void export_uid(object ob)
Set the uid of object ob to the current object's effective uid.
It is only possible when object ob has an effective uid of 0.
Since 3.2.1@47, this efun is availabe only when using euids.
Since 3.2.7, this efun is always available.
seteuid(E), getuid(E), geteuid(E), uids(C), native(C)