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Saivaneri Web Tutor

CHAPTER 26

CAPTCHA Form Validation Script with Word Test

 

My site www.Saivaneri.org had been a target to various form filling spiders/spammers/robots/hackers which fill up the form automatically like a human and spam my database with their advertisements like “Buy Cialis” “Buy ViNagpur” “Enlarge your organs” etc.. I was fed up. I had to manually delete these arrogant entries in the matrimonial database where users are aghast to find such records of “Brides” “Grooms”. So I was constantly worried for the past 2 weeks and took enough time to delete these rogue entries from the mySql database.

 

Help was at hand, sooner than later with a Carnegie Mellon University originated CAPTCHA script!. Thank God!.

 

I used the keyword “Avoid Form Validation by robots” “Avoid Form Hackers” etc. The results were not to my requirement.

 

Many people, including me have noticed such Avoidance of Automatic form filling in the form of WORD check, AUDIO check, IMAGE check as found in serious sites like yahoo, google, blogspot etc.

 

But I didn’t know the script used to differentiate between a human and a robot is called a CAPTCHA project developed in CMU USA.
(a trademarked
acronym for "completely automated public Turing test to tell computers

and humans apart" owned by Carnegie Mellon University) read more at : http://en.wikipedia.org/wiki/Captcha

 

So I had to use other keywords like “Form Validation with Image”  “Form validation with script” and finally landed on this CAPTCHA one day.

 

Now the search results became more accurate, and I could straight away search for “Free PHP CAPTCHA scripts”

 

There is ASP, Java CAPTCHA scripts as well, which doesn’t suit me in the first place.

 

So now Google & puremango.co.uk became [as usual] a liberator for me from the clutches of spammers/hackers.

 

Thanks Oh Good Fellas on the Internet!

 

You can test my deliverance at www.Saivaneri.org/php/add/php

 

How I implemented it?

 

OK, the FREE CAPTCHA is found, but I had to use it on my site?.
How?

 

Read on:

Firstly, test the script at localhost [at your own machine] equipped with apache, php 4.1. or above with GD library version 2.

 

To test the version of your php, type http://localhost/phpinfo? [with question mark) At your browser.

 

If you have a GD library version 2, it is shown in c:\apache\php\extensions\php_gd2.dll [php_gd.dll ver. 1 wont help]

 

Amend your php.ini to load php extension php_gd2.dll [by default it loads php_gd.dll version 1]

 

Download the script from http://www.puremango.co.uk/cm_php_captcha_script_113.php#

 

Extract the zip files into your php directory of your site.

 

[mine is http://localhost/saivaneri/php/]

 

That’s it!, now type this address in the browser:
http://localhost/saivaneri/php/freecap_wrap.php

 

If you see the CAPTCHA running, Well Done!

 

Upload all the php folder of your local site to remote site.

 

Confirm that your site also has php 4.1.0 or above, GD library 2.

 

Check the script running at www.

 

Now you can proudly call you as a script kiddie!

 

[Lastly, if you have time BRAG like this in mails/blogs]

 

:-}) [laughing with moustache]

To Sgt Neduncheralathan only: - Thank you for your Greetings through 56/APO 


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