<?php
function retrieveURL($relativeURL){
    $uname = "user";    //this is the privileged user to the relative url we want
    $upswd = "pass";
    $domain = $_SERVER['HTTP_HOST'];
    $prefix = $_SERVER['HTTPS'] ? 'https://' : 'http://';

    $url_get_key = $prefix.$domain."index.php?option=com_users";

    //GET return & key
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, $url_get_key );
    curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, FALSE );
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, TRUE );

    curl_setopt($ch, CURLOPT_COOKIEJAR, dirname(__FILE__).'/cookie.txt');   //as far as i understand, this stores a *new* session to a cookie file
    curl_setopt($ch, CURLOPT_COOKIEFILE, dirname(__FILE__).'/cookie.txt');
    curl_setopt($ch, CURLOPT_HEADER, 0 );

    $results = curl_exec($ch);

    preg_match_all("(<input type="hidden" name="return" value="(.*)" />)siU", $results, $matches1);   //Should not be needed if username and password are correct
    preg_match_all("(<input type="hidden" name="(.*)" value="1" />(.*)</fieldset>)iU", $results, $matches2); //Same as above

    // POST
    $url_post = $prefix.$domain."index.php?option=com_users&task=user.login";
    $postdata = "username=".urlencode($uname)."&password=".urlencode($upswd)."&return=".urlencode($matches1[1][0])."&".urlencode($matches2[1][0])."=1";
    curl_setopt($ch, CURLOPT_URL, $url_post);
    curl_setopt($ch, CURLOPT_POST, TRUE);
    curl_setopt($ch, CURLOPT_POSTFIELDS, $postdata);
    $results1 = curl_exec($ch);

    $url_data = $prefix.$domain.$relativeURL;
    curl_setopt($ch, CURLOPT_URL, $url_data);   //Now we can retrieve the proper url

    $results2 = curl_exec($ch);
    $error = curl_error($ch);
    $errno = curl_errno($ch);

    curl_close($ch);
    return $results2;   //could probably use a bit more error checking
}
?>