them so you know which application they belong to. When you want to uninstall the application, move the Makefile to another directory, rename it to its original name, and then run the uninstall command. Once you’ve uninstalled the application, you can delete the Makefile.

#9: Installing for the wrong architecture

You might notice that many rpm files will have an i386, i586, i686, PPC, 64, etc. There is a reason for this. Unless the rpm file has noarch included in the filename, that rpm file was created for a specific architecture. And when those files were created for that architecture, they were optimized for it, so they’ll will run better. Does that mean you can’t install an i586 on a standard 386 machine? Of course not. But it will not run as efficiently as it will on the indicated architecture. Now, you can’t install a PPC rpm on an x86 architecture. The PPC architecture is for the Motorola chipset. Nor can you install the 64 bit on a 32 bit. You can, however, install the 32 bit on a 64 bit (as in the case when you want to get Firefox running with Flash on a 64-bit machine).

#10: Failing to address problems with kernel updates

It used to be that updating kernels was a task left to the silverback geeks. No more. With the new package management systems, anyone can update a kernel. But there are some gotchas you should know about. One issue is that of space. With every update of a kernel, your old kernel is retained. If you continually update kernels, your system storage can quickly fill up. It’s always a good idea to check to see what older kernels you can get rid of. If you’re using rpm, issue the command rpm -qa | grep kernel to see what you have installed. You can remove all but the last two installed. It’s always best to keep two in case the one you are running gets fubar’d.

So guys who are using Ubuntu or any other distros please keep this things in mind while installing anything in your distros and you will never be in any problem.

Video recording comes to iPhone

noreply@blogger.com (Aurobindo) — Mon, 25 Aug 2008 15:40:00 +0000

One feature that ranks up there on most people’s iPhone wishlist (somewhere between Copy and Paste and MMS) is video recording. Now there are two options for recording video on the iPhone – the only caveat is that you have to jailbreak your iPhone to use them.

iSmashphone posted a review of the two video recording apps, Cycorder (free) and Video Recorder (US$20).

Cycorder features real-time compression but doesn’t have audio recording. Video Recorder features audio, portrait mode and YouTube sharing but no real-time compression (”it took over 2 minutes to encode a 30-second video.”)

Screen shots and video samples are at iSmashphone.com.

Your E-Mail address says a lot about you

noreply@blogger.com (Aurobindo) — Sun, 24 Aug 2008 13:10:00 +0000

What is in a E-mail address you should ask. Isn't it? But after reading this you will never ask it to anyone for sure.
If you happen to be iamthegreatest@gmail.com, for example, will people think you a narcissist? And if they do, will they be right? People really do judge others based on the e-mail addresses they choose. What's more interesting, however, is that these judgments tend to be right.

In a research paper published recently in the Journal of Research in Personality, the scientists took a look at just under 600 e-mail addresses and had the people who created them fill out a brief personality questionnaire. Then, they asked 100 students to rate these same addresses to find out if the e-mail names seemed to be neurotic, open, agreeable, conscientious, narcissistic or extroverted. The first thing they discovered is that the students tended to judge people based on their addresses. For example, people who used words like "little" or "sweet" or "baby" combined with cute animal names like "mousie" or "bunny" were thought to be more agreeable ... and neurotic. On the other hand, words like "King" or "thebest" were linked to narcissism. Even more interesting, these judgments tended to be right in five of the six personality categories they measured. Openness was the easiest thing to correctly gauge, but when it came to extroversion, the students' assessments tended to miss the mark. Study participants had strong opinions about whether e-mail addresses were owned by extroverts -- they just didn't happen to be particularly accurate.
As per the researchers say it's astonishing that the sliver of information that you pass on in your e-mail address can be enough for people to get a valid read on your personality. So what if you don't want people to judge you based on your Gmail account? No way, say the researchers. Even if you choose a totally neutral address, you're still giving away information about yourself. Their advice is simple: Choose an address you like. After all, is it really such a bad thing for others to see you the way you are?

So next time you want to sign up for a new mail account please be sure about this. Please choose a separate email address always for your job search purposes. In this way you can beat others and make an impression on the employees. So never be late in that or maybe you just loose a job to a other guy who used my advice.

Best Of luck.

