使用很简单，只要在需要的地方

<?php
include_once("./pr.inc.php");
echo getPR($urlToQuery);
?>

即可显示出指定url的PageRank的数值。知道了这个数值再在其基础上模拟出Google Toolbar上面的图形化的pr显示也就不是难事了。实际上实现原理说白了也很简单，就是传递特定的查询参数到Google的搜索引擎，然后抓取返回的页面内容。

演示页面请参见 : Google PageRank Query

本文代码素材来源: http://forums.seochat.com/archive/t-17286/Php-Pagerank-checker ；NewGCH方法实现参考于Firefox的工具栏扩展插件SearchStatus的相关代码实现。

网上还有一个开源的pr状态查询的项目: http://pagerankstatus.mozdev.org/source.html , 可以从cvs上直接抓取完整的源代码(cvs用户密码 guest):

cvs -d :pserver:guest@mozdev.org:/cvs login
cvs -d :pserver:guest@mozdev.org:/cvs co pagerankstatus

一个专门提供pr显示接口的网站： http://www.prchecker.info/

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pr.inc.php源文件如下（Updated 2008-05-04 14:29 -- Google修改了checksum的计算算法，需要在原有的GCH方法之后再套一层NewGCH方法来得到正确的checksum，同时引发的php int overflow及64位机器兼容性问题请参照以下源代码的变化部分）：

