--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2009-05-26  John W. Eaton  <jwe@octave.org>
+
+	* src/dirfns.cc (Fpathsep): Allow path separator to be set.
+
 2009-03-17  Thomas Weber  <thomas.weber.mail at gmail.com>
 
         * configure.in: fix typo with regards to termios.h

--- a/liboctave/pathsearch.h
+++ b/liboctave/pathsearch.h
@@ -88,6 +88,11 @@
     return static_members::path_sep_char ();
   }
 
+  static void path_sep_char (char c)
+  {
+    static_members::path_sep_char (c);
+  }
+
   static std::string path_sep_str (void)
   {
     return static_members::path_sep_str ();
@@ -131,6 +136,15 @@
       return instance_ok () ? instance->xpath_sep_char : 0;
     }
 
+    static void path_sep_char (char c)
+    {
+      if (instance_ok ())
+	{
+	  instance->xpath_sep_char = c;
+	  instance->xpath_sep_str = std::string (1, c);
+	}
+    }
+
     static std::string path_sep_str (void)
     {
       return instance_ok () ? instance->xpath_sep_str : std::string ();

--- a/src/dirfns.cc
+++ b/src/dirfns.cc
@@ -671,19 +671,47 @@
   return retval;
 }
 
-DEFUN (pathsep, args, ,
+DEFUN (pathsep, args, nargout,
     "-*- texinfo -*-\n\
-@deftypefn {Built-in Function} {} pathsep ()\n\
-Return the system-dependent character used to separate directories in\n\
+@deftypefn {Built-in Function} {@var{val} =} pathsep ()\n\
+@deftypefn {Built-in Function} {@var{old_val} =} pathsep (@var{new_val})\n\
+Query or set the character used to separate directories in\n\
 a path.\n\
 @seealso{filesep, dir, ls}\n\
 @end deftypefn")
 {
   octave_value retval;
 
-  if (args.length () == 0)
+  int nargin = args.length ();
+
+  if (nargout > 0 || nargin == 0)
     retval = dir_path::path_sep_str ();
-  else
+
+  if (nargin == 1)
+    {
+      std::string sval = args(0).string_value ();
+
+      if (! error_state)
+	{
+	  switch (sval.length ())
+	    {
+	    case 1:
+	      dir_path::path_sep_char (sval[0]);
+	      break;
+
+	    case 0:
+	      dir_path::path_sep_char ('\0');
+	      break;
+
+	    default:
+	      error ("pathsep: argument must be a single character");
+	      break;
+	    }
+	}
+      else
+	error ("pathsep: argument must be a single character");
+    }
+  else if (nargin > 1)
     print_usage ();
 
   return retval;