Data URI scheme encoder

duri.rb

#!/usr/bin/ruby -w

require 'optparse'
require 'base64'

options = {}
optparse = OptionParser.new do |opts|
  opts.banner = "Usage: #$0 [options] FILE"

  options[:type] = nil
  opts.on('-m TYPE', '--mime TYPE', 'Specify MIME type') do |t|
    options[:type] = t
  end

  options[:wrap] = 80
  opts.on('-w COLS', '--wrap COLS', 'Wraps (default 80, 0 = no wrap)') do |w|
    options[:wrap] = w.to_i
  end
end
optparse.parse!

if ARGF.filename == '-'
  STDIN.tty? && abort('No file specified!')
  options[:type].nil? && abort('Cannot determine filetype!')
end

if options[:type].nil?
  options[:type] = `file --mime -b #{ARGF.filename}`.chomp
end

out = "data:#{options[:type]};base64,"
out << Base64.encode64(ARGF.binmode.read).delete("\n")

options[:wrap] > 0 && out.gsub!(/.{#{options[:wrap]}}/, "\\0\n")
puts out