Book Image

Mastering Linux Shell Scripting - Second Edition

By : Mokhtar Ebrahim, Andrew Mallett
5 (1)
Book Image

Mastering Linux Shell Scripting - Second Edition

5 (1)
By: Mokhtar Ebrahim, Andrew Mallett

Overview of this book

In this book, you’ll discover everything you need to know to master shell scripting and make informed choices about the elements you employ. Grab your favorite editor and start writing your best Bash scripts step by step. Get to grips with the fundamentals of creating and running a script in normal mode, and in debug mode. Learn about various conditional statements' code snippets, and realize the power of repetition and loops in your shell script. You will also learn to write complex shell scripts. This book will also deep dive into file system administration, directories, and system administration like networking, process management, user authentications, and package installation and regular expressions. Towards the end of the book, you will learn how to use Python as a BASH Scripting alternative. By the end of this book, you will know shell scripts at the snap of your fingers and will be able to automate and communicate with your system with keyboard expressions.
Table of Contents (17 chapters)

Controlling the visibility of the entered text

Even though we have limited the input to a single character, we do get to see the text on the screen. In the same way, if we type the name, we get to see the entered text before we hit Enter. In this case, it is just untidy, but if we are entering sensitive data, such as a PIN or a password, we should hide the text. We can use the silent option, or -s, to achieve this. A simple edit in the script will set this in place:

#!/bin/bash
read -p "May I ask your name: " name
echo "Hello $name"
read -sn1 -p "Press any key to exit"
echo
exit 0

Now, when we use a key to continue, it will not be displayed on the screen. We can see the behavior of the script in the following screenshot: