3 Major Anti-spamming techniques used:
- Mathematical Operation like Random number + Random Number = -> The user must specify the answer
- Random word -> User must type the word
- Random question -> Obvious one which the user should answer correctly [ex: Are you human?]
<?php //This should be the first line as in the rule book :D session_start(); //These variables store the Question and the answer $ques = ""; $ans = ""; //This is the MAJOR array, this holds all the random things, //like the question you need to ask. You can add up new ones easily $words = array(
0 => array("Num" => "Num"),
1 => array("Are you human?" => "yes"),
2 => array("Type 'one' " => "one"),
3 => array("Type 'test' " => "test"),
4 => array("AxHGA" => "AxHGA"),
5 => array("zontek" => "zontek"),
6 => array("12terd " => "12terd")
);
//Now we need to pic up a random question, //array_rand is the perfect thing to this
$r = array_rand($words);
//Then we check about what we have in the select array
switch(key($words[$r])){
//If we have the "NUM" selected, that is a special one
//Num means the user will be prompted to //do a simple addition like 5+6
case "Num":
//Pretty basic stuff, generate 2 random numbers and //tell the user to put the addition
$i = rand(1,10);
$j = rand(1,10);
$ans = $i+$j;
$ques = "$i + $j = ";
break;
default:
//If not a number, ask the user a question or //ask him to type a word
$key = key($words[$r]);
$ques = $key;
$ans = $words[$r][$key];
break;
}
//NOW we put up the answer to the session variable $_SESSION['cap'] = strtolower($ans); //This would change the content type, //or in english this would tell the browser that
//what ever retuened by this script is an image header('Content-Type: image/png');
//Following code is to generate the image from the test
//We first specify colour ranges, you can refer to the php manaul for more $img = imagecreatetruecolor(250,30); //In the above code, the image size is set to 250x30 $white = imagecolorallocate($img,255,255,255); $grey = imagecolorallocate($img,128,128,128); $black = imagecolorallocate($img,0,0,0); //Filling the rectangle with white as we need black text on white imagefilledrectangle($img,0,0,399,29, $white); $text = $ques; //THE below code is CRITICAL. This is the palce where we tell which font to use.
//Choose any ttf you like and name it as font.ttf //or change the following code, make sue
//you put the path to the file correctly //[i used STENCIL so that parsers will find it hard to detect] $font = "./font.ttf"; imagettftext($img,20,0,11,21,$grey,$font,$text); imagettftext($img,20,0,10,20,$black,$font,$text); //Creating a PNG image, i use png cuz i <3 png//[really its so small and efficient ;)] imagepng($img); //And then remove the memory parts once the output is given imagedestroy($img); ?>Write down index.php accordingly! It's done!
