## Copyright (C) 2003-2012 John W. Eaton
##
## 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} {[@var{dir}, @var{name}, @var{ext}, @var{ver}] =} fileparts (@var{filename})
## Return the directory, name, extension, and version components of
## @var{filename}.
## @seealso{fullfile}
## @end deftypefn

function [directory, name, extension, version] = fileparts (filename)

  if (nargin == 1)
    if (ischar (filename))
      ds = strchr (filename, filesep ("all"), 1, "last");
      if (isempty (ds))
        ds = 0;
      endif
      es = rindex (filename, ".");
      ## These can be the same if they are both 0 (no dir or ext).
      if (es <= ds)
        es = length (filename)+1;
      endif
      if (ds == 0)
        directory = "";
      elseif (ds == 1)
        directory = filename(1);
      else
        directory = filename(1:ds-1);
      endif
      name = filename(ds+1:es-1);
      if (es > 0 && es <= length (filename))
        extension = filename(es:end);
      else
        extension = "";
      endif
      version = "";
    else
      error ("fileparts: expecting FILENAME argument to be a string");
    endif
  else
    print_usage ();
  endif

endfunction


%!test
%! [d, n, e] = fileparts ("file");
%! assert (strcmp (d, "") && strcmp (n, "file") && strcmp (e, ""));

%!test
%! [d, n, e] = fileparts ("file.ext");
%! assert (strcmp (d, "") && strcmp (n, "file") && strcmp (e, ".ext"));

%!test
%! [d, n, e] = fileparts ("/file.ext");
%! assert (strcmp (d, "/") && strcmp (n, "file") && strcmp (e, ".ext"));

%!test
%! [d, n, e] = fileparts ("dir/file.ext");
%! assert (strcmp (d, "dir") && strcmp (n, "file") && strcmp (e, ".ext"));

%!test
%! [d, n, e] = fileparts ("./file.ext");
%! assert (strcmp (d, ".") && strcmp (n, "file") && strcmp (e, ".ext"));

%!test
%! [d, n, e] = fileparts ("d1/d2/file.ext");
%! assert (strcmp (d, "d1/d2") && strcmp (n, "file") && strcmp (e, ".ext"));

%!test
%! [d, n, e] = fileparts ("/d1/d2/file.ext");
%! assert (strcmp (d, "/d1/d2") && strcmp (n, "file") && strcmp (e, ".ext"));

%!test
%! [d, n, e] = fileparts ("/.ext");
%! assert (strcmp (d, "/") && strcmp (n, char (zeros (1, 0))) && strcmp (e, ".ext"));

%!test
%! [d, n, e] = fileparts (".ext");
%! assert (strcmp (d, "") && strcmp (n, char (zeros (1, 0))) && strcmp (e, ".ext"));