This book is meant for SAS programmers of virtually all skill levels. However, it is expected that you
have at least a basic knowledge of the SAS language, including the DATA step, and how to use SAS
PROCs.
      This book provides all the tools you need to learn how to harness the power of regular expressions
within the SAS programming language. The information provided lays the foundation for fairly
advanced applications, which are discussed briefly as motivating examples later in this chapter. They are
not presented to intimidate or overwhelm, but instead to encourage you to work through the coming
pages with the anticipation of being able to rapidly implement what you are learning.
      This book covers all PRX functions and call routines.