Usage:

    rvm Action [Implementation] [Options]

  Action:

    * usage  - Show this usage information
    use      - Switch to using a specific ruby versio (new login shell)
    info     - Show information for current ruby
    gemdir   - Switch to gem directory for installation (new login shell)
    srcdir   - Switch to src directory for the current ruby installation
    gemdup   - Clone source implementation version gems to currently used version
    install  - Install a ruby version, default is from source
    debug    - Emit environment and configuration information for debugging

  Implementation:

    * ruby   - MRI/YARV Ruby (The Standard), defaults to 1.8.6
    jruby    - jRuby
    ree      - Ruby Enterprise Edition
    rubinius - Rubinius (NIY)
    default  - Resets to the default system ruby
    all      - Used with install, installs all latest known versions
  
  Options: 

    -v|--version    - Ruby Package Version, defaults to 'latest'
    -l|--level      - Patch level for the specified Ruby version
    -p|--prefix     - Package and source directory prefix, with trailing slash!
                      Default is a users home directory and /usr/local/ for root
    -c|--configure  - Options for source compile (default: --enable-shared)
    -d|--debug      - Toggle debug mode on for extra messages (NIY)

  Notes:

    * Defaults above are denoted with a '*' prefix.
    * rvm is intended to be run as an individual user (not root, yet)
    * All ruby installation, configuration and source files are in ~/.rvm
    * To manually reset to defaults: "rm -f ~/.rvm/current", then open new shell
    * To preserve previous gem installations for a particular ruby version copy,
      move, symlink or copy the old gem directory to (1.8 for 1.8.X): 
      ~/.gem/$interpreter/$version

  Examples:

    $ gem install rvm       # Install the rvm gem
    $ rvm-install           # Install rvm, adds source hooks to ~/.bash_profile
    $ rvm install jruby     # Install jRuby, default 1.3.1
    $ rvm use ruby -v 1.9.1 # Use Ruby 1.9, install first if not installed
    $ rvm use -v 1.9        # Equivalent to above, because of defaults
    $ rvm use default       # Use the system default (as if no rvm)

  TODO: (in order)

    * Documentation
    * Change gemdup to simply allow for a path to base gem dir to clone from
    * rvm gemdir default
    * Debug level messages
    * Rubinius (not in first revisions)
    * Shell detection instead of simply assuming bash (not in first revisions)