rpi chapter 17

They are - you can either assign the list slice to an array (as in the commented lines), or assign it to individual variables declared in array context (as you've done).  Although your commented line appears to pull out the wrong elements from the `stat` list...

You could also have condensed it further to skip the array assignment and potentially save a smidge more memory:  `printf "%20s%20d%20d\n", $_, ( stat $_ )[8,9];`