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Shell scripting is an essential skill for aspiring DevOps engineers. In this comprehensive guide, we will explore the importance of shell scripting in the DevOps world, how to get started with it, the best free resources to learn shell scripting, real-world use cases, and common interview questions. Whether you are a beginner or an experienced IT professional, this guide will help you master shell scripting and take your DevOps skills to the next level.

Why Shell Scripting is Important for DevOps Engineers

Shell scripting plays a crucial role in a DevOps engineer’s toolkit. According to the Stackoverflow 2021 survey, 27% of respondents reported using shell scripting in their work. While there are various automation tools available, shell scripting is still relevant in the DevOps workflow. It is often used in conjunction with automation tools and for ad-hoc tasks.

For example, when configuring AWS user data or creating AMI images using Packer, shell scripting comes in handy. It is also used with configuration management tools and containers. Shell scripts are particularly useful for repeatable development tasks like setting up a Vagrant VM or creating a development environment.

Moreover, hands-on scripting and programming skills are increasingly becoming mandatory in preliminary DevOps interviews. Therefore, learning shell scripting is essential for both daily work and career advancement.

Getting Started with Shell Scripting

Before diving into shell scripting, it’s important to have hands-on experience with Linux. If you are new to the Linux world, start by spinning up Linux servers locally using tools like Vagrant or on cloud platforms such as AWS or Google Cloud. These platforms often provide free credits for beginners, allowing you to get started easily.

Once you are comfortable with Linux, it’s time to start learning the basics of shell scripting. Create a GitHub repository and organize your scripts into folders, documenting your work as you go. This documentation will not only help you retain knowledge but also benefit others in the DevOps community. Consider sharing your repository on platforms like LinkedIn to showcase your expertise.

Best Free Resources for Learning Shell Scripting

Learning shell scripting doesn’t have to be expensive. There are plenty of free resources available that can help you master this skill. Here are some recommended resources:

  1. Shell Scripting Tutorial: This web-based tutorial covers shell scripting basics, including variables, conditions, loops, and command-line arguments.
  2. Bash Academy: Bash Academy offers interactive shell scripting tutorials that allow you to practice your skills directly in the browser.
  3. LinuxCommand: LinuxCommand provides a comprehensive guide to shell scripting with examples and exercises to reinforce your learning.
  4. Shell Scripting Tutorial for Beginners: Guru99 offers a beginner-friendly tutorial that covers the fundamentals of shell scripting.
  5. The Linux Documentation Project: The Linux Documentation Project hosts the Advanced Bash-Scripting Guide, a detailed resource for those looking to deepen their knowledge of shell scripting.

While these resources provide web-based content, interactive tutorials, and PDF materials, some individuals may prefer guided courses. If you are more comfortable with structured learning, consider enrolling in paid courses that specialize in shell scripting.

Real-World Shell Scripting Use Cases

To gain practical experience with shell scripting, it’s beneficial to explore real-world use cases. If you work in a company, you can examine project documentation and infrastructure automation codes to see how shell scripts are used. If you don’t have access to such resources, open-source community repositories can provide insights into real-world shell scripting scenarios.

For example, take a look at the GitHub repository for popular Docker base images like Nginx. In the repository’s “entrypoint” folder, you will find shell scripts that are used during container initialization. Analyzing these scripts will expose you to various concepts and logic that can be applied in your own shell scripting projects.

Remember, real-world scenarios can vary greatly, so it’s crucial to continue exploring different projects, repositories, and automation tools to expand your knowledge and skills.

Shell Scripting Real-Life Scenarios

To further enhance your understanding of shell scripting, it’s helpful to practice with real-life scenarios commonly encountered in DevOps engineer interviews. Here are some examples to get you started:

  1. Write a shell script function to find and kill all zombie processes.
  2. Find the ten largest files in the file system and write the output to a file.
  3. Create a shell script to gracefully unmount a disk.
  4. Develop a shell script to send an email.
  5. Monitor CPU, memory, and disk usage, and send the output to a file in table format. Send an alert if any of them exceed a certain threshold.
  6. Write a shell script to find recently created files and their sizes. Accept the number of days or a date range as input.
  7. Automate the process of creating new user accounts on a Linux server and setting up their permissions and SSH access.
  8. List the users logged in by date and write the information to an output file.
  9. Copy files recursively to remote hosts using a shell script.
  10. Count the number of failed login attempts by IP address and location using a shell script.
  11. Parse a log file, extract specific values with timestamps, and write them to an output file.
  12. Automate the rotation of log files and compressing old files to save disk space.
  13. Check the status of a list of URLs and send an email notification if any of them are down.
  14. Update a list of servers with the latest security patches using a shell script.

