Detecting where your library has been required from

app1.rb

# Some userland app code

$LOAD_PATH.unshift "."

require 'lib'

app2.rb

# Some other userland app code

$LOAD_PATH.unshift "."

require 'lib'

lib.rb

# Your library
require 'rbconfig'

def in_my_codebase?(f)
  File.basename(f) == File.basename(__FILE__)
end

def in_local_ruby?(f)
  f.index(RbConfig::TOPDIR) == 0
end

def detect_requiring_file
  requiring_file = nil
  begin
    raise RuntimeError
  rescue RuntimeError => e
    files = e.backtrace.map { |line| line.split(":").first }
    files.reject! { |f| in_my_codebase?(f) }
    files.reject! { |f| in_local_ruby?(f) }
    requiring_file = files.first

  end
  requiring_file
end

p "required_from #{detect_requiring_file}"

output.txt

$ ruby app1.rb
required from app1.rb
$ ruby app2.rb
required from app2.rb