Step1 — Install brew (if you installed, skip it)

ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"

Step2 — Install zsh and change shell to zsh

brew install zsh
chsh -s /usr/local/bin/zsh

Step3 — Install oh-my-zsh

git clone git://github.com/robbyrussell/oh-my-zsh.git ~/.oh-my-zsh
cp ~/.oh-my-zsh/templates/zshrc.zsh-template ~/.zshrc

Step4 — Install zsh-completions

brew install zsh-completions

Step5 — 調整設定

vim ~/.zshrc
@@ -1,8 +1,11 @@
# Path to your oh-my-zsh configuration.
ZSH=$HOME/.oh-my-zsh

+# zsh-completions
+fpath=(/usr/local/share/zsh-completions $fpath)

# Set name of the theme to load.
# Look in ~/.oh-my-zsh/themes/
# Optionally, if you set this to "random", it'll load a random theme each
# time that oh-my-zsh is loaded.
#ZSH_THEME="robbyrussell"

如果你想更換主題的話請到.zshrc中 #ZSH_THEME 更換, 以下是所以主題的資訊

http://zshthem.es/all/

Other

如果有遇到中文亂碼的問題 open terminal 輸入 vim ~/.zshrc, 在文件内容末端添加

export LC_ALL=en_US.UTF-8  
export LANG=en_US.UTF-8

接著再重啟terminal就好.