Highest Paid Executives in US

noreply@blogger.com (Aurobindo) — Fri, 22 Aug 2008 13:16:00 +0000

Recently Associated Press published a list of 500 highest-paid public company executives. A few from them are:

Larry Ellison, Oracle Corp. (ORCL), $84.6 mln
John Thain, Merrill Lynch & Co. (MERPO), $83.1 mln
Leslie Moonves, CBS Corp. (CBS), $67.6 mln
Richard Adkerson, Freeport-McMoran Copper & Gold Inc., $65.3 mln
Bob Simpson, XTO Energy Inc. (XTO), $56.6 mln
Lloyd Blankfein, Goldman Sachs Group Inc. (GS), $53.9 mln
Kenneth Chenault, American Express Co. (AXP), $51.7 mln
Eugene Isenberg, Nabors Industries Ltd. (NBR), $44.6 mln
John Mack, Morgan Stanley (MS), $41.7 mln
Glenn Murphy, Gap Inc. (GPS), $39.1 mln

They are basically US based public company executives.

Amazon's Elastic Book Store(EBS)

noreply@blogger.com (Aurobindo) — Fri, 22 Aug 2008 04:19:00 +0000

Amazon Web Services said today that it is enhancing its Elastic Compute Cloud by adding block storage.

Amazon Elastic Block Store allows applications to store data in EC2 without having to send it to Amazon's other storage service, Simple Storage Service (S3).

"EBS starts out really simple: you create a volume from 1GB to 1TB in size and then you mount it on a device (like /dev/sdj) on an instance, format it, and off you go. Later you can detach it, let it sit for a while, and then reattach it to a different instance. You can also snapshot the volume at any time to S3, and if you want to restore your snapshot you can create a fresh volume from the snapshot. Sounds simple, eh? It is but the devil is in the detail!" writes the RightScale blog in another post.

In the sense for reliability rightscale blog pointed that "EBS volumes have redundancy built-in, which means that they will not fail if an individual drive fails or some other single failure occurs. But they are not as redundant as S3 storage which replicates data into multiple availability zones: an EBS volume lives entirely in one availability zone. This means that making snapshot backups, which are stored in S3, is important for long-term data safeguarding."

For defining Volume Performance rightscale blog explained some extreme features like; "EBS volumes are network attached disk storage and thus take a slice off the instance’s overall network bandwidth. The speed of light here is evidently 1GBps, which means that the peak sequential transfer rate is 120MBytes/sec. “Any number larger than that is an error in your math.” We see over 70MB/sec using sysbench on a m1.small instance, which is hot! Presumably we didn’t get much network contention from other small instances on the same host when running the benchmarks. For random access we’ve seen over 1000 I/O ops/sec, but it’s much more difficult to benchmark those types of workloads. The bottom line though is that performance exceeds what we’ve seen for filesystems striped across the four local drives of x-large instances."

Now come the most simple to use and hard to understand feature come up that is Snapshot Backup. Here is the explanation given by the rightscale blog:

Snapshot backups are simultaneously the most useful and the most difficult to understand feature of EBS. Let me try to explain. A snapshot of an EBS volume can be taken at any time, it causes a copy of the data in the volume to be written to S3 where it is stored redundantly in multiple availability zones (like all data in S3). The first peculiarity is that snapshots do not appear in your S3 buckets, thus you can’t access them using the standard S3 API. You can only list the snapshots using the EC2 API and you can restore a snapshot by creating a new volume from it. The second peculiarity is that snapshots are incremental, which means that in order to create a subsequent snapshot, EBS only saves the disk blocks that have changed since previous snapshots to S3.

How the incremental snapshots work conceptually is depicted in the diagram below. Each volume is divided up into blocks. When the first snapshot of a volume is taken all blocks of the volume that have ever been written are copied to S3, and then a snapshot table of contents is written to S3 that lists all these blocks. Now, when the second snapshot is taken of the same volume only the blocks that have changed since the first snapshot are copied to S3. The table of contents for the second snapshot is then written to S3 and lists all the blocks on S3 that belong to the snapshot. Some are shared with the first snapshot, some are new. The third snapshot is created similarly and can contain blocks copied to S3 for the first, second and third snapshots.

There are two nice things about the incremental nature of the snapshots: it saves time and space. Taking subsequent snapshots can be very fast because only changed blocks need to be sent to S3, and it saves time because you’re only paying for the storage in S3 of the incremental blocks. What is difficult to answer is how much space a snapshot uses. Or, to put it differently, how much space would be saved if a snapshot were deleted. If you delete a snapshot, only the blocks that are only used by that snapshot (i.e. are only referenced by that snapshot’s table of contents) are deleted.

