PHP queries the PR value of the site

PR value is one of the important criteria for google to measure websites. The pr value is obtained according to the results provided by google, such as:
http://toolbarqueries.google.com.hk/tbr?client=navclient-auto & features=Rank: & q=info:phpddt.com & ch=8fabc62ea

<?php
/*
* function : right URL coding 
* Parameters that :$web_url  Web site URL , does not contain "http://"
*/
function HashURL($url)
{   
    $SEED = "Mining PageRank is AGAINST GOOGLE'S TERMS OF SERVICE. Yes, I'm talking to you, scammer.";
    $Result = 0x01020345;
    for ($i=0; $i<strlen($url); $i++) 
    {
        $Result ^= ord($SEED{$i%87}) ^ ord($url{$i});
        $Result = (($Result >> 23) & 0x1FF) | $Result << 9;
    }
    return sprintf("8%x", $Result);
}
/*
* function : According to the google To provide the pr Query interface acquisition pagerank
* Parameters that :$domain  Domain name, not included "http://"
*/
function pagerank($domain)
{    
    $StartURL = "http://toolbarqueries.google.com/tbr?client=navclient-auto&features=Rank:&q=info:";
    $GoogleURL = $StartURL.$domain. '&ch='.HashURL($domain);
    echo $GoogleURL.'<br>';
    $fcontents = file_get_contents("$GoogleURL");
    $pagerank = substr($fcontents,9);
    if (!$pagerank) return "0";else return $pagerank;
}
echo pagerank("phpddt.com");
?>