Installs RubyGems itself. This command is ordinarily only available from a RubyGems checkout or tarball.
 
               # File rubygems/commands/setup_command.rb, line 15
def initialize
  require 'tmpdir'
  super 'setup', 'Install RubyGems',
        :format_executable => true, :document => %w[ri],
        :force => true,
        :site_or_vendor => 'sitelibdir',
        :destdir => '', :prefix => '', :previous_version => '',
        :regenerate_binstubs => true,
        :regenerate_plugins => true
  add_option '--previous-version=VERSION',
             'Previous version of RubyGems',
             'Used for changelog processing' do |version, options|
    options[:previous_version] = version
  end
  add_option '--prefix=PREFIX',
             'Prefix path for installing RubyGems',
             'Will not affect gem repository location' do |prefix, options|
    options[:prefix] = File.expand_path prefix
  end
  add_option '--destdir=DESTDIR',
             'Root directory to install RubyGems into',
             'Mainly used for packaging RubyGems' do |destdir, options|
    options[:destdir] = File.expand_path destdir
  end
  add_option '--[no-]vendor',
             'Install into vendorlibdir not sitelibdir' do |vendor, options|
    options[:site_or_vendor] = vendor ? 'vendorlibdir' : 'sitelibdir'
  end
  add_option '--[no-]format-executable',
             'Makes `gem` match ruby',
             'If Ruby is ruby18, gem will be gem18' do |value, options|
    options[:format_executable] = value
  end
  add_option '--[no-]document [TYPES]', Array,
             'Generate documentation for RubyGems',
             'List the documentation types you wish to',
             'generate.  For example: rdoc,ri' do |value, options|
    options[:document] = case value
                         when nil   then %w[rdoc ri]
                         when false then []
                         else            value
                         end
  end
  add_option '--[no-]rdoc',
             'Generate RDoc documentation for RubyGems' do |value, options|
    if value
      options[:document] << 'rdoc'
    else
      options[:document].delete 'rdoc'
    end
    options[:document].uniq!
  end
  add_option '--[no-]ri',
             'Generate RI documentation for RubyGems' do |value, options|
    if value
      options[:document] << 'ri'
    else
      options[:document].delete 'ri'
    end
    options[:document].uniq!
  end
  add_option '--[no-]regenerate-binstubs',
             'Regenerate gem binstubs' do |value, options|
    options[:regenerate_binstubs] = value
  end
  add_option '--[no-]regenerate-plugins',
             'Regenerate gem plugins' do |value, options|
    options[:regenerate_plugins] = value
  end
  add_option '-f', '--[no-]force',
             'Forcefully overwrite binstubs' do |value, options|
    options[:force] = value
  end
  add_option('-E', '--[no-]env-shebang',
             'Rewrite executables with a shebang',
             'of /usr/bin/env') do |value, options|
    options[:env_shebang] = value
  end
  @verbose = nil
end
             
             
               # File rubygems/commands/setup_command.rb, line 112
def check_ruby_version
  required_version = Gem::Requirement.new '>= 2.3.0'
  unless required_version.satisfied_by? Gem.ruby_version
    alert_error "Expected Ruby version #{required_version}, is #{Gem.ruby_version}"
    terminate_interaction 1
  end
end
             
