Gen DDL of tablespaces without using dbms_metadata.get_ddl

I don't want to use dbms_metadata.get_ddl as it doesn't give me option to change the original config

I am writing the following but don't know how to loop all tablespaces, and idea ?

select * from
(
(select 'Create tablespace ' || tablespace_name || ' ' || LOGGING ||' datafile ' from dba_tablespaces where tablespace_name='USERS')
union all
(select '''' || file_name || ''' size 100M AUTOEXTEND ' || DECODE(AUTOEXTENSIBLE,'YES','ON','NO','OFF') || ' NEXT 1M MAXSIZE ' || MAXBYTES/1024/1024 || 'M' from dba_data_files where tablespace_name='USERS')
)
union all
(select 'EXTENT MANAGEMENT ' || EXTENT_MANAGEMENT || ' SEGMENT SPACE MANAGEMENT '|| SEGMENT_SPACE_MANAGEMENT || ' ' || ALLOCATION_TYPE || ';' from dba_tablespaces where tablespace_name='USERS')