Shell Scripting Tutorial | Shell Scripting Crash Course | Linux Certification Training | Edureka

Introduction

This tutorial provides a comprehensive guide to shell scripting in Linux, derived from Edureka's Shell Scripting Crash Course. It covers essential concepts such as variables, operators, loops, and functions, making it useful for anyone looking to enhance their Linux skills or prepare for Linux certification.

Step 1: Getting Started with Linux

• Familiarize yourself with the Linux environment.
• Understand the command line structure, which is essential for writing and executing shell scripts.
• Learn about different Linux distributions and their characteristics.

Step 2: Command Line Essentials

• Master basic commands like ls, cd, cp, mv, and rm.
• Learn how to navigate the file system using command line instructions.
• Understand file permissions and how to change them using chmod.

Step 3: Shell Script Basics

• Create your first shell script file:
  • Open a terminal and type nano myscript.sh to create a new script.
  • Start your script with a shebang line:

    #!/bin/bash
    

• Make the script executable:

  chmod +x myscript.sh
  

• Run your script:

  ./myscript.sh
  

Step 4: Using Variables

• Learn how to declare variables:

  my_variable="Hello, World!"
  

• Access variables using the $ sign:

  echo $my_variable
  

• Understand variable scopes and types (local vs. global).

Step 5: Basic Operations

• Perform arithmetic operations using expr or double parentheses:

  result=$((5 + 3))
  echo $result
  

• Use conditional statements to make decisions in scripts:

  if [ $result -gt 5 ]; then
      echo "Result is greater than 5"
  fi
  

Step 6: Shell Loops

• Implement loops to execute commands multiple times:
  • For loop example:

    for i in {1..5}
    do
        echo "Iteration $i"
    done
    

  • While loop example:

    count=1
    while [ $count -le 5 ]
    do
        echo "Count $count"
        ((count++))
    done
    

Step 7: Shell Functions

• Define functions for reusable code blocks:

  my_function() {
      echo "This is my function"
  }
  

• Call your function within the script:

  my_function
  

Step 8: Use-Case Scenarios

• Apply your knowledge through a practical example:
  • Create a backup script that utilizes variables, loops, and functions to automate the backup process for specified directories.
• Ensure to test your script in a safe environment before deploying it.

Conclusion

This shell scripting tutorial provides a solid foundation for understanding and writing scripts in Linux. Key takeaways include mastering the command line, using variables and functions effectively, and implementing loops for automation. For further learning, consider exploring more complex scripting scenarios or enrolling in a Linux administration course to deepen your knowledge.