A small Ruby script that modifies source code so that variables in the form "mName" are changed to "_name"

convert_members.rb

#!/usr/bin/ruby

if ARGV.count < 1
  puts "Usage: #{script_name} source_path"
  puts "  (e.g. ../src/starling/)"
  exit
end

search_path = ARGV[0]

Dir[search_path + "**/*.as"].each do |source_file|

  puts "converting " + source_file

  lines = []
  File.open(source_file, "r") do |file|
    file.each do |line|
      line_changes = false
      while m = line.match(/(\W)(m[A-Z]\w*)/) do
        line_changes = true
        old_word = m[2]
        new_word =
          if old_word == "mID" then "_id"
          else '_' + old_word[1].downcase + old_word[2..-1] end
        line[m.begin(2)...m.end(2)] = new_word
      end
      line = line.rstrip + "\n" if line_changes
      lines << line
    end
  end

  File.open(source_file, "w") do |file|
    file << lines.join
  end

end

This code was used to modify all of Starling's member variables from the "m"-prefix to the more widely used underscore ("_").
Note that the file ending (".as") is hard-coded in this script. If you want to use it for different file types, modify line 11.