--- a/src/utils.cc	Sat Sep 03 19:41:47 2011 -0400
+++ b/src/utils.cc	Sun Sep 04 01:19:09 2011 -0400
@@ -114,6 +114,17 @@
   return retval;
 }
 
+/*
+%!error isvarname ();
+%!error isvarname ("foo", "bar");
+
+%!assert (isvarname ("foo"), true);
+%!assert (isvarname ("_foo"), true);
+%!assert (isvarname ("_1"), true);
+%!assert (isvarname ("1foo"), false);
+%!assert (isvarname (""), false);
+*/
+
 // Return TRUE if F and G are both names for the same file.
 
 bool
@@ -325,6 +336,24 @@
   return retval;
 }
 
+/*
+%!error file_in_loadpath ();
+%!error file_in_loadpath ("foo", "bar", 1);
+
+%!test
+%! f = file_in_loadpath ("plot.m");
+%! assert (ischar (f));
+%! assert (! isempty (f));
+
+%!test
+%! f = file_in_loadpath ("$$probably_!!_not_&&_a_!!_file$$");
+%! assert (f, "");
+
+%!test
+%! lst = file_in_loadpath ("$$probably_!!_not_&&_a_!!_file$$", "all");
+%! assert (lst, {});
+*/
+
 DEFUN (file_in_path, args, ,
   "-*- texinfo -*-\n\
 @deftypefn  {Built-in Function} {} file_in_path (@var{path}, @var{file})\n\
@@ -390,6 +419,25 @@
   return retval;
 }
 
+/*
+%!error file_in_path ();
+%!error file_in_path ("foo");
+%!error file_in_path ("foo", "bar", "baz", 1);
+
+%!test
+%! f = file_in_path (path (), "plot.m");
+%! assert (ischar (f));
+%! assert (! isempty (f));
+
+%!test
+%! f = file_in_path (path (), "$$probably_!!_not_&&_a_!!_file$$");
+%! assert (f, "");
+
+%!test
+%! lst = file_in_path (path (), "$$probably_!!_not_&&_a_!!_file$$", "all");
+%! assert (lst, {});
+*/
+
 std::string
 file_in_path (const std::string& name, const std::string& suffix)
 {
@@ -623,6 +671,20 @@
   return retval;
 }
 
+/*
+%!error do_string_escapes ();
+%!error do_string_escapes ("foo", "bar");
+
+%!assert (do_string_escapes ('foo\nbar'), "foo\nbar");
+%!assert (do_string_escapes ("foo\\nbar"), "foo\nbar");
+%!assert (do_string_escapes ("foo\\nbar"), ["foo", char(10), "bar"]);
+
+%!assert (do_string_escapes ('\a\b\f\n\r\t\v'), "\a\b\f\n\r\t\v");
+%!assert (do_string_escapes ("\\a\\b\\f\\n\\r\\t\\v"), "\a\b\f\n\r\t\v");
+%!assert (do_string_escapes ("\\a\\b\\f\\n\\r\\t\\v"),
+%!        char ([7, 8, 12, 10, 13, 9, 11]));
+*/
+
 const char *
 undo_string_escape (char c)
 {
@@ -729,6 +791,20 @@
   return retval;
 }
 
+/*
+%!error undo_string_escapes ();
+%!error undo_string_escapes ("foo", "bar");
+
+%!assert (undo_string_escapes ("foo\nbar"), 'foo\nbar');
+%!assert (undo_string_escapes ("foo\nbar"), "foo\\nbar");
+%!assert (undo_string_escapes (["foo", char(10), "bar"]), "foo\\nbar");
+
+%!assert (undo_string_escapes ("\a\b\f\n\r\t\v"), '\a\b\f\n\r\t\v');
+%!assert (undo_string_escapes ("\a\b\f\n\r\t\v"), "\\a\\b\\f\\n\\r\\t\\v");
+%!assert (undo_string_escapes (char ([7, 8, 12, 10, 13, 9, 11])),
+%!        "\\a\\b\\f\\n\\r\\t\\v");
+*/
+
 DEFUN (is_absolute_filename, args, ,
   "-*- texinfo -*-\n\
 @deftypefn {Built-in Function} {} is_absolute_filename (@var{file})\n\
@@ -747,6 +823,13 @@
   return retval;
 }
 
+/*
+%!error is_absolute_filename ();
+%!error is_absolute_filename ("foo", "bar");
+
+FIXME -- we need system-dependent tests here.
+*/
+
 DEFUN (is_rooted_relative_filename, args, ,
   "-*- texinfo -*-\n\
 @deftypefn {Built-in Function} {} is_rooted_relative_filename (@var{file})\n\
@@ -765,6 +848,13 @@
   return retval;
 }
 
+/*
+%!error is_rooted_relative_filename ();
+%!error is_rooted_relative_filename ("foo", "bar");
+
+FIXME -- we need system-dependent tests here.
+*/
+
 DEFUN (make_absolute_filename, args, ,
   "-*- texinfo -*-\n\
 @deftypefn {Built-in Function} {} make_absolute_filename (@var{file})\n\
@@ -789,6 +879,13 @@
   return retval;
 }
 
+/*
+%!error make_absolute_filename ();
+%!error make_absolute_filename ("foo", "bar");
+
+FIXME -- we need system-dependent tests here.
+*/
+
 DEFUN (find_dir_in_path, args, ,
   "-*- texinfo -*-\n\
 @deftypefn  {Built-in Function} {} find_dir_in_path (@var{dir})\n\
@@ -829,6 +926,13 @@
   return retval;
 }
 
+/*
+%!error find_dir_in_path ();
+%!error find_dir_in_path ("foo", "bar", 1);
+
+FIXME -- need to create tests using current path, pathsep, and dirsep.
+*/
+
 DEFUNX ("errno", Ferrno, args, ,
   "-*- texinfo -*-\n\
 @deftypefn  {Built-in Function} {@var{err} =} errno ()\n\
@@ -873,6 +977,21 @@
   return retval;
 }
 
+/*
+%!error errno ("foo", 1);
+
+%!assert (isnumeric (errno ()));
+
+%!test
+%! lst = errno_list ();
+%! fns = fieldnames (lst);
+%! oldval = errno (fns{1});
+%! assert (isnumeric (oldval));
+%! errno (oldval);
+%! newval = errno ();
+%! assert (oldval, newval);
+*/
+
 DEFUN (errno_list, args, ,
   "-*- texinfo -*-\n\
 @deftypefn {Built-in Function} {} errno_list ()\n\
@@ -889,6 +1008,12 @@
   return retval;
 }
 
+/*
+%!error errno_list ("foo");
+
+%!assert (isstruct (errno_list ()));
+*/
+
 static void
 check_dimensions (octave_idx_type& nr, octave_idx_type& nc, const char *warnfor)
 {
@@ -1352,6 +1477,14 @@
   return retval;
 }
 
+/*
+%!error isindex ();
+
+%!assert (isindex ([1, 2, 3]));
+%!assert (isindex (1:3));
+%!assert (isindex ([1, 2, -3]), false);
+*/
+
 octave_value_list
 do_simple_cellfun (octave_value_list (*fun) (const octave_value_list&, int),
                    const char *fun_name, const octave_value_list& args,