/* rexx - compare 2 files in one cycle */
do forever
   "execio 1 diskr FILE1"
   if rc > 0 then leave
   parse pull file1
   adid= substr(file1,1,9)
   adws= substr(file1,11,4)
   adop= substr(file1,16,3)
   index.adid.adws.adop=1
 end
do forever
   "execio 1 diskr FILE2"
   if rc > 0 then leave
   parse pull file2
   xdid= substr(file2,21,9)
   xdws= substr(file2,41,4)
   xdop= substr(file2,36,3)
   if index.xdid.xdws.xdop /= 1 then do
     ...
   end
   else do
     ...
   end
 end