用PHP程序获取网站的PR值

PR是Google的PageRank技术的缩写，PR值反映了一个网站在互联网中的“地位”！用PHP脚本程序获取网站的PR值的主要代码如下：

<?php

// 3/20/2008 - Updated by Roger Collins (http://www.rogercollins.com/)

// to remove graphing step

//PageRank Lookup v1.1 by HM2K (update: 31/01/07)

//based on an alogoritham found here: http://pagerank.gamesaga.net/

//settings - host and user agent

$googlehost=‘toolbarqueries.google.com’;

$googleua=‘Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.0.6) Gecko/20060728 Firefox/1.5′;

echo getpr(”http://www.xydw.com”);

//convert a string to a 32-bit integer

function StrToNum($Str, $Check, $Magic) {

$Int32Unit = 4294967296; // 2^32

$length = strlen($Str);

for ($i = 0; $i < $length; $i++) {

$Check *= $Magic;

//If the float is beyond the boundaries of integer (usually +/- 2.15e+9 = 2^31),

// the result of converting to integer is undefined

// refer to http://www.php.net/manual/en/language.types.integer.php

if ($Check >= $Int32Unit) {

$Check = ($Check - $Int32Unit * (int) ($Check / $Int32Unit));

//if the check less than -2^31

$Check = ($Check < -2147483648) ? ($Check + $Int32Unit) : $Check;

}

$Check += ord($Str{$i});

}

return $Check;

}

//genearate a hash for a url

function HashURL($String) {

$Check1 = StrToNum($String, 0×1505, 0×21);

$Check2 = StrToNum($String, 0, 0×1003F);

$Check1 >>= 2;

$Check1 = (($Check1 >> 4) & 0×3FFFFC0 ) | ($Check1 & 0×3F);

$Check1 = (($Check1 >> 4) & 0×3FFC00 ) | ($Check1 & 0×3FF);

$Check1 = (($Check1 >> 4) & 0×3C000 ) | ($Check1 & 0×3FFF);

$T1 = (((($Check1 & 0×3C0) << 4) | ($Check1 & 0×3C)) <<2 ) | ($Check2 & 0xF0F );

$T2 = (((($Check1 & 0xFFFFC000) << 4) | ($Check1 & 0×3C00)) << 0xA) | ($Check2 & 0xF0F0000 );

return ($T1 | $T2);

}

//genearate a checksum for the hash string

function CheckHash($Hashnum) {

$CheckByte = 0;

$Flag = 0;

$HashStr = sprintf(‘%u’, $Hashnum) ;

$length = strlen($HashStr);

for ($i = $length - 1; $i >= 0; $i –) {

$Re = $HashStr{$i};

if (1 === ($Flag % 2)) {

$Re += $Re;

$Re = (int)($Re / 10) + ($Re % 10);

}

$CheckByte += $Re;

$Flag ++;

}

$CheckByte %= 10;

if (0 !== $CheckByte) {

$CheckByte = 10 - $CheckByte;

if (1 === ($Flag % 2) ) {

if (1 === ($CheckByte % 2)) {

$CheckByte += 9;

}

$CheckByte >>= 1;

}

}

return ‘7′.$CheckByte.$HashStr;

}

//return the pagerank checksum hash

function getch($url) { return CheckHash(HashURL($url)); }

//return the pagerank figure

function getpr($url) {

global $googlehost,$googleua;

$pr = 0; // default return

$ch = getch($url);

$fp = fsockopen($googlehost, 80, $errno, $errstr, 30);

if ($fp) {

$out = “GET /search?client=navclient-auto&ch=$ch&features=Rank&q=info:$url HTTP/1.1/r/n”;

//echo “<pre>$out</pre>/n”; //debug only

$out .= “User-Agent: $googleua/r/n”;

$out .= “Host: $googlehost/r/n”;

$out .= “Connection: Close/r/n/r/n”;

fwrite($fp, $out);

//$pagerank = substr(fgets($fp, 128), 4); //debug only

//echo $pagerank; //debug only

while (!feof($fp)) {

$data = fgets($fp, 128);

//echo $data;

$pos = strpos($data, “Rank_”);

if($pos === false){} else{

$pr=substr($data, $pos + 9);

$pr=trim($pr);

$pr=str_replace(“/n”,”,$pr);

return $pr;

}

}

//else { echo “$errstr ($errno)<br />/n”; } //debug only

fclose($fp);

}

return $pr;

}

?>