run if file

gistfile1.txt

# Only run the following code when this file is the main file being run
# instead of having been required or loaded by another file
if __FILE__==$0
  # Find the parent directory of this file and add it to the front
  # of the list of locations to look in when using require
  $:.unshift File.expand_path("../../", __FILE__)  
end

# http://stackoverflow.com/questions/4687680/what-does-if-file-0-mean-in-ruby