These scenarios cover a range of shell scripting concepts, such as variable definitions, text processing with cut, awk, and grep, input/output/error redirections, conditionals, loops, command-line arguments, and more.

Shell Scripting Languages

When discussing shell scripting, it’s important to note that there are no specific shell scripting languages. Instead, shell scripting refers to the use of shell interpreters like sh, bash, csh, and tcsh. In this guide, we primarily focus on bash shell scripting, as it is an interpreted scripting language for Unix-based systems.

While bash is the most commonly used shell scripting language, other scripting languages like PowerShell, Python, Pearl, and Groovy are also widely used in the DevOps world. The choice of scripting language depends on the project requirements and the tools being used. For example, PowerShell is commonly used in Windows environments, while Python is versatile and widely applicable.

Shell Scripting DevOps Interview Questions

To prepare for DevOps engineer interviews, it’s important to familiarize yourself with common shell scripting interview questions. The complexity of these questions may vary depending on the company and the role. Here are some examples:

  1. Can you explain how shell scripting fits into a larger DevOps workflow?
  2. What is the need for shell scripts when there are automation tools available?
  3. In what scenarios would you choose shell scripting over programming languages like Python or Golang?
  4. How would you approach writing a shell script to automate a specific task?
  5. How do you perform static analysis for shell scripts?
  6. How do you ensure error-free shell scripts in your CI/CD pipeline?
  7. How do you handle errors and exceptions in shell scripts?
  8. Write a shell script to reverse a string.
  9. Parse a log file, find all occurrences of a word, and write them to an output file.
  10. Send the first ten lines of a file to another file using a shell script.
  11. Merge(concatenate) two files and write the output to a third file.
  12. Find all duplicate strings in a file and replace them with another string.
  13. Extract IP addresses from a log file and write them to another file.
  14. How would you debug a malfunctioning shell script?
  15. What is the difference between a “for” loop and a “while” loop in shell scripting?

Preparing for these interview questions will not only enhance your shell scripting skills but also boost your confidence during interviews.

Frequently Asked Questions about Shell Scripting

Aspiring DevOps engineers often have common questions about learning and using shell scripting. Here are answers to some frequently asked questions:

How difficult is it to learn Linux shell scripting?

Learning shell scripting is similar to learning any other technology. With a good foundational knowledge of Linux, you can easily learn shell scripting. It is important to follow a disciplined learning path and practice regularly to master this skill.

Is scripting required for DevOps engineers?

Yes, scripting knowledge is crucial for DevOps engineers. From development environments to production systems, DevOps engineers often need to create useful utilities using scripting to automate tasks and streamline operations.

Which scripting language is best for DevOps?

The choice of scripting language depends on project requirements and the tools being used. However, bash, PowerShell, and Python are commonly used scripting languages in DevOps projects. If you are working with Jenkins, Groovy is also essential.

Is shell scripting used for automation?

While full-fledged automation is often achieved through automation tools, shell scripting is still used for supporting functionalities. For example, shell scripts are commonly used with tools like Packer to build VM images.


Shell scripting is a fundamental skill for DevOps engineers. By mastering shell scripting, you can effectively automate tasks, streamline operations, and enhance your overall DevOps expertise. In this guide, we explored the importance of shell scripting, how to get started, the best free resources for learning, real-world use cases, and common interview questions.

Now it’s your turn to take action. Whether you choose to start with the basics, focus on interview-based questions, or explore real-life scenarios, remember to practice regularly and document your progress. By continuously honing your shell scripting skills, you’ll become an invaluable asset in the DevOps world.

Let us know in the comments which part of shell scripting you’re most excited to explore first. Happy scripting!

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