Bash Scripting Tutorial


Welcome to our comprehensive Linux Bash scripting tutorial, where we explore the world of Linux shell scripting and guide you through the process of automating your Linux tasks using the Bash shell.

Bash is a command line interpreter (CLI) that allows you to run commands or scripts on Linux systems. Bash is also known as the Bourne Again Shell. It was originally developed at AT&T Bell Labs in 1984 and released under the GNU General Public License.

It is widely used across various platforms such as Mac OS X, Windows, Unix/Linux, etc. It has become very popular because of its simplicity and ease of use.

What You’ll Learn

In this tutorial, we cover the following key aspects of Bash scripting:

Introduction to Linux Bash Scripting Tutorial: Gain a solid understanding of Bash scripting and its role in automating repetitive tasks in the Linux environment. Explore the basics of the Bash shell, variables, control structures, and functions that form the foundation of shell scripting.

Writing Your First Linux Shell Script: Learn how to create and run your first Bash script. Discover the essential syntax and conventions, such as shebangs, comments, and file permissions. Dive into variable assignment, command substitution, and basic input/output operations to build your scripting skills.

Conditional Statements and Loops: Explore the power of conditional statements and loops in Bash scripting. Learn how to perform branching and decision-making using if-else and case statements. Discover different loop constructs, including for loops, while loops, and until loops, to automate repetitive tasks.

Working with Files and Directories: Master file and directory operations in Linux Bash scripting tutorial. Learn how to manipulate files, such as creating, reading, writing, and deleting. Explore directory navigation, file globbing, and file permissions management to enhance your script’s file-handling capabilities.

Command-line Arguments and Input Validation: Discover techniques for accepting command-line arguments in your Bash scripts. Learn how to process arguments, perform input validation, and handle user prompts. Explore options for error handling and graceful script termination.

Functions and Modularization: Understand the power of functions in Linux Bash scripting. Learn how to define and call functions to encapsulate reusable code blocks. Explore techniques for modularizing your scripts and creating libraries for increased code maintainability and reusability.

Advanced Scripting Techniques: Delve into advanced topics to level up your Linux Bash scripting skills. Explore regular expressions, string manipulation, arithmetic operations, and process control. Learn how to interact with external programs and leverage command substitution and pipelines to enhance script functionality.

Throughout this tutorial, we provide practical examples, code snippets, and command-line instructions to help you become proficient in Bash scripting. We aim to make the intricacies of Bash scripting accessible to both beginners and experienced Linux users, empowering you to automate tasks and streamline your workflows.

By the end of this tutorial, you will have a comprehensive understanding of Bash scripting and be equipped with the skills to create efficient and robust automation scripts. Whether you are a system administrator, developer, or Linux enthusiast, our Shell scripting tutorial will guide you every step of the way to enhance your career goal towards multi-dynamic in DevOps.

Chapters (Linux Bash Scripting)

Chapter 1 : Bash script Introduction & Local environment setup

Before we start learning how to write a simple Bash script, let us first understand what exactly a Bash script is.

Here, in this section you will learn basics about bash script and also get the information to setup the local environment for bash script practice.

TopicsRead Time
Introduction to Bash Scripting
Setting Up Your Local Environment
Your First Bash Script
Script Organization
Practice Exercises
Resources for Further Learning
Linux Shell Script Fundamentals

Chapter 2 : Linux filesystem, Linux Permission schema & File Manipulation

In this section, you will learn all about Linux file system, Linux permission schema and basic file manipulation which helps you a lot at the time of writing bash script for files operation.

You will also learn how to create directories and files in Linux to implement those operation using your scripts.

TopicsRead Time
Understanding the root directory (“/”).
Exploring common system directories (“/bin,” “/usr,” “/etc,” etc.).
Navigating user directories (“/home”).
Recognizing special directories (e.g., “/dev,” “/proc,” “/tmp”).
File and directory permissions (read, write, execute).
Changing permissions with chmod and chown.
Special permissions (setuid, setgid, sticky bit).
Listing files and directories with ls.
Copying files and directories with cp.
Moving and renaming files and directories with mv.
Removing files and directories with rm.
Creating directories with mkdir.
Creating empty files with touch.
Finding files and directories with find.
Recognizing hidden files and directories.
Identifying file types (regular files, directories, symlinks, etc.).
Understanding symbolic links and their usage.
Checking file sizes and disk usage with du and df.
Topics on Linux filesystem, Linux Permission schema & File Manipulation

Chapter 3 : Variables and User Input

This section deals with variables and user input. Here, you will learn different types of variable like String, Integer, Float, Boolean, Array, Dictionary, List, Set, etc.

Also, you will learn how to read user input through command line interface.

TopicsRead Time
What are variables in Bash?
How to declare and initialize variables.
Variable data types (string, integer, etc.).
Variable naming conventions and best practices.
Overview of different types of variables (local, global).
Environment variables (e.g., PATHHOMEUSER).
User Input with read
Variable Manipulation
Arithmetic Operations
User inputs and variables in Linux Shell Scripting

Chapter 4 : Error checking and Handling

In this section, you will learn error handling in Bash script. This will help you to handle errors while running any bash script.

