Check if a process from the task list is active

uses TlHelp32;


function processExists(exeFileName: string): Boolean;
var
  ContinueLoop: BOOL;
  FSnapshotHandle: THandle;
  FProcessEntry32: TProcessEntry32;
begin
  FSnapshotHandle := CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0);
  FProcessEntry32.dwSize := SizeOf(FProcessEntry32);
  ContinueLoop := Process32First(FSnapshotHandle, FProcessEntry32);
  Result := False;
  while Integer(ContinueLoop) <> 0 do
  begin
    if ((UpperCase(ExtractFileName(FProcessEntry32.szExeFile)) =
      UpperCase(ExeFileName)) or (UpperCase(FProcessEntry32.szExeFile) =
      UpperCase(ExeFileName))) then
    begin
      Result := True;
    end;
    ContinueLoop := Process32Next(FSnapshotHandle, FProcessEntry32);
  end;
  CloseHandle(FSnapshotHandle);
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
  if processExists('notepad.exe') then
    ShowMessage('process is running')
  else
    ShowMessage('process not running');
end;

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