             
               # File rubygems/commands/setup_command.rb, line 150
def execute
  @verbose = Gem.configuration.really_verbose
  install_destdir = options[:destdir]
  unless install_destdir.empty?
    ENV['GEM_HOME'] ||= File.join(install_destdir,
                                  Gem.default_dir.gsub(/^[a-zA-Z]:/, ''))
  end
  check_ruby_version
  require 'fileutils'
  if Gem.configuration.really_verbose
    extend FileUtils::Verbose
  else
    extend FileUtils
  end
  extend MakeDirs
  lib_dir, bin_dir = make_destination_dirs install_destdir
  install_lib lib_dir
  install_executables bin_dir
  remove_old_bin_files bin_dir
  remove_old_lib_files lib_dir
  install_default_bundler_gem bin_dir
  if mode = options[:dir_mode]
    @mkdirs.uniq!
    File.chmod(mode, @mkdirs)
  end
  say "RubyGems #{Gem::VERSION} installed"
  regenerate_binstubs if options[:regenerate_binstubs]
  regenerate_plugins if options[:regenerate_plugins]
  uninstall_old_gemcutter
  documentation_success = install_rdoc
  say
  if @verbose
    say "-" * 78
    say
  end
  if options[:previous_version].empty?
    options[:previous_version] = Gem::VERSION.sub(/[0-9]+$/, '0')
  end
  options[:previous_version] = Gem::Version.new(options[:previous_version])
  show_release_notes
  say
  say "-" * 78
  say
  say "RubyGems installed the following executables:"
  say bin_file_names.map { |name| "\t#{name}\n" }
  say
  unless bin_file_names.grep(/#{File::SEPARATOR}gem$/)
    say "If `gem` was installed by a previous RubyGems installation, you may need"
    say "to remove it by hand."
    say
  end
  if documentation_success
    if options[:document].include? 'rdoc'
      say "Rdoc documentation was installed. You may now invoke:"
      say "  gem server"
      say "and then peruse beautifully formatted documentation for your gems"
      say "with your web browser."
      say "If you do not wish to install this documentation in the future, use the"
      say "--no-document flag, or set it as the default in your ~/.gemrc file. See"
      say "'gem help env' for details."
      say
    end
    if options[:document].include? 'ri'
      say "Ruby Interactive (ri) documentation was installed. ri is kind of like man "
      say "pages for Ruby libraries. You may access it like this:"
      say "  ri Classname"
      say "  ri Classname.class_method"
      say "  ri Classname#instance_method"
      say "If you do not wish to install this documentation in the future, use the"
      say "--no-document flag, or set it as the default in your ~/.gemrc file. See"
      say "'gem help env' for details."
      say
    end
  end
end
             
             
               # File rubygems/commands/setup_command.rb, line 462
def generate_default_dirs(install_destdir)
  prefix = options[:prefix]
  site_or_vendor = options[:site_or_vendor]
  if prefix.empty?
    lib_dir = RbConfig::CONFIG[site_or_vendor]
    bin_dir = RbConfig::CONFIG['bindir']
  else
    # Apple installed RubyGems into libdir, and RubyGems <= 1.1.0 gets
    # confused about installation location, so switch back to
    # sitelibdir/vendorlibdir.
    if defined?(APPLE_GEM_HOME) and
      # just in case Apple and RubyGems don't get this patched up proper.
      (prefix == RbConfig::CONFIG['libdir'] or
       # this one is important
       prefix == File.join(RbConfig::CONFIG['libdir'], 'ruby'))
      lib_dir = RbConfig::CONFIG[site_or_vendor]
      bin_dir = RbConfig::CONFIG['bindir']
    else
      lib_dir = File.join prefix, 'lib'
      bin_dir = File.join prefix, 'bin'
    end
  end
  unless install_destdir.empty?
    lib_dir = File.join install_destdir, lib_dir.gsub(/^[a-zA-Z]:/, '')
    bin_dir = File.join install_destdir, bin_dir.gsub(/^[a-zA-Z]:/, '')
  end
  [lib_dir, bin_dir]
end
             
