http://metalink.oracle.com/metalink/plsql/ml2_documents.showNOT?p_id=206272.1

Using the new method CREATE DIRECTORY in place of the old way of using UTL_FILE_DIR does not necessarily need code change, even though the first argument to the fopen function is no longer the physical path to the directory object name. The trick is to use a directory name that is named the same as the physical path and surround the name with double quotes. But used in utl_file.fopen, you continue to use single quotes. The practical use of this trick may be preserving existing PL/SQL code to reduce maintenance cost while taking advantage of the new CREATE DIRECTORY feature at the same time (no need to bounce database for a directory change, for instance). But I don't know how long Oracle allows us to use this trick.

This of course works (normal way, as documented):

create directory mytest as 'c:\temp';
grant read on directory mytest to public;
create or replace function f1 return number is
 v_output_file1 utl_file.file_type;
begin
 v_output_file1 := utl_file.fopen('MYTEST', 'NEW.txt', 'a');
 utl_file .put_line(v_output_file1, 'NATURE and Beauty');
 utl_file.fclose_all;
 return 1;
 end;
/
var x number
exec :x := f1


This does NOT work (/ is not allowed as directory name on Windows):

drop directory "/whatever/dontcare";
create directory "/whatever/dontcare" as 'c:\temp';
grant read on directory "/whatever/dontcare" to public;
create or replace function f1 return number is
 v_output_file1 utl_file.file_type;
begin
 v_output_file1 := utl_file.fopen('/whatever/dontcare', 'NEW.txt', 'a');
 utl_file .put_line(v_output_file1, 'NATURE and Beauty');
 utl_file.fclose_all;
 return 1;
 end;
/
var x number

SQL> exec :x := f1
BEGIN :x := f1; END;

*
ERROR at line 1:
ORA-29280: invalid directory path
ORA-06512: at "SYS.UTL_FILE", line 18
ORA-06512: at "SYS.UTL_FILE", line 424
ORA-06512: at "SYS.F1", line 4
ORA-06512: at line 1


But this works:

SQL> conn / as sysdba
Connected.
SQL> select * from v$version;

BANNER
----------------------------------------------------------------
Oracle9i Enterprise Edition Release 9.2.0.1.0 - Production
PL/SQL Release 9.2.0.1.0 - Production
CORE    9.2.0.1.0       Production
TNS for 32-bit Windows: Version 9.2.0.1.0 - Production
NLSRTL Version 9.2.0.1.0 - Production

SQL> create directory "c:\temp" as 'c:\temp';

Directory created.

SQL> grant read on directory "c:\temp" to public;

Grant succeeded.

SQL> create or replace function f1 return number is
  2   v_output_file1 utl_file.file_type;
  3  begin
  4   v_output_file1 := utl_file.fopen('c:\temp', 'NEW.txt', 'a');
  5   utl_file .put_line(v_output_file1, 'NATURE and Beauty');
  6   utl_file.fclose_all;
  7   return 1;
  8   end;
  9  /

Function created.

SQL> var x number
SQL> exec :x := f1

PL/SQL procedure successfully completed.

SQL> host type c:\temp\NEW.txt
NATURE and Beauty

SQL> show parameter utl_file_dir

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
utl_file_dir                         string



And on UNIX, this also works (tested on dbvrfy1.ea.com, Solaris 2.8):

...
Enter user-name: / as sysdba

Connected to:
Oracle9i Enterprise Edition Release 9.2.0.4.0 - Production
With the Partitioning, OLAP and Oracle Data Mining options
JServer Release 9.2.0.3.0 - Production

SQL> set pages 100
SQL> create directory '/tmp' as '/tmp';
create directory '/tmp' as '/tmp'
                 *
ERROR at line 1:
ORA-22929: invalid or missing directory name


SQL> create directory "/tmp" as '/tmp';

Directory created.

SQL> grant read on directory "/tmp" to public;

Grant succeeded.

SQL> create or replace function f1 return number is
  2   v_output_file1 utl_file.file_type;
  3  begin
  4   v_output_file1 := utl_file.fopen('/tmp', 'NEW.txt', 'a');
  5   utl_file .put_line(v_output_file1, 'NATURE and Beauty');
  6   utl_file.fclose_all;
  7   return 1;
  8   end;
  9  /

Function created.

SQL> var x number
SQL> exec :x := f1

PL/SQL procedure successfully completed.

SQL> !
$ cd /tmp
$ more NEW.txt
NATURE and Beauty
/tmp>exit

SQL> select value from v$parameter where name = 'utl_file_dir';

VALUE
---------------------------------------------------------------
/eacom/hyb006/oradump/edump