Oodles of really useful real world tips & tricks on this guys blog and book. Ashamed to say even as an AWK fan since 90's I did not know about the bash cmd 'nl' for line numbers!<p>Anybody into data science should have a look at this material - I myself have resorted to using sqlite based tools (like sqlnotebook) to get around Excel's limitations in working directly with large data sets. But plain text storage, with a good toolset, is arguably the best approach for vast amounts of textual data.