restrict direct access to a controller in CodeIgniter (not tested much, feel free to make changes)

.htaccess

RewriteCond %{REQUEST_URI} commandline
RewriteRule .* / [R=301,L]

readme.txt

Change "commandline" in .htaccess with the controller you want to restrict access to. It redirects the controller to 
your websites homepage.

For me the CommandLine.php file is a controller for CLI functions,
"getFacebookFeed" should only be called from the command line, like in a cron job.

I have not tested it much, so feel free to fork and change things. :-)

CommandLine.php

<?php
defined('BASEPATH') OR exit('No direct script access allowed');

class CommandLine extends CI_Controller {
	
	public function __construct() {
    parent::__construct();
    //your code here
	}
  public function getFacebookFeed($limit = 6, $length = 150, $force_refresh = false) {
    /*
      if(is_cli()) {
        //your code here
      } else {
        redirect(base_url(), 'location', 301);
      }
     */
  }
}