Oracle 10g: Displaying All Connected Sessions

---Code---

ttitle "dbname Database|UNIX/Oracle Sessions";

set heading off;
select 'Sessions on database '||substr(name,1,8) from v$database;
set heading on;

select
substr(a.spid,1,9) pid,
substr(b.sid,1,5) sid,
substr(b.serial#,1,5) ser#,
substr(b.machine,1,6) box,
substr(b.username,1,10) username,
-- b.server,
substr(b.osuser,1,8) os_user,
substr(b.program,1,30) program
from v$session b, v$process a
where
b.paddr = a.addr
and type='USER'
order by spid;

ttitle off;

spool off;