             
               # File rubygems/commands/setup_command.rb, line 389
def install_default_bundler_gem(bin_dir)
  specs_dir = Gem.default_specifications_dir
  specs_dir = File.join(options[:destdir], specs_dir) unless Gem.win_platform?
  mkdir_p specs_dir, :mode => 0755
  # Workaround for non-git environment.
  gemspec = File.open('bundler/bundler.gemspec', 'rb'){|f| f.read.gsub(/`git ls-files -z`/, "''") }
  File.open('bundler/bundler.gemspec', 'w'){|f| f.write gemspec }
  bundler_spec = Gem::Specification.load("bundler/bundler.gemspec")
  bundler_spec.files = Dir.chdir("bundler") { Dir["{*.md,{lib,exe,man}/**/*}"] }
  bundler_spec.executables -= %w[bundler bundle_ruby]
  # Remove bundler-*.gemspec in default specification directory.
  Dir.entries(specs_dir).
    select {|gs| gs.start_with?("bundler-") }.
    each {|gs| File.delete(File.join(specs_dir, gs)) }
  default_spec_path = File.join(specs_dir, "#{bundler_spec.full_name}.gemspec")
  Gem.write_binary(default_spec_path, bundler_spec.to_ruby)
  bundler_spec = Gem::Specification.load(default_spec_path)
  # Remove gemspec that was same version of vendored bundler.
  normal_gemspec = File.join(Gem.default_dir, "specifications", "bundler-#{bundler_spec.version}.gemspec")
  if File.file? normal_gemspec
    File.delete normal_gemspec
  end
  # Remove gem files that were same version of vendored bundler.
  if File.directory? bundler_spec.gems_dir
    Dir.entries(bundler_spec.gems_dir).
      select {|default_gem| File.basename(default_gem) == "bundler-#{bundler_spec.version}" }.
      each {|default_gem| rm_r File.join(bundler_spec.gems_dir, default_gem) }
  end
  bundler_bin_dir = bundler_spec.bin_dir
  bundler_bin_dir = File.join(options[:destdir], bundler_bin_dir) unless Gem.win_platform?
  mkdir_p bundler_bin_dir, :mode => 0755
  bundler_spec.executables.each do |e|
    cp File.join("bundler", bundler_spec.bindir, e), File.join(bundler_bin_dir, e)
  end
  require 'rubygems/installer'
  Dir.chdir("bundler") do
    built_gem = Gem::Package.build(bundler_spec)
    begin
      installer = Gem::Installer.at(built_gem, env_shebang: options[:env_shebang], format_executable: options[:format_executable], force: options[:force], install_as_default: true, bin_dir: bin_dir, wrappers: true)
      installer.install
    ensure
      FileUtils.rm_f built_gem
    end
  end
  bundler_spec.executables.each {|executable| bin_file_names << target_bin_path(bin_dir, executable) }
  say "Bundler #{bundler_spec.version} installed"
end
             
             
               # File rubygems/commands/setup_command.rb, line 250
def install_executables(bin_dir)
  prog_mode = options[:prog_mode] || 0755
  executables = { 'gem' => 'bin' }
  executables.each do |tool, path|
    say "Installing #{tool} executable" if @verbose
    Dir.chdir path do
      bin_files = Dir['*']
      bin_files -= %w[update_rubygems]
      bin_files.each do |bin_file|
        dest_file = target_bin_path(bin_dir, bin_file)
        bin_tmp_file = File.join Dir.tmpdir, "#{bin_file}.#{$$}"
        begin
          bin = File.readlines bin_file
          bin[0] = shebang
          File.open bin_tmp_file, 'w' do |fp|
            fp.puts bin.join
          end
          install bin_tmp_file, dest_file, :mode => prog_mode
          bin_file_names << dest_file
        ensure
          rm bin_tmp_file
        end
        next unless Gem.win_platform?
        begin
          bin_cmd_file = File.join Dir.tmpdir, "#{bin_file}.bat"
          File.open bin_cmd_file, 'w' do |file|
            file.puts <<-TEXT
@ECHO OFF
IF NOT "%~f0" == "~f0" GOTO :WinNT
@"#{File.basename(Gem.ruby).chomp('"')}" "#{dest_file}" %1 %2 %3 %4 %5 %6 %7 %8 %9
GOTO :EOF
:WinNT
@"#{File.basename(Gem.ruby).chomp('"')}" "%~dpn0" %*
TEXT
          end
          install bin_cmd_file, "#{dest_file}.bat", :mode => prog_mode
        ensure
          rm bin_cmd_file
        end
      end
    end
  end
end
             
