Book Image

Linux Command Line and Shell Scripting Techniques

By : Vedran Dakic, Jasmin Redzepagic
Book Image

Linux Command Line and Shell Scripting Techniques

By: Vedran Dakic, Jasmin Redzepagic

Overview of this book

Linux Command Line and Shell Scripting Techniques begins by taking you through the basics of the shell and command-line utilities. You’ll start by exploring shell commands for file, directory, service, package, and process management. Next, you’ll learn about networking - network, firewall and DNS client configuration, ssh, scp, rsync, and vsftpd, as well as some network troubleshooting tools. You’ll also focus on using the command line to find and manipulate text content, via commands such as cut, egrep, and sed. As you progress, you'll learn how to use shell scripting. You’ll understand the basics - input and output, along with various programming concepts such as loops, variables, arguments, functions, and arrays. Later, you’ll learn about shell script interaction and troubleshooting, before covering a wide range of examples of complete shell scripts, varying from network and firewall configuration, through to backup and concepts for creating live environments. This includes examples of performing scripted virtual machine installation and administration, LAMP (Linux, Apache, MySQL, PHP) stack provisioning and bulk user creation for testing environments. By the end of this Linux book, you’ll have gained the knowledge and confidence you need to use shell and command-line scripts.
Table of Contents (19 chapters)

Chapter 15: Troubleshooting Shell Scripts

If you have come this far, you must have a lot of ideas about how to write a shell script, and even more questions about the ways you can make particular things in scripts work. This is completely normal. Your scripting journey has just started. No amount of reading can make up for time spent writing scripts, trying out different solutions, and understanding how different commands work.

We have some good news and some bad news for you. Being good at scripting takes a long time and, in scripting, most of that time is going to be spent trying to understand what your script should be doing and, usually, why it is doing it wrong. The good news is that scripting is never boring.

In this chapter, we will try to give you the tools needed to debug and troubleshoot scripts quickly and without a lot of confusion. The tools are going to be in the form of different methods you can use to maximize your ability to find logical and, sometimes, syntactical...