GNU SED

You are likely to be familiar with the "Find and Replace" dialog box from a text editor, word processor, IDE, etc to search for something and replace it with something else. sed is a command line tool that is similar, but much more versatile and feature-rich.

The book heavily leans on examples to present features of sed as well as regular expressions one by one. It is recommended that you manually type each example and experiment with them. Understanding both the nature of sample input string and the output produced is essential.

You should have prior experience working with command line and bash shell, should know concepts like file redirection, command pipeline and so on.

Exercises are also included to test your understanding.