这是一个在JPG图片中隐藏Zip压缩文件的脚本。

hide_secret_in_jpg.rb

#!/usr/bin/env ruby
require 'rubygems'
require 'zip'
class HideSecretInJpg
  def file_to_zip(filename)
    floder = File.expand_path(File.dirname(filename))
    zipfile = File.basename(filename, ".*") + ".zip"
    #zipfile = filename.sub(/\.\w+$/,"") + ".zip"

    input_filenames = [filename]
    Zip::File.open(zipfile, Zip::File::CREATE) do |zf|
      input_filenames.each do |fn|
        zf.add(fn, floder + '/' + fn)
      end
    end
    return zipfile
  end

  def zip_to_jpg(zip_file, jpg_file = "default.jpg")
    jpg = File.open(jpg_file, 'rb') { |f| f.read }
    zip = File.open(zip_file, 'rb') { |f| f.read }
    jpg_zip = jpg + zip
    File.open(File.basename(zip_file, ".*") + ".jpg", 'w') { |f| f.write(jpg_zip) }
  end

  def hide_secret_in_jpg(input_file, jpg_file = "default.jpg")
    if input_file
      if File.exist?(input_file) 
        zip_to_jpg(file_to_zip(input_file))
        File.delete(input_file.sub(/\.\w+$/,"") + ".zip")
      else
        puts "#{input_file} doesn't exist in current directory!"
      end
    else
      puts "You haven't choose which file to hide!"
    end
  end
end

file = HideSecretInJpg.new
file.hide_secret_in_jpg(ARGV[0])