I am not able to switch the current Ruby version:
➜ ~ rvm list rvm rubies ruby-1.9.2-p290 [ x86_64 ] ruby-1.9.3-p0 [ x86_64 ] ➜ ~ rvm use ruby-1
The above solution will only work, if RVM is installed for the current user. A more general solution would use the RVM path variable:
# The following code loads RVM as user or system install: [[ -s "$rvm_path/scripts/rvm" ]] && . "$rvm_path/scripts/rvm"