File.open("filename.7z", "rb") do |file|
  SevenZipRuby::Reader.open(file) do |szr|
    szr.extract_all "path_to_dir"
  end
end

File.open("filename.7z", "rb") do |file|
  SevenZipRuby::Reader.extract_all(file, "path_to_dir")
end

File.open("filename.7z", "rb") do |file|
  SevenZipRuby::Reader.open(file) do |szr|
    list = szr.entries
    p list
    # => [ "#<EntryInfo: 0, dir, dir/subdir>", "#<EntryInfo: 1, file, dir/file.txt>", ... ]
  end
end

File.open("filename.7z", "rb") do |file|
  SevenZipRuby::Reader.open(file, { password: "Password String" }) do |szr|
    szr.extract_all "path_to_dir"
  end
end

File.open("filename.7z", "rb") do |file|
  SevenZipRuby::Reader.extract_all(file, "path_to_dir", { password: "Password String" })
end

File.open("filename.7z", "rb") do |file|
  SevenZipRuby::Reader.verify(file)
  # => true/false
end

File.open("filename.7z", "wb") do |file|
  SevenZipRuby::Writer.open(file) do |szr|
    szr.add_directory("dir")
  end
end

File.open("filename.7z", "wb") do |file|
  SevenZipRuby::Writer.add_directory(file, "dir")
end

File.open("filename.7z", "rb") do |file|
  SevenZipRuby::Reader.open(file) do |szr|
    small_files = szr.entries.select{ |i| i.file? && i.size < 1024 }
    szr.extract(small_files, "path_to_dir")
  end
end

data = nil
File.open("filename.7z", "rb") do |file|
  SevenZipRuby::Reader.open(file) do |szr|
    smallest_file = szr.entries.select(&:file?).min_by(&:size)
    data = szr.extract_data(smallest_file)
  end
end
p data
#  => File content is shown.

File.open("filename.7z", "rb") do |file|
  SevenZipRuby::Writer.open(file) do |szr|
    szr.add_file "entry1.txt"
    szr.mkdir "dir1"
    szr.mkdir "dir2"

    data = [0, 1, 2, 3, 4].pack("C*")
    szr.add_data data, "entry2.txt"
  end
end

File.open("filename.exe", "rb") do |file|
  # :gui and :console can be specified as :sfx parameter.
  SevenZipRuby::Writer.open(file, sfx: :gui) do |szr|
    szr.add_data "file content", "file.txt"
  end
end

# random data
data = 50000000.to_enum(:times).map{ rand(256) }.pack("C*")

a = StringIO.new("")
start = Time.now
SevenZipRuby::Writer.open(a) do |szr|
  szr.method = "BZIP2"     # Set compression method to "BZIP2"
  szr.multi_thread = false # Disable multi-threading mode
  szr.add_data(data, "test.bin")
end
p(Time.now - start)
#  => 11.180934

a = StringIO.new("")
start = Time.now
SevenZipRuby::Writer.open(a) do |szr|
  szr.method = "BZIP2"     # Set compression method to "BZIP2"
  szr.multi_thread = true  # Enable multi-threading mode (default)
  szr.add_data(data, "test.bin")
end
p(Time.now - start)
#  => 3.607563    # Faster than single-threaded compression.