Shell Scripting for Beginners – Taking Input & Automating Real Tasks

Once you’re comfortable writing basic shell scripts, the next step is making them interactive and dynamic.

In this blog, we’ll learn how to:

✅ Take user input
✅ Handle arguments and parameters
✅ Automate common daily tasks like creating folders, renaming files, and monitoring memory
✅ Write cleaner, reusable shell code

Let’s get started with a very common requirement: asking the user for input.

🗣️ Taking Input from User

Let’s make a script that asks the user’s name and greets them.

#!/bin/bash

echo "What is your name?"
read username

echo "Hello, $username! Welcome to shell scripting."

Run it:

chmod +x welcome.sh
./welcome.sh

💡 read is used to capture what the user types in.

📦 Task 1: Create a Folder with User-Defined Name

#!/bin/bash

echo "Enter the folder name to create:"
read foldername

mkdir "$foldername"
echo "Folder '$foldername' created successfully!"

👉 You can now create folders without typing mkdir manually every time.

🛠️ Task 2: Rename Multiple Files Automatically

Let’s rename all .txt files to .bak format with user confirmation.

#!/bin/bash

for file in *.txt
do
  echo "Rename $file to ${file%.txt}.bak? (y/n)"
  read answer
  if [[ $answer == "y" ]]; then
    mv "$file" "${file%.txt}.bak"
    echo "Renamed $file"
  fi
done

🧠 This introduces you to loops plus conditional statements with user choices.

💡 Task 3: CPU & Memory Usage Checker

Let’s create a quick monitoring tool using shell:

#!/bin/bash

echo "Checking system performance..."

echo "CPU Load:"
uptime

echo "Memory Usage:"
free -h

echo "Top 5 memory-hogging processes:"
ps aux --sort=-%mem | head -n 6

🧠 This is how system admins use shell scripts to keep servers healthy.

📂 Task 4: Bulk File Creation

Need 10 log files for testing? Automate it!

#!/bin/bash

echo "Enter number of files to create:"
read count

for ((i = 1; i <= count; i++))
do
  touch "logfile_$i.log"
done

echo "$count log files created successfully."

🧾 Understanding Script Parameters

You can pass values directly when running your script:

#!/bin/bash

echo "Hello $1! You are learning $2."

Save as intro.sh, and run:

./intro.sh Alice "Shell Scripting"

Output:

Hello Alice! You are learning Shell Scripting.

🧠 $1, $2, etc. are positional parameters.

⚙️ Task 5: Backup with Arguments

#!/bin/bash

src=$1
dest=$2

if [ -d "$src" ]; then
  tar -czf "$dest/backup-$(date +%F).tar.gz" "$src"
  echo "Backup completed!"
else
  echo "Source directory does not exist."
fi

Usage:

./backup.sh /home/user/docs /home/user/backups

🧼 BONUS: Create a Cleanup Script with Confirmation

#!/bin/bash

echo "This will delete all .log files in the current directory."
read -p "Are you sure? (y/n): " confirm

if [[ $confirm == "y" ]]; then
  rm *.log
  echo "All .log files deleted."
else
  echo "Aborted!"
fi

Safety first! Scripts that delete files should always ask for confirmation.

🧠 Final Tips for Beginner Scripters

• Use echo often to understand what your script is doing.
• Keep testing small blocks before combining them.
• Learn how to debug using bash -x script.sh.
• Save your scripts in a ~/scripts folder and add it to your PATH.
• Explore select, case, and functions for better control.

🧳 Summary

Today, you learned how to:

✅ Accept user input
✅ Handle command-line arguments
✅ Create folders, rename files, and monitor memory
✅ Use loops, conditionals, and parameters in real-world tasks

Shell scripting is not just about commands — it’s about automation, efficiency, and saving time. As you keep writing more scripts, you’ll discover just how powerful your terminal can be.