module Gem

# File lib/rubygems.rb, line 281
def self.activate_and_load_bin_path(name, exec_name = nil, *requirements)
  spec = find_and_activate_spec_for_exe name, exec_name, requirements

  if spec.name == "bundler"
    # Old versions of Bundler need a workaround to support nested `bundle
    # exec` invocations by overriding `Gem.activate_bin_path`. However,
    # RubyGems now uses this new `Gem.activate_and_load_bin_path` helper in
    # binstubs, which is of course not overridden in Bundler since it didn't
    # exist at the time. So, include the override here to workaround that.
    load ENV["BUNDLE_BIN_PATH"] if ENV["BUNDLE_BIN_PATH"] && spec.version <= "2.5.22"

    # Make sure there's no version of Bundler in `$LOAD_PATH` that's different
    # from the version we just activated. If that was the case (it happens
    # when testing Bundler from ruby/ruby), we would load Bundler extensions
    # to RubyGems from the copy in `$LOAD_PATH` but then load the binstub from
    # an installed copy, causing those copies to be mixed and yet more
    # redefinition warnings.
    #
    require_path = $LOAD_PATH.resolve_feature_path("bundler").last.delete_suffix("/bundler.rb")
    Gem.load_bundler_extensions(spec.version) if spec.full_require_paths.include?(require_path)
  end

  load spec.bin_file(exec_name)
end

# File lib/rubygems.rb, line 624
def self.activated_gem_paths
  @activated_gem_paths ||= 0
end

# File lib/rubygems.rb, line 631
def self.add_to_load_path(*paths)
  @activated_gem_paths = activated_gem_paths + paths.size

  # gem directories must come after -I and ENV['RUBYLIB']
  $LOAD_PATH.insert(Gem.load_path_insert_index, *paths)
end

# File lib/rubygems.rb, line 229
def self.bin_path(name, exec_name = nil, *requirements)
  requirements = Gem::Requirement.default if
    requirements.empty?

  find_spec_for_exe(name, exec_name, requirements).bin_file exec_name
end

# File lib/rubygems.rb, line 324
def self.binary_mode
  "rb"
end

# File lib/rubygems.rb, line 331
def self.bindir(install_dir = Gem.dir)
  return File.join install_dir, "bin" unless
    install_dir.to_s == Gem.default_dir.to_s
  Gem.default_bindir
end

# File lib/rubygems/defaults.rb, line 147
def self.cache_home
  @cache_home ||= ENV["XDG_CACHE_HOME"] || File.join(Gem.user_home, ".cache")
end

# File lib/rubygems.rb, line 1317
def clear_default_specs
  @path_to_default_spec_map.clear
end

# File lib/rubygems.rb, line 349
def self.clear_paths
  @paths         = nil
  @user_home     = nil
  Gem::Specification.reset
  Gem::Security.reset if defined?(Gem::Security)
end

# File lib/rubygems/defaults.rb, line 133
def self.config_file
  @config_file ||= find_config_file
end

# File lib/rubygems/defaults.rb, line 114
def self.config_home
  @config_home ||= ENV["XDG_CONFIG_HOME"] || File.join(Gem.user_home, ".config")
end

# File lib/rubygems.rb, line 359
def self.configuration
  @configuration ||= Gem::ConfigFile.new []
end

# File lib/rubygems.rb, line 367
def self.configuration=(config)
  @configuration = config
end

# File lib/rubygems/defaults.rb, line 154
def self.data_home
  @data_home ||= ENV["XDG_DATA_HOME"] || File.join(Gem.user_home, ".local", "share")
end

