Book Image

Linux Shell Scripting Cookbook, Second Edition - Second Edition

Book Image

Linux Shell Scripting Cookbook, Second Edition - Second Edition

Overview of this book

The shell remains one of the most powerful tools on a computer system — yet a large number of users are unaware of how much one can accomplish with it. Using a combination of simple commands, we will see how to solve complex problems in day to day computer usage.Linux Shell Scripting Cookbook, Second Edition will take you through useful real-world recipes designed to make your daily life easy when working with the shell. The book shows the reader how to effectively use the shell to accomplish complex tasks with ease.The book discusses basics of using the shell, general commands and proceeds to show the reader how to use them to perform complex tasks with ease.Starting with the basics of the shell, we will learn simple commands with their usages allowing us to perform operations on files of different kind. The book then proceeds to explain text processing, web interaction and concludes with backups, monitoring and other sysadmin tasks.Linux Shell Scripting Cookbook, Second Edition serves as an excellent guide to solving day to day problems using the shell and few powerful commands together to create solutions.
Table of Contents (16 chapters)
Linux Shell Scripting Cookbook
About the Authors
About the Reviewers

Automating interactive input

Automating interactive input for command-line utilities are extremely useful for writing automation tools or testing tools. There will be many situations when we deal with commands that read input interactively. An example of executing a command and supplying the interactive input is as follows:

$ command
Enter a number: 1
Enter name : hello
You have entered 1,hello

Getting ready

Creating utilities that can automate the acceptance of input are useful to supply input to local commands, as well as for remote applications. Let us see how to automate them.

How to do it...

Think about the sequence of an interactive input. From the previous code, we can formulate the steps of the sequence as follows:


Converting the preceding steps 1, Return, hello, and Return by observing the characters that are actually typed in the keyboard, we can formulate the following string:


The \n character is sent when we press return. By appending the return...