Customization

oh-my-zsh is fully configurable to your needs with the help of the $ZSH_CUSTOM variable, whether you want to change its internals, plugins or the rich theme set - and all that without forking!

Initially $ZSH_CUSTOM points to oh-my-zsh's custom directory. Whatever you place inside of it will take precedence over the built-in configuration.

Overriding and adding plugins

Let's say you created your own plugin foobar and want to add it to your configuration.

# Your .zshrc
plugins=(git bundler foobar)

Then, create a foobar directory inside the plugins folder and an initialization script to launch your plugin. This script has to follow a naming convention, as all plugin files must have an ending of .plugin.zsh. Your file tree should look like this:

zsh_custom
└── plugins
    └── foobar
        └── foobar.plugin.zsh

Also follow these steps if you want to override plugins that ship with your oh-my-zsh installation. In case it's the rvm plugin you want to override, create the directory custom/plugins/rvm and place a file called rvm.plugin.zsh inside of it.

A word of warning: None of the original rvm plugin files will get sourced if you define a custom rvm plugin. If you want to customize just a single public function of a plugin, use the approach as outlined in the section below that tells you about how to override internals.

Overriding and adding themes

Adding and customizing your own themes pretty much works the same as with plugins.

Themes are located in a themes folder and must end with .zsh-theme.

zsh_custom
└── themes
    └── my_awesome_theme.zsh-theme

and within your .zshrc,

ZSH_THEME="my_awesome_theme"

Remember that customizations always take precedence over built-ins. If you happen to enjoy a particular theme that comes packaged with oh-my-zsh, but would like to change just a little detail inside of it - let's say you love the agnoster theme, it will be the easiest to copy the agnoster.zsh-theme file to your custom/themes directory and customize it.

If you don't change its filename, your .zshrc file can stay the same: ZSH_THEME="agnoster" will be perfect and still take your changes into account. You might also want to consider this before filing a new issue or pull request that just changes a trivial detail inside of a built-in theme.

Hint: Using a random theme with $ZSH_THEME="random" will not look into your custom themes directory. Only built-in themes will be used.

Overriding internals

oh-my-zsh's internals are defined in its lib directory. To change them just create a file inside the custom directory (its name doesn't matter, as long as it has a .zsh ending) and start customizing whatever you want. Unsatisfied with the way git_prompt_info() works? Ride your own implementation!

# custom/my_patches.zsh
function git_prompt_info() {
  # prove that you can do better
}

Such customization files will always be the last thing that oh-my-zsh sources before handing over control to your terminal. Also use this approach if you want to override specific details of built-in plugins.

Using another customization directory

If you don't want to use the built-in custom directory itself, just change the path of $ZSH_CUSTOM inside your .zshrc to a directory of your own liking. Everything will be fine as long as you adhere to the conventional file hierarchy.

# your .zshrc
ZSH_CUSTOM=$HOME/my_customizations

File tree inside of your home directory:

$HOME
└── my_customizations
    ├── my_lib_patches.zsh
    ├── plugins
    │   └── my_plugin
    │       └── my_plugin.plugin.zsh
    └── themes
        └── my_awesome_theme.zsh-theme

Version control of customizations

By default git is set to ignore the custom directory, so that oh-my-zsh's update process does not interfere with your customizations. If you want to use a version control system like git for your personal changes, just initialize an own repository inside the custom directory (git init), or point $ZSH_CUSTOM to another directory you have under version control.