# File lib/rubygems/defaults.rb, line 204
def self.default_bindir
  RbConfig::CONFIG["bindir"]
end

# File lib/rubygems/defaults.rb, line 228
def self.default_cert_path
  default_cert_path = File.join Gem.user_home, ".gem", "gem-public_cert.pem"

  unless File.exist?(default_cert_path)
    default_cert_path = File.join Gem.data_home, "gem", "gem-public_cert.pem"
  end

  default_cert_path
end

# File lib/rubygems/defaults.rb, line 37
def self.default_dir
  @default_dir ||= File.join(RbConfig::CONFIG["rubylibprefix"], "gems", RbConfig::CONFIG["ruby_version"])
end

# File lib/rubygems/defaults.rb, line 186
def self.default_exec_format
  exec_format = begin
                  RbConfig::CONFIG["ruby_install_name"].sub("ruby", "%s")
                rescue StandardError
                  "%s"
                end

  unless exec_format.include?("%s")
    raise Gem::Exception,
      "[BUG] invalid exec_format #{exec_format.inspect}, no %s"
  end

  exec_format
end

# File lib/rubygems/defaults.rb, line 48
def self.default_ext_dir_for(base_dir)
  nil
end

# File lib/rubygems/defaults.rb, line 215
def self.default_key_path
  default_key_path = File.join Gem.user_home, ".gem", "gem-private_key.pem"

  unless File.exist?(default_key_path)
    default_key_path = File.join Gem.data_home, "gem", "gem-private_key.pem"
  end

  default_key_path
end

# File lib/rubygems/defaults.rb, line 175
def self.default_path
  path = []
  path << user_dir if user_home && File.exist?(user_home)
  path << default_dir
  path << vendor_dir if vendor_dir && File.directory?(vendor_dir)
  path
end

# File lib/rubygems/defaults.rb, line 55
def self.default_rubygems_dirs
  nil # default to standard layout
end

# File lib/rubygems/defaults.rb, line 15
def self.default_sources
  @default_sources ||= %w[https://rubygems.org/]
end

# File lib/rubygems/defaults.rb, line 23
def self.default_spec_cache_dir
  default_spec_cache_dir = File.join Gem.user_home, ".gem", "specs"

  unless File.exist?(default_spec_cache_dir)
    default_spec_cache_dir = File.join Gem.cache_home, "gem", "specs"
  end

  default_spec_cache_dir
end

# File lib/rubygems/defaults.rb, line 62
def self.default_specifications_dir
  @default_specifications_dir ||= File.join(Gem.default_dir, "specifications", "default")
end

# File lib/rubygems.rb, line 374
def self.deflate(data)
  require "zlib"
  Zlib::Deflate.deflate data
end

# File lib/rubygems.rb, line 422
def self.dir
  paths.home
end

# File lib/rubygems.rb, line 759
def self.done_installing(&hook)
  @done_installing_hooks << hook
end

# File lib/rubygems.rb, line 1040
def self.dynamic_library_suffixes
  @dynamic_library_suffixes ||= suffixes - [".rb"]
end

# File lib/rubygems.rb, line 473
def self.ensure_default_gem_subdirectories(dir = Gem.dir, mode = nil)
  ensure_subdirectories(dir, mode, REPOSITORY_DEFAULT_GEM_SUBDIRECTORIES)
end

# File lib/rubygems.rb, line 460
def self.ensure_gem_subdirectories(dir = Gem.dir, mode = nil)
  ensure_subdirectories(dir, mode, REPOSITORY_SUBDIRECTORIES)
end

# File lib/rubygems.rb, line 908
def self.env_requirement(gem_name)
  @env_requirements_by_name ||= {}
  @env_requirements_by_name[gem_name] ||= begin
    req = ENV["GEM_REQUIREMENT_#{gem_name.upcase}"] || ">= 0"
    Gem::Requirement.create(req)
  end
end

# File lib/rubygems/defaults.rb, line 121
def self.find_config_file
  gemrc = File.join Gem.user_home, ".gemrc"
  if File.exist? gemrc
    gemrc
  else
    File.join Gem.config_home, "gem", "gemrc"
  end
end

