Category Archives: PHP

ROT13 Encoder Source Code

The ROT13 encoder is a fun programming exercise that my students enjoyed recently. I have included my source code here in PHP and C. PHP <?php   function rot13($char)   {     $ascii = ord($char);     if (($ascii >= 65) && ($ascii <= 90))     {       $val = ($ascii – 51) % 26;       if ($val == 0)       {         $val = 26;       }       $val += 64;     }     else if (($ascii >= 97) && ($ascii <= 122))      {       $val = ($ascii – 83) % 26;       if ($val == 0)       {         $val = 26;       }       $val += 96;     }     else     {       $val = $ascii;     }     return (chr($val));   }   function main()   {… Read More »

Sanitising User Form Input Before Processing in PHP

Sanitising user form input before processing the data is an IMPORTANT security step to prevent malicious input wreaking havoc on your program or other unsuspecting users. The function below can take the $_POST array as input and return it sanitised for use. function cleanse($input) { // Clean the input before use to make sure we don’t… Read More »