A Ruby script for replacing header files in multiple projects at once.

header_substituter.rb

#!/usr/bin/env ruby

projects = %w[CSV Caboodle Transcript Recipes Mockingbird Bindings WhatsYourFine Typewriter Specify Posit Braille Handsy]

# a regular expression to identify the existing header format
# in this case, I had been using the format from the Xcode file templates
existing_format = /\/\/\n\/\/  .*\n\/\/  .*\n\/\/\n\/\/.*\n\/\/.*\n\/\/\n/

# the new format to replace the old
# in my case, I didn't want to include file names or the project name,
# but by changing this to a regular expression and identify capture groups in the existing format, this would be an easy extension
new_format = <<EOF
// The MIT License
// 
// Copyright (c) 2013 Ryan Davies
// 
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
// 
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
EOF

projects.each do |project|
  # I use the `hub` command to work with GitHub (https://github.com/defunkt/hub)
  # switch to `git clone git@github.com:user/#{project}.git` if you're not using `hub`
  system "hub clone #{project}"
  Dir.chdir(project)
  
  Dir["**/*.{h,m}"].entries.each do |filename|
    unless File.directory?(filename)
      contents = File.read(filename)
      contents.sub!(existing_format, new_format)
      if contents
        File.write(filename, contents)
        puts "#{filename} processed."
      else
        puts "#{filename} contained no matching header."
      end
    else
      puts "#{filename} skipped as is a directory."
    end
  end
  
  system "git add -A"
  system "git commit -m \"Updated headers to include MIT license.\""
  system "git push"
  
  Dir.chdir('..')
  
  system "rm -Rf #{project}"
end