How do I see my OS userID from an oracle session

I want to see my OS ID from oracle session.  I am using this script

sys@d11cr20>!cat get_env.sql

set serveroutput on

declare

v_oh varchar2(500);

v_tns varchar2(500);

v_path varchar2(4000);

v_login varchar2(4000);

v_logname varchar2(4000);

begin

dbms_system.get_env('HOME',v_tns);

dbms_system.get_env('LOGIN',v_login);

dbms_system.get_env('LOGNAME',v_logname);

dbms_system.get_env('ORACLE_BASE',v_path);

dbms_output.put_line('HOME: '||v_tns);

dbms_output.put_line('LOGIN: '||v_login);

dbms_output.put_line('LOGNAME: '||v_logname);

dbms_output.put_line('ORACLE_BASE: '||v_path);