Thread

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

$img_array = array ("src"=> "/codeigniter_shopping/images/dummy-thumb.jpg",  "width" => "180px", "border"=>"0", "alt"=>"some text");
echo anchor (img($img_array ));

<div class='productlisting'>images/dummy-thumb.jpg

<h4>Dress 1</h4>
<p><a href="http://127.0.0.1/codeigniter_shopping/welcome/product/10" title="see details">see details</a><br><br />
<a href="http://127.0.0.1/codeigniter_shopping/welcome/cart/10" title="add to cart">add to cart</a><br />
</div>

site_url()

Returns your site URL, as specified in your config file. The index.php file 
(or whatever you have set as your site index_page in your config file) 
will be added to the URL, as will any URI segments you pass to the function.

You are encouraged to use this function any time you need to generate a local URL
so that your pages become more portable in the event your URL changes.

Segments can be optionally passed to the function as a string or an array.

READ CodeIgniter user guide.

Basepath: C:\xampp\htdocs\ci_day6/system/
Apppath: application/
Ext: .php
Fcpath: C:\xampp\htdocs\ci_day6\index.php
Self: index.php
baseurl: <a href="http://127.0.0.1/ci_day6/">http://127.0.0.1/ci_day6/</a>
site_url(): <a href="http://127.0.0.1/ci_day6/index.php">http://127.0.0.1/ci_day6/index.php</a>
current_url(): <a href="http://127.0.0.1/ci_day6/index.php/welcome">http://127.0.0.1/ci_day6/index.php/welcome</a>
uri_string(): /welcome
index_page(): index.php
realpath(__FILE__): C:\xampp\htdocs\ci_day6\application\views\welcome_message.php
realpath(dirname(__FILE__)): C:\xampp\htdocs\ci_day6\application\views
realpath(dirname(__FILE__)): C:\xampp\htdocs\ci_day6\application\views/
str_replace: C:/xampp/htdocs/ci_day6/application/views
getcwd(), current working directory: C:\xampp\htdocs\ci_day6

Place in application/config/constants.php

/*
|--------------------------------------------------------------------------
| Docment root folders
|--------------------------------------------------------------------------
|
| These constants use existing location information to work out web root, etc.
|
*/

// Base URL (keeps this crazy sh*t out of the config.php
if (isset($_SERVER['HTTP_HOST']))
{
    $base_url  = isset($_SERVER['HTTPS']) && strtolower($_SERVER['HTTPS']) == 'on' ? 'https' : 'http';
    $base_url .= '://'. $_SERVER['HTTP_HOST'];
    $base_url .= str_replace(basename($_SERVER['SCRIPT_NAME']), '', $_SERVER['SCRIPT_NAME']);

    // Base URI (It's different to base URL)
    $base_uri = parse_url($base_url, PHP_URL_PATH);

    if (substr($base_uri, 0, 1) != '/')
    {
        $base_uri = '/'.$base_uri;
    }

    if (substr($base_uri, -1, 1) != '/')
    {
        $base_uri .= '/';
    }
}
else
{
    $base_url = 'http://localhost/';
    $base_uri = '/';
}

// Define these values to be used later on
define('BASE_URL', $base_url);
define('BASE_URI', $base_uri);
define('APPPATH_URI', BASE_URI.APPPATH);
define('ASSETS_URL', $base_url."assets/");
define('CSS_URL', ASSETS_URL."css/");
define('IMAGE_URL', ASSETS_URL."images/");
define('JS_URL', ASSETS_URL."js/");
define('UPLOAD_URL', ASSETS_URL."upload/");
define('DOWNLOAD_URL', ASSETS_URL."download/");


// We dont need these variables any more
unset($base_uri, $base_url);

...
<base href="<?=base_url();?>">
...