How to find the path a Ruby Gem is installed at (i.e. Gem.lib_path c.f. Gem.bin_path)

Question

Gem.bin_path('cucumber', 'cucumber') 

Will return the binary/executable's path. It seems there is no such function to return the library path. Which in this case would, ideally, return:

/home/hedge/.rvm/gems/ruby-1.9.2-p136@bbb-bdd-meta-bdd/gems/cucumber-0.10.0/lib 

Have I missed something or is there a simple/one method way to get this information?

Updated: No CLI or non-stdlib suggestions please.

Answer 1

The problem with the checked answer is that you must "require" the rubygem or it won't work. Often this is undesireable because if you're working with an executable gem, you don't want to "require" it or you'll get a bunch of warnings.

This is a universal solution for executables and libs:

spec = Gem::Specification.find_by_name("cucumber") gem_root = spec.gem_dir gem_lib = gem_root + "/lib" 

If you want to get really technical, there isn't just one lib directory. The gemspec has a "require_paths" array of all the directorys to search (added to $LOAD_PATH). So, if you want an array of the require_paths, use this:

gem_lib = gem_root + "/" + spec.require_paths[0] 

No need for bundler.