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)

Creating a file and folder inventory

Let's start with something basic – a script that reports in terms of folder and file inventory. As simple as this is, this type of script can use a variety of different tools, including commands, built-in CLI applications, loops – there are a lot of choices to be made. We're going to do this in the simplest way possible – by taking advantage of our knowledge of commands and CLI applications. We're going to create a couple of different versions of this script as it can be used in a variety of different ways – for example, as input into future shell scripts or as plain text reporting tools.

How to do it…

Let's start by creating a script that's just going to tell us the following:

  • The number of folders in the current folder and their sizes, sorted by size in descending order
  • The number of files in the current folder and their size, sorted by size in descending order
...