             
               # File rubygems/commands/setup_command.rb, line 315
def install_file(file, dest_dir)
  dest_file = File.join dest_dir, file
  dest_dir = File.dirname dest_file
  unless File.directory? dest_dir
    mkdir_p dest_dir, :mode => 0755
  end
  install file, dest_file, :mode => options[:data_mode] || 0644
end
             
             
               # File rubygems/commands/setup_command.rb, line 325
def install_lib(lib_dir)
  libs = { 'RubyGems' => 'lib' }
  libs['Bundler'] = 'bundler/lib'
  libs.each do |tool, path|
    say "Installing #{tool}" if @verbose
    lib_files = rb_files_in path
    lib_files.concat(template_files) if tool == 'Bundler'
    pem_files = pem_files_in path
    Dir.chdir path do
      lib_files.each do |lib_file|
        install_file lib_file, lib_dir
      end
      pem_files.each do |pem_file|
        install_file pem_file, lib_dir
      end
    end
  end
end
             
             
               # File rubygems/commands/setup_command.rb, line 348
def install_rdoc
  gem_doc_dir = File.join Gem.dir, 'doc'
  rubygems_name = "rubygems-#{Gem::VERSION}"
  rubygems_doc_dir = File.join gem_doc_dir, rubygems_name
  begin
    Gem.ensure_gem_subdirectories Gem.dir
  rescue SystemCallError
    # ignore
  end
  if File.writable? gem_doc_dir and
     (not File.exist? rubygems_doc_dir or
      File.writable? rubygems_doc_dir)
    say "Removing old RubyGems RDoc and ri" if @verbose
    Dir[File.join(Gem.dir, 'doc', 'rubygems-[0-9]*')].each do |dir|
      rm_rf dir
    end
    require 'rubygems/rdoc'
    fake_spec = Gem::Specification.new 'rubygems', Gem::VERSION
    def fake_spec.full_gem_path
      File.expand_path '../../../..', __FILE__
    end
    generate_ri   = options[:document].include? 'ri'
    generate_rdoc = options[:document].include? 'rdoc'
    rdoc = Gem::RDoc.new fake_spec, generate_rdoc, generate_ri
    rdoc.generate
    return true
  elsif @verbose
    say "Skipping RDoc generation, #{gem_doc_dir} not writable"
    say "Set the GEM_HOME environment variable if you want RDoc generated"
  end
  return false
end
             
             
               # File rubygems/commands/setup_command.rb, line 449
def make_destination_dirs(install_destdir)
  lib_dir, bin_dir = Gem.default_rubygems_dirs
  unless lib_dir
    lib_dir, bin_dir = generate_default_dirs(install_destdir)
  end
  mkdir_p lib_dir, :mode => 0755
  mkdir_p bin_dir, :mode => 0755
  return lib_dir, bin_dir
end
             
             
               # File rubygems/commands/setup_command.rb, line 494
def pem_files_in(dir)
  Dir.chdir dir do
    Dir[File.join('**', '*pem')]
  end
end
             
             
               # File rubygems/commands/setup_command.rb, line 500
def rb_files_in(dir)
  Dir.chdir dir do
    Dir[File.join('**', '*rb')]
  end
end
             
             
               # File rubygems/commands/setup_command.rb, line 623
def regenerate_binstubs
  require "rubygems/commands/pristine_command"
  say "Regenerating binstubs"
  args = %w[--all --only-executables --silent]
  if options[:env_shebang]
    args << "--env-shebang"
  end
  command = Gem::Commands::PristineCommand.new
  command.invoke(*args)
end
             
