GNU awk

gawk is a powerful pattern-matching and processing language. It is based on the language AWK.

Several kinds of tasks occur repeatedly when working with text files. You might want to extract

certain lines and discard the rest. Or you may need to make changes wherever certain patterns appear,

but leave the rest of the file alone. Writing single-use programs for these tasks in languages such

as C, C++, or Java is time-consuming and inconvenient. Such jobs are often easier with awk. The awk

utility interprets a special-purpose programming language that makes it easy to handle simple

data-reformatting jobs.

The GNU implementation of awk is called gawk; if you invoke it with the proper options or environment

variables (see Options), it is fully compatible with the POSIX specification of the awk language and

with the Unix version of awk maintained by Brian Kernighan.

Using awk (or gawk) allows you to

Manage small, personal databases

Generate reports

Validate data

Produce indexes and perform other document preparation tasks

Experiment with algorithms that you can adapt later to other computer languages

Also, gawk provides facilities that make it easy to

Extract bits and pieces of data for processing

Sort data

Perform simple network communications.