Introduction to Unix and Shell Programming

9

AWK

Chapter Objectives

• The awk’s syntax with its selection criteria and action components
• Structure of an awk script
• The awk’s operational mechanism
• Types of awk variables, fields and records
• Addressing—context and line addressing
• Patterns and operators
• Decision and loop-control structures
• Functions in awk—predefined and user-defined functions
• Developing and executing an awk script
• Working with associative arrays

awk is a filter program that was originally developed in 1977 by Aho, Weinberger and Kernighan as a pattern-scanning language. The name awk is derived from the first letters of its developer’s surnames. It is a programming language with C-like control structures, functions and variables. It was designed to work with structured ...