Au contraire, it seems to, indeed, reverse the order of the lines:

$ perl rev.pl
Enter some lines, then press Ctrl-D:
test
123
done
[download]

Output:

done
123
test
[download]

Perhaps you are interpreting the meaning of "reverse" differently. What, exactly, are you expecting for output?

(By the way, it is good practice to use warnings; use strict; in your perl programs. Doing so will save you time in the long run by catching silly mistakes while improving your coding habits.)