PHP Simple CAPTCHA
A simple yet effective captcha PHP class.
$captcha = new Captcha();
echo $captcha->generate();
Live example according to your IP:
class Captcha{
/**
* @author Webarto.com
* @copyright 2010
*/
var $multiplier = 31; //Set multiplication number, bigger number, more chars.
public function build(){
$ip = explode(".", $_SERVER["REMOTE_ADDR"]);
return strtoupper(dechex($ip[2].$ip[3] * $this->multiplier)); //Do not touch. Fragile.
}
public function check($input){ //Checks if entered captcha is valid
if($input == $this->build()){
return true;
}else{
return false;
}
}
public function generate(){ //Generate image, use in separate file, headers sent.
$string = $this->build();
$im = @imagecreate(strlen($string) * 8, 16); //Width based on length
$backgroundColor = imagecolorallocate($im, 255, 255, 255);
$textColor = imagecolorallocate($im, 33, 33, 33);
imagestring($im, 4, 0, 0, $string, $textColor);
header("Content-type: image/png");
imagepng($im);
imagedestroy($im);
}
}
