Well, if you're confident that file size won't cause a problem with memory consumption, you could do this:

open( IN, "file" );
@lines = <IN>;
close IN;

print reverse @lines;
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On the other hand, if file size and memory constraints are an issue, you'd probably want to go through the file line by line, store the bytes offsets (from "tell()") for each, then do a loop consisting of: seek(); $_=<>; print(); going through the offsets in reverse order.