The simplest way of iterating through keys
in the dbm doesn't even seem to work properly
in the Windows version of DBM:

for ($key=dbmfirstkey($db_id); 
     $key;
     $key=dbmnextkey($db_id,$key)) {
 $keys[]=$key;
}

Either the keys returned contain the wrong
characters or no key is returned at all

I've found the Windows DBM to be so bug-ridden
it's unusable.