Transform columns from S3's Server Access Log Format into the more useful Combined Logfile Format. In the Unix world, we could easily pull this off with sed. In this case though, we might actually want to process each line by hand, since we still need to...

5. Concatenate and Sort records into a single file. There are lots of ways to accomplish this, and they're all a bit painful and slow. When I did this myself, I wrote a little combined transformer/sorter that spun through all the files at once and accomplished steps 4 and 5 in a single pass. Still, there's lots of room here for speed tweaking, so I'll leave this one as an exercise for the reader.