dbms_metadata.get_ddl table

-- 4000 characters max
SELECT dbms_metadata.get_ddl('PROCOBJ', 'job_name', 'owner') FROM DUAL;
SELECT dbms_metadata.get_ddl('PROCOBJ', 'program_name', 'owner') FROM DUAL;
SELECT dbms_metadata.get_ddl('TABLE', 'table_name', 'owner') FROM DUAL;
SELECT dbms_metadata.get_ddl('VIEW', 'view_name', 'owner') FROM DUAL;

SELECT dbms_metadata.get_ddl('PACKAGE', 'pkg_name', 'owner') FROM DUAL; 
SELECT dbms_metadata.get_ddl('PROCEDURE', 'proc_name', 'owner') FROM DUAL; 

SELECT dbms_metadata.get_ddl('INDEX', 'index_name', 'owner') FROM DUAL;
SELECT dbms_metadata.get_ddl('TYPE', 'type_name', 'owner') FROM DUAL;