Generate multiple awr report - oracle database script

SET lines 150
SET pages 500 col BEGIN_INTERVAL_TIME
FOR a30 col END_INTERVAL_TIME
FOR a30
SELECT SNAP_ID,
       BEGIN_INTERVAL_TIME,
       END_INTERVAL_TIME
FROM dba_hist_snapshot
WHERE trunc(BEGIN_INTERVAL_TIME)=trunc(sysdate-&NO)
ORDER BY 1;

CREATE OR REPLACE DIRECTORY awr_reports_dir AS '/tmp/awrreports';

DECLARE -- Adjust before use. l_snap_start NUMBER := 4884; --Specify Initial Snap ID l_snap_end NUMBER := 4892; --Specify End Snap ID l_dir VARCHAR2(50) := 'AWR_REPORTS_DIR';  l_last_snap NUMBER := NULL; l_dbid v$database.dbid%TYPE; l_instance_number v$instance.instance_number%TYPE; l_file UTL_FILE.file_type; l_file_name VARCHAR(50);  BEGIN SELECT dbid INTO l_dbid FROM v$database;  SELECT instance_number INTO l_instance_number FROM v$instance;  FOR cur_snap IN (SELECT snap_id FROM dba_hist_snapshot WHERE instance_number = l_instance_number AND snap_id BETWEEN l_snap_start AND l_snap_end ORDER BY snap_id) LOOP IF l_last_snap IS NOT NULL THEN l_file := UTL_FILE.fopen(l_dir, 'awr_' || l_last_snap || '_' || cur_snap.snap_id || '.html', 'w', 32767);  FOR cur_rep IN (SELECT output FROM TABLE(DBMS_WORKLOAD_REPOSITORY.awr_report_html(l_dbid, l_instance_number, l_last_snap, cur_snap.snap_id))) LOOP UTL_FILE.put_line(l_file, cur_rep.output); END LOOP; UTL_FILE.fclose(l_file); END IF; l_last_snap := cur_snap.snap_id; END LOOP;  EXCEPTION WHEN OTHERS THEN IF UTL_FILE.is_open(l_file) THEN UTL_FILE.fclose(l_file); END IF; RAISE; END; /