How to get the version of the files?

For Packages:

   SELECT text
   FROM   all_source
   WHERE  name = Upper('&package_name')
   AND line = 2;

   SELECT af.subdir, 
          af.filename, 
          afv.version 
   FROM   ad_files af, 
          ad_file_versions afv 
   WHERE  af.file_id = afv.file_id 
   AND af.filename = '&file_name';