There is also a sequel, More Programming Pearls. I have both, and they are good. In one of them, Bentley shows some advanced uses of awk, involving its associ

There is also a sequel, More Programming Pearls. I have both, and they are good. In one of them, Bentley shows some advanced uses of awk, involving its associative arrays, in a short awk program to do some sort of processing, and says that an equivalent C program would be a few hundred lines, IIRC.