Book Image

Linux Shell Scripting Bootcamp

By : James K Lewis
Book Image

Linux Shell Scripting Bootcamp

By: James K Lewis

Overview of this book

Linux Shell Scripting Bootcamp is all about learning the essentials of script creation, validating parameters, and checking for the existence of files and other items needed by the script. We will use scripts to explore iterative operations using loops and learn different types of loop statements, with their differences. Along with this, we will also create a numbered backup script for backup files. Further, you will get well-versed with how variables work on a Linux system and how they relate to scripts. You’ll also learn how to create and call subroutines in a script and create interactive scripts. The most important archive commands, zip and tar, are also discussed for performing backups. Later, you will dive deeper by understanding the use of wget and curl scripts and the use of checksum and file encryption in further chapters. Finally, you will learn how to debug scripts and scripting best practices that will enable you to write a great code every time! By the end of the book, you will be able to write shell scripts that can dig data from the web and process it efficiently.
Table of Contents (19 chapters)
Linux Shell Scripting Bootcamp
About the Author
About the Reviewer
Customer Feedback

Indenting your code

This is probably a good time to talk about indenting. In the past (that is, 30+ years ago) everyone used a text editor with a mono-spaced font to write their code and so it was relatively easy to keep everything lined up with just a one space indent. Later, when people started using word processors with a variable pitched font, it became harder to see the indentation and so more spaces (or tabs) were used. My suggestion is to use what you feel most comfortable with. However, with that said you may have to learn to read and use whatever code style that is in place for your company.

So far we have only talked about the while statement. Now let's look at an until loop in the next section:

Chapter 3 - Script 6

# 5/3/2017
echo "script6 - Linux Scripting Book"

echo "This shows the while loop"

while [ $x -lt 11 ]          # perform the loop while the condition 
do                           # is true
 echo "x: $x"
 let x++

echo "This shows the until loop...