--- a/scripts/miscellaneous/untar.m
+++ b/scripts/miscellaneous/untar.m
@@ -15,83 +15,76 @@
 ## Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 
 ## -*- texinfo -*-
-## @deftypefn {Function File} untar (@var{filename})
-## @deftypefnx {Function File} untar (@var{filename}, @var{outputdir})
-## Unpacks the archive @var{filename} using the tar program.
-## The resulting files are placed in the directory @var{outputdir},
-## which defaults to the current directory.
-## The used uncompressing algorithm depends on the extension of
-## @var{filename}. If @var{filename} doesn't have an extension a list
-## of supported extensions is tried.
+## @deftypefn {Function File} untar (@var{tarfile}, @var{dir})
+## Unpack the TAR archive @var{tarfile} to the directory @var{dir}.
+## If @var{dir} is not specified, it defaults to the current directory.
+## @seealso{tar, gzip, gunzip, zip, unzip}
 ## @end deftypefn
 
-## Author: Søren Hauberg <hauberg at gmail dot com>
+## Author: Søren Hauberg <hauberg@gmail.com>
+## Adapted-By: jwe
 
-# XXX: how do we support returning the extracted filenames?
-# If strip was sane, we could simply return strip(output),
-# which is what is currently done. However this is not
-# Matlab compatible, since Matlab returns a cellstr and
-# this implementation returns a matrix.
-function out = untar(filename, outputdir)
-    if (nargin == 0)
-        print_usage("untar");
-    elseif (nargin == 1)
-        outputdir = ".";
-    endif
-    
-    ## If filename is a sq_string, convert it to a string
-    filename = sprintf("%s", filename);
-    
-    ## XXX: what about "" (i.e. no extension) ?
-    supported_extensions = {"tar", "tar.gz", "tgz", "tar.bz", "tar.bz2", "tbz", "tbz2"};
+function files = untar (tarfile, dir)
 
-    ## Make sure filename and outputdir are strings
-    if (!ischar(filename) || !ischar(outputdir))
-        error("All arguments must be strings.\n");
-    endif
-    
-    ## Get extension of filename
-    dots = find(filename == ".");
-    for dot = dots
-        curext = filename(dot+1:end);
-        if (any(strcmp(curext, supported_extensions)))
-            ext = curext;
-            break;
-        endif
-    endfor
+  if (nargin == 1 || nargin == 2)
 
-    ## If no extension was found, iterate over possible extensions
-    ## and try to append them to filename
-    if (!exist("ext", "var"))
-        for i = 1:length(supported_extensions)
-            curext = supported_extensions{i};
-            if (exist([filename "." curext], "file"))
-                filename = [filename "." curext];
-                ext = curext;
-                break;
-            endif
-        endfor
+    if (nargin == 1)
+      dir = ".";
     endif
 
-    ## If no usable extension was found give an error    
-    if (!exist("ext", "var"))
-        error("No supported extension was found for %s\n", filename);
+    if (ischar (tarfile) && ischar (dir))
+
+      orig_dir = pwd ();
+
+      tarfile = canonicalize_file_name (tarfile);
+
+      s = stat (dir);
+      if (isempty (s))
+	[status, msg] = mkdir (dir);
+	if (! status)
+	  error ("untar: mkdir failed to create %s: %s", dir, msg);
+	endif
+      elseif (! S_ISDIR (s.mode))
+	error ("untar: %s: not a directory", dir);
+      endif
+
+      unwind_protect
+	chdir (dir);
+	[status, output] = system (sprintf ("tar -x -v -f %s", tarfile));
+      unwind_protect_cleanup
+	chdir (orig_dir);
+      end_unwind_protect
+
+      if (status == 0)
+	if (nargout > 0)
+	  fs = filesep ();
+	  if (dir(end) != fs)
+	    dir = strcat (dir, fs);
+	  endif
+	  ## Sadly not reliable if a filename contains a newline
+	  ## character!
+	  if (output(end) == "\n")
+	    output(end) = [];
+	  endif
+	  files = cellstr (split (output, "\n"));
+	  if (! strcmp (dir, "."))
+	    nf = length (files);
+	    for i = 1:nf
+	      files{i} = strcat (dir, files{i});
+	    endfor
+	  endif
+	  files = files';
+	endif
+      else
+	error ("tar: tar exited with status = %s", status);
+      endif
+
+    else
+      error ("untar: expecting arguments to be character strings");
     endif
-    
-    ## Determine which flags to use with tar
-    switch (ext)
-        case {"tar"} flag = "";
-        case {"tar.gz", "tgz"} flag = "z";
-        case {"tar.bz", "tar.bz2", "tbz", "tbz2"} flag = "j";
-    endswitch
 
-    ## Call tar
-    [output, status] = system(["tar -" flag "xvf " filename " -C " outputdir]);
-    if (status != 0)
-        error("tar returned the following error: %s\n", output);
-    endif
-    
-    if (nargout > 0)
-        out = split(output, "\n");
-    endif
+  else
+    print_usage ("untar");
+  endif
+
 endfunction