--- /dev/null
+## Copyright (C) 2007-2012 Thomas Treichl
+##
+## This file is part of Octave.
+##
+## Octave is free software; you can redistribute it and/or modify it
+## under the terms of the GNU General Public License as published by
+## the Free Software Foundation; either version 3 of the License, or (at
+## your option) any later version.
+##
+## Octave is distributed in the hope that it will be useful, but
+## WITHOUT ANY WARRANTY; without even the implied warranty of
+## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+## General Public License for more details.
+##
+## You should have received a copy of the GNU General Public License
+## along with Octave; see the file COPYING. If not, see
+## <http://www.gnu.org/licenses/>.
+
+## -*- texinfo -*-
+## @deftypefn {Function File} {} ismac ()
+## Return true if Octave is running on a Mac OS X system and false otherwise.
+## @seealso{isunix, ispc}
+## @end deftypefn
+
+function retval = ismac ()
+
+ if (nargin == 0)
+ retval = octave_config_info ("mac");
+ else
+ print_usage ();
+ endif
+
+endfunction
+
+%!error ismac (1);
+%!assert (islogical (ismac ()));