Show full path name of the ruby file when it get loaded

Question

When reading source code, I always want to know the full path of the file when it is loaded, is there any callback method in ruby to accomplish this, or any other way to do this? thanks in advance.

EDIT Clarification from the comments:

I want to know where the loaded "somefile" is located while I execute this line: "load somefile"

Answer 1

Show a file's pathname in Ruby

How about simple (from a quicky test in Camping):

File.expand_path(File.dirname(__FILE__))

?

Answer 2

The best way I can think of is to patch the Kernel module. According to the docs Kernel::load searches $: for the filename. We can do the same thing and print the path if we find it.

module Kernel
  def load_and_print(string)
    $:.each do |p|
      if File.exists? File.join(p, string)
        puts File.join(p, string)
        break
      end
    end
    load_original(string)
  end

  alias_method :load_original, :load
  alias_method :load, :load_and_print

end

We use alias_method to store the original load method, which we call at the end of ours.

Answer 3

Gordon Wilson's answer is great, just wanted to add that you can also see which libraries were loaded (and their complete path!) , by looking at the output of the variable $" (returns an array of absolute file names)

e.g. the path of the most recently loaded library is at the end of the array