Days 6–8: Shell Scripting — Practiced, Scripted, Pushed

So here we are, wrapping up Days 6 7 and 8 of my 40 Days of DevOps Reset — and this one was all about Shell Scripting.

I thought it would be more of a refresher, but turns out it was a solid learning zone. I didn’t just practice commands — I wrote actual scripts, tested them, and ended up with a proper GitHub repo full of Bash files. Feels good.

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🎥 What I Watched

To kick things off, I followed this YouTube video:

"Shell Scripting in 1 Shot" by TrainWithShubham
It covers everything from variables to loops, conditionals, and even real use cases like log cleanup and automation.

The format was great — short segments, easy examples, and clean explanations. I watched a section, paused, tried it out in my terminal, then repeated the process. No binge-watching, just hands-on learning.

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🛠️ What I Practiced

Here’s the breakdown of what I wrote and worked on over the two days.

✅ 01–03: The Basics

• 01_hello.sh: My first classic “Hello World” in Bash

• 02_variables.sh: Declaring, modifying, printing variables

• 03_input_output.sh: Using read, echo, piping data around

🔁 04–06: Logic and Control

• 04_arguments.sh: Playing with $1, $2, $#, and checking args

• 05_if_else.sh: Conditional logic, nested if, elif, else

• 06_loops.sh: while, for, until — looping over lists and conditions

🔧 07–09: More Real Use

• 07_functions.sh: Reusable logic with parameters

• 08_error_handling.sh: Exit codes, trap, and safety

• 09_deploy_django_app.sh: Script to clone and start a Django app

📁 10–13: File Utilities

• 10_logrotation_cleanup.sh: Deleting logs older than X days

• 11_count_no_of_files.sh: Count files in a directory

• 12_greeting.sh: Auto greet based on time of day

• 13_file_extension_check.sh: If-else script based on file extension

🧮 14–15: Utilities & Math

• 14_simple_calculator.sh: Calculator using expr and read

• 15_directory_creator.sh: Script to create directories based on input

🛠️ 16–18: Useful Scripts

• 16_file_backup.sh: Copy files to a backup folder with timestamp

• 17_log_file_analyzer.sh: Reads logs and filters error patterns

• 18_disk_monitor.sh: Disk space monitoring and alert if low

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💡 What Helped Me Learn

• I didn’t skip practicing — everything was hands-on

• Used nano and VS Code together for writing and testing

• Debugged using bash -x, used chmod +x to make scripts executable

• Tried to run each script with valid and invalid inputs to test cases

• Built simple functions inside loops to reuse logic

• I kept it very real — no perfect code, just working and readable

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😅 What Was Tricky

• Forgetting to quote variables caused weird bugs

• Confused between [ and [[ at first

• Using expr vs arithmetic expansion $(( ))

• Debugging missing fi or done — classic Bash errors

• Remembering file permissions when scripts wouldn’t run

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💻 Repo Is Live!

You can check all my scripts here:
👉 Shell Scripting Practice GitHub Repo

It’s public, structured, and fully commented in most places. I’ll probably keep improving it as I revisit during later phases.

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🧠 Takeaway from Day 6-8

Shell scripting might look “easy” from the outside, but writing clean, functional scripts takes practice. These two days were pure practice mode — and now I can confidently say I can script out small utilities or automations when needed.

It’s like giving your Linux terminal superpowers.

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Next up: Git, Gitlab and Containerization .
Let’s see how that goes in Day 9 and 10. 👀
Back to YAML, images, volumes… you know the drill.

Stay tuned. 🚀
— Areeba Hassan