php微博短网址算法 php生成短网址的实现代码

//php生成短网址
function code62($x) {
$show = '';
while($x > 0) {
  $s = $x % 62;
  if ($s > 35) {
    $s = chr($s+61);
  } elseif ($s > 9 && $s     $s = chr($s + 55);
  }
  $show .= $s;
  $x = floor($x/62);
}
return $show;
}

function shorturl($url) {
   $url = crc32($url);
   $result = sprintf("%u", $url);
   //return $url;
   //return $result;
   return code62($result);
}
echo shorturl("http://bbs.it-home.org/tags/phpduanwangzhi.html");
?>