PR值全稱為PageRank.PageRank(網頁級別)是Google用於評測一個網頁重要性的一種方法.在揉合了諸如Title標識和Keywords標識等所有其它因素之後.Google通過PageRank來調整結果.使那些更具重要性的網頁在搜索結果中另網站排名獲得提升.從而提高搜索結果的相關性和質量.PR值最高為10.一般PR值達到4.就算是一個不錯的網站了.
PageRank是google搜索排名算法中的一個組成部分,級別從1到10級,10級為滿分,PR值越高說明該網頁在搜索排名中的地位越重要,也就是說,在其他條件相同的情況下,PR值高的網站在google搜索結果的排名中有優先權.
< ?php
// Edit this to your website url:
$myWebSite = http://www.mycodes.net;
define('GMAG', 0xE6359A60);
//unsigned shift right
function zeroFill($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,$c);
}
function GCH($url, $length=null, $init=GMAG) {
if(is_null($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 $result;
}
function getPR($_url) {
$url = 'info:'.$_url;
$ch = GCH(strord($url));
$url='info:'.urlencode($_url);
$pr = file("http://www.google.com/search?client=navclient-auto&ch=6$ch&ie=UTF-8&oe=UTF-8&features=Rank&q=$url");
$pr_str = implode("", $pr);
return substr($pr_str,strrpos($pr_str, ":")+1);
}
echo "<br>The PR of $myWebsite is: ".getPR($myWebSite);
?>
