Where is Ruby Installed?

How to find where Ruby is installed?

Question: Where is Ruby installed? How to check where Ruby is located.

To find out where Ruby is installed, use the which command:

$ which ruby
/usr/bin/ruby

If Ruby is not installed, the which command will show you Ruby is missing:

$ which ruby
ruby not found

You can use the which command with flag -a to see if more than one Ruby executable is installed:

$ which -a ruby
/Users/daniel/.asdf/shims/ruby
/usr/bin/ruby

The which or which -a commands may show the Ruby version number in the file path. To be certain what Ruby version you are using, use the ruby -v command. See the article Check Ruby version on Mac for more details.

MacOS comes with a "system Ruby" pre-installed. Use the which command to see if you are using the system Ruby:

$ which ruby
/usr/bin/ruby

If you see /usr/bin/ruby, it is the pre-installed macOS system Ruby. It's a bad idea to use the Mac system Ruby. See the article Do not use the MacOS system Ruby. That's why developers use a version manager such as asdf, chruby, rbenv, or rvm. A version manager can also help if you're juggling multiple projects that can't be updated all at once.

For a guide that compares version managers and shows the best way to install Ruby, see Install Ruby on a Mac.

Use the gem env command

The gem env command gives you a full picture of your local Ruby environment, including the Ruby installation directory:

gem env
RubyGems Environment:
  - RUBYGEMS VERSION: 3.2.7
  - RUBY VERSION: 3.0.0 (2020-12-25 patchlevel 0) [x86_64-darwin19]
  - INSTALLATION DIRECTORY: /Users/daniel/.asdf/installs/ruby/3.0.0/lib/ruby/gems/3.0.0
  - USER INSTALLATION DIRECTORY: /Users/daniel/.gem/ruby/3.0.0
  - RUBY EXECUTABLE: /Users/daniel/.asdf/installs/ruby/3.0.0/bin/ruby
  - GIT EXECUTABLE: /usr/local/bin/git
  - EXECUTABLE DIRECTORY: /Users/daniel/.asdf/installs/ruby/3.0.0/bin
  - SPEC CACHE DIRECTORY: /Users/daniel/.gem/specs
  - SYSTEM CONFIGURATION DIRECTORY: /Users/daniel/.asdf/installs/ruby/3.0.0/etc
  - RUBYGEMS PLATFORMS:
     - ruby
     - x86_64-darwin-19
  - GEM PATHS:
     - /Users/daniel/.asdf/installs/ruby/3.0.0/lib/ruby/gems/3.0.0
     - /Users/daniel/.gem/ruby/3.0.0
  - GEM CONFIGURATION:
     - :update_sources => true
     - :verbose => true
     - :backtrace => false
     - :bulk_threshold => 1000
     - "gem" => "--no-document"
  - REMOTE SOURCES:
     - https://rubygems.org/
  - SHELL PATH:
     - /Users/daniel/.asdf/installs/ruby/3.0.0/bin
     - /Users/daniel/.asdf/shims
     - /usr/local/opt/asdf/bin
     - /usr/local/bin
     - /usr/bin
     - /bin
     - /usr/sbin
     - /sbin

This is a typical Ruby installation with the asdf version manager.