How to generate awr in a rac instance for every one hour ( snapshot)

How to generate awr in a rac instance for every one hour ( snapshot)

# Jeyaseelan

if [ $# -ne 2 ] ; then
 echo usage : ./awr.sh instance_number date
 echo         ./awr.sh 1 12-JUN-2011
exit
fi
# Directory where this script resides
set -xv
STATSDIR=.
STATSREP=.
INSTANCE_NUMBER=$1
CURR_DATE=$2

AWRREPORT=snap.sql
# -------------------------------------------------->
# ---------- Start of program

rm  $AWRREPORT
echo "Generating reports in $STATSREP ... Pls wait ..."
sqlplus -s /nolog <<!
conn / as sysdba
set serveroutput on size 1000000
set feed off term off trims on linesize 300
 dbms_output.put_line('database connection');
spool $AWRREPORT
declare
    min_snap number;
    next_snap number;
    min_snap_time varchar2(20);
    next_snap_time varchar2(20);
    fileName varchar2(255);
    cursor c1 is select instance_number,snap_id, to_char(startup_time,'ddmm_hh24mi') snap_time from dba_hist_snapshot where instance_number=$INSTANCE_NUMBER and to_char(BEGIN_INTERVAL_TIME,'dd-MON-yyyy') = '$CURR_DATE' order by snap_id;
    c1_rec c1%rowtype;
begin
    for c1_rec in c1 loop
        select min(snap_id) into next_snap from dba_hist_snapshot  where snap_id > c1_rec.snap_id and instance_number=$INSTANCE_NUMBER;
        select to_char(end_interval_time,'ddmonyyy_hh24mi') into next_snap_time from dba_hist_snapshot where instance_number=$INSTANCE_NUMBER and   snap_id = next_snap;
        dbms_output.put_line('define begin_snap='||c1_rec.snap_id);
        dbms_output.put_line('define end_snap='||next_snap);
       fileName := '$STATSREP'||'/'||'$ORACLE_SID'||'_awrrpt'||'_'||c1_rec.instance_number||'_'||c1_rec.snap_id||'_'||next_snap||'.lst';
      dbms_output.put_line('define report_name='||fileName);
        dbms_output.put_line('define report_type='||'text');
        dbms_output.put_line('define num_days='||'3');
        dbms_output.put_line('@$ORACLE_HOME/rdbms/admin/awrrpt');
    end loop;
exception
    when no_data_found then
        -- Only last snap remaining
        null;
    when others then
        dbms_output.put_line(sqlerrm);
end;
/
spool off
!
echo test
sqlplus -s /nolog  <<!
 conn / as sysdba
        @$AWRREPORT
!