Learn AWK command in Linux with examples

The awk command is used for text processing in Linux. Although, the sed command is also used for text processing, but it has some limitations, so the awk command becomes a handy option for text processing. It provides powerful control to the data.

The Awk is a powerful scripting language used for text scripting. It searches and replaces the texts and sorts, validates, and indexes the database.

Awk is a general-purpose scripting language designed for advanced text processing. It is mostly used as a reporting and analysis tool.

Unlike most other programming languages that are procedural, awk is data-driven, which means that you define a set of actions to be performed against the input text. It takes the input data, transforms it, and sends the result to standard output.

It is one of the most widely used tools for the programmer, as they write the scaled-down effective program in the form of a statement to define the text patterns and designs. It acts as a filter in Linux. It is also referred as gawk (GNU awk) In Linux.

AWK is suitable for pattern search and processing. The script runs to search one or more files to identify matching patterns and if the said patterns perform specific tasks. In this guide, we take a look into AWK Linux command and see what it can do.

Features of AWK command

Various features of the Awk command are as follows:

It scans a file line by line.
It splits a file into multiple fields.
It compares the input text or a segment of a text file.
It performs various actions on a file like searching a specified text and more.
It formats the output lines.
It performs arithmetic and string operations.
It applies the conditions and loops on output.
It transforms the files and data on a specified structure.
It produces the format reports.

AWK Command Syntax:

$ awk options ‘selection _criteria {action }’ input-file > output-file

Awk has a number of built-in variables that contain useful information and allows you to control how the program is processed. Below are some of the most common built-in Variables:

NF – The number of fields in the record.

NR – The number of the current record.

FILENAME – The name of the input file that is currently processed.

FS – Field separator.

RS – Record separator.

OFS – Output field separator.

ORS – Output record separator.

AWK Command Examples:

In the examples below, we will use a file named “teams.txt” that looks like the one below:

Name	Span	Runs	Average
SR Tendulkar	1989-2013	34357	48.52
R Dravid	1996-2012	24064	45.57
V Kohli	2008-2022	23409	54.69
SC Ganguly	1992-2008	18433	41.42
MS Dhoni	2004-2019	17092	44.74