# File lib/rubygems.rb, line 1302
def find_default_spec(path)
  @path_to_default_spec_map[path]
end

# File lib/rubygems.rb, line 524
def self.find_files(glob, check_load_path = true)
  files = []

  files = find_files_from_load_path glob if check_load_path

  gem_specifications = @gemdeps ? Gem.loaded_specs.values : Gem::Specification.stubs

  files.concat gem_specifications.flat_map {|spec|
    spec.matches_for_glob("#{glob}#{Gem.suffix_pattern}")
  }

  # $LOAD_PATH might contain duplicate entries or reference
  # the spec dirs directly, so we prune.
  files.uniq! if check_load_path

  files
end

# File lib/rubygems.rb, line 561
def self.find_latest_files(glob, check_load_path = true)
  files = []

  files = find_files_from_load_path glob if check_load_path

  files.concat Gem::Specification.latest_specs(true).flat_map {|spec|
    spec.matches_for_glob("#{glob}#{Gem.suffix_pattern}")
  }

  # $LOAD_PATH might contain duplicate entries or reference
  # the spec dirs directly, so we prune.
  files.uniq! if check_load_path

  files
end

# File lib/rubygems.rb, line 1309
def find_unresolved_default_spec(path)
  default_spec = @path_to_default_spec_map[path]
  default_spec if default_spec && loaded_specs[default_spec.name] != default_spec
end

# File lib/rubygems.rb, line 214
def self.finish_resolve(request_set = Gem::RequestSet.new)
  request_set.import Gem::Specification.unresolved_deps.values
  request_set.import Gem.loaded_specs.values.map {|s| Gem::Dependency.new(s.name, s.version) }

  request_set.resolve_current.each do |s|
    s.full_spec.activate
  end
end

# File lib/rubygems.rb, line 1098
def self.freebsd_platform?
  RbConfig::CONFIG["host_os"].to_s.include?("bsd")
end

# File lib/rubygems.rb, line 596
def self.host
  @host ||= Gem::DEFAULT_HOST
end

# File lib/rubygems.rb, line 602
def self.host=(host)
  @host = host
end

# File lib/rubygems.rb, line 585
def self.install(name, version = Gem::Requirement.default, *options)
  require_relative "rubygems/dependency_installer"
  inst = Gem::DependencyInstaller.new(*options)
  inst.install name, version
  inst.installed_gems
end

# File lib/rubygems.rb, line 1084
def self.java_platform?
  RUBY_PLATFORM == "java"
end

# File lib/rubygems.rb, line 933
def self.latest_rubygems_version
  latest_version_for("rubygems-update") ||
    raise("Can't find 'rubygems-update' in any repo. Check `gem source list`.")
end

# File lib/rubygems.rb, line 920
def self.latest_spec_for(name)
  dependency   = Gem::Dependency.new name
  fetcher      = Gem::SpecFetcher.fetcher
  spec_tuples, = fetcher.spec_for_dependency dependency

  spec, = spec_tuples.last

  spec
end

# File lib/rubygems.rb, line 941
def self.latest_version_for(name)
  latest_spec_for(name)&.version
end

# File lib/rubygems.rb, line 668
def self.load_bundler_extensions(version)
  return unless version <= "2.6.9"

  previous_platforms = {}

  platform_const_list = ["JAVA", "MSWIN", "MSWIN64", "MINGW", "X64_MINGW_LEGACY", "X64_MINGW", "UNIVERSAL_MINGW", "WINDOWS", "X64_LINUX", "X64_LINUX_MUSL"]

  platform_const_list.each do |platform|
    previous_platforms[platform] = Gem::Platform.const_get(platform)
    Gem::Platform.send(:remove_const, platform)
  end

  require "bundler/rubygems_ext"

  platform_const_list.each do |platform|
    Gem::Platform.send(:remove_const, platform) if Gem::Platform.const_defined?(platform)
    Gem::Platform.const_set(platform, previous_platforms[platform])
  end
end

