rvm-prompt

To display the current ruby selection string in your prompt add this to your profile:

PS1="\$(~/.rvm/bin/rvm-prompt) $PS1"

By default rvm-prompt outputs the fully qualified ruby string necessary to select the particular ruby currently selected and nothing when system ruby is selected. You can change this default behavior and control the verbosity of rvm-prompt by combining the following parameters:

(i)nterpreter  - interpreter abreviation    (default)
(v)ersion      - version                    (default)
(p)atchlevel   - patch level                (default)
(g)emset       - current gemset             (default)
(r)evision     - revison
(a)rchitecture - architecture
(u)nicode      - single unicode character representation of interpreter
(s)ystem       - echo "system" when using system ruby

Below are some examples of running rvm-prompt with various arguments on different rubies.

∴ rvm 1.9.1 ; rvm-prompt i v p g # default
  
  ruby-1.9.1-p243
  
∴ rvm 1.9.1@rails ; rvm-prompt i v p g # default

  ruby-1.9.1-p243@rails
  
∴ rvm ree-1.8.7 ; rvm-prompt i v

  ree-1.8.7

∴ rvm jruby ; rvm-prompt v i

  1.5.1-jruby
  
∴ rvm jruby ; rvm-prompt u

  ☯

∴ rvm system ; rvm-prompt

  
  
∴ rvm system ; rvm-prompt s i v p
  
  system