You will also learn some useful functions to check if a string contains another string or not.

TopicsRead Time
Understanding Errors
Exit Codes and Status Values
Conditional Error Handling
Error Messages
Debugging Techniques
Logging Errors
Handling Script Interruptions
Error Handling Best Practices
Testing and Debugging Practices
Practical Examples
Bash Scripting Error Checking and Handling

Chapter 5 : Regular expression

In this section, you will see regular expressions. A regular expression is a pattern matching language.

You can use regular expressions to match strings within text. For example, you can search for a particular word in a sentence. The syntax of regular expressions is similar to C-like languages.

TopicsRead Time
Introduction to Regular Expressions
Basic Regex Syntax
Regex Quantifiers
Character Classes
Anchors and Boundaries
Grouping and Capturing
Regex in Bash
Practical Examples
Regular expression in Linux Scripting

Chapter 6 : Conditional testing and Scripting loop

In this section, you will learn conditional testing and scripting loop. These are two important concepts in bash script. You will learn how to test whether a condition is true or false.

You will learn also to execute set of code several time till the condition not get satisfied. In this way, you can do something until the condition gets satisfied.

TopicsRead Time
Introduction to conditional statements in Bash.
Using ifelif (else if) for multiple conditions.
Incorporating else for default actions.
Logical operators (&& for AND, || for OR, ! for NOT) for combining conditions.
Comparison operators (-eq-ne-lt-le-gt-ge) for comparing values.
Nesting if statements for complex conditionals.
Syntax and usage of for loops.
Introduction to while loops and using while loops for user input validation.
Introduction to until loops and their use cases.
Loop control with break and continue statements.
Practical Examples
Condition and Loop in Linux Shell Scripting

Chapter 7 : Pipe and Redirection

In this section, you will learn pipe and redirection. Pipes allow data from one program to be passed to another program as an output. Redirections allow data to be sent to a file instead of being displayed on the screen.

Here, you will learn how to use these concept into your script to do long operation in single command on in small script.

TopicsRead Time
Input and Output Redirection
Pipes and Data Flow
Error Handling and Redirection
Advanced Redirection Techniques
Practical Examples
Pipe and Redirection using in Linux Shell Script

Chapter 8 : Bash Functions

In this section, you will learn about bash function. A bash function is a block of code that is executed when it is called.

It has its own scope and variables defined inside it cannot be accessed outside.

You will learn here how to define and call a bash function.

TopicsRead Time
Understanding Functions
Function Parameters and Arguments
Returning Values from Functions
Variable Scope
Recursive Functions
Function Libraries
Testing and Debugging Functions
Function Reusability
Practical Examples
Using Functions in Linux Shell Scripting

Chapter 9 : Scheduling and logging

In this section, I will explain you about scheduling and logging.

Scheduling means setting up a task to run at a certain time. Logging is used to record events.

Logging is very helpful in debugging problems.

Here, you will learn how schedule tasks and log events.

TopicsRead Time
Introduction to Scheduling
Using cron
Scheduling One-Time Tasks
Recurring Task Scheduling
Task Output and Notifications
Introduction to Logging
Log Rotation
Log Management
Script Debugging with Logs
Log Analysis and Monitoring
Practical Examples
Scheduling and logging in Linux Scripting

Chapter 10 : Parsing Bash script arguments, Bash parameter substitution and expansion

Arguments are the values given by the users to your script. They may contain spaces, tabs, newlines, quotes, backslashes, etc.

Parameter substitution is a process where the value of a variable is replaced by the contents of another variable.

Expansion is the process of replacing occurrences of special characters (such as $) with their corresponding values.

In this section, you will learn these concepts to use in your script.

TopicsRead Time
Command-Line Arguments
Argument Parsing
Parameter Substitution and Expansion
Advanced Script Configuration
Practical Examples
Bash script Arguments and Parameters

Chapter 11 : Tips and Tricks with cheat sheet

This section will give you tips and tricks to make your life easier. This is a bonus section to use shortcut to do your operation. I request you to don’t use it before learning above section otherwise it will make you script kid not expert.

TopicsRead Time
Working with arrays (indexed and associative arrays).
Advanced string manipulation techniques.
Handling signal trapping for graceful script termination.
Cheat Sheet Creation
Parsing complex data formats (e.g., JSON, XML).
Advanced debugging techniques (e.g., using set -x).
Integrating Bash scripts with other tools and languages (e.g., Python, awk).
Linux Shell scripting Tips and Techniques

Frequently Asked Questions (FAQ)

What is Bash scripting, and why should I learn it?

Bash scripting is a powerful skill for automating tasks and managing systems using the command line. Learning Bash scripting can save time, streamline repetitive tasks, and enhance your efficiency as a Linux or Unix user.

Is this tutorial suitable for beginners with no prior scripting experience?

What prerequisites do I need to get started with this tutorial?

What topics are covered in this Bash scripting tutorial?

How long does it take to complete the tutorial?

Can I access the tutorial for free?

Is there any certification or assessment offered upon completion?

Can I ask questions or seek help while going through the tutorial?

Do you provide advanced tutorials for Bash scripting after completing this one?

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