PHP生成全球唯一码
<? function guid() { $charid = strtoupper(md5(uniqid(mt_rand(), true))); $uuid = substr($charid, 0, 8). substr($charid, 8, 4). substr($charid,12, 4). substr($charid,16, 4). substr($charid,20,12); return $uuid; } echo strlen(guid()); ?>