# File lib/rubygems.rb, line 1133
def self.load_env_plugins
  load_plugin_files find_files_from_load_path("rubygems_plugin")
end

# File lib/rubygems.rb, line 610
def self.load_path_insert_index
  $LOAD_PATH.each_with_index do |path, i|
    return i if path.instance_variable_defined?(:@gem_prelude_index)
  end

  index = $LOAD_PATH.index RbConfig::CONFIG["sitelibdir"]

  index || 0
end

# File lib/rubygems.rb, line 1124
def self.load_plugins
  Gem.path.each do |gem_path|
    load_plugin_files Gem::Util.glob_files_in_dir("*#{Gem.plugin_suffix_pattern}", plugindir(gem_path))
  end
end

# File lib/rubygems.rb, line 656
def self.load_safe_marshal
  return if @safe_marshal_loaded

  require_relative "rubygems/safe_marshal"

  @safe_marshal_loaded = true
end

# File lib/rubygems.rb, line 643
def self.load_yaml
  return if @yaml_loaded

  require "psych"
  require_relative "rubygems/psych_tree"

  require_relative "rubygems/safe_yaml"

  @yaml_loaded = true
end

# File lib/rubygems.rb, line 702
def self.location_of_caller(depth = 1)
  caller[depth] =~ /(.*?):(\d+).*?$/i
  file = $1
  lineno = $2.to_i

  [file, lineno]
end

# File lib/rubygems.rb, line 713
def self.marshal_version
  "#{Marshal::MAJOR_VERSION}.#{Marshal::MINOR_VERSION}"
end

# File lib/rubygems.rb, line 206
def self.needs
  rs = Gem::RequestSet.new

  yield rs

  finish_resolve rs
end

# File lib/rubygems.rb, line 849
def self.open_file(path, flags, &block)
  File.open(path, flags, &block)
end

# File lib/rubygems.rb, line 867
def self.open_file_with_flock(path, &block)
  # read-write mode is used rather than read-only in order to support NFS
  mode = IO::RDWR | IO::APPEND | IO::CREAT | IO::BINARY
  mode |= IO::SHARE_DELETE if IO.const_defined?(:SHARE_DELETE)

  File.open(path, mode) do |io|
    begin
      # Try to get a lock without blocking.
      # If we do, the file is locked.
      # Otherwise, explain why we're waiting and get a lock, but block this time.
      if io.flock(File::LOCK_EX | File::LOCK_NB) != 0
        warn "Waiting for another process to let go of lock: #{path}"
        io.flock(File::LOCK_EX)
      end
      io.puts(Process.pid)
    rescue Errno::ENOSYS, Errno::ENOTSUP
    end
    yield io
  end
end

# File lib/rubygems.rb, line 856
def self.open_file_with_lock(path, &block)
  file_lock = "#{path}.lock"
  open_file_with_flock(file_lock, &block)
ensure
  require "fileutils"
  FileUtils.rm_f file_lock
end

# File lib/rubygems/defaults.rb, line 286
def self.operating_system_defaults
  {}
end

# File lib/rubygems.rb, line 426
def self.path
  paths.path
end

# File lib/rubygems/defaults.rb, line 168
def self.path_separator
  File::PATH_SEPARATOR
end

# File lib/rubygems.rb, line 382
def self.paths
  @paths ||= Gem::PathSupport.new(ENV)
end

# File lib/rubygems.rb, line 392
  def self.paths=(env)
    clear_paths
    target = {}
    env.each_pair do |k,v|
      case k
      when "GEM_HOME", "GEM_PATH", "GEM_SPEC_CACHE"
        case v
        when nil, String
          target[k] = v
        when Array
          unless Gem::Deprecate.skip
            warn <<-EOWARN
Array values in the parameter to `Gem.paths=` are deprecated.
Please use a String or nil.
An Array (#{env.inspect}) was passed in from #{caller[3]}
            EOWARN
          end
          target[k] = v.join File::PATH_SEPARATOR
        end
      else
        target[k] = v
      end
    end
    @paths = Gem::PathSupport.new ENV.to_hash.merge(target)
    Gem::Specification.dirs = @paths.path
  end

