# Antigen
  
  Antigen is a small set of functions that help you easily manage your shell (zsh)
  plugins, called bundles. The concept is pretty much the same as bundles in a
  typical vim+pathogen setup. Antigen is to zsh, what [Vundle][] is to vim.
  
  # Quick Usage
  
  The usage should be very familiar to you if you use Vundle. A typical `.zshrc`
  might look like this
  
      source ~/labs/antigen/antigen.zsh
  
      # Load the oh-my-zsh's library.
      bundle-lib
  
      # Bundles from the default repo (robbyrussell's oh-my-zsh).
      bundle --loc=plugins/git
      bundle --loc=plugins/heroku
      bundle --loc=plugins/pip
      bundle --loc=plugins/lein
      bundle --loc=plugins/command-not-found
  
      # Syntax highlighting bundle.
      bundle zsh-users/zsh-syntax-highlighting
  
      # Load the theme.
      bundle-theme robbyrussell
  
  Open your zsh with this zshrc and run `bundle-install` and you should be ready
  to roll. The complete syntax for the `bundle` command is discussed further down
  on this page.
  
  # Motivation
  
  If you use zsh and [oh-my-zsh][], you know that having many different plugins
  that are developed by many different authors in a single (sub)repo is not a very
  easy to maintain. There are some really fantastic plugins and utilities in
  oh-my-zsh, but having them all in a single repo doesn't really scale well. And I
  admire robbyrussell's efforts for reviewing and mergine the gigantic number of
  pull requests the project gets. It needs a better way of plugin management.
  
  This was discussed on [a][1] [few][2] [issues][3], but it doesn't look like
  there was any progress made. So, I'm trying to start this off with antigen,
  hoping to better this situation. Please note that I'm by no means a zsh or any
  shell script expert (far from it).
  
  [1]: https://github.com/robbyrussell/oh-my-zsh/issues/465
  [2]: https://github.com/robbyrussell/oh-my-zsh/issues/377
  [3]: https://github.com/robbyrussell/oh-my-zsh/issues/1014
  
  Inspired by vundle, antigen can pull oh-my-zsh style plugins from various github
  repositories. You are not limited to use plugins from the oh-my-zsh repository
  only and you don't need to maintain your own fork and pull from upstream every
  now and then.
  
  Antigen also lets you switch the prompt theme with one command, just like that
  
      bundle-theme candy
  
  and your prompt is changed, just for this session of course.
  
  # Commands
  
  ## bundle
  
  This is the command you use to tell antigen that you want to use a plugin. The
  simplest usage follows the following syntax
  
      bundle [<url> [<loc> [<name>]]]
  
  where `<url>` is the repository url and it defaults to [robbyrussell's
  oh-my-zsh][oh-my-zsh] repo. `<loc>` is the path under this repository which has
  the zsh plugin. This is typically the directory that contains a `*.plugin.zsh`
  file, but it could contain a completion file too. `<loc>` defaults to `/`, which
  indicates the repository itself is a plugin. `<name>` is the name with which
  this plugin will be identified. This plugin will be installed in the bundles
  directory with this name used as the directory name. If the `<name>` is not
  given, antigen tries to make an intelligent guess based on the other given
  arguments.
  
  An example invocation would be
  
      bundle https://github.com/robbyrussell/oh-my-zsh.git plugins/ant
  
  This would install the ant plugin (with `<name>` as `ant`) from robbyrussell's
  oh-my-zsh repo. Of course, github url's can be shortened.
  
      bundle robbyrussell/oh-my-zsh plugins/ant
  
  And since this is the default, even that isn't necessary. But we can't specify
  the `loc` without giving the first argument.
  
  For this and a few other reasons, `bundle` also supports a simple keyword
  argument syntax, using which we can rewrite the above as
  
      bundle --loc=plugins/ant
  
  Note that you can mix and match positional and keyword arguments. But you can't
  have positional arguments after starting keyword arguments.
  
      bundle robbyrussell/oh-my-zsh --loc=plugins/ant
  
  And keyword arguments don't care about the order in which the arguments are
  specified. The following is perfectly valid.
  
      bundle --loc=plugins/ant --url=robbyrussell/oh-my-zsh --name=ant
  
  In addition to the above discussed arguments, `bundle` also takes the following
  arguments but only as keyword arguments.
  
  `load` &mdash; Set to `true` (default) or `false`. If this is set to `false`,
  the plugin specified is only recorded, may be for future use. It is not loaded
  into the environment. But with `true`, the plugin is immediately sourced and
  is ready to use, which is the default behavior.
  
  ## bundle-install
  
  This is something you might not want to put in your `.zshrc`. Instead, run it to
  install all the recorded bundles, using the `bundle` command. It has the
  following syntax.
  
      bundle-install [--update]
  
  The optional `--update` argument can be given to update all your plugins from
  the server. By default, `bundle-install` does *not* check for updates on the
  plugins. It just installs them, if there is a cached copy available and if its
  not already installed.
  
  ## bundle-install!
  
  This is the same as running
  
      bundle-install --update
  
  That is, it installs the recorded plugins, and updates them to the latest
  available versions.
  
  ## bundle-cleanup
  
  Used to clean up unused bundles. It takes no arguments. When this is run, it
  lists out the plugins that are installed but are not recorded with a `bundle`
  command, and will ask you if you want to delete them.
  
  This command currently cannot run in a non-interactive mode. So it won't be very
  pleasant to use it in your `.zshrc`.
  
  ## bundle-lib
  
  This currently exists only to make is possible to use oh-my-zsh's library, since
  its organisation is different from that of plugins. If you want to load
  oh-my-zsh's library, which you very likely do, put a
  
      bundle-lib
  
  in  your `.zshrc`, before any `bundle` declarations. It takes no arguments.
  
  ## bundle-theme
  
  Used for switching the prompt theme. Invoke it with the name of the theme you
  want to use.
  
      bundle-theme fox
  
  Currently, themes are pulled from robbyrussell's oh-my-zsh repo, but it will
  support getting themes from other repos as well in the future.
  
  # Configuration
  
  The following environment variables can be set to customize the behavior of
  antigen. Make sure you set them *before* sourceing `antigen.zsh`.
  
  `ANTIGEN_DEFAULT_REPO_URL` &mdash; This is the default repository url that is
  used for `bundle` commands. The default value is robbyrussell's oh-my-zsh repo,
  but you can set this to the fork url of your own fork.
  
  `ANTIGEN_REPO_CACHE` &mdash; This is where the cloned repositories are cached.
  Defaults to `$HOME/.antigen/cache`
  
  `ANTIGEN_BUNDLE_DIR` &mdash; This is where the plugins are installed and sourced
  from. Defaults to `$HOME/.antigen/bundles`
  
  # Meta
  
  Please note that I built this over night and should be considered very alpha.
  However, I am using it full time now on my work machine.
  
  Project is licensed with the MIT License. To contribute, just fork, make changes
  and send a pull request. If its a rather long/complicated change, please
  consider opening an [issue][] first so we can discuss it out.
  
  [Vundle]: https://github.com/gmarik/vundle
  [oh-my-zsh]: https://github.com/robbyrussell/oh-my-zsh
  [issue]: https://github.com/sharat87/antigen/issues