CREATE OR REPLACE FUNCTION f_os_user RETURN varchar2 IS

/******************************************************
*Heiko Hommes
*Rückgabe des angemeldetetn OS USER
*
*********************************************************/
v_os_user varchar2(50);
BEGIN
   select sys_context('USERENV', 'OS_USER') into v_os_user from dual;
   return v_os_user;
END f_os_user;