计算Google PageRank的php代码
可以方便调用。这段代码在windows和linux下都能用。
<?php
class PageRank
{
//settings – host and user agent
var $googlehost='www.google.com';
var $googleua='Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.0.6) Gecko/20060728 Firefox/1.5';
//convert a string to a 32-bit integer
function StrToNum($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 = $this->StrToNum($String, 0×1505, 0×21);
$Check2 = $this->StrToNum($String, 0, 0x1003F);
$Check1 >>= 2;
$Check1 = (($Check1 >> 4) & 0x3FFFFC0 ) | ($Check1 & 0x3F);
$Check1 = (($Check1 >> 4) & 0x3FFC00 ) | ($Check1 & 0x3FF);
$Check1 = (($Check1 >> 4) & 0x3C000 ) | ($Check1 & 0x3FFF);
$T1 = (((($Check1 & 0x3C0) << 4) | ($Check1 & 0x3C)) <<2 ) | ($Check2 & 0xF0F );
$T2 = (((($Check1 & 0xFFFFC000) << 4) | ($Check1 & 0x3C00)) << 0xA) | ($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 $this->CheckHash($this->HashURL($url)); }
//return the pagerank figure
function getrank($url)
{
$urlinfo=parse_url($url);
$start=$urlinfo["scheme"]<>""?strlen($urlinfo["scheme"]."://"):0;
$url=substr($url,$start);
$pr = -1; // default return
$ch = $this->getch($url);
$fp = fsockopen("www.google.com", 80, $errno, $errstr, 30);
if ($fp) {
$out = "GET /search?client=navclient-auto&ch=$ch&features=Rank&q=info:$url HTTP/1.1
";
//echo "<pre>$out</pre>"; //debug only
$out .= "User-Agent: {$this->googleua}
";
$out .= "Host: www.google.com
";
$out .= "Connection: Close";
fwrite($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);
$pr=str_replace("",'',$pr);
return $pr;
}
}
//else { echo "$errstr ($errno)<br />"; } //debug only
fclose($fp);
}
return $pr;
}
}
//$gpr = new PageRank();
//echo $gpr->printrank("http://www.baidu.com/");
?>
近期评论