This book shows you how to process data productively with Perl. It discusses general munging techniques and how to think about data munging problems. You will learn how to decouple the various stages of munging programs, how to design data structures, how to emulate the Unix filter model, etc. If you need to work with complex data formats it will teach you how to do that and also how to build your own tools to process these formats. The book includes detailed techniques for processing HTML and XML. And, it shows you how to build your own parsers to process data of arbitrary complexity.