AWK - Overview

AWK is an interpreted programming language. It is very powerful and specially designed for text processing. Its name is derived from the family names of its authors − Alfred Aho, Peter Weinberger, and Brian Kernighan.

AWK - Environment

This chapter describes how to set up the AWK environment on your GNU/Linux system.

Installation Using Package Manager

AWK - Workflow

To become an expert AWK programmer, you need to know its internals. AWK follows a simple workflow − Read, Execute, and Repeat. The following diagram depicts the workflow of AWK −

AWK - Basic Syntax

AWK is simple to use. We can provide AWK commands either directly from the command line or in the form of a text file containing AWK commands.

AWK - Basic Examples

This chapter describes several useful AWK commands and their appropriate examples. Consider a text file marks.txt to be processed with the following content −

1) Amit     Physics   80
2) Rahul    Maths     90
3) Shyam    Biology   87
4) Kedar    English   85
5) Hari     History   89

AWK - Built-in Variables

AWK provides several built-in variables. They play an important role while writing AWK scripts. This chapter demonstrates the usage of built-in variables.

Standard AWK variables

The standard AWK variables are discussed below.

AWK - Operators

Like other programming languages, AWK also provides a large set of operators. This chapter explains AWK operators with suitable examples.

AWK - Regular Expressions

AWK is very powerful and efficient in handling regular expressions. A number of complex tasks can be solved with simple regular expressions. Any command-line expert knows the power of regular expressions.
This chapter covers standard regular expressions with suitable examples.

AWK - Arrays

AWK has associative arrays and one of the best thing about it is – the indexes need not to be continuous set of number; you can use either string or number as an array index. Also, there is no need to declare the size of an array in advance – arrays can expand/shrink at runtime.
Its syntax is as follows −

AWK - Control Flow

Like other programming languages, AWK provides conditional statements to control the flow of a program. This chapter explains AWK's control statements with suitable examples.

AWK - Loops

This chapter explains AWK's loops with suitable example. Loops are used to execute a set of actions in a repeated manner. The loop execution continues as long as the loop condition is true.

AWK - Built-in Functions

AWK has a number of functions built into it that are always available to the programmer. This chapter describes Arithmetic, String, Time, Bit manipulation, and other miscellaneous functions with suitable examples.

AWK - User Defined Functions

Functions are basic building blocks of a program. AWK allows us to define our own functions. A large program can be divided into functions and each function can be written/tested independently. It provides re-usability of code.
Given below is the general format of a user-defined function −

AWK - Output Redirection

So far, we displayed data on standard output stream. We can also redirect data to a file. A redirection appears after the print or printf statement. Redirections in AWK are written just like redirection in shell commands, except that they are written inside the AWK program. This chapter explains redirection with suitable examples.

AWK - Pretty Printing

So far we have used AWK's print and printf functions to display data on standard output. But printf is much more powerful than what we have seen before. This function is borrowed from the C language and is very helpful while producing formatted output. Below is the syntax of the printf statement −

AWK - Quick Guide

AWK - Overview

AWK is an interpreted programming language. It is very powerful and specially designed for text processing. Its name is derived from the family names of its authors − Alfred Aho, Peter Weinberger, and Brian Kernighan.

AWK - Useful Resources

The following resources contain additional information on AWK. Please use them to get more in-depth knowledge on this.

Discuss AWK

This tutorial takes you through AWK, one of the most prominent text-processing utility on GNU/Linux. It is very powerful and uses simple programming language. It can solve complex text processing tasks with a few lines of code.