Show a list of currently running oracle sessions using a shell script

oracle_sessions.sh

#!/bin/ksh
#########################################################################
# Script Name      : oracle_sessions.sh
# Notes            : List all ACTIVE database sessions
#########################################################################
sqlplus -s <<- !
    / AS SYSDBA

    SET LINES 160
    SET PAGES 1000
    SET LINESIZE 200

    COL inst#    FORMAT 9
    COL username     FORMAT A14
    COL osuser     FORMAT A09
    COL fg_pid     FORMAT A9
    COL o_pid     FORMAT A9
    COL sid     FORMAT 9999
    COL serial#     FORMAT 99999
    COL program    FORMAT A10 TRUNC
    COL machine    FORMAT A10 TRUNC
    COL login    FORMAT A18
    COL service_name FORMAT A9
    COL last_call    FORMAT A10
    COL wait    FORMAT A27 TRUNC
--    COL duration    FORMAT A10
    COL wtime    FORMAT A10
    COL wsecs    FORMAT 99999

    SELECT    s.inst_id inst#
        , s.sid
        , s.serial#
        , s.username
--        , s.status
        , s.osuser
        , s.process fg_pid
        , p.spid    o_pid
        , LTRIM(DECODE( s.osuser,
                NULL , SUBSTR(p.program,
                          INSTR(p.program, '(') + 1,
                                              LENGTH(p.program) - INSTR(p.program,'(') - 1),
                s.program)) program
        , s.machine
        , s.service_name
--        , TO_CHAR(s.logon_time, 'DD-MON-YY HH24:MI:SS') login
        , LPAD( DECODE( TRUNC(s.last_call_et/3600),
                0, NULL,
                LTRIM( TO_CHAR(TRUNC(s.last_call_et/3600), '90')) || 'h ') ||
                           DECODE( TRUNC(s.last_call_et/60),
                           0, NULL,
                           LPAD(LTRIM(TO_CHAR(MOD(TRUNC(s.last_call_et/60), 60), '90')), 2) ||
                    'm ') ||
                LPAD(TO_CHAR(MOD(s.last_call_et, 60)), 2),
              10) last_call
        , sql_hash_value                                hash_value
        , DECODE(w.state,'WAITING',w.EVENT,NULL)                    wait
        , LPAD( DECODE( TRUNC(w.seconds_in_wait/3600),
                    0, NULL,
                        LTRIM( TO_CHAR(TRUNC(w.SECONDS_IN_WAIT/3600), '90')) || 'h ') ||
                       DECODE( TRUNC(w.SECONDS_IN_WAIT/60),
                               0, NULL,
                           LPAD(LTRIM(TO_CHAR(MOD(TRUNC(w.seconds_in_wait/60), 60), '90')), 2) ||
                       'm ') ||
                LPAD(TO_CHAR(MOD(w.seconds_in_wait, 60)), 2),
              10) wtime
    FROM       gv\$session s
        , gv\$process p
        , gv\$session_wait w
    WHERE     p.addr    = s.paddr
    AND      s.inst_id = p.inst_id
    AND      s.inst_id = w.inst_id(+)
    AND      s.sid     = w.sid(+)
    AND      s.status NOT IN ('INACTIVE')
    -- Hide parallel slaves that are are waiting for the parent co-ordinator process
        -- Slave will show as ACTIVE sessions, but are actually idle waiting for the parent
    --  process
    AND      w.event NOT IN ('PX Deq: Execution Msg','PX Deq Credit: send blkd')
    AND      s.username IS NOT NULL
    ORDER BY  s.last_call_et DESC
        , s.osuser
        , s.username
        , s.machine
        , s.program
        , s.logon_time;
!

exit $?