Something to be very careful about with snapshots is consistency. A snapshot is taken at a precise moment in time even though the blocks may trickle out to S3 over many minutes. But in most situations you will really want to control what’s on disk vs. what’s in-flight at the moment of the snapshot. This is particularly important when using a database. We recommend you freeze the database, freeze the file system, take the snapshot, then unfreeze everything. At the file system level we’ve been using xfs for all the large local drives and EBS volumes because it’s fast to format and supports freezing. Thus when taking a snapshot we perform an xfs freeze, take the snapshot, and unfreeze. When running mysql we also “flush all tables with read lock” to briefly halt writes. All this ensures that the snapshot doesn’t contain partial updates that need to be recovered when the snapshot is mounted. It’s like USB dongles: if you pull the dongle out while it’s being written to “your mileage may vary” when you plug it back into another machine…

While explaining situations generally arise in our systems like:

You create a volume, mount it on an instance, format it, and write some data to it.
Then you periodically snapshot the volume for backup purposes.
If you don’t need the instance anymore, you may terminate it and, after unmounting the volume you always take a final snapshot. If the instance crashes instead of properly terminating, you also always take a final snapshot of the volume as it was left.
When you launch a new instance on which you want the same data, you create a fresh volume from your snapshot of choice. This may be the last snapshot, but it could also be a prior one if it turns out that the last one is corrupt (e.g. in the case of an instance crash or of some software failure).

By creating a volume from the snapshot you achieve two things: one, you are independent of the availability zone of the original volume, and second, you have a repeatable process in case mounting the volume fails, which can easily happen especially if the unmount wasn’t clean.

Now, of course, in some situations you can directly remount the original volume instead of creating a new volume from a snapshot as an optimization. This applies if the new instance is in the same availability zone, the volume corresponds to the snapshot that we’d like to mount, and the volume is guaranteed not to have been modified since (e.g. by a failed prior mount). The best is to think of the volume as a high-speed cache for the snapshot.

Estimating the costs of EBS is really quite tricky. The easy part is the storage cost of $0.10 per GB per month. Once you create a volume of a certain size you’ll see the charge. The $0.10 per million I/O transactions are much harder to estimate. To get a rough estimate you can look at /proc/diskstats on your servers. This will include something like this:



3    0   hda 446216 784926 9550688 4382310 424847 312726 5922052 19310380 0 3376340 23705160
3    1   hda1 35486 38030 38030 38030

Now some help to understand the above segment:
if you look at /sys/block/hda/stat, you'll find just the eleven fields, beginning with 446216. If you look at /proc/diskstats, the eleven fields will be preceded by the major and minor device numbers, and device name. Each of these formats provide
eleven fields of statistics, each meaning exactly the same things. All fields except field 9 are cumulative since boot. Field 9 should go to zero as I/Os complete; all others only increase. Yes, these are 32 bit unsigned numbers, and on a very busy or long-lived system they may wrap. Applications should be prepared to deal with that; unless your observations are measured in large numbers of minutes or hours,
they should not wrap twice before you notice them. As described by rightscale blog,
you should sum the first number (reads completed) and the fifth number (writes completed) to arrive at the number of I/O transactions (9847+1912664 for /dev/sdk above). This is not 100% accurate but should be close (I believe subtracting the 2nd and 6th numbers gets you closer yet, but I prefer an over-estimate). As a point of reference, our main database server is pretty busy and chugs along at an average of 17 transactions per second, which should total to around $4.40 per month. But our monitoring servers, prior to some recent optimizations, hammered the disks as fast as they would go at over 1000 random writes per second sustained 24×7. That would end up costing over $250 per month! As far as I can tell, for most situations the EBS transaction costs will be in the noise, but you can make it expensive if you’re not careful.

In the conclusion we can say, All in all it’s amazing how simple EBS is, yet how complex a universe of options it opens. Between snapshots, availability zones, pricing, and performance there are many options to consider and a lot of automation to provide. Of course at RightScale we’re busy working out a lot of these for you, but beyond that it is not an overstatement to say that Amazon’s Elastic Block Store brings cloud computing to a whole new level. I’ll repeat what I’ve said before: if you’re using traditional forms of hosting it’s gonna get pretty darn hard for you to keep up with the cloud, and you’ve probably already fallen behind at this point!

Forbes Asia published a Thailand rich list : Nishita Shah ranked No. 19

noreply@blogger.com (Auros Blog) — Wed, 20 Aug 2008 13:42:00 +0000

Forbes Asia published a Thailand rich list on July, 10 2008 in Singapore. The rankings are almost filled with the same face as in the lists of 2006 and 2007. The Asia rich lists have been sponsored by SG Private Banking (Asia Pacific).

