Creating a simple CAPTCHA with PHP with made script.

A CAPTCHA is a type of challenge-response test used in computing to determine whether the user is human. “CAPTCHA” is an acronym for “Completely Automated Public Turing test to tell Computers and Humans Apart”, trademarked by Carnegie Mellon University.

Here is a small CAPTCHA class that will help you get rid of the nasty spam on your blog/forum/gallery. Written in PHP of course.

class Captcha
{
	private $text;
 
	/**
	 * Class constructor and seed the random number generator
	 *
	 * @return Captcha
	 */
	public function __construct()
	{
		srand((double)microtime()*1000000^getmypid());
	}
 
	/**
	 * Create the actual captcha image
	 *
	 * @param integer $width
	 * @param integer $height
	 * @return string
	 */
	public function Create_Image($width = 180, $height = 45)
	{
		header("Content-type:image/jpeg");
		$img = imagecreate($width, $height);
		$black = imagecolorallocate($img, 0, 0, 0);
		$white = imagecolorallocate($img, 255, 255, 255);
		$other = imagecolorallocate($img, 160, 160, 160);
		$num = rand(0, 5);
		for ($i = $num; $i < = $width; $i += 16)
		{
			imageline($img, $i, 0, $i, 45, $other);
		}
		for ($i = $num; $i <= $height + 10; $i += 16)
		{
			imageline($img, 0, $i, 180, $i, $other);
		}
		$string = substr(strtolower(md5(uniqid(rand(), 1))), 0, 7);
		$string = str_replace('0', 'x', $string);
		$font = imageloadfont('some_font.gdf');
		imagestring($img, $font, 10, 8, $string, $white);
		imagejpeg($img);
		imagedestroy($img);
		return $this->text = $string;
	}
}

PHP:

And, you use it with:

require('Captcha.php');
session_start();
$CP = &new Captcha;
$_SESSION['captcha'] = $CP->Create_Image();

PHP:

 

hmm new member thanks man

 

thanks for sharing

 

this is not working