# File lib/rubygems/defaults.rb, line 305
def self.platform_defaults
  {}
end

# File lib/rubygems.rb, line 727
def self.platforms
  @platforms ||= []
  if @platforms.empty?
    @platforms = [Gem::Platform::RUBY, Gem::Platform.local]
  end
  @platforms
end

# File lib/rubygems.rb, line 720
def self.platforms=(platforms)
  @platforms = platforms
end

# File lib/rubygems.rb, line 1013
def self.plugin_suffix_pattern
  @plugin_suffix_pattern ||= "_plugin#{suffix_pattern}"
end

# File lib/rubygems.rb, line 1020
def self.plugin_suffix_regexp
  @plugin_suffix_regexp ||= /_plugin#{suffix_regexp}\z/
end

# File lib/rubygems.rb, line 340
def self.plugindir(install_dir = Gem.dir)
  File.join install_dir, "plugins"
end

# File lib/rubygems.rb, line 742
def self.post_build(&hook)
  @post_build_hooks << hook
end

# File lib/rubygems.rb, line 750
def self.post_install(&hook)
  @post_install_hooks << hook
end

# File lib/rubygems.rb, line 767
def self.post_reset(&hook)
  @post_reset_hooks << hook
end

# File lib/rubygems.rb, line 776
def self.post_uninstall(&hook)
  @post_uninstall_hooks << hook
end

# File lib/rubygems.rb, line 785
def self.pre_install(&hook)
  @pre_install_hooks << hook
end

# File lib/rubygems.rb, line 793
def self.pre_reset(&hook)
  @pre_reset_hooks << hook
end

# File lib/rubygems.rb, line 802
def self.pre_uninstall(&hook)
  @pre_uninstall_hooks << hook
end

# File lib/rubygems.rb, line 811
def self.prefix
  prefix = File.dirname RUBYGEMS_DIR

  if prefix != File.expand_path(RbConfig::CONFIG["sitelibdir"]) &&
     prefix != File.expand_path(RbConfig::CONFIG["libdir"]) &&
     File.basename(RUBYGEMS_DIR) == "lib"
    prefix
  end
end

# File lib/rubygems/rdoc.rb, line 13
def self.rdoc_hooks_defined_via_plugin?
  Gem::Version.new(::RDoc::VERSION) >= Gem::Version.new("6.9.0")
end

# File lib/rubygems.rb, line 831
def self.read_binary(path)
  File.binread(path)
end

# File lib/rubygems.rb, line 824
def self.refresh
  Gem::Specification.reset
end

# File lib/rubygems.rb, line 1277
def register_default_spec(spec)
  extended_require_paths = spec.require_paths.map {|f| f + "/" }
  new_format = extended_require_paths.any? {|path| spec.files.any? {|f| f.start_with? path } }

  if new_format
    prefix_group = extended_require_paths.join("|")
    prefix_pattern = /^(#{prefix_group})/
  end

  spec.files.each do |file|
    if new_format
      file = file.sub(prefix_pattern, "")
      next unless $~
    end

    spec.activate if already_loaded?(file)

    @path_to_default_spec_map[file] = spec
    @path_to_default_spec_map[file.sub(suffix_regexp, "")] = spec
  end
end

# File lib/rubygems.rb, line 891
def self.ruby
  if @ruby.nil?
    @ruby = RbConfig.ruby

    @ruby = "\"#{@ruby}\"" if /\s/.match?(@ruby)
  end

  @ruby
end

# File lib/rubygems.rb, line 904
def self.ruby_api_version
  @ruby_api_version ||= target_rbconfig["ruby_version"].dup
end

