I came back to this code and tried again but gave me some errors, so I've reworked it partially based on the previous answer I've formulated before with this new one (working nice on Joomla! 3.4.5)
// build the JInput object
$jinput = JFactory::getApplication()->input;
// retrieve the array of values from the request (stored in the application environment) to form the query
$uriQuery = $jinput->getArray();
// build the the query as a string
echo 'index.php?' . JUri::buildQuery($uriQuery);
Joomla! API Docs: JInput
- JUri
PREVIOUS ANSWER:
Googling around I found this:
<?php
// "unparse" the Joomla SEF url to get the internal joomla URL
JURI::current();// It's very strange, but without this line at least Joomla 3 fails to fulfill the task
$router =& JSite::getRouter();// get router
$query = $router->parse(JURI::getInstance()); // Get the real joomla query as an array - parse current joomla link
$url = 'index.php?'.JURI::getInstance()->buildQuery($query);
?>
I've tested it with Joomla! 3.4.4 and its working fine! Dunno if it can work with 1.5