Table Space Status Script

Script to identify the table space status:
SELECT Substr(ddf.tablespace_name,1,20) "Tablespace Name",
Round(ddf.bytes/1024/1024,2) "Allocated Bytes(MB)",
Round(de.used_bytes/1024/1024,2) "Used Bytes(MB)",
Round(dfs.free_bytes/1024/1024,2) "Free Bytes(MB)",
Round((de.used_bytes/ddf.bytes)*100,2) "% Used Bytes ",
Round((dfs.free_bytes/ddf.bytes)*100,2) "% Free Bytes"
FROM DBA_DATA_FILES DDF,
(SELECT file_id,
Sum(Decode(bytes,NULL,0,bytes)) used_bytes
FROM dba_extents
GROUP by file_id) DE,
(SELECT Max(bytes) free_bytes,
file_id
FROM dba_free_space
GROUP BY file_id) dfs
WHERE de.file_id = ddf.file_id
AND ddf.file_id = dfs.file_id
ORDER BY ddf.tablespace_name;