Author: William Gerbert

Convert from UNC notation to Drive letter?

Answer:

The function ExpandUNCFileName function converts a mapped path/file to UNC, but how 
can this process be reversed?

There is no simple function that would do the trick, you have to go through all 
existing 'remote' drives, look at their UNC name and compare them with the one you 
are interested in: 


1   program P;
2   
3   procedure TForm1.Button1Click(Sender: TObject);
4   const
5     YOURUNCFILENAME = '\\ISS\VOL1\ISS\SHARE\';
6   var
7     Drive: Char;
8     Drlist: TStringList;
9     Filist: TStringList;
10    I: integer;
11  begin
12    Drlist := TStringList.Create;
13    Filist := TStringList.Create;
14    for Drive := 'a' to 'z' do
15      case GetDriveType(PChar(Drive + ':\')) of
16        DRIVE_REMOTE:
17          begin
18            Filist.Add(expanduncfilename(Drive + ':\'));
19            Drlist.Add(Drive)
20          end
21      end;
22    {......}
23    I := Filist.indexof(YOURUNCFILENAME);
24    if I > -1 then
25      ShowMessage(YOURUNCFILENAME + 'Mapped to drive ' + Drlist[I]);
26  
27    Drlist.Free;
28    Filist.Free
29  end;
30  
31  end.