Find out all currenct connections in for Oracle SQL

Select from v$session and v$process

select

substr(a.spid,1,9) pid,

substr(b.sid,1,5) sid,

substr(b.serial#,1,5) ser#,

substr(b.machine,1,6) machine,

substr(b.username,1,10) username,

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;