Make Sure the Url Helper is loaded before calling the function –
$this->load->helper('url');
load “url” helper before use current_url()
$this->load->helper('url');
$currentURL = current_url();
print_r($currentURL);
Load the URL helper To get currents url
echo $this->input->get('my_id');
//or
// Load the URL helper To get currents url
$currentURL = current_url(); //http://myhost/main
$params = $_SERVER['QUERY_STRING']; //my_id=1,3
$fullURL = $currentURL . '?' . $params;
echo $fullURL; //http://myhost/main?my_id=1,3
For currents url
echo base_url(uri_string());
I hope you get an idea about CodeIgniter -> Get currents URL relative to base url.