Conventional method 

   'EXECIO * DISKR INPUT DATA A (FINIS'
   N=0
   do queued()
     N=N+1
     parse pull ARRAY.N
   end

or

   N=0
   do forever
     N=N+1
     'EXECIO 1 DISKR INPUT DATA A (VAR ARRAY.'N
     if RC>0 then leave
   end

Suggested method 

   'EXECIO * DISKR INPUT DATA A (STEM ARRAY.'

Note: ARRAY.0 contains the number of array elements used