BASH Tutorial

💻 Introduction to Bash

Bash stands for Bourne Again SHell. It's one of the most widely used shell environments for Linux and Unix systems. Bash is a command-line interface that allows users to interact with the operating system and automate tasks using shell scripts.

🛠️ What Can Bash Do?

• Run Linux commands interactively or from a file
• Automate system tasks (backups, file management, etc.)
• Use variables and control structures (if, loops)
• Chain commands using pipes, redirection, and logical operators

📦 Sample Bash Commands

# Print text to screen
echo "Hello, world!"

# List files and directories
ls -l

# Change directory
cd /home/user

# Make a new directory
mkdir my_folder

# Remove a file
rm myfile.txt
  

📄 Writing a Bash Script

Save your commands in a .sh file and make it executable:

#!/bin/bash

echo "Starting backup..."
cp -r /home/user/documents /home/user/backup
echo "Backup completed!"
  

Make it executable and run:

chmod +x backup.sh
./backup.sh

🔁 Control Structures

Bash allows basic logic like conditions and loops:

#!/bin/bash

# If condition
if [ -f "myfile.txt" ]; then
  echo "File exists."
else
  echo "File not found."
fi

# Loop
for i in {1..5}; do
  echo "Number $i"
done
  

📌 Real-World Uses

• 🔄 Automate system backups
• 🧪 Setup development environments
• 📤 Deploy web servers or services
• 📁 Manage large file systems quickly

🎯 Conclusion

Bash is powerful for both beginners and professionals. Once you get the hang of writing scripts, you can automate virtually anything in a Linux system. Whether you're managing files or configuring servers, Bash makes your life easier.