Re: untar.m on Solaris with non-GNU tar

[John W. Eaton]

On 20-Oct-2006, Bill Denney wrote:

| function files = bunzip2 (varargin)
| 
|   if ! (nargin == 1 || nargin == 2)
|     print_usage ();
|   endif
| 
|   args = varargin;
|   if (nargin < 2)
|     args{2} = ".";
|   endif
|   f = unpack (args{:}, "bunzip2");
|   if nargout > 0
|     files = f;
|   endif
| 
| endfunction

You don't really need varargin for a function like this.  It might be
clearer to write

  function filelist = bunzip2 (files, outputdir)
    if (nargin == 1 || nargin == 2)
      if (nargin == 1)
        outputdir = ".";
      endif
      tmp = unpack (files, outputdir, "bunzip2");
      if (nargout > 0)
        filelist = tmp;
      endif
    else
      print_usage ();
    endif
  endfunction

Also, it looks like we are always asking unpack to get and return the
file list, even if it is not requested.  Should we maybe make it so
that step is avoided if we don't want it (omit the -v options in the
commands used by unpack and the output parsing if nargout is zero)?
Also, we could use mfilename to get the last arg for unpack.  Then all
these functions could be identical except for the function names.

  function varargout = bunzip2 (files, outputdir)
    if (nargin == 1 || nargin == 2)
      if (nargin == 1)
        outputdir = ".";
      endif
      varargout = cell (1, nargout);
      [varargout{:}] = unpack (files, outputdir, mfilename ());
    else
      print_usage ();
    endif
  endfunction

Hmm, don't see a way to push any of this duplication into the unpack
function given its current definition, but if print_usage accepted an
argument, then I suppose we could write

  function varargout = bunzip2 (varargin)
    varargout = cell (1, nargout);
    [varargout{:}] = __unarchive_common__ (mfilename (), varargin{:})
  endfunction

  function varargout = gunzip (varargin)
    varargout = cell (1, nargout);
    [varargout{:}] = __unarchive_common__ (mfilename (), varargin{:})
  endfunction

  function varargout = untar (varargin)
    varargout = cell (1, nargout);
    [varargout{:}] = __unarchive_common__ (mfilename (), varargin{:})
  endfunction

  function varargout = unzip (varargin)
    varargout = cell (1, nargout);
    [varargout{:}] = __unarchive_common__ (mfilename (), varargin{:})
  endfunction

  function varargout = __unarchive_common__ (fcn_name, files, outputdir)
    if (nargin == 2 || nargin == 3)
      if (nargin == 2)
        outputdir = ".";
      endif
      varargout = cell (1, nargout);
      [varargout{:}] = unpack (files, outputdir, fcn_name);
    else
      print_usage (fcn_name);
    endif
  endfunction

OTOH, maybe that is going too far.

jwe