Filesystem in Ruby - accessing parent files based on current folder/file path

puts File.expand_path(File.dirname(__FILE__) + "/../src/google_finance.rb")
puts File.dirname(__FILE__)

puts File.expand_path(File.dirname(__FILE__) + "/../../data")

#Webser            -- Root folder
#  +--data          --folder
#  +--sample         --folder
#    +--lib
#    +--src
#         +--google.rb
#         +--testing.rb
#    +--config.rb  

#to access data folder:
puts File.expand_path(File.dirname(__FILE__) + "/../../data")
#Output: C:/Users/user/workspace/WebservicesTest/data

#to access current folder:
puts File.dirname(__FILE__)
#C:/Users/user/workspace/WebservicesTest/sample/src

#to access google.rb file from testing.rb file:
puts File.expand_path(File.dirname(__FILE__) + "/../src/google_finance.rb")
#C:/Users/user/workspace/WebservicesTest/sample/src/google_finance.rb

#WE CAN REQUIRE LIKE THIS AS WELL
#require File.expand_path(File.dirname(__FILE__) + "/../lib/wrest")