Please review it. The discussion about the function die on p.109-111 is very instructive. Chapter 7 clovers the perl version of regular expressions. That should be quite new for most of you. That's why we will spend a week and a half covering that chapter.
Regular expressions are quite hard to explain.
There are quite a few introductory tutorials on this topic, but none of them is really easy because the topic is hard. Instead of trying to write another tutorial of my own, I will direct you to a few existing ones and go over some examples. They contain plenty of examples. Perl Regular Expression Tutorial by Carl Franklin and Gary Wisniewski. Regular Expression Tutorial from Exploring Perl.