Techniques for using Perl to recognize, parse, transform, and filter data.
Need to get every headline from an RSS feed? Or report the three users with the most processes running, as listed by `ps`? Or extract the first paragraph from each of a thousand HTML files? Or make a .tsv file based on all the "From:" and "Subject:" lines in your mailbox file? If those sorts of tasks sound familiar to you, then this is the book you've been looking for. It has working code for doing these sorts of things, involving lots of different common kinds of formats.
By tech book standards, this book is short (300 pages), but it's clear and direct and to the point -- no bloat here. Every page tells you something you need to know, with useful examples for every idea that it explains.
As I said, it may be good for data-processing beginners, but Perl experts will hardly find lot's of new information in it.
P.S. I trust him and therefore follow his advices in every script I start to think of ( especially the one about "UNIX filter model" ).