"As a technical book reviewer, I enjoy getting books on
topics that aren't overpublished. For instance, if I never see
another book on basic networking or HTML, that will be fine by me.
On the other hand, awk is one of those topics that is probably
underpublished, so I was happy to see Effective awk Programming
show up.
There are a few flavors of awk floating around. This book is
primarily about the GNU implementation, gawk. Happily, for anyone
who learned awk prior to the GNU version, Appendix A gives a
detailed look at how awk has changed over the years, including
features of gawk that aren't in the POSIX specs. (If you write a
POSIX-compliant awk program, it should work with gawk of course,
but not necessarily the other way around.)
Not to let the cat out of the bag too early (just an expression,
mind you -- I don't need PETA knocking at my door...), but I really
like this book. It's what you need to have on hand when working
with awk."