现在好多URL连接都使用的短地址不知道什么意思，网上找了篇例子读了一下代码做参考
<?php
??class Short_Url {
???????#字符表
???????public static $charset = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
???????public static function short($url) {
???????????$key = "alexis";
???????????$urlhash = md5($key . $url);
???????????$len = strlen($urlhash);
???????????#将加密后的串分成4段，每段4字节，对每段进行计算，一共可以生成四组短连接
???????????for ($i = 0; $i < 4; $i++) {
???????????????$urlhash_piece = substr($urlhash, $i * $len / 4, $len / 4);
???????????????#将分段的位与0x3fffffff做位与，0x3fffffff表示二进制数的30个1，即30位以后的加密串都归零
???????????????$hex = hexdec($urlhash_piece) & 0x3fffffff; #此处需要用到hexdec()将16进制字符串转为10进制数值型，否则运算会不正常
???????????????$short_url = "http://t.cn/";
???????????????#生成6位短连接
???????????????for ($j = 0; $j < 6; $j++) {
???????????????????#将得到的值与0x0000003d,3d为61，即charset的坐标最大值
???????????????????$short_url .= self::$charset[$hex & 0x0000003d];
???????????????????#循环完以后将hex右移5位
???????????????????$hex = $hex >> 5;
???????????????}
???????????????$short_url_list[] = $short_url;
???????????}
???????????return $short_url_list;
???????}
???}
???$url = "http://www.cnblogs.com/zemliu/";
???$short = Short_Url::short($url);
???print_r($short);
url短地址
原文地址：https://www.cnblogs.com/caoql/p/8799318.html