Install Ruby

The recommended way to install Ruby on a new system is via rbenv. Here are 2 ways to install rbenv:

  1. Install rbenv with git
  2. Install rbenv with homebrew

1. Install rbenv with git

You can also simply install rbenv by cloning down the rbenv repo to ~/.rbenv.

git clone https://github.com/rbenv/rbenv.git ~/.rbenv

cat << 'EOF' >> ~/.bash_profile
export PATH="$HOME/.rbenv/bin:$PATH"
eval "$(rbenv init -)"
EOF

# install ruby-build as an rbenv plugin
mkdir -p ~/.rbenv/plugins
git clone https://github.com/rbenv/ruby-build.git ~/.rbenv/plugins/ruby-build

With the rbenv git approach, you’ll be able to use the latest available rubies by updating the ruby-build plugin repo directly.

cd ~/.rbenv/plugins/ruby-build && git pull

Then install different ruby versions. Example:

rbenv install 3.0.3
rbenv global 3.0.3
echo 3.0.3 > ~/.ruby-version # on some systems this is needed

Start a new terminal and confirm that you’re using ruby provided by rbenv. You should see something like this:

$ type ruby
ruby is /Users/tung/.rbenv/shims/ruby

Uninstall Ruby and rbenv

The nice thing about using rbenv is that the Ruby installation is isolated to ~/.rbenv. So you could always remove it with:

rm -rf ~/.rbenv

And removing the 2 lines of rbenv configuration in ~/.bash_profile.

2. Install rbenv with homebrew

You can install rbenv with homebrew also:

brew install rbenv

You should see something like this:

$ type rbenv
rbenv is /usr/local/bin/rbenv
$ type ruby-build
ruby-build is /usr/local/bin/ruby-build

Note, ruby-build is installed as a part of rbenv by brew.

Rbenv installs different versions of ruby in the ~/.rbenv folder. To complete the setup process: Add this to your ~/.bash_profile

export PATH="$HOME/.rbenv/bin:$PATH"
eval "$(rbenv init)"

And start a new terminal. You should be able to see something like this:

$ type ruby
ruby is /Users/tung/.rbenv/shims/ruby

Then install different ruby versions. Example:

rbenv install 3.0.3
rbenv global 3.0.3
echo 3.0.3 > ~/.ruby-version # on some systems this is needed

Uninstall Ruby and rbenv

To uninstall with homebrew:

brew uninstall rbenv

Notes

  • With rbenv, you sometimes have to run rbenv rehash to generate the shims.
  • rvm is also a ruby version manager similar to rbenv and is another way to install and manage multiple versions of ruby.
  • Generally, have not used brew install ruby because it doesn’t always seem to regenerate the right executables in /usr/local/bin when installing gems.