BTW, you can't read a file backwards, at least not on any architectures I have seen. File::ReadBackwards cheats by seeking to within n bytes of EOF, then caching a chunk of data by reading forwards. It only appears to be reading in reverse.
That is correct; by default it grabs 8kb chunks, starting at the end. The implementation is quite efficient, however, and the method used to achieve the appearance of reading backwards is fairly transparent to the user.