How can I quickly generate an unique computer id for a delphi app?
I used to do it easly with c#, but this failed sometimes. I do want the ID to be "static" but I don't care if the id changes because of a hardware change or OS reinstallation, I was planning to store it in the registry and check it when the app starts, and if it changed update the registry. (I know how to code the registry part, I only need help for the unique id).
Thanks.
Use the hard disk serial number or MAC address:
How to get serial number from hard disks?
Generating a unique machine id
Have a look at SysUtils.CreateGUID which creates a globally unique identifier. Syntax:
function CreateGUID(out Guid: TGUID): HResult; stdcall;
A small example taken from D2010's help:
{
This example demonstrates the usage of some GUID
related routines along with the type itself.
}
procedure TForm2.FormCreate(Sender: TObject);
var
MyGuid0, MyGuid1 : TGUID;
begin
{ Create a new GUID from the string representation. }
MyGuid0 := StringToGUID('{00020400-0000-0000-C000-000000000046}');
Memo1.Lines.Add('The GUID is: ' + GUIDToString(MyGuid0));
{
Accessing GUID's internal fields
Using the Format function to obtain the same output as GUIDToString
}
Memo1.Lines.Add(Format('GUID using formatting is: ' +
'{%0.8X-%0.4X-%0.4X-%0.2X%0.2X-%0.2X%0.2X%0.2X%0.2X%0.2X%0.2X}',
[MyGuid0.D1, MyGuid0.D2, MyGuid0.D3,
MyGuid0.D4[0], MyGuid0.D4[1], MyGuid0.D4[2], MyGuid0.D4[3],
MyGuid0.D4[4], MyGuid0.D4[5], MyGuid0.D4[6], MyGuid0.D4[7]]));
{ Autogenerate a random GUID at run time. }
if CreateGUID(MyGuid1) <> 0 then
Memo1.Lines.Add('Creating GUID failed!')
else
Memo1.Lines.Add('The generated guid is: ' + GUIDToString(MyGuid1));
{ Generating second random GUID. }
CreateGUID(MyGuid0);
{ Testing if two guids are equal. }
if IsEqualGUID(MyGuid0, MyGuid1) then
Memo1.Lines.Add('This cannot happen! CreateGUID guarantees that ' +
'2 randomly generated GUIDs cannot be equal!');
end;
HTH
I'm not exactly sure what you're asking? It might help if you clarified why you need the "unique computer id".
Option 1
The bit:
"I was planning to store it in the registry and check it when the app starts, and if it changed update the registry."
gives me the impression you're trying to detect a different (newer) version of the app and/or identify different apps within a suite.
If this is the case, then simply pressing Ctrl+Shift+G
will generate a unique GUID for you and insert it at your current cursor position in code.
You may want to also look at the version information; perhaps auto-increment build numbers?
Option 2
If you're trying to in some way identify unique installations on different computers, take a look at the CreateGUID
function in plainth's answer.
Option 3
You mentioned that you "don't care if the id changes because of a hardware change or OS reinstallation". I'm not sure if this is an important fact like: you're trying to detect hardware changes? After all, you did say you don't care; but then why mention this at all?
Option 4
Something else I haven't considered?
You may try using an UUID algorithm for the following reasons:
- It independs hardware
- It`s really random
- It is platform independent.
But watch out: to achieve hardware independence, you must choose some algorithm which does not use the MAC address of the machine. Microsoft`s GUID uses it (this was how they discovered who wrote that LOVE YOU virus, remember it?)