<?php // url get method macro. define('G_PR_GET_TYPE_FILE', 1); // use fopen() function define('G_PR_GET_TYPE_SOCKET', 2); // use standard fsocketopen function // main function to be called function getPR($_url,$gettype=G_PR_GET_TYPE_SOCKET){ $url = 'info:'.$_url; $ch = GCH(strord($url)); $ch = NewGCH($ch); $url=str_replace("_","%5F",'info:'.urlencode($_url)); $googlePRUrl = "http://toolbarqueries.google.com/search?client=navclient-auto&ch=6" .$ch."&ie=UTF-8&oe=UTF-8&features=Rank&q=".$url; $pr_str = retrieveURLContent($googlePRUrl,$gettype); return substr($pr_str,strrpos($pr_str, ":")+1); } //unsigned shift right function zeroFill($a, $b){ $z = hexdec('8'.implode('',array_fill(0,PHP_INT_SIZE*2-1,'0'))); if ($z & $a){ $a = ($a>>1); $a &= (~$z); $a |= hexdec('4'.implode('',array_fill(0,PHP_INT_SIZE*2-1,'0'))); $a = ($a>>($b-1)); } else{ $a = ($a>>$b); } return $a; } // discard bits beyonds 32 bit. function trunkbitForce32bit($n){ if(PHP_INT_SIZE <= 4){ settype($n,'float'); if ( $n < 0 ) $n += 4294967296; return $n; } else{ $clearbit = ''; for($i=0;$i<PHP_INT_SIZE-4;$i++){ $clearbit .= '00'; } for($i=0;$i<4;$i++){ $clearbit .= 'ff'; } return ($n & hexdec($clearbit)); } } function bigxor($m,$n){ //if(function_exists('gmp_init')){ // return floatval(gmp_strval(gmp_xor($m,$n))); //} //else{ return $m ^ $n; //} } function mix($a,$b,$c){ $a = trunkbitForce32bit($a); $b = trunkbitForce32bit($b); $c = trunkbitForce32bit($c); $a -= $b; $a = trunkbitForce32bit($a); $a -= $c; $a = trunkbitForce32bit($a); $a = bigxor($a,(zeroFill($c,13))); $a = trunkbitForce32bit($a); $b -= $c; $b = trunkbitForce32bit($b); $b -= $a; $b = trunkbitForce32bit($b); $b = bigxor($b,trunkbitForce32bit($a<<8)); $b = trunkbitForce32bit($b); $c -= $a; $c = trunkbitForce32bit($c); $c -= $b; $c = trunkbitForce32bit($c); $c = bigxor($c,(zeroFill($b,13))); $c = trunkbitForce32bit($c); $a -= $b;$a = trunkbitForce32bit($a); $a -= $c;$a = trunkbitForce32bit($a); $a = bigxor($a,(zeroFill($c,12)));$a = trunkbitForce32bit($a); $b -= $c;$b = trunkbitForce32bit($b); $b -= $a;$b = trunkbitForce32bit($b); $b = bigxor($b,trunkbitForce32bit($a<<16)); $c -= $a; $c = trunkbitForce32bit($c); $c -= $b; $c = trunkbitForce32bit($c); $c = bigxor($c,(zeroFill($b,5))); $c = trunkbitForce32bit($c); $a -= $b;$a = trunkbitForce32bit($a); $a -= $c;$a = trunkbitForce32bit($a); $a = bigxor($a,(zeroFill($c,3)));$a = trunkbitForce32bit($a); $b -= $c;$b = trunkbitForce32bit($b); $b -= $a;$b = trunkbitForce32bit($b); $b = bigxor($b,trunkbitForce32bit($a<<10)); $c -= $a; $c = trunkbitForce32bit($c); $c -= $b; $c = trunkbitForce32bit($c); $c = bigxor($c,(zeroFill($b,15))); $c = trunkbitForce32bit($c); return array($a,$b,$c); } function NewGCH($ch){ $ch = ( trunkbitForce32bit( ( $ch / 7 ) << 2 ) | ( ( myfmod( $ch,13 ) ) & 7 ) ); $prbuf = array(); $prbuf[0] = $ch; for( $i = 1; $i < 20; $i++ ) { $prbuf[$i] = $prbuf[$i-1] - 9; } $ch = GCH( c32to8bit( $prbuf ) ); return $ch; } function myfmod($x,$y){ $i = floor( $x / $y ); return ( $x - $i * $y ); } function c32to8bit($arr32){ $arr8 = array(); for( $i = 0; $i < count($arr32); $i++ ) { for( $bitOrder = $i * 4; $bitOrder <= $i * 4 + 3; $bitOrder++ ) { $arr8[$bitOrder] = $arr32[$i] & 255; $arr32[$i] = zeroFill( $arr32[$i], 8 ); } } return $arr8; } function GCH($url, $length=null){ if(is_null($length)) { $length = sizeof($url); } $init = 0xE6359A60; $a = 0x9E3779B9; $b = 0x9E3779B9; $c = 0xE6359A60; $k = 0; $len = $length; $mixo = array(); while( $len >= 12 ){ $a += ($url[$k+0] +trunkbitForce32bit($url[$k+1]<<8) +trunkbitForce32bit($url[$k+2]<<16) +trunkbitForce32bit($url[$k+3]<<24)); $b += ($url[$k+4] +trunkbitForce32bit($url[$k+5]<<8) +trunkbitForce32bit($url[$k+6]<<16) +trunkbitForce32bit($url[$k+7]<<24)); $c += ($url[$k+8] +trunkbitForce32bit($url[$k+9]<<8) +trunkbitForce32bit($url[$k+10]<<16) +trunkbitForce32bit($url[$k+11]<<24)); $mixo = mix($a,$b,$c); $a = $mixo[0]; $b = $mixo[1]; $c = $mixo[2]; $k += 12; $len -= 12; } $c += $length; switch( $len ) { case 11: $c += trunkbitForce32bit($url[$k+10]<<24); case 10: $c+=trunkbitForce32bit($url[$k+9]<<16); case 9 : $c+=trunkbitForce32bit($url[$k+8]<<8); case 8 : $b+=trunkbitForce32bit($url[$k+7]<<24); case 7 : $b+=trunkbitForce32bit($url[$k+6]<<16); case 6 : $b+=trunkbitForce32bit($url[$k+5]<<8); case 5 : $b+=trunkbitForce32bit($url[$k+4]); case 4 : $a+=trunkbitForce32bit($url[$k+3]<<24); case 3 : $a+=trunkbitForce32bit($url[$k+2]<<16); case 2 : $a+=trunkbitForce32bit($url[$k+1]<<8); case 1 : $a+=trunkbitForce32bit($url[$k+0]); } $mixo = mix( $a, $b, $c ); $mixo[2] = trunkbitForce32bit($mixo[2]); if( $mixo[2] < 0 ){ return ( hexdec('1'. implode('', array_fill(0,PHP_INT_SIZE*2,'0'))) + $mixo[2] ); } else{ return $mixo[2]; } } // converts a string into an array of integers // containing the numeric value of the char function strord($string){ for($i=0;$i<strlen($string);$i++){ $result[$i] = ord($string{$i}); } return $result; } // return url page content or false if failed. function retrieveURLContent($url,$gettype){ switch($gettype){ case G_PR_GET_TYPE_FILE: return retrieveURLContentByFile($url); break; default: return retrieveURLContentBySocket($url); break; } } function retrieveURLContentByFile($url){ $fd = @fopen($url,"r"); if(!$fd){ return false; } $result = ""; while($buffer = fgets($fd, 4096)) { $result .= $buffer; } fclose($fd); return $result; } function retrieveURLContentBySocket($url, $host="", $port=80, $timeout=30){ if($host == ""){ if(!($pos = strpos($url,'://'))){ return false; } $host = substr( $url, $pos+3, strpos($url,'/',$pos+3) - $pos - 3); $uri = substr($url,strpos($url,'/',$pos+3)); } else{ $uri = $url; } $request = "GET ".$uri." HTTP/1.0\r\n" ."Host: ".$host."\r\n" ."Accept: */*\r\n" ."User-Agent: ZealGet\r\n" ."\r\n"; $sHnd = @fsockopen ($host, $port, $errno, $errstr, $timeout); if(!$sHnd){ return false; } @fputs ($sHnd, $request); // Get source $result = ""; while (!feof($sHnd)){ $result .= fgets($sHnd,4096); } fclose($sHnd); $headerend = strpos($result,"\r\n\r\n"); if (is_bool($headerend)) { return $result; } else{ return substr($result,$headerend+4); } }