//com = g_strdup_printf ("dot %s -Tpng -o %s.png; eog %s.png", fn, fn, fn);
com = g_strdup_printf ("dot %s -Tps -o %s.ps;gv %s.ps", fn, fn, fn);
_i = system (com);
g_free (com);
//com = g_strdup_printf ("dot %s -Tpng -o %s.png; eog %s.png", fn, fn, fn);
com = g_strdup_printf ("dot %s -Tps -o %s.ps;gv %s.ps", fn, fn, fn);
_i = system (com);
g_free (com);