Zsh vs Bash Configuration - Complete Guide

# macOS (using Homebrew)
brew install zsh

# Ubuntu/Debian
sudo apt update
sudo apt install zsh

# CentOS/RHEL
sudo yum install zsh

# Set as default shell
chsh -s $(which zsh)

# Verify installation
zsh --version

# Install Oh My Zsh
sh -c "$(curl -fsSL https://raw.github.com/ohmyzsh/ohmyzsh/master/tools/install.sh)"

# Manual installation
git clone https://github.com/ohmyzsh/ohmyzsh.git ~/.oh-my-zsh
cp ~/.oh-my-zsh/templates/zshrc.zsh-template ~/.zshrc

# Reload configuration
source ~/.zshrc

# Path to your oh-my-zsh installation
export ZSH="$HOME/.oh-my-zsh"

# Theme selection
ZSH_THEME="robbyrussell"

# Plugins
plugins=(
  git
  zsh-autosuggestions
  zsh-syntax-highlighting
  docker
  docker-compose
  node
  npm
  yarn
)

# Load Oh My Zsh
source $ZSH/oh-my-zsh.sh

# Custom aliases
alias ll="ls -alF"
alias la="ls -A"
alias l="ls -CF"
alias ..="cd .."
alias ...="cd ../.."

# Custom functions
mkcd() {
    mkdir -p "$1" && cd "$1"
}

# Environment variables
export EDITOR="code"
export PATH="$HOME/.local/bin:$PATH"

# Bash configuration
# If not running interactively, don't do anything
case $- in
    *i*) ;;
      *) return;;
esac

# History settings
HISTCONTROL=ignoreboth
HISTSIZE=1000
HISTFILESIZE=2000
shopt -s histappend

# Check window size after each command
shopt -s checkwinsize

# Enable color support
if [ -x /usr/bin/dircolors ]; then
    test -r ~/.dircolors && eval "$(dircolors -b ~/.dircolors)" || eval "$(dircolors -b)"
    alias ls='ls --color=auto'
    alias grep='grep --color=auto'
    alias fgrep='fgrep --color=auto'
    alias egrep='egrep --color=auto'
fi

# Custom aliases
alias ll='ls -alF'
alias la='ls -A'
alias l='ls -CF'
alias ..='cd ..'
alias ...='cd ../..'

# Custom functions
mkcd() {
    mkdir -p "$1" && cd "$1"
}

# Environment variables
export EDITOR="code"
export PATH="$HOME/.local/bin:$PATH"

# Profile file hierarchy
~/.bash_profile    # Login shells (macOS)
~/.bashrc         # Interactive non-login shells
~/.bash_login     # Login shells (Linux)
~/.profile        # Fallback for login shells

# Source bashrc from bash_profile
if [ -f ~/.bashrc ]; then
    source ~/.bashrc
fi

# Reload configuration
source ~/.bashrc

# Zsh advanced globbing
ls **/*.js          # Recursive file search
ls *(.)             # Only files
ls *(/)             # Only directories
ls *.(js|ts)        # Multiple extensions
ls **/node_modules  # Recursive directory

# Bash basic globbing
ls *.js             # Current directory
ls ?.js             # Single character
ls [a-z]*.js        # Character range
ls {*.js,*.ts}      # Brace expansion

# Install plugins
git clone https://github.com/zsh-users/zsh-autosuggestions ${ZSH_CUSTOM:-~/.oh-my-zsh/custom}/plugins/zsh-autosuggestions
git clone https://github.com/zsh-users/zsh-syntax-highlighting.git ${ZSH_CUSTOM:-~/.oh-my-zsh/custom}/plugins/zsh-syntax-highlighting
git clone https://github.com/zsh-users/zsh-completions ${ZSH_CUSTOM:-~/.oh-my-zsh/custom}/plugins/zsh-completions

# Add to plugins array
plugins=(
  git
  zsh-autosuggestions
  zsh-syntax-highlighting
  zsh-completions
  docker
  docker-compose
  node
  npm
  yarn
  python
  pip
)

# Install bash-completion
# Ubuntu/Debian
sudo apt install bash-completion

# macOS
brew install bash-completion

# Add to ~/.bashrc
if [ -f /usr/share/bash-completion/bash_completion ]; then
    . /usr/share/bash-completion/bash_completion
elif [ -f /etc/bash_completion ]; then
    . /etc/bash_completion
fi

# Custom completions
complete -W "start stop restart status" docker
complete -W "add commit push pull status" git

# Measure shell startup time
time zsh -i -c exit
time bash -i -c exit

# Typical results:
# Zsh: 0.1-0.3 seconds (with Oh My Zsh)
# Bash: 0.05-0.1 seconds (minimal config)

# Optimize Zsh startup
# Use lazy loading for plugins
zinit light zsh-users/zsh-autosuggestions
zinit light zsh-users/zsh-syntax-highlighting

# 1. Backup existing configuration
cp ~/.bashrc ~/.bashrc.backup
cp ~/.bash_profile ~/.bash_profile.backup

# 2. Install Zsh
brew install zsh  # macOS
sudo apt install zsh  # Ubuntu

# 3. Install Oh My Zsh
sh -c "$(curl -fsSL https://raw.github.com/ohmyzsh/ohmyzsh/master/tools/install.sh)"

# 4. Migrate aliases and functions
# Copy from ~/.bashrc to ~/.zshrc

# 5. Test configuration
zsh
source ~/.zshrc

# 6. Set as default shell
chsh -s $(which zsh)

# 1. Backup Zsh configuration
cp ~/.zshrc ~/.zshrc.backup

# 2. Create Bash configuration
touch ~/.bashrc

# 3. Migrate essential settings
# Copy aliases, functions, and environment variables

# 4. Set Bash as default
chsh -s /bin/bash

# 5. Test configuration
bash
source ~/.bashrc

# Custom Zsh prompt
autoload -U promptinit; promptinit
prompt custom

# Or use Powerlevel10k
git clone --depth=1 https://github.com/romkatv/powerlevel10k.git ${ZSH_CUSTOM:-$HOME/.oh-my-zsh/custom}/themes/powerlevel10k
ZSH_THEME="powerlevel10k/powerlevel10k"

# Custom Bash prompt
export PS1='\[\033[01;32m\]\u@\h\[\033[00m\]:\[\033[01;34m\]\w\[\033[00m\]\$ '

# With Git branch
parse_git_branch() {
    git branch 2> /dev/null | sed -e '/^[^*]/d' -e 's/* \(.*\)/(\1)/'
}
export PS1="\u@\h \[\033[32m\]\w\[\033[33m\]\$(parse_git_branch)\[\033[00m\] $ "

# Use Zsh for:
- Interactive development work
- Complex command line workflows
- Plugin-rich environments
- Modern scripting needs
- Team environments with shared configs
- macOS development (default since Catalina)

# Use Bash for:
- Server environments
- Scripting and automation
- POSIX compliance requirements
- Legacy system support
- Minimal resource environments
- Universal compatibility needs