Each app process has a unique process ID. Alternative if you want uniqueness also across VMs on same machine and across machines in general you could create new GUID value each time an app starts.

I don't remember the WIN API call to get process ID - but I expect you can find it between free code samples at TopWiz Programming.

I have C# assembly that calls the get new GUID. Many databases also have a GUID generator function. I'm sure WIN API also has a CreateNewGuid( ) function. I can post my C# code if relevant.

HTH /Michael

Update:
   The GetProcessID API requires a HANDLE, which is fine except that my problem is that the HANDLE I get from the PB function HANDLE and from the FindWindowA API is always zero. That's not going to work for me.  :/

   Heck, if the HANDLE returned a non-zero number that's what I would use.

   Ah well, back to Google....

~~~~~~~~~~~~~~~~~~~~~~~~~~

Thanks, Michael.
Using your tip I found the GetProcessID API:
   https://docs.microsoft.com/en-us/windows/win32/api/processthreadsapi/nf-processthreadsapi-getprocessid

However, if Roland has already done the work in turning this into PowerBuilder code, I would be more than happy to steal, I mean "borrow", his code!  :)

Thanks Again,
Olan

Use the handle of an Application object when passing to GetProcessID:

Application la_app
Long ll_handle

la_app = GetApplication()

ll_handle = Handle(la_app)

Hi Olan,

Handle(GetApplication( ))  -- or in app's Open event -- Handle(this)

That function returns zero when you run your app from PB IDE (it runs subordinate to the PB IDE process).

However, run as separate executable it returns non-zero value!

Unfortunately, it returns the SAME non-zero value at each "Run" no matter how I start the .EXE.

HTH /Michael