The intended audience for this book is people who know Perl basics and who now need to mix those basics into useful programs. Its readers are expected to access its content in both sequential and random modes, according to their immediate needs.

The book begins with a brief foreword by Perl creator Larry Wall and a preface by the authors. The most useful component of these is probably the bibliography.

In chapter 1, “Strings,” the authors observe that “Perl was designed for text manipulation.” Among the useful examples included in this chapter are tab expansion, trailing-blank deletion, soundex matching, and word substitution.

Chapter 2 is about numbers. The issues covered include checking whether a string represents a valid number, comparing and rounding floating-point numbers, and operations on series of integers. There are also suggestions about random-number generation, matrix multiplication, complex numbers, and computation of prime factors.

In chapter 3, “Dates and Times,” I found a solution to a problem that has been annoying me for some time--how to easily generate a simple timezone formula from values of local time and universal time. The exact solution does not appear there, but I discovered enough examples of similar things to make my work easy. This provides a good indication of how the book might be used as a general workplace companion.

Arrays are covered in chapter 4. Among the items immediately useful to me were a mechanism for finding the first item that satisfies a test condition (and skipping subsequent items), a couple of sorting examples, and an implementation of circular lists.

Chapter 5, “Hashes,” includes a brief introduction to the concept of an associative array through a “foods and their colors” example. This is extended to illustrate element insertion and removal, printing, sorting, and inversion. The chapter ends with an example that prints a tree-formatted version of the output from the Unix du command.

The usefulness of the next 12 chapters will depend on your background. There are chapters about pattern matching, file access and locking procedures, library modules, and subroutines. There are also chapters about database access (using the DBM library), user interfaces (via the curses and Tk modules available from Perl archive sites), and sockets. I found the last of these especially interesting; it includes suggestions about identifying who is using a socket connection and about setting up bidirectional sockets.

The last three chapters deal with Internet services, CGI programming, and Web automation. The examples in these chapters include accessing a POP3 server, Internet order processing, and detecting “stale” links. There are also some valuable suggestions concerning security.

The Perl language is now being used in a wide range of systems software, application software, and Web service packages. If your job or your pastime requires you to implement Perl programs in such areas, you could do much worse to than buy this book. It is well written and accurate, although its size may prove a little daunting at first. To properly understand this book, you should also own or have access to Programming Perl [1].