Simple script to replace lambda to proc in all files within a directory for rails named_scopes. Can be used for any other text replacement by just modifying the regex and substitution code

lambda_to_proc

#!/usr/bin/ruby

directory = "app/models"
all_files = Dir.glob(File.join('app/models', '**', '*.rb'))

puts "Potentially modifying #{all_files.size}. Do you want to continue? [y/n]"
reply = gets
exit unless  %w(y yes).include? reply.chomp.downcase

all_files.each do |filename|
  file_modified = false
  lines = IO.readlines(filename)

  lines.each_with_index do |line, i|
    r = Regexp.new /named_scope\s+:(.*),\s+(lambda)/
    if r.match(line)
      lines[i] = line.sub('lambda', 'proc')

      puts "Old line:\n#{line.strip}\n----------"
      puts "New line:\n#{lines[i].strip}\n----------"
      file_modified = true
    end
  end

  puts "Updated #{filename}\n\n" if file_modified
  File.open(filename, 'w') {|f| f.puts lines}
end