Find Method at Runtime
with tags DokuWiki ruby -How to find the source location of a Ruby method at runtime.
Taken from the Stack Overflow answer by wesgarrison.
I take no credit for the work.
# How to find out where a method comes from.
# Learned this from Dave Thomas while teaching Advanced Ruby Studio
# Makes the case for separating method definitions into
# modules, especially when enhancing built-in classes.
module Perpetrator
def crime
end
end
class Fixnum
include Perpetrator
end
p 2.method(:crime)
#<Method: Fixnum(Perpetrator)#crime>
If you’re on Ruby 1.9+, you can use source_location
require 'csv'
p CSV.new('string').method(:flock)
# => #<Method: CSV#flock>
CSV.new('string').method(:flock).source_location
# => ["/path/to/ruby/1.9.2-p290/lib/ruby/1.9.1/forwardable.rb", 180]
Note that this won’t work on everything, like native compiled code. The Method class has some neat functions, too, like Method#owner which returns the file where the method is defined.
EDIT: Also see the __file__
and __line__
and notes for REE in the other answer, they’re handy too. – wg