As of OS X Yosemite, the built-in version of ZSH is 5.0.5. If you’re, like me, a fan of the latest and greatest, you might be tempted to use the Homebrew version of ZSH instead of the default system one. As of the writing of this post, the latest version of ZSH is 5.1. Here’s how you install and set it as the default shell.
This very short guide assumes that you’re already familiar with Homebrew and have it installed. Once that’s sorted, install ZSH.
$ brew install zsh
Edit /etc/shells to add a new entry for the Homebrew ZSH.
$ sudo vim /etc/shells
At the end of the file add /usr/local/bin/zsh, which is the path to the Homebrew binary for ZSH. Your /etc/shells should look like this:
# List of acceptable shells for chpass(1).
# Ftpd will not allow users to connect who are not using
# one of these shells.
/bin/bash
/bin/csh
/bin/ksh
/bin/sh
/bin/tcsh
/bin/zsh
/usr/local/bin/zsh
Now we need to set our Homebrew ZSH as the default shell.
$ chsh -s /usr/local/bin/zsh
Now open up a new terminal, and we’re done! Welcome to the bleeding edge of ZSH!