Quick'n'dirty script for figuring out which methods are unused in a Rails project

gistfile1.rb

#!/usr/bin/env ruby

grep_result = `grep -ri "def " #{ARGV.join(' ')}`
methods = grep_result.split("\n").collect do |line|
  md = line.match(/.*:\s+def ([a-z_]+)(\((.*)\))?/i)
  md.to_a[1]
end

filtered_methods = methods.uniq - ["initialize"]
dirs = (Dir.glob("*") - ['vendor', 'log']).join(" ")

filtered_methods.each do |method_name|
  cmd = "grep -ri #{method_name} #{dirs}"
  lines = `#{cmd}`
  puts "#{method_name} only found once" if lines.split("\n").size < 2
end