Master Zsh: From Basics to Oh‑My‑Zsh Full Configuration

1. Zsh Introduction

1.1 Linux Shell

Linux/Unix offers many shells; developers often create new ones to simplify complex tasks. Common shells include sh, bash, csh, etc. To list available shells on your system, run: cat /etc/shells The output shows the installed shells.

1.2 What Is Zsh?

Zsh is a powerful Linux shell. Although most Linux distributions ship with bash as the default, Zsh is widely available and can be installed via package managers such as apt‑get, yum, or urpmi.

Key Zsh features include:

Programmable command‑line completion for parameters and options.

Shared command history across all running shells.

Extended globbing that can replace external find commands.

Improved variable and array handling.

Multi‑line command editing in the buffer.

Compatibility modes (e.g., mimicking Bourne shell).

Customizable prompts, including right‑side information that hides on long commands.

Loadable modules for TCP/Unix‑domain sockets, FTP client, and extended math functions.

Full customizability.

1.3 Zsh and Oh‑My‑Zsh Ultimate Configuration

Inspired by an article titled “Ultimate Shell—Zsh,” the author adopted Zsh for its auto‑completion and extended features. Oh‑My‑Zsh builds on Zsh, offering easy plugin management, theme customization, and attractive completions.

Oh‑My‑Zsh repository: https://github.com/robbyrussell/oh-my-zsh

2. Installing Zsh

2.1 Install Zsh

On a typical Ubuntu system with proper repositories configured, install Zsh with:

sudo apt‑get install zsh

2.2 Configure Zsh

Zsh configuration can be complex; you can copy a ready‑made .zshrc file to your home directory. You may also reuse your Bash configuration by copying ~/.bash_profile or ~/.profile to ~/.zshrc , as Zsh is Bash‑compatible.

2.3 Make Zsh the Default Shell

sudo usermod -s /bin/zsh username

Or:

chsh -s /bin/zsh

chsh -s `which zsh`

To revert to Bash: chsh -s /bin/bash If you prefer not to change the default shell, you can start Zsh manually with zsh and exit with exit.

2.4 Install Oh‑My‑Zsh

Because Zsh is powerful but complex, Oh‑My‑Zsh simplifies its usage.

Clone the repository:

git clone git://github.com/robbyrussell/oh-my-zsh.git ~/.oh-my-zsh

Backup existing .zshrc and replace it:

cp ~/.zshrc ~/.zshrc.orig
cp ~/.oh-my-zsh/templates/zshrc.zsh-template ~/.zshrc

Or install via script:

sh -c "$(curl -fsSL https://raw.githubusercontent.com/robbyrussell/oh-my-zsh/master/tools/install.sh)"

sh -c "$(wget https://raw.githubusercontent.com/robbyrussell/oh-my-zsh/master/tools/install.sh -O -)"

Configure Theme

Oh‑My‑Zsh includes many themes located in oh-my-zsh/theme. Set the desired theme in ~/.zshrc:

ZSH_THEME="agnoster"  # example of a fancy theme

Or enable random selection:

ZSH_THEME="random"

Configure Plugins

Edit the plugins array in ~/.zshrc:

plugins=(git bundler osx rake ruby)

Update Oh‑My‑Zsh

By default you are prompted to check for updates weekly. To disable prompts, add: disable_update_prompt=true Or disable automatic updates entirely: disable_auto_update=true To manually upgrade at any time:

upgrade_oh_my_zsh

Uninstall Oh‑My‑Zsh

To remove Oh‑My‑Zsh and restore previous configurations, run:

uninstall_oh_my_zsh zsh