# File lib/rubygems/defaults.rb, line 208
def self.ruby_engine
  RUBY_ENGINE
end

# File lib/rubygems.rb, line 948
def self.ruby_version
  return @ruby_version if defined? @ruby_version
  version = RUBY_VERSION.dup

  if RUBY_PATCHLEVEL == -1
    if RUBY_ENGINE == "ruby"
      desc = RUBY_DESCRIPTION[/\Aruby #{Regexp.quote(RUBY_VERSION)}([^ ]+) /, 1]
    else
      desc = RUBY_DESCRIPTION[/\A#{RUBY_ENGINE} #{Regexp.quote(RUBY_ENGINE_VERSION)} \(#{RUBY_VERSION}([^ ]+)\) /, 1]
    end
    version << ".#{desc}" if desc
  end

  @ruby_version = Gem::Version.new version
end

# File lib/rubygems.rb, line 967
def self.rubygems_version
  return @rubygems_version if defined? @rubygems_version
  @rubygems_version = Gem::Version.new Gem::VERSION
end

# File lib/rubygems.rb, line 444
def self.set_target_rbconfig(rbconfig_path)
  @target_rbconfig = Gem::TargetRbConfig.from_path(rbconfig_path)
  Gem::Platform.local(refresh: true)
  Gem.platforms << Gem::Platform.local unless Gem.platforms.include? Gem::Platform.local
  @target_rbconfig
end

# File lib/rubygems.rb, line 1091
def self.solaris_platform?
  RUBY_PLATFORM.include?("solaris")
end

# File lib/rubygems.rb, line 1232
def self.source_date_epoch
  Time.at(source_date_epoch_string.to_i).utc.freeze
end

# File lib/rubygems.rb, line 1216
def self.source_date_epoch_string
  specified_epoch = ENV["SOURCE_DATE_EPOCH"]

  # If it's empty or just whitespace, treat it like it wasn't set at all.
  specified_epoch = nil if !specified_epoch.nil? && specified_epoch.strip.empty?

  epoch = specified_epoch || DEFAULT_SOURCE_DATE_EPOCH.to_s

  epoch.strip
end

# File lib/rubygems.rb, line 976
def self.sources
  source_list = configuration.sources || default_sources
  @sources ||= Gem::SourceList.from(source_list)
end

# File lib/rubygems.rb, line 988
def self.sources=(new_sources)
  if !new_sources
    @sources = nil
  else
    @sources = Gem::SourceList.from(new_sources)
  end
end

# File lib/rubygems.rb, line 430
def self.spec_cache_dir
  paths.spec_cache_dir
end

# File lib/rubygems/defaults.rb, line 140
def self.state_file
  @state_file ||= File.join(Gem.state_home, "gem", "last_update_check")
end

# File lib/rubygems/defaults.rb, line 161
def self.state_home
  @state_home ||= ENV["XDG_STATE_HOME"] || File.join(Gem.user_home, ".local", "state")
end

# File lib/rubygems.rb, line 999
def self.suffix_pattern
  @suffix_pattern ||= "{#{suffixes.join(",")}}"
end

# File lib/rubygems.rb, line 1006
def self.suffix_regexp
  @suffix_regexp ||= /#{Regexp.union(suffixes)}\z/
end

# File lib/rubygems.rb, line 1027
def self.suffixes
  @suffixes ||= ["",
                 ".rb",
                 *%w[DLEXT DLEXT2].map do |key|
                   val = RbConfig::CONFIG[key]
                   next unless val && !val.empty?
                   ".#{val}"
                 end].compact.uniq
end

# File lib/rubygems.rb, line 440
def self.target_rbconfig
  @target_rbconfig || Gem::TargetRbConfig.for_running_ruby
end

# File lib/rubygems.rb, line 1048
def self.time(msg, width = 0, display = Gem.configuration.verbose)
  now = Time.now

  value = yield

  elapsed = Time.now - now

  ui.say format("%2$*1$s: %3$3.3fs", -width, msg, elapsed) if display

  value
end

# File lib/rubygems.rb, line 181
def self.try_activate(path)
  # finds the _latest_ version... regardless of loaded specs and their deps
  # if another gem had a requirement that would mean we shouldn't
  # activate the latest version, then either it would already be activated
  # or if it was ambiguous (and thus unresolved) the code in our custom
  # require will try to activate the more specific version.