             
               # File rubygems/commands/setup_command.rb, line 636
def regenerate_plugins
  require "rubygems/commands/pristine_command"
  say "Regenerating plugins"
  args = %w[--all --only-plugins --silent]
  command = Gem::Commands::PristineCommand.new
  command.invoke(*args)
end
             
             
               # File rubygems/commands/setup_command.rb, line 522
  def remove_old_bin_files(bin_dir)
    old_bin_files = {
      'gem_mirror' => 'gem mirror',
      'gem_server' => 'gem server',
      'gemlock' => 'gem lock',
      'gemri' => 'ri',
      'gemwhich' => 'gem which',
      'index_gem_repository.rb' => 'gem generate_index',
    }
    old_bin_files.each do |old_bin_file, new_name|
      old_bin_path = File.join bin_dir, old_bin_file
      next unless File.exist? old_bin_path
      deprecation_message = "`#{old_bin_file}` has been deprecated. Use `#{new_name}` instead."
      File.open old_bin_path, 'w' do |fp|
        fp.write <<-EOF
#!#{Gem.ruby}
abort "#{deprecation_message}"
    EOF
      end
      next unless Gem.win_platform?
      File.open "#{old_bin_path}.bat", 'w' do |fp|
        fp.puts %Q{@ECHO.#{deprecation_message}}
      end
    end
  end
             
             
               # File rubygems/commands/setup_command.rb, line 554
def remove_old_lib_files(lib_dir)
  lib_dirs = { File.join(lib_dir, 'rubygems') => 'lib/rubygems' }
  lib_dirs[File.join(lib_dir, 'bundler')] = 'bundler/lib/bundler'
  lib_dirs.each do |old_lib_dir, new_lib_dir|
    lib_files = rb_files_in(new_lib_dir)
    lib_files.concat(template_files_in(new_lib_dir)) if new_lib_dir =~ /bundler/
    old_lib_files = rb_files_in(old_lib_dir)
    old_lib_files.concat(template_files_in(old_lib_dir)) if old_lib_dir =~ /bundler/
    to_remove = old_lib_files - lib_files
    to_remove.delete_if do |file|
      file.start_with? 'defaults'
    end
    Dir.chdir old_lib_dir do
      to_remove.each do |file|
        FileUtils.rm_f file
        warn "unable to remove old file #{file} please remove it by hand" if
          File.exist? file
      end
    end
  end
end
             
             
               # File rubygems/commands/setup_command.rb, line 305
def shebang
  if options[:env_shebang]
    ruby_name = RbConfig::CONFIG['ruby_install_name']
    @env_path ||= ENV_PATHS.find {|env_path| File.executable? env_path }
    "#!#{@env_path} #{ruby_name}\n"
  else
    "#!#{Gem.ruby}\n"
  end
end
             
             
               # File rubygems/commands/setup_command.rb, line 581
def show_release_notes
  release_notes = File.join Dir.pwd, 'History.txt'
  release_notes =
    if File.exist? release_notes
      history = File.read release_notes
      history.force_encoding Encoding::UTF_8
      history = history.sub(/^# coding:.*?(?=^=)/m, '')
      text = history.split(HISTORY_HEADER)
      text.shift # correct an off-by-one generated by split
      version_lines = history.scan(HISTORY_HEADER)
      versions = history.scan(VERSION_MATCHER).flatten.map do |x|
        Gem::Version.new(x)
      end
      history_string = ""
      until versions.length == 0 or
            versions.shift <= options[:previous_version] do
        history_string += version_lines.shift + text.shift
      end
      history_string
    else
      "Oh-no! Unable to find release notes!"
    end
  say release_notes
end
             
            for installation of bundler as default gems
 
               # File rubygems/commands/setup_command.rb, line 507
def template_files
  Dir.chdir "bundler/lib" do
    (Dir[File.join('bundler', 'templates', '**', '{*,.*}')]).
      select{|f| !File.directory?(f)}
  end
end