The notable and outstanding rich woman in all rankings is clearly seen to be Nishita Shah, an Indian origin who is the youngest on the list along with her family, she is ranked No. 19 and worth $375 million. The 28-year old is featured in a profile story in this week’s issue of Forbes Asia. She spoke about her plan of launching her own fashion label “Nsha” on three continents at the end of the year as well as helping to manage her family’s 140-year old business which includes Thai-listed Precious Shipping as her farther, Kirit Shah, last year made her a managing director of GP Group.

Nishita was born to be a business woman. To follow her father’s steps, she had graduated from Boston University with a degree in business and finance. For four years she learned all about the various companies, visiting most of them.

“My dad said I could study anything I wanted as long as it was business,” is her favorite speech. Not business alone she concentrated on, but she also has gone through something “creative” as she like to say. Her father suggested that she had fulfilled one of his own dreams and study flying. She earned an instrument rating for a single-engine plane and a private pilot’s license. In between flights she took yoga and surfing lessons.

With her clothing company “Burn Baby” with a mission statement “luxury active wear” for “modern urbanite women”. Nishita is a hands-on executive. At the same time she continues to read coal, shipping and metal reports every morning and sits in on meetings on the 15 days of the month when her father is overseas. Aside from Nishita Shah’s companies, her father, Kirit, has collected stakes in all sorts of companies for the GP Group. Here are some of what GP’s invested in, including the clan’s percentage stakes: Alva Aluminum 75%, Amari Atrium Hotel 95, Ambika 100, Eka 75, Mega LifeSciences 75 , MJets 50 and Premthai Energy 100.

Celebrity golfer Tiger Woods also have made his way into the list of next generation billionaires compiled by American US business magazine Forbes. Noting that the world’s current crop of billionaires has plenty of money but “not much youth”, the American magazine said the average age of the 1,125 people on Forbes’ list of the world’s wealthiest is 61.

So you could be the next now. How?
To know more follow my links here.

iPhone 3G launching in India on 22 Aug

noreply@blogger.com (Aurobindo) — Wed, 20 Aug 2008 11:17:00 +0000

Vodafone is delighted to announce that the iPhone 3G will be available in India from August 22, 2008
It will be available in 8GB & 16GB models, priced at Rs 31,000 and Rs 36,100 respectively.

Be the first to get the iPhone
As they have received a large number of registrations. As there are limited stocks, make sure that you get yours first, by paying an advance of Rs 10,000 to confirm your booking.

Where can you make this advance payment?
The iPhone 3G will be available at select Vodafone Stores. All you need to do is drop in at any select Vodafone Store between August 20 and 21 and make the advance payment by cash or credit card. Don´t forget to show the iPhone booking SMS, which you would have received from them, when you visit the Vodafone Store to pay the advance. To find a Vodafone Store near you, click here

Get an appointment now. No queues for you.
Once you pay the advance, they will immediately give you an appointment date and time, starting
August 22 when you can go and experience a full demonstration and collect your iPhone, all ready to use with your contacts and settings, by paying the balance amount.

Hurry! Limited stocks.
Remember, the sooner you confirm your booking, the earlier you´ll get your iPhone. We have limited stocks and it will be on first come, first serve basis.

Buy a Vodafone connection now!
If you are not a Vodafone customer, you will need a Vodafone connection for your iPhone 3G.
They would recommend that when you go to confirm your booking, please do get yourself a Vodafone connection too. Remember to carry a passport sized picture, photo ID proof and address proof as these are required for activating your Vodafone SIM card.

Happy to help
If you have any queries, log on to www.vodafone.in/iphone or call us on 9732097320 and we´ll be happy to help.
Hurry and be one of the first to make the iPhone 3G your own.

I just got the mail from Vodafone Customer Service and thought of sharing it with you. I know people are wondering here and there for the exact price of iPhone 3G in india. So go ahead and grab your own iPhone.

Rail Sampark 139

noreply@blogger.com (Aurobindo) — Wed, 20 Aug 2008 09:07:00 +0000

Indian Railways introduce a whole new Integrated Train Enquiry System(ITES) with modern, improved customer centric facilities. This service can be accessed by dialing ‘139′ from any landline, mobile or cdma phones. Rail Sampark -139 is a round the clock service. In addition to hindi and english the service is also available in other regional languages in South east and west zones. Through this system customers have choice of either getting the desired information through Interactive Voice Response System(IVR) or they can press * to speak to a highly skilled customer care executive to get instant information on arrival/departure, PNR status, Accommodation Availability, fare enquiry to name a few.
As they said this is gift to the nation from Indian Railways.

