My 1988 copy of *The AWK Programming Language* was in the mail today. It's a good book! If you're into UNIX in general, and the history of UNIX and retro computing in particular, this is a recommendation!
After the usual tutorial introduction it does not only go into every detail of awk, but it shows how to build a relational database, implement "little languages", such as a model assembler, offers various implementations of desktop calculators and even a version of *make* written in AWK. #unix