Get class location from class object

FYI, In Rails's console or debugging sessions of Rails apps, you can find out the disk-location of the file where that particular class is defined. like

> show-source Job

this will give you

From: /home/john/projects/iisifix/app/models/job.rb @ line 13:
Class name: Job
Number of monkeypatches: 6. Use the `-a` option to display all available monkeypatches
Number of lines: 66

class Job < ApplicationRecord
  belongs_to :quote_request
  belongs_to :garage

For Methods and Procs Ruby 1.9 has method called source_location:

Returns the Ruby source filename and line number containing this method or nil if this method was not defined in Ruby (i.e. native)

So you can request for the method:

m = Foo::Bar.method(:create)

And then ask for the source_location of that method:

m.source_location

This will return an array with filename and line number. E.g for ActiveRecord::Base#validates this returns:

ActiveRecord::Base.method(:validates).source_location
# => ["/Users/laas/.rvm/gems/ruby-1.9.2-p0@arveaurik/gems/activemodel-3.2.2/lib/active_model/validations/validates.rb", 81]

For classes and modules, Ruby does not offer built in support, but there is an excellent Gist out there that builds upon source_location to return file for a given method or first file for a class if no method was specified:

• ruby where_is module

EDIT: For Ruby 1.8.7 there is a gem that backports source_location:

• ruby18_source_location