TODO:

- Function/subroutine to set the preferred directory
- If not set, use c:\tmp, c:\temp or /tmp (not in that order, by the way)
- Use the paradigm of a buffer that gets filled, so the user does not
  directly write to file
- Add a buffer size element to the interface
- Alternative module: memory-mapped files
- Alternatives needed for sleep() - now via DFLIB
