Extract ddl with "dbms metadata.get ddl"

set pagesize 0
set linesize 30000
set long 500000
set longchunksize 500000
set trimspool on
set feed off

select 'select dbms_metadata.get_ddl(INDEX,||object_name||,&&schema)||chr(10)||/ from dual;'
from dba_objects where owner = UPPER('&&schema')
and object_type = 'INDEX'
and ...
/