RVM Notes (Ruby Version Manager)

rvm_notes.txt

RVM Notes

Install a new version of ruby:
$ rvm install 1.9.2

use that version:
$ rvm use 1.9.2

check the version of ruby being used
$ ruby -v

find where that ruby version is stored
$ which ruby

Use the default system ruby typcially found here: /usr/bin/ruby
$ rvm system

list the existing versions of ruby that you have installed
$ rvm list

list all ruby versions that are available for install
$ rvm list known

Those are the version of ruby you are using.  Now lets create and use gemsets.

list all existing gemsets
rvm gemset list

rvm gemset use rore

shortcut to change to a specific ruby and gemset combo:
rvm use 1.9.2-p180@rore


Create a gemset 
(this gemset will use the current ruby version you declared above)
$ rvm gemset create rails300
Gemset 'rails300' created.

Of course, your going to want to automatically switch to that gemset every time you navigate to the project directory, so create a file as such.

$ vi .rvmrc
insert this line of code
	 	rvm use 1.9.2-p180@rore
save and exit file .rvmrc


***** workflow starts here ******
Use 'which ruby' command above to find out what version of ruby you are currently running, then you can switch into the gemset you just created
$ which ruby
/Users/nelsonhernandez/.rvm/rubies/ruby-1.8.7-p299/bin/ruby

$ rvm 1.8.7-p299@rails300

You are now in the ruby version 1.8.7-p299@rails300 gemspace.  Your system gems are no longer available at this point.
Note from the rvm site:
* RVM gives you a separate gem directory for each and every Ruby version and gemset. * What this means is that gems will have to be explicitly installed for each revision and gemset. RVM provides you with a way to manage this process; see the ' RVM gem ' page. 

So let's start by installing rails 3:
$ gem install rails

typical usage

#use a ruby version, usually 1.8.7 for rails 235 apps, 1.9.2-p180 for rails 3 apps
rvm use 1.9.2-p180

rvm gemset create myProjectName

rvm gemset use 1.9.2-p180@myProjectName

#create the .rvmrc file in the project directory so that 
vi .rvmrc
    rvm use 1.9.2-p180@myProjectName


#install bundler gem, then install base project directory gems.
gem install bundler
bundle install