What is Google PageRank?
PageRank is a numeric value that represents how important a page is on the web. It is Google's way of measuring the importance of web site.
Here is how Google explains PageRank:
PageRank relies on the uniquely democratic nature of the web by using its vast link structure as an indicator of an individual page's value. Google interprets a link from page A to page B as a vote, by page A, for page B. But Google looks at more than the sheer volume of votes, or links a page receives; it also analyzes the page that casts the vote. Votes cast by pages that are themselves "important" weigh more heavily and help to make other pages "important."
Google PageRank is mostly discussed by SEO's but also webmasters, web advertisers and publishers. For example, webmasters will not exchange links with websites whose PageRank is less then 4 or 5. Often, web publishers will pay less money for ads on websites with lower PageRanks. So how do you know what a PageRank of a website is? Simplest way to do it is to install Google toolbar. There are also various tools and scripts out there that will tell you the PageRank. One of the popular scripts was the one published by www.googlecommunity.com.
Below is modified version of that script. I used the code to create a PHP class that can be easily implemented with your projects. I also included images for visual representation of the PageRank.
To see the implementation of the code below visit BeWebmaster.com link directory.
pagerank.php
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<?php
define('GOOGLE_MAGIC', 0xE6359A60);
class pageRank{
var $pr;
function zeroFill($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; $a ^= ($this->zeroFill($c,13));
$b -= $c; $b -= $a; $b ^= ($a<<8);
$c -= $a; $c -= $b; $c ^= ($this->zeroFill($b,13));
$a -= $b; $a -= $c; $a ^= ($this->zeroFill($c,12));
$b -= $c; $b -= $a; $b ^= ($a<<16);
$c -= $a; $c -= $b; $c ^= ($this->zeroFill($b,5));
$a -= $b; $a -= $c; $a ^= ($this->zeroFill($c,3));
$b -= $c; $b -= $a; $b ^= ($a<<10);
$c -= $a; $c -= $b; $c ^= ($this->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 = $this->mix($a,$b,$c);
$a = $mix[0]; $b = $mix[1]; $c = $mix[2];
$k += 12;
$len -= 12;
}
$c += $length;
switch($len){
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]);
}
$mix = $this->mix($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 $result;
}
function printrank($url){
$ch = "6".$this->GoogleCH($this->strord("info:" . $url));
$fp = fsockopen("www.google.com", 80, $errno, $errstr, 30);
if (!$fp) {
echo "$errstr ($errno)<br />\n";
} else {
$out = "GET /search?client=navclient-auto&ch=" . $ch . "&features=Rank&q=info:" . $url . " HTTP/1.1\r\n" ;
$out .= "Host: www.google.com\r\n" ;
$out .= "Connection: Close\r\n\r\n" ;
fwrite($fp, $out);
while (!feof($fp)) {
$data = fgets($fp, 128);
$pos = strpos($data, "Rank_");
if($pos === false){
}else{
$pagerank = substr($data, $pos + 9);
$this->pr_image($pagerank);
}
}
fclose($fp);
}
}
//display pagerank image. Create your own or download images I made for this script. If you make your own make sure to call them pr0.gif, pr1.gif, pr2.gif etc.
function pr_image($pagerank){
if($pagerank == 0){
$this->pr = "<img src=\"images/pr0.gif\" alt=\"PageRank " .$pagerank. " out of 10\">" ;
}elseif($pagerank == 1){
$this->pr = "<img src=\"images/pr1.gif\" alt=\"PageRank " .$pagerank. " out of 10\">" ;
}elseif($pagerank == 2){
$this->pr = "<img src=\"images/pr2.gif\" alt=\"PageRank " .$pagerank. " out of 10\">" ;
}elseif($pagerank == 3){
$this->pr = "<img src=\"images/pr3.gif\" alt=\"PageRank " .$pagerank. " out of 10\">" ;
}elseif($pagerank == 4){
$this->pr = "<img src=\"images/pr4.gif\" alt=\"PageRank " .$pagerank. " out of 10\">" ;
}elseif($pagerank == 5){
$this->pr = "<img src=\"images/pr5.gif\" alt=\"PageRank " .$pagerank. " out of 10\">" ;
}elseif($pagerank == 6){
$this->pr = "<img src=\"images/pr6.gif\" alt=\"PageRank " .$pagerank. " out of 10\">" ;
}elseif($pagerank == 7){
$this->pr = "<img src=\"images/pr7.gif\" alt=\"PageRank " .$pagerank. " out of 10\">" ;
}elseif($pagerank == 8){
$this->pr = "<img src=\"images/pr8.gif\" alt=\"PageRank " .$pagerank. " out of 10\">" ;
}elseif($pagerank == 9){
$this->pr = "<img src=\"images/pr9.gif\" alt=\"PageRank " .$pagerank. " out of 10\">" ;
}else{
$this->pr = "<img src=\"images/pr10.gif\" alt=\"PageRank " .$pagerank. " out of 10\">" ;
}
}
function get_pr(){
return $this->pr;
}
}
?> |
Usage
Do following:
- Save the code above as pagerank.php.
- Download or create your own images to display each rank.
- Create a directory "images" containing all page rank images.
- See code below on how to use the class.
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<?php
include("pagerank.php");
$gpr = new pageRank();
$gpr->printrank("http://www.yahoo.com");
//display image
echo $gpr->get_pr();
?> |
Again to see the class in action visit BeWebmaster.com link exchange directory at: http://www.bewebmaster.com/beseen/
