How to get and change URL variable PHP

Question

Hi could anyone help me with this I have a URL like

parent/child/a=1&b=2$c=3

then I have a link that would add variable to that URL

Answer 1

modify_url_query($url, array('limit' => 50));

My function for modifying query in url

function modify_url_query($url, $mod){

$purl = parse_url($url);

$params = array();

if (($query_str=$purl['query']))
{
    parse_str($query_str, $params);

    foreach($params as $name => $value)
    {
        if (isset($mod[$name]))
        {
            $params[$name] = $mod[$name];
            unset($mod[$name]);
        }
    }
}        

$params = array_merge($params, $mod);

$ret = "";

if ($purl['scheme'])
{
    $ret = $purl['scheme'] . "://";
}    

if ($purl['host'])
{
    $ret .= $purl['host'];
}    

if ($purl['path'])
{
    $ret .= $purl['path'];
}    

if ($params)
{
    $ret .= '?' . http_build_query($params);
}    


if ($purl['fragment'])
{
    $ret .= "#" . $purl['fragment'];
}        

return $ret;

}