Question: What is equalient of $\_SERVER in codeigniter ?

Answer: 
Réjôme is spot on, but remember that $\_SERVER still works fine.
Use the codigniter "way" for input such as $\_POST and $\_SERVER. CodeIgniter's input class has built in functionality to prevent XSS attacks. Using the input class will also make your code much more extendable, if for example, you wish to build in some kind of intrusion systems, such as PHP IDS.

<http://codeigniter.com/user_guide/libraries/input.html>

<http://www.phpids.org/>

The three functions are:

```
$this->input->post()
$this->input->cookie()
$this->input->server()

```