Book Image

Learning AWK Programming

By : Kalkhanda
5 (1)
Book Image

Learning AWK Programming

5 (1)
By: Kalkhanda

Overview of this book

AWK is one of the most primitive and powerful utilities which exists in all Unix and Unix-like distributions. It is used as a command-line utility when performing a basic text-processing operation, and as programming language when dealing with complex text-processing and mining tasks. With this book, you will have the required expertise to practice advanced AWK programming in real-life examples. The book starts off with an introduction to AWK essentials. You will then be introduced to regular expressions, AWK variables and constants, arrays and AWK functions and more. The book then delves deeper into more complex tasks, such as printing formatted output in AWK, control flow statements, GNU's implementation of AWK covering the advanced features of GNU AWK, such as network communication, debugging, and inter-process communication in the GAWK programming language which is not easily possible with AWK. By the end of this book, the reader will have worked on the practical implementation of text processing and pattern matching using AWK to perform routine tasks.
Table of Contents (11 chapters)

Things you don't know about GAWK

All features which are there in AWK are available as default in GAWK. In addition to these features, there are some other features of GAWK that essentially require a mention—they are covered in this section. These are not interrelated, so moving from one feature to another will be like picking up a random tool from a box filled with essential utilities.

Reading non-decimal input

The non-decimal values are like octal numbers or hexadecimal numbers. We cannot use these values to print their decimal equivalent with AWK; GAWK provides the option, --non-decimal-data, to print non-decimal values in the output. Octal values need to be prefixed with 0 and hexadecimal values need to be prefixed...