Test DLL Object Pascal

program test_call_lib;
type
   TLibReport = (LibOK, LibUnkown, LibNoMethod);

function CallProc(const idLib, idProc : string) : TLibReport;
const
   LIBEXT = {$ifdef windows} '.dll' {$else} '.so' {$endif}
type
   TProc = procedure; stdcall;
var
   dll  : Cardinal;
   proc : TProc;

begin
   CallProc := LibOK;
   dll := LoadLibrary(idLib + LIBEXT);
   if dll <> 0 then begin
      @proc := GetProcAddress(dll, idProc);
      if Assigned(proc) then
         proc
      else
         CallProc := LibNoMethod;
      FreeLibrary(dll);
   end else
      CallProc := LibUnknown;
end;


begin
   case CallProc('libexample', 'foo') of
      LibOK       : writeln('[Done]');
      LibUnknown  : writeln('Library not found');
      LibNoMethod : writeln('Library doesn''t have the method.');
   end;
   {$ifdef windows} readln; {$endif}  // pause for Windows
end.