I just got the mail stating all this information from Indian Railways Tourism Department and thought of sharing with you. With this what you think The Indian Railways is improving a lot after Mr. Lallu Prasad had taken the lead. I can say No One Can stop India Now. The day is not too far when we will be a developed nation.

Make hidden folders

noreply@blogger.com (Aurobindo) — Sat, 09 Aug 2008 12:56:00 +0000

This is a trick to make folders to keep your personal files safely.
1. Right Click on the free space and click on new folder.
2. While naming the folder just press ALT key and enter 0160
3. Now you can just select the folder and og to its properties.
4. There in the advanced option you can change the icon for the folder you created.
5. You can easily choose a blank image there.

And now you are done. If confused just watch the video:
http://www.metacafe.com/watch/376945/lock_hidden_folders_in_windows_vista_and_xp/

Solitaire

noreply@blogger.com (Aurobindo) — Sat, 09 Aug 2008 12:36:00 +0000

Now you can do a awesome trick to your Solitaire games comes by default with your windows xp version.
Just press the Key "Alt"+"Shift"+2 all the same like Ctrl+Alt+Del

You can win by this small trick while watching a amazing thing!!

Enjoy!

3D PinBall Trivk

noreply@blogger.com (Aurobindo) — Sat, 09 Aug 2008 12:25:00 +0000

You never know what you can do with your pinball games comes with your windows xp installation. Just see the video here and amaze your friends:

http://www.metacafe.com/watch/297793/windows_3d_pinball_hidden_trick/

How to get your system information in Ubuntu

noreply@blogger.com (Aurobindo) — Sat, 09 Aug 2008 10:14:00 +0000

I stumbled upon the nifty “lshw” tool today. lshw lists your hardware. Try it now:
$sudo lshw

You can get specific details by using the -C flag:
$sudo lshw -C disk
will list all you hard disks.

It create an html page with your hardware details if you do a:

$sudo lshw -html > your-file-name.html

UUID

noreply@blogger.com (Aurobindo) — Sat, 09 Aug 2008 10:05:00 +0000

You can run command to generate a uuid randomly:

sudo uuidgen

you can also run a perl script to get a randomly generated uuid:

#!/usr/bin/perl
#UUID generator

$uuid = `uuidgen`;
chomp $uuid;
print $uuid;

If you want to get UUID customized according to your need::

You will need UUID.pm file to get the below code running and you can get that by this command

sudo cpan Data::UUID

Synopsis:

use Data::UUID;

 $ug    = new Data::UUID;
 $uuid1 = $ug->create();
 $uuid2 = $ug->create_from_name(, );

 $res   = $ug->compare($uuid1, $uuid2);

 $str   = $ug->to_string( $uuid );

This modules provides several methods to create a UUID:

# creates binary (16 byte long binary value) UUID.
  $ug->create();
  $ug->create_bin();

  # creates binary (16-byte long binary value) UUID based on particular
  # namespace and name string.
  $ug->create_from_name(, );
  $ug->create_from_name_bin(, );

  # creates UUID string, using conventional UUID string format,
  # such as: 4162F712-1DD2-11B2-B17E-C09EFE1DC403
  $ug->create_str();
  $ug->create_from_name_str(, );

  # creates UUID string as a hex string,
  # such as: 0x4162F7121DD211B2B17EC09EFE1DC403
  $ug->create_hex();
  $ug->create_from_name_hex(, );

  # creates UUID string as a Base64-encoded string
  $ug->create_b64();
  $ug->create_from_name_b64(, );

  Binary UUIDs can be converted to printable strings using following methods:

  # convert to conventional string representation
  $ug->to_string();

  # convert to hex string
  $ug->to_hexstring();

  # convert to Base64-encoded string
  $ug->to_b64string();

  Conversly, string UUIDs can be converted back to binary form:

  # recreate binary UUID from string
  $ug->from_string();
  $ug->from_hexstring();

  # recreate binary UUID from Base64-encoded string
  $ug->from_b64string();

  Finally, two binary UUIDs can be compared using the following method:

  # returns -1, 0 or 1 depending on whether uuid1 less
  # than, equals to, or greater than uuid2

Examples:

use Data::UUID qw(:all);

  # this creates a new UUID in string form, based on the standard namespace
  # UUID NameSpace_URL and name "www.mycompany.com"

  $ug = new Data::UUID;

  print $ug->create_from_name_str(NameSpace_URL, "www.mycompany.com");