count-line-endings.rb

#/ Usage: ruby count-line-endings.rb file1 file2 ...
#/
#/ Reports how many of each kind of line endings there are in the files.

ARGV.each do |file|
  File.open(file, 'rb') do |f|
    puts "#{file}:"
    state = :none
    dos = unix = mac = 0
    f.read.each_char do |c|
      case c
      when "\r"
        state = :r
      when "\n"
        if state == :r
          dos += 1
        else
          unix += 1
        end
        state = :none
      else
        if state == :r
          mac += 1
        end
        state = :none
      end
    end
    puts "  \\n:  #{unix}" if unix > 0
    puts "  \\r\\n: #{dos}" if dos > 0
    puts "  \\r:  #{mac}" if mac > 0
    puts "  total: #{unix + dos + mac}"
  end
end

if ARGV.empty?
  puts File.readlines(__FILE__).select { |line| line =~ /^#\// }.map { |line| line[3..-1] }
end