Bash

Overview

Bash (GNU Bourne-Again Shell) is the default shell on most Linux distributions and was the default on macOS until Catalina. Created by Brian Fox in 1989 as a free software replacement for the Bourne shell, Bash has become the de facto standard for shell scripting.

Who Should Use Bash?

• System administrators - Automation and server management
• Developers - Build scripts and development workflows
• Linux users - Default interactive shell on most systems
• Script writers - Portable scripts across Unix-like systems

Installation

Bash is pre-installed on most Unix-like systems.

# Check Bash version
bash --version

# Install on macOS (if needed)
brew install bash

# Install on Debian/Ubuntu
sudo apt install bash

# Set as default shell
chsh -s /bin/bash

Basic Usage

Basic Bash commands and syntax.

# Variables
NAME="World"
echo "Hello, $NAME!"

# Arrays
fruits=("apple" "banana" "cherry")
echo ${fruits[0]}  # apple

# Conditionals
if [ -f "file.txt" ]; then
  echo "File exists"
fi

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

Configuration

Bash configuration files and customization.

# ~/.bashrc - Interactive non-login shells
# ~/.bash_profile - Login shells

# Add to ~/.bashrc
export PS1="\u@\h:\w\$ "  # Custom prompt
export PATH="$HOME/bin:$PATH"

# Aliases
alias ll='ls -la'
alias gs='git status'

# Reload configuration
source ~/.bashrc

Key Features

FAQ

Summary

Key takeaways for Bash:

• Most widely used shell with extensive documentation
• Pre-installed on almost all Linux distributions
• Powerful scripting capabilities with POSIX compatibility
• Large ecosystem of tools and frameworks