Mimick tac with python.

[Christian Gollwitzer]

Am 30.01.16 um 05:58 schrieb Random832:
> On Fri, Jan 29, 2016, at 23:46, Hongyi Zhao wrote:
>> awk '{a[NR]=$0} END {while (NR) print a[NR--]}' input_file
>> perl -e 'print reverse<>' input_file
>
> Well, both of those read the whole file into memory - tac is sometimes
> smarter than that, but that makes for a more complex program.

Now I'm curious. How is it possible to output the first line as last 
again if not by remembering it from the every beginning? How could tac 
be implemented other than sucking up everything into memory?

	Christian