gem 'rubyzip', '>= 1.0.0' # will load new rubyzip version
gem 'zip-zip' # will load compatibility for old rubyzip API.

gem 'rubyzip'

require 'rubygems'
require 'zip'

folder = "Users/me/Desktop/stuff_to_zip"
input_filenames = ['image.jpg', 'description.txt', 'stats.csv']

zipfile_name = "/Users/me/Desktop/archive.zip"

Zip::File.open(zipfile_name, Zip::File::CREATE) do |zipfile|
  input_filenames.each do |filename|
    # Two arguments:
    # - The name of the file as it will appear in the archive
    # - The original file, including the path to find it
    zipfile.add(filename, File.join(folder, filename))
  end
  zipfile.get_output_stream("myFile") { |f| f.write "myFile contains just this" }
end

require 'zip'

# This is a simple example which uses rubyzip to
# recursively generate a zip file from the contents of
# a specified directory. The directory itself is not
# included in the archive, rather just its contents.
#
# Usage:
#   directory_to_zip = "/tmp/input"
#   output_file = "/tmp/out.zip"
#   zf = ZipFileGenerator.new(directory_to_zip, output_file)
#   zf.write()
class ZipFileGenerator
  # Initialize with the directory to zip and the location of the output archive.
  def initialize(input_dir, output_file)
    @input_dir = input_dir
    @output_file = output_file
  end

  # Zip the input directory.
  def write
    entries = Dir.entries(@input_dir) - %w(. ..)

    ::Zip::File.open(@output_file, ::Zip::File::CREATE) do |zipfile|
      write_entries entries, '', zipfile
    end
  end

  private

  # A helper method to make the recursion work.
  def write_entries(entries, path, zipfile)
    entries.each do |e|
      zipfile_path = path == '' ? e : File.join(path, e)
      disk_file_path = File.join(@input_dir, zipfile_path)
      puts "Deflating #{disk_file_path}"

      if File.directory? disk_file_path
        recursively_deflate_directory(disk_file_path, zipfile, zipfile_path)
      else
        put_into_archive(disk_file_path, zipfile, zipfile_path)
      end
    end
  end

  def recursively_deflate_directory(disk_file_path, zipfile, zipfile_path)
    zipfile.mkdir zipfile_path
    subdir = Dir.entries(disk_file_path) - %w(. ..)
    write_entries subdir, zipfile_path, zipfile
  end

  def put_into_archive(disk_file_path, zipfile, zipfile_path)
    zipfile.get_output_stream(zipfile_path) do |f|
      f.write(File.open(disk_file_path, 'rb').read)
    end
  end
end

Zip::File.open('foo.zip') do |zip_file|
  # Handle entries one by one
  zip_file.each do |entry|
    # Extract to file/directory/symlink
    puts "Extracting #{entry.name}"
    entry.extract(dest_file)

    # Read into memory
    content = entry.get_input_stream.read
  end

  # Find specific entry
  entry = zip_file.glob('*.csv').first
  puts entry.get_input_stream.read
end

Zip::OutputStream.write_buffer(::StringIO.new(''), Zip::TraditionalEncrypter.new('password')) do |out|
  out.put_next_entry("my_file.txt")
  out.write my_data
end.string

buffer = Zip::OutputStream.write_buffer do |out|
  @zip_file.entries.each do |e|
    unless [DOCUMENT_FILE_PATH, RELS_FILE_PATH].include?(e.name)
      out.put_next_entry(e.name)
      out.write e.get_input_stream.read
     end
  end

  out.put_next_entry(DOCUMENT_FILE_PATH)
  out.write xml_doc.to_xml(:indent => 0).gsub("\n","")

  out.put_next_entry(RELS_FILE_PATH)
  out.write rels.to_xml(:indent => 0).gsub("\n","")
end

File.open(new_path, "wb") {|f| f.write(buffer.string) }

Zip.on_exists_proc = true

Zip.continue_on_exists_proc = true

Zip.unicode_names = true

Zip.warn_invalid_date = false

Zip.default_compression = Zlib::DEFAULT_COMPRESSION

Zip.force_entry_names_encoding = 'UTF-8'

  Zip.setup do |c|
    c.on_exists_proc = true
    c.continue_on_exists_proc = true
    c.unicode_names = true
    c.default_compression = Zlib::BEST_COMPRESSION
  end

Zip.write_zip64_support = true