install rbenv and fast boot ruby

rbenvosx10.7.sh

#!/bin/bash
# Nathan Tsoi 2012
# mad props:
#  https://github.com/sstephenson/rbenv
#  https://github.com/sstephenson/ruby-build
#  https://github.com/mxcl/homebrew/wiki/installation
#  https://raw.github.com/gist/1688857

#remove rvm
rvm &>/dev/null
if [ ! $? -gt 0 ] ; then
  echo please remove or comment out the rvm import from your ~/.bash_profile
  echo it probably looks like:
  echo  '[[ -s "$HOME/.rvm/scripts/rvm" ]] && . "$HOME/.rvm/scripts/rvm"'
  exit 0
fi


#rbenv
rbenv &>/dev/null
if [ $? -gt 0 ] ; then
  cd ~
  git clone git://github.com/sstephenson/rbenv.git .rbenv
  echo '# rbenv' >> ~/.bash_profile
  echo 'export PATH="$HOME/.rbenv/bin:$PATH"' >> ~/.bash_profile
  echo 'eval "$(rbenv init -)"' >> ~/.bash_profile
  source ~/.bash_profile
else
  echo 'rbenv is installed, skipping'
fi

#rbenv-gemset
PLUGINS=~/.rbenv/plugins
if [ ! -d $PLUGINS/rbenv-gemset ] ; then
  mkdir -p $PLUGINS
  cd $PLUGINS
  git clone git://github.com/jamis/rbenv-gemset.git
else
  echo rbenv-gemset is installed, skipping
fi

#apple-gcc42, required for ruby-build
brew list &>/dev/null
if [ $? -gt 0 ] ; then
  echo 'you need homebrew: https://github.com/mxcl/homebrew/wiki/installation'
  exit 0
fi
brew list apple-gcc42 &>/dev/null
if [ $? -gt 0 ] ; then
  brew update
  brew tap homebrew/dupes
  brew install apple-gcc42
  brew link apple-gcc42
else
  echo 'apple-gcc42 is installed, skipping'
fi

#ruby-build
ruby-build --definitions &>/dev/null
if [ $? -gt 0 ] ; then
  git clone git://github.com/sstephenson/ruby-build.git
  cd ruby-build
  ./install.sh
else
  echo 'ruby-build is installed, skipping'
fi

#install some ruby 1.9.2
ONENINETWO=1.9.2-p290
rbenv versions | grep $ONENINETWO &>/dev/null
if [ $? -gt 0 ] ; then
  rbenv install $ONENINETWO 
  rbenv rehash
else
  echo ruby $ONENINETWO is installed, skipping
fi

#and superfast ruby 1.9.3
ONENINETHREE=1.9.3-p125-perf
rbenv versions | grep $ONENINETHREE &>/dev/null
if [ $? -gt 0 ] ; then
  curl https://raw.github.com/gist/1688857/rbenv.sh | sh
  # set the global default to 1.9.3
  rbenv global 1.9.3-p125-perf
  echo "# https://raw.github.com/gist/1688857
  export RUBY_HEAP_MIN_SLOTS=1000000
  export RUBY_HEAP_SLOTS_INCREMENT=1000000
  export RUBY_HEAP_SLOTS_GROWTH_FACTOR=1
  export RUBY_GC_MALLOC_LIMIT=1000000000
  export RUBY_HEAP_FREE_MIN=500000" >> ~/.bash_profile
else
  echo ruby $ONENINETHREE is installed, skipping
fi