((c-mode . ((indent-tabs-mode . nil)
            (fill-column . 100)
            (c-file-style . "gnu")))
 (c++-mode . ((indent-tabs-mode . nil)
              (fill-column . 100)
              (c-file-style . "gnu")))
 (makefile-mode . ((indent-tabs-mode . t)))
 (octave-mode . ((indent-tabs-mode . nil)
                 (octave-block-offset . 4))))