By now, you know enough about Perl to write many useful programs. You've discovered that Perl is powerful enough to enable you to perform complicated tasks, and simple enough to accomplish them quickly.
The previuos chapters covers most of the features of the language not covered in the first chapters and describes some of the many library functions supplied with Perl. Here's a summary of what you'll learn.
Chapter 8, "More Control Structures," discusses the control flow statements not previously covered.
Chapter 9, "Using Subroutines," shows how you can break down your program into more manageable chunks.
Chapter 10, "Associative Arrays," introduces one of the most powerful and useful constructs in Perl, associative arrays, and it shows how you can use these arrays to simulate other data structures.
Chapter 11, "Formatting Your Output," shows how you can use Perl to produce tidy reports.
Chapter 12, "Working with the File System," shows how you can interact with your system's directory structure.
Chapter 13, "Process, String, and Mathematical Functions," describes the library functions that interact with processes running on the system, operate on text strings, and perform mathematical operations.
Chapter 14, "Scalar-Conversion and List-Manipulation Functions," describes the library functions that convert values from one form to another and work with lists and array variables.
By the end of the next couple of chapters, you'll have mastered almost all of the features of Perl and you'll have learned about many of the library functions supplied with the language.