ORACLE - To check list of inactive users or inactive sessions

In many cases you need to check the list of inactive users or inactive sessions in your database. 

The script below produces the list of inactive users and inactive sessions. Run the script using sysdba 

set heading on feedback on pages 100 lines 140

column userinfo heading "ORACLE/OS User" format a19
column machine heading "Client Machine" format a20
column terminal heading "Terminal" format a10
column process heading "Parent|Process ID" format a10
column spid heading "Shadow|Process ID" format a10
column seq# heading "Wait|Sequence" format 99999990
select s.username||' '||s.osuser userinfo,s.machine, s.terminal, s.sid, s.serial#,
p.spid,
s.process , w.seq#
from v$session s, v$process p
,v$session_wait w
where p.addr = s.paddr
and s.sid = w.sid
and w.event = 'SQL*Net message from client'
and s.status = 'INACTIVE'
order by s.osuser, s.machine
/