最近对google的PageRank比较感兴趣，一直想知道如何不用google toolbar来获取pr值。用嗅探工具获得google toolbar发出请求的url为:http://toolbarqueries.google.com//search?client=navclient-auto&ch=64170410360&ie=UTF-8&oe=UTF-8&features=Rank:FVN&q=info:http%3A//www.ugia.cn,其中的关键部分为ch=64170410360,即CheckSum,不知道这个是用的什么算法得出来的。

　　苦苦搜索之后,找到如下代码:

　　转自: http://meese.ath.cx/google via 思路(http://silu.spirezone.com)

>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<= 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

$result[$i] = ord($string{$i});

}

return $result;

}

// http://www.example.com/ - Checksum: 6540747202

$url = 'info:'.$_GET['url'];

$ch = GoogleCH(strord($url));

$url='info:'.urlencode($_GET['url']);

echo file_get_contents("http://www.google.com/search?client=

navclient-auto&ch=6$ch&ie=UTF-8&oe=UTF-8&features=Rank&q=$url");

/* use curl send the user angent

$curl = curl_init("http://www.google.com/search?client=navclient-auto&ch=6$

ch&ie=UTF-8&oe=UTF-8&features=Rank&q=$url");

curl_setopt ($curl, CURLOPT_USERAGENT, "Mozilla/4.0 (compatible;

GoogleToolbar 2.0.110-big; Windows 2000 5.0)");

curl_exec($curl);

*/

?>