Redirection In index.php page in Codeigniter - codeigniter

Question

Iam developing a site in codeigniter.This is my url http://myserver.net/visio/UBwXo.
Here http://myserver.net/visio/ is my base_url.
After /visio/ here have a variable.When there have any value after /visio/ then i wantto take the corresponding url from database to this value.
That means in my database,
UBwXo => "*any url***"
jshom => "*any url***"
So when getting value after /visio/ i want to take the corresponding url from databse and redirect it in to that url without using htaccess.
I want to done this redirection process in index.php page of root folder.
Is this possible?
The orginal url for http://myserver.net/visio/UBwXo like myserver.net/visio/index.php/admin/index/UBwXo
the default controller is admin

Answer 1

First, create redirect.php file in the controllers folder (application/controllers) and add this code to this file:
if (!defined('BASEPATH'))
exit('No direct script access allowed');
class Redirect extends CI_Controller
{
/**
* Method to redirect from an alias to a full URL
*/
public function index()
{
$alias = $this->uri->segment(1);
$this->db->select('url');
$query = $this->db->get_where('links', array('alias' => $alias), 1, 0);
if ($query->num_rows() > 0)
{
foreach ($query->result() as $row)
{
$this->load->helper('url');
redirect($row->url, 'refresh', 301);
}
}
else
{
echo "Sorry, alias '$alias' not found";
}
}
}
Then create table in your database. Your table must be like this:
CREATE TABLE IF NOT EXISTS `links` (
`id` int(11) unsigned NOT NULL AUTO_INCREMENT,
`alias` varchar(6) CHARACTER SET utf8 DEFAULT NULL,
`url` text CHARACTER SET utf8,
PRIMARY KEY (`id`),
UNIQUE KEY `alias` (`alias`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=11 ;
After that, set default controller value to the redirect class.
Open application/config/routes.php. Find $route['default_controller'] , then set redirect as a value to this variable, like this:
$route['default_controller'] = "redirect";
Then enjoy life ;)
EDIT:
I had forgotten to mention URI routing in config/routes.php for redirecting:
$route[':any'] = "redirect/index/$1";

Answer 2

Your best resource here will be the CodeIgniter guides, specifically the page on Controllers. The section on Remapping Function calls should be exactly what you need in this case.
Since the default behavior is to look for a controller method with the name of the first segment after the base url, we need to change this to pass it as an argument to some function. Your controller might look something like this:
class Shortener extends CI_Controller {
private function shorten( $token ){
// Find the URL that belongs to the token and redirect
}
public function _remap( $method, $params = array() ) {
// Catch other controller methods, pulled from the CodeIgniter docs
if ( method_exists( $this, $method ) ) {
return call_user_func_array( array( $this, $method ), $params );
}
$this->shorten( $method );
}
}