http://v.youku.com/v_show/id_XNjA5MjE5OTM2.html
<?php /** * @author Kevin van Zonneveld <[email protected]> * @author Simon Franz * @author Deadfish * @copyright 2008 Kevin van Zonneveld (http://kevin.vanzonneveld.net) * @license http://www.opensource.org/licenses/bsd-license.php New BSD Licence * @version SVN: Release: $Id: alphaID.inc.php 344 2009-06-10 17:43:59Z kevin $ * @link http://kevin.vanzonneveld.net/ * * @param mixed $in String or long input to translate * @param boolean $to_num Reverses translation when true * @param mixed $pad_up Number or boolean padds the result up to a specified length * @param string $passKey Supplying a password makes it harder to calculate the original ID * * @return mixed string or long */ function alphaID($in, $to_num = false, $pad_up = false, $passKey = null) { $index = "abcdefghijklmnopqrstuvwxyz0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"; if ($passKey !== null) { // Although this function's purpose is to just make the // ID short - and not so much secure, // with this patch by Simon Franz (http://blog.snaky.org/) // you can optionally supply a password to make it harder // to calculate the corresponding numeric ID for ($n = 0; $n<strlen($index); $n++) { $i[] = substr( $index,$n ,1); } $passhash = hash('sha256',$passKey); $passhash = (strlen($passhash) < strlen($index)) ? hash('sha512',$passKey) : $passhash; for ($n=0; $n < strlen($index); $n++) { $p[] = substr($passhash, $n ,1); } array_multisort($p, SORT_DESC, $i); $index = implode($i); } $base = strlen($index); if ($to_num) { // Digital number < 0) { $out -= pow($base, $pad_up); } } $out = sprintf('%F', $out); $out = substr($out, 0, strpos($out, '.')); } else { // Digital number -->> alphabet letter code if (is_numeric($pad_up)) { $pad_up--; if ($pad_up > 0) { $in += pow($base, $pad_up); } } $out = ""; for ($t = floor(log($in, $base)); $t >= 0; $t--) { $bcp = bcpow($base, $t); $a = floor($in / $bcp) % $base; $out = $out . substr($index, $a, 1); $in = $in - ($a * $bcp); } $out = strrev($out); // reverse } return $out; }
使用举例
<?php alphaID(9007199254740989);
<?php alphaID('fE2XnNGpF', true);