filename parent "/lvl1/lvl2";

  data files_and_folders;
    length name $50;
    drop rc did i;
    did=dopen("parent");
    if did > 0 then do;
      do i=1 to dnum(did);
        name=dread(did,i);
        output;
        end;
      rc=dclose(did);
      end;
    else put 'Could not open directory';
  run;

This simple, straightforward method should work on multiple platforms (other methods involving OS specific commands and pipes are less flexible).

Output list of files and folders to a dataset

SAS