Starting in Ruby with RVM
Written by Arvinder Singh / June 29, 2012 / 3 mins read / Filed under Ruby, / Rvm
This piece is a contribution to Intermediate Ruby Programming - a free ruby course for newcomers run by rubylearning.org.
One of the problems that many new-bees in a language face while following while following a book or tutorial is the problem on dealing with different versions of the language e.g. version 1.8.7 and version 1.9.2 in the case of Ruby. If you are running Linux or OS X, do not worry - we got rvm
power!
What is RVM?
Ruby enVironment (Version) Manager (RVM) is a command-line tool developed by Wayne E. Seguin which allows you to easily install, manage, and work with multiple ruby environments from interpreters to sets of gems. You can install and separately manage more than one Ruby interpreter including MRI, JRuby and the kind.
Prerequisites
Most Linux/OS X using bash will have the necessary tools, including git - required to install RVM. However you can check the location of installed tools typing this on your bash
prompt.
for name in {bash,awk,sed,grep,ls,cp,tar,curl,gunzip,bunzip2,git,svn} ; do which $name ; done
If any of the tool is missing, you may install the missing package using apt-get
in Linux or using Homebrew on OS X.
Installing RVM
The simplest way to install rvm is using rvm-installer
script by typing the following on your bash
prompt:
bash < <(curl -s https://raw.github.com/wayneeseguin/rvm/master/binscripts/rvm-installer)
If you don’t trust the installer script, you can follow the instructions given here and download and inspect the script before installing.
Loading RVM into your shell
To make sure you can use rvm as a function or command from your bash shell, add the following at the end of your .bash_profile
file located in your home folder.
echo '[[ -s "$HOME/.rvm/scripts/rvm" ]] && . "$HOME/.rvm/scripts/rvm" # Load RVM function' >> ~/.bash_profile
Reload shell configuration and test
The simplest way to reload a shell is to close and restart it. If you are lazy like me and don’t want to do that, try reloading your .bash_profile
source .bash_profile
Now lets test if all went well
type rvm | head -1
If all went well, you should see this response
rvm is a function
Install a ruby interpreter
To see a list of Ruby interpreters available to us, run this command
rvm list known
You should see a list of Ruby interpreters available to be installed. For the purpose of this class, we’ll install Ruby 1.9.2
rvm install 1.9.2
Once the installation completes, lets give this new ruby a spin
rvm use 1.9.2
ruby -v
You should see something like following depending on your OS and installed version.
ruby 1.9.2p290 (2011-07-09 revision 32553) [x86_64-darwin10.8.0]
To load this version as our default version of Ruby, run the following command
rvm use 1.9.2 --default
Thats all! Enjoy creating fun in Ruby.