.DT
file_name
Discworld efun help
file_name

string file_name(object ob)

.SP 5 5
Get the file name of an object. If the object is a cloned object, then it 
will not have any corresponding file name, but rather a new name based on 
the original file name.

Example: find_object(file_name(ob)) == ob is guaranteed to be true for
all objects ob.
.EP
