PHP生成唯一用户标识GUID

代码如下：

//生成唯一用户标识idfunction create_guid() {   聚拢的近义词 $charid = strtoupper(md5(uniqid(mt_rand(), true)));    $hyphen = chr(45);// "-"    $uuid = chr(123)// "{"        .substr($charid, 0, 8).$hyphe血脉相连n        .substr($charid, 8,童话世界 4).$hyphen        .substr($charid,12, 4).$hyphen        .substr($charid,16, 4).$hyphen        .substr($charid,辩题20,12)        .chr(125);// "}"    retur曹芙嘉简历n $uuid;}