fix_whitespace

#!/usr/bin/env ruby -w

# find . -type f -iname '*.rb' -exec fix_whitespace {} \;

require 'fileutils'

# set to nil if you don't want to backup anything
backup_dir = File.expand_path('~/.whitespace-backup')

unless backup_dir.nil? || File.directory?(backup_dir)
  FileUtils.mkdir_p(backup_dir)
end

while filename = ARGV.shift
  if File.file?(filename)
    # remove trailing white spaces
    filelines = File.readlines(filename)
    nicelines = filelines.map { |line| line.gsub(/[\t\ ]+\Z/, '') }
    # ensure that there are no empty lines at the end of the file
    nicelines.pop while nicelines[-1] == "\n"
    # the last line should end in a newline character
    nicelines[-1] += "\n" if nicelines[-1] !~ /\n\Z/
    # overwrite file if anything changed
    unless filelines == nicelines
      unless backup_dir.nil?
        # create backup
        timestamped = filename.split("/").last + '.' + Time.now.strftime("%Y%m%d%H%M%S")
        backup_file = File.expand_path(timestamped, backup_dir)
        FileUtils.copy(filename, backup_file)
        puts "backed up #{filename} to #{backup_file}"
      end
      File.open(filename, "w") { |f| f << nicelines }
      puts "changed #{filename}"
    end
  end
end