Defining methods at the top level scope

a.rb

#!/usr/bin/env ruby

def do_something_probably_just_in_this_script!
  puts "called in #{self} from #{caller[-1]}"
end

module HeresAnother
  def this_one
    puts "called in #{self} from #{caller[-1]}"
  end
end

include HeresAnother

do_something_probably_just_in_this_script!

require "./b"

b.rb

class Something
  def a_method
    send :do_something_probably_just_in_this_script!
  end
end

Something.new.a_method

String.new.send :do_something_probably_just_in_this_script!

puts String.private_methods.grep /do_somet/
puts String.new.private_methods.grep /do_som/


send :this_one

output

$ ruby temp.rb
called in main from temp.rb:15:in `<main>'
called in #<Something:0x007f8a3b82d9b8> from temp.rb:17:in `<main>'
called in  from temp.rb:17:in `<main>'
do_something_probably_just_in_this_script!
do_something_probably_just_in_this_script!
called in main from temp.rb:17:in `<main>'