What this book covers
Chapter 1, Getting Started with AWK Programming, introduces AWK's essentials. In this chapter, you will learn how to set up an AWK environment on a Linux machine. You will run AWK programs in different ways with basic examples. This chapters lays the foundation for other chapters.
Chapter 2, Working with Regular Expressions, introduces regular expressions and explains how they are handled with AWK. You will get to know regular expressions with suitable examples.
Chapter 3, AWK Variables and Constants, focuses on the usage of AWK variables. You will understand how to use built-in and user-defined variables while writing AWK programs and command lines. You will also learn how string and numeric constants can be used to process different fields in data files.
Chapter 4, Working with Arrays in AWK, focuses on associative arrays in AWK. You will understand various features of associative arrays, such as these: indexes do not need to be in order, one can use either a string or a number as an array index, and array size can expand/shrink at runtime and is not statically defined.
Chapter 5, Printing Output in AWK, focuses on the print and printf functions and how they can be used efficiently to produce formatted reports. You will also learn how to use redirections in an AWK program.
Chapter 6, AWK Expressions, describes the expressions that build the core logic of a program in any programming language. The reader will learn how to create and use different types of expression in AWK language.
Chapter 7, AWK Control Flow Statements, covers the usage of different conditional statements to control the flow of AWK programs, with examples.
Chapter 8, AWK Functions, covers the different types of built-in functions available in AWK. In addition, you will learn the usage of user-defined functions to perform repetitive tasks in AWK.
Chapter 9, GNU's Implementation of AWK – GAWK (GNU AWK), covers the advanced features of GNU AWK, such as network communication, debugging, and inter-process communication in GAWK. These are not present in AWK.
Chapter 10, Practical Implementation of AWK, illustrates various use cases of text processing. You will learn how a system administrator can use the AWK command line and scripts to automate repetitive tasks. Programmers and data scientists dealing with raw data in text files will learn how to clean raw data and produce formatted reports.