7. Patterns, Actions, and Variables

As you have already seen, each awk statement consists of a pattern with an associated action. This chapter describes how you build patterns and actions, what kinds of things you can do within actions, and awk's built-in variables.

The pattern-action rules and the statements available for use within actions form the core of awk programming. In a sense, everything covered up to here has been the foundation that programs are built on top of. Now it's time to start building something useful.

7.1 Pattern Elements		What goes into a pattern.
7.2 Using Shell Variables in Programs		How to use shell variables with awk.
7.3 Actions		What goes into an action.
7.4 Control Statements in Actions		Describes the various control statements in detail.
7.5 Built-in Variables		Summarizes the built-in variables.