Some functions in Controller

1. you can create application/core/MY_Controller.php 

and all you controllers will extend MY_Controller instead of CI_Controller

MY_Controller.php:

PHP Code:

class MY_Controller extends CI_Controller {

    public function __construct() {

        parent::__construct();
}

protected function yourfunction(){
 //...
}
} 


2. or you can use models
 put your function in a model