  spec = Gem::Specification.find_by_path path
  return false unless spec
  return true if spec.activated?

  begin
    spec.activate
  rescue Gem::LoadError => e # this could fail due to gem dep collisions, go lax
    spec_by_name = Gem::Specification.find_by_name(spec.name)
    if spec_by_name.nil?
      raise e
    else
      spec_by_name.activate
    end
  end

  true
end

# File lib/rubygems.rb, line 1063
def self.ui
  require_relative "rubygems/user_interaction"

  Gem::DefaultUserInteraction.ui
end

# File lib/rubygems.rb, line 1157
def self.use_gemdeps(path = nil)
  raise_exception = path

  path ||= ENV["RUBYGEMS_GEMDEPS"]
  return unless path

  path = path.dup

  if path == "-"
    Gem::Util.traverse_parents Dir.pwd do |directory|
      dep_file = GEM_DEP_FILES.find {|f| File.file?(f) }

      next unless dep_file

      path = File.join directory, dep_file
      break
    end
  end

  unless File.file? path
    return unless raise_exception

    raise ArgumentError, "Unable to find gem dependencies file at #{path}"
  end

  ENV["BUNDLE_GEMFILE"] ||= File.expand_path(path)
  require_relative "rubygems/user_interaction"
  require "bundler"
  begin
    Gem::DefaultUserInteraction.use_ui(ui) do
      Bundler.ui.silence do
        @gemdeps = Bundler.setup
      end
    ensure
      Gem::DefaultUserInteraction.ui.close
    end
  rescue Bundler::BundlerError => e
    warn e.message
    warn "You may need to `bundle install` to install missing gems"
    warn ""
  end
end

# File lib/rubygems.rb, line 1073
def self.use_paths(home, *paths)
  paths.flatten!
  paths.compact!
  hash = { "GEM_HOME" => home, "GEM_PATH" => paths.empty? ? home : paths.join(File::PATH_SEPARATOR) }
  hash.delete_if {|_, v| v.nil? }
  self.paths = hash
end

# File lib/rubygems/defaults.rb, line 103
def self.user_dir
  gem_dir = File.join(Gem.user_home, ".gem")
  gem_dir = File.join(Gem.data_home, "gem") unless File.exist?(gem_dir)
  parts = [gem_dir, ruby_engine]
  parts << RbConfig::CONFIG["ruby_version"] unless RbConfig::CONFIG["ruby_version"].empty?
  File.join parts
end

# File lib/rubygems/defaults.rb, line 96
def self.user_home
  @user_home ||= find_home
end

# File lib/rubygems/win_platform.rb, line 23
def self.win_platform?
  if @@win_platform.nil?
    ruby_platform = RbConfig::CONFIG["host_os"]
    @@win_platform = !WIN_PATTERNS.find {|r| ruby_platform =~ r }.nil?
  end

  @@win_platform
end

# File lib/rubygems.rb, line 838
def self.write_binary(path, data)
  File.binwrite(path, data)
rescue Errno::ENOSPC
  # If we ran out of space but the file exists, it's *guaranteed* to be corrupted.
  File.delete(path) if File.exist?(path)
  raise
end

# File lib/rubygems.rb, line 1368
def already_loaded?(file)
  $LOADED_FEATURES.any? do |feature_path|
    feature_path.end_with?(file) && default_gem_load_paths.any? {|load_path_entry| feature_path == "#{load_path_entry}/#{file}" }
  end
end

# File lib/rubygems.rb, line 1374
def default_gem_load_paths
  @default_gem_load_paths ||= $LOAD_PