Author: Christian Cristofori

Sometimes, when you develop a software you need to disable the execution of the 
code from certain types of media, for example, if your application uses a database 
file, you can't write on it if it's located on a CR-ROM.
How to manage this in a easy way? There's the solution.

Answer:

Just write down these short routines:

1   function IsOnHDD: boolean;
2   begin
3     result := GetDriveType(pChar(uppercase(copy(ParamStr(0), 1, 3)))) = DRIVE_FIXED;
4   end;
5   
6   function IsOnCD: boolean;
7   begin
8     result := GetDriveType(pChar(uppercase(copy(ParamStr(0), 1, 3)))) = DRIVE_CDROM;
9   end;
10  
11  function IsOnRemoveable: boolean;
12  begin
13    result := GetDriveType(pChar(uppercase(copy(ParamStr(0), 1, 3)))) = 
14  DRIVE_REMOVABLE;
15  end;
16  
17  //The use them in your project file (.DPR) like this:
18  
19  program Project1;
20  
21  uses
22    Windows, // Added manually
23    SysUtils, // Added manually
24    Dialogs, // Added manually
25    Forms,
26    Unit1 in 'Unit1.pas' {Form1};
27  
28  {$R *.RES}
29  
30  function IsOnCD: boolean;
31  begin
32    result := GetDriveType(pChar(uppercase(copy(ParamStr(0), 1, 3)))) = DRIVE_CDROM;
33  end;
34  
35  begin
36    Application.Initialize;
37    if IsOnCD then
38    begin
39      ShowMessage('This program cannot be executed from a CD-ROM drive.');
40      Application.Terminate;
41    end
42    else
43    begin
44      Application.CreateForm(TForm1, Form1);
45      Application.Run;
46    end;
47  end.


This program will not start if located on a CD-ROM. And no other code than the 
necessary one will be executed.

Christian Cristofori