Bash — Get Started

Check Bash installation

# Check if Bash is installed
bash --version

# Check default shell
echo $SHELL

# List available shells
cat /etc/shells

Your first script

#!/bin/bash
# This is a comment

echo "Hello, World!"
echo "Current date: $(date)"
echo "Current user: $(whoami)"

Running scripts

# Method 1: Make executable
chmod +x script.sh
./script.sh

# Method 2: Run with bash
bash script.sh

# Method 3: Source (runs in current shell)
source script.sh

Shebang line

#!/bin/bash          # Bash
#!/bin/sh            # POSIX shell
#!/usr/bin/env bash  # Portable Bash

Essential commands

# File operations
ls -la           # List files
pwd              # Print working directory
cd /path         # Change directory
mkdir dir        # Create directory
touch file       # Create empty file
cp src dest      # Copy
mv src dest      # Move/rename
rm file          # Remove
rm -rf dir       # Remove directory

# Text operations
cat file         # Print file contents
head -n 10 file  # First 10 lines
tail -n 10 file  # Last 10 lines
grep pattern file # Search
wc -l file       # Count lines

Mini Practice

1. Create a script with the shebang line
2. Run it with chmod +x and ./
3. Use basic file operations
4. Create a script that prints system information

Up Next

In the next lesson, you'll learn about Syntax — Bash's basic syntax.