php 生成短网址原理及代码

/** 生成短网址 * @param String $url 原网址 * @return String */ function dwz($url){ $code = sprintf('%u', crc32($url)); $surl = ''; while($code){ $mod = $code % 62; if($mod>9 && $mod<=35){ $mod = chr($mod + 55); }elseif($mod>35){ $mod = chr($mod + 61); } $surl .= $mod; $code = floor($code/62); } return $surl; }