Thanks, I was interested in an Awk learning resource, and this looks like exactly what I would want.
The awk chapters in Bentley's _Programming Pearls_ and _More Programming Pearls_ and Peteris Krumins's Awk One-Liners series (http://www.catonmat.net/blog/awk-one-liners-explained-part-o...) are worth a read, as is the source for awk. (nawk, at least - haven't looked at gawk).