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());
?>
