RVM home page: http://rvm.beginrescueend.com

Install RVM
------------

See http://rvm.beginrescueend.com/rvm/install/

  bash < <(curl -s https://raw.github.com/wayneeseguin/rvm/master/binscripts/rvm-installer)

Install rvm for all users
--------------------------

Fairly complicated; make sure to read
http://rvm.beginrescueend.com/deployment/system-wide/

Upgrade to the latest version of rvm from github
-------------------------------------------------

  rvm update --head

Ruby on Rails 3 Tutorial says to follow this with

  rvm reload
  rvm install 1.8.7
  rvm install 1.9.2

and, if you need a patchlevel, do something like

  rvm install 1.8.7-p174

Install a given version of ruby
--------------------------------

  rvm install 1.9.2

If this fails with compiler errors, you may need to install some packages.

  rvm pkg install openssl
  rvm pkg install zlib
  rvm pkg install readline
  rvm pkg install iconv
  rvm pkg install libxml2
  rvm install 1.9.2 --with-openssl-dir=$rvm_path/usr \
                    --with-zlib-dir=$rvm_path/usr \
                    --with-readline-dir=$rvm_path/usr \
                    --with-iconv-dir=$rvm_path/usr \
                    --with-libxml2-dir=$rvm_path/usr

On Mac, you may need to install some libraries via MacPorts.

  sudo port install ncurses
  sudo port install libyaml
  sudo port install zlib  
  rvm install 1.9.2 --with-libyaml-dir=/opt/local \
    --with-openssl-dir=$HOME/.rvm/usr \
    --with-readline-dir=$HOME/.rvm/usr \
    --with-iconv-dir=$HOME/.rvm/usr

More at http://rvm.beginrescueend.com/rubies/installing/

Open a new shell and rvm!
-------------------------

  rvm use 1.9.1 
  >> Switching to ruby 1.9.1 ... 

  ruby -v 
  >> ruby 1.9.1p243 (2009-07-16 revision 24175) [x86_64-linux] 

  which ruby 
  >> /home/wayne/.rvm/ruby-1.9.1-p243/bin/ruby

Make 1.9.2 default for all new shells
--------------------------------------

  rvm --default 1.9.2

Reverting to system default
----------------------------

  rvm system
  ruby -v 
  >> ruby 1.8.7 (2008-08-11 patchlevel 72) [universal-darwin10.0] 
  which ruby 
  >> /usr/bin/ruby

Installing gems in multiple ruby versions
------------------------------------------

  rvm 1.8.6,1.9.1 gem install rspec json --no-rdoc --no-ri

Starting a new project? Create a Gemset and rvmrc at the same time:
-------------------------------------------------------------------
  rvm --create --rvmrc ree@project_name

Working with gemsets
--------------------

  rvm 1.8.7                       # use the ruby to manage gemsets for
  rvm gemset create project_name  # create a gemset
  rvm gemset use project_name     # use a gemset in this ruby
  rvm gemset list                 # list gemsets in this ruby
  rvm gemset delete project_name  # delete a gemset
  rvm 1.9.1@other_project_name    # use another ruby and gemset

The global gemset
-----------------

  With every ruby, rvm creates the global gemset.  Gems installed into this
  gemset are available to all gemsets in the ruby.

    rvm 1.8.7
    rvm gemset create project_name
    gem list # no gems :(

    rvm gemset use global
    gem install rake
    rvm gemset use project_name
    gem list # rake :)

  Install a gem directly into the global gemset:

    rvm 1.8.7@global gem install shoulda

  Install cheat in the global gemset when you install a new ruby:

    echo "cheat" >> ~/.rvm/gemsets/global.gems

.rvmrc
------

  rvm can automatically use a ruby and gemset when you cd to a project
  directory.

  echo "rvm 1.8.7@project_name" > ~/projects/project_name/.rvmrc

Lots more help
---------------

  rvm help
  http://rvm.beginrescueend.com/