Patterns and Actions (The GNU Awk User’s Guide)

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 predefined 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.

• Pattern Overview		What goes into a pattern.
• Using Shell Variables		How to use shell variables with `awk`.
• Action Overview		What goes into an action.
• Statements		Describes the various control statements in detail.
• Built-in Variables		Summarizes the predefined variables.
• Pattern Action Summary		Patterns and Actions summary.