The graphical interface can be disabled if the ``-x'' option is given in the command line arguments. Under these circumstances the program setup can only be entered via configuration file (see section 2.3). This mode can be useful for batch execution or when an X-window terminal is not available.
Note that even in text mode the program needs to link the ``libX11.so.6'' dynamic library. If you don't want to use the X-window environment nor library at all you must edit the ``Makefile'' file and recompile the source code.