Finding the gem root

Question

Is there a way to know the root path of my gem? I am trying to load a default config from a yaml inside the gems path. How do I get the gems root directory with ruby?

Answer 1

Given the following project structure:

your_gem/   lib/     your_gem.rb 

Here's how I would do it:

# your_gem.rb  module YourGem   def self.root     File.expand_path '../..', __FILE__   end end 

Ruby 2.0 introduced the Kernel#__dir__ method; it enables a considerably shorter solution:

# your_gem.rb  module YourGem   def self.root     File.dirname __dir__   end end 

If you need access to the other directories, you can simply build upon root:

module YourGem   def self.bin     File.join root, 'bin'   end    def self.lib     File.join root, 'lib'   end end 

Answer 2

This is a universal solution for executables and libs. It loads the specification using the Gem API, so the path is always correct:

spec = Gem::Specification.find_by_name("your_gem_name") gem_root = spec.gem_dir yaml_obj = YAML.load(gem_root + "/file_name.yaml")