[php] Redirect with CodeIgniter

Can anyone tell me why my redirect helper does not work the way I'd expect it to? I'm trying to redirect to the index method of my main controller, but it takes me www.mysite.com/index/provider1/ when it should route to www.mysite.com/provider1. Does this make sense to anyone? I have index page in config set to blank, although I don't think that it is the issue. Does anyone have advice on how to fix this issue? Thanks in advance!

Controller:

if($provider == '') {
    redirect('/index/provider1/', 'location');
}

.htaccess:

RewriteEngine on

RewriteCond %{REQUEST_URI} !^(index\.php|files|images|js|css|robots\.txt|favicon\.ico)

RewriteCond %{HTTP_HOST} ^mysite.com/ttnf/
RewriteRule (.*) http://www.mysite.com/ttnf/$1 [R=301,L]

RewriteBase /ttnf/
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*)$ index.php/$1 [L]

php_flag display_errors On

first, you need to load URL helper like this type or you can upload within autoload.php file:

$this->load->helper('url');

if (!$user_logged_in)
{
  redirect('/account/login', 'refresh');
}

If you want to redirect previous location or last request then you have to include user_agent library:

$this->load->library('user_agent');

and then use at last in a function that you are using:

redirect($this->agent->referrer());

its working for me.

If your directory structure is like this,

site
  application
         controller
                folder_1
                   first_controller.php
                   second_controller.php
                folder_2
                   first_controller.php
                   second_controller.php

And when you are going to redirect it in same controller in which you are working then just write the following code.

 $this->load->helper('url');
    if ($some_value === FALSE/TRUE) //You may give 0/1 as well,its up to your logic
    {
         redirect('same_controller/method', 'refresh');
    }

And if you want to redirect to another control then use the following code.

$this->load->helper('url');
if ($some_value === FALSE/TRUE) //You may give 0/1 as well,its up to your logic
{
     redirect('folder_name/any_controller_name/method', 'refresh');
}

Here is .htacess file that hide index file

#RewriteEngine on
#RewriteCond $1 !^(index\.php|images|robots\.txt)
#RewriteRule ^(.*)$ /index.php/$1 [L]

<IfModule mod_rewrite.c>
        RewriteEngine On
        RewriteBase /

        # Removes index.php from ExpressionEngine URLs
        RewriteCond %{THE_REQUEST} ^GET.*index\.php [NC]
        RewriteCond %{REQUEST_URI} !/system/.* [NC]
        RewriteRule (.*?)index\.php/*(.*) /$1$2 [R=301,NE,L]

        # Directs all EE web requests through the site index file
        RewriteCond %{REQUEST_FILENAME} !-f
        RewriteCond %{REQUEST_FILENAME} !-d
        RewriteRule ^(.*)$ index.php/$1 [L]
</IfModule>