PHP Google PageRank Calculator Script

<?php
//original code is flanked with $$$$$$$$$

//$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
// PHP Google PageRank Calculator Script
// -------------------------- April 2005
// Contact author: pagerankscript@googlecommunity.com

// for updates, visit:
// http://www.googlecommunity.com/scripts/google-pagerank.php

// provided by www.GoogleCommunity.com
// an unofficial community of Google fans
// ---------------------------------------

// Instructions
// Upload pagerank.php to your server
// Call it like this: http://www.example.com/pagerank.php?url=http://www.yahoo.com/
// example.com is your website. yahoo.com is the website to get the PR of
// The code below displays the PR for $url

/*
This code is released unto the public domain
*/
//header("Content-Type: text/plain; charset=utf-8");
define('GOOGLE_MAGIC', 0xE6359A60);

//unsigned shift right
function zeroFill($a, $b)
{
$z = hexdec(80000000);
if ($z & $a)
{
$a = ($a>>1);
$a &= (~$z);
$a |= 0x40000000;
$a = ($a>>($b-1));
}
else
{
$a = ($a>>$b);
}
return $a;
}

function mix($a,$b,$c) {
$a -= $b; $a -= $c; $a ^= (zeroFill($c,13));
$b -= $c; $b -= $a; $b ^= ($a<<8);
$c -= $a; $c -= $b; $c ^= (zeroFill($b,13));
$a -= $b; $a -= $c; $a ^= (zeroFill($c,12));
$b -= $c; $b -= $a; $b ^= ($a<<16);
$c -= $a; $c -= $b; $c ^= (zeroFill($b,5));
$a -= $b; $a -= $c; $a ^= (zeroFill($c,3));
$b -= $c; $b -= $a; $b ^= ($a<<10);
$c -= $a; $c -= $b; $c ^= (zeroFill($b,15));

return array($a,$b,$c);
}

function GoogleCH($url, $length=null, $init=GOOGLE_MAGIC) {
if(is_null($length)) {
$length = sizeof($url);
}
$a = $b = 0x9E3779B9;
$c = $init;
$k = 0;
$len = $length;
while($len >= 12) {
$a += ($url[$k+0] +($url[$k+1]<<8) +($url[$k+2]<<16) +($url[$k+3]<<24));
$b += ($url[$k+4] +($url[$k+5]<<8) +($url[$k+6]<<16) +($url[$k+7]<<24));
$c += ($url[$k+8] +($url[$k+9]<<8) +($url[$k+10]<<16)+($url[$k+11]<<24));
$mix = mix($a,$b,$c);
$a = $mix[0]; $b = $mix[1]; $c = $mix[2];
$k += 12;
$len -= 12;
}

$c += $length;
switch($len) /* all the case statements fall through */
{
case 11: $c+=($url[$k+10]<<24);
case 10: $c+=($url[$k+9]<<16);
case 9 : $c+=($url[$k+8]<<8);
/* the first byte of c is reserved for the length */
case 8 : $b+=($url[$k+7]<<24);
case 7 : $b+=($url[$k+6]<<16);
case 6 : $b+=($url[$k+5]<<8);
case 5 : $b+=($url[$k+4]);
case 4 : $a+=($url[$k+3]<<24);
case 3 : $a+=($url[$k+2]<<16);
case 2 : $a+=($url[$k+1]<<8);
case 1 : $a+=($url[$k+0]);
/* case 0: nothing left to add */
}
$mix = mix($a,$b,$c);
/*-------------------------------------------- report the result */
return $mix[2];
}

//converts a string into an array of integers containing the numeric value of the char
function strord($string) {
for($i=0;$i<strlen($string);$i++) {
$result[$i] = ord($string{$i});
}
return $result;
}

function getrank($url) {
$url = 'info:'.$url;
$ch = GoogleCH(strord($url));
$file = "http://www.google.com/search?client=navclient-auto&ch=6$ch&features=Rank&q=$url";
$data = file($file);
$rankarray = explode (':', $data[2]);
$rank = $rankarray[2];
return $rank;
}
// PR of one URL from GET query
/*
echo 'PageRank: '.getrank($_REQUEST["url"]).'<br /><small>provided by <a href="http://www.googlecommunity.com/"
target="_blank">Google Community.com</a></small>';
*/
//$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$



if ($_POST['post']=='go_goo_go')
{
set_time_limit(0);
$urls = explode ("\n", $_POST['mes']);
echo "<h3>Results</h3>";
for ($i=0;$i<count($urls);$i++)
{
echo trim($urls[$i]).' PR '.getrank(trim($urls[$i]))."<BR>";
flush();
}

echo "<form method=post action=$SCRIPT_NAME>";
echo " <input type=submit name=post value='more'></form>";

}
else
{
echo '<table width="80%" border=1>';
echo "<tr><td><h3>URLs list</h3><form method=post action=$SCRIPT_NAME>";
echo " <textarea name=mes cols=80 rows=20></textarea><br>";
echo " <input type=submit name=post value='go_goo_go'></form> </td></tr>";
echo "</table>";
}


?>