PHP生成类似类似优酷、腾讯视频等其他视频链的ID

不知道你注意了没有，类似优酷、腾讯视频等其他视频链接似乎类似这样的

http://v.youku.com/v_show/id_XNjA5MjE5OTM2.html

注意id_xxx那段，是不是看不懂了，但你无可否认这个就是id，这不国外的一位牛人早在09年就写了针对PHP/Python/Javascript/Java/SQL的生成方法，可见我现在是多么的落伍，下面我把代码贴出来，希望分享精神永存。

PHP代码（Get from GitHub）

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146

<?php /**   * Translates a number to a short alhanumeric version   *   * Translated any number up to 9007199254740992   * to a shorter version in letters e.g.:   * 9007199254740989 --> PpQXn7COf  *  * specifiying the second argument true, it will  * translate back e.g.:  * PpQXn7COf --> 9007199254740989  *  * this function is based on any2dec && dec2any by  * fragmer[at]mail[dot]ru  * see: http://nl3.php.net/manual/en/function.base-convert.php#52450  *  * If you want the alphaID to be at least 3 letter long, use the  * $pad_up = 3 argument  *  * In most cases this is better than totally random ID generators  * because this can easily avoid duplicate ID's.  * For example if you correlate the alpha ID to an auto incrementing ID  * in your database, you're done.  *  * The reverse is done because it makes it slightly more cryptic,  * but it also makes it easier to spread lots of IDs in different  * directories on your filesystem. Example:  * $part1 = substr($alpha_id,0,1);  * $part2 = substr($alpha_id,1,1);  * $part3 = substr($alpha_id,2,strlen($alpha_id));  * $destindir = "/".$part1."/".$part2."/".$part3;  * // by reversing, directories are more evenly spread out. The  * // first 26 directories already occupy 26 main levels  *  * more info on limitation:  * - http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-talk/165372  *  * if you really need this for bigger numbers you probably have to look  * at things like: http://theserverpages.com/php/manual/en/ref.bc.php  * or: http://theserverpages.com/php/manual/en/ref.gmp.php  * but I haven't really dugg into this. If you have more info on those  * matters feel free to leave a comment.  *  * The following code block can be utilized by PEAR's Testing_DocTest  * <code>  * // Input //  * $number_in = 2188847690240;  * $alpha_in  = "SpQXn7Cb";  *  * // Execute //  * $alpha_out  = alphaID($number_in, false, 8);  * $number_out = alphaID($alpha_in, true, 8);  *  * if ($number_in != $number_out) {  *    echo "Conversion failure, ".$alpha_in." returns ".$number_out." instead of the ";  *    echo "desired: ".$number_in." ";  * }  * if ($alpha_in != $alpha_out) {  *    echo "Conversion failure, ".$number_in." returns ".$alpha_out." instead of the ";  *    echo "desired: ".$alpha_in." ";  * }  *  * // Show //  * echo $number_out." => ".$alpha_out." ";  * echo $alpha_in." => ".$number_out." ";  * echo alphaID(238328, false)." => ".alphaID(alphaID(238328, false), true)." ";  *  * // expects:  * // 2188847690240 => SpQXn7Cb  * // SpQXn7Cb => 2188847690240  * // aaab => 238328  *  * </code>  *  * @author   Kevin van Zonneveld <kevin@vanzonneveld.net>  * @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

1 2	<?php alphaID(9007199254740989);

执行结果将被返回“fE2XnNGpF”，我们可以把它认为是加密，进行反解密则

1 2	<?php alphaID('fE2XnNGpF', true);

那么就转换成真实的数字“9007199254740989”。方法还可以支持使用key进行加密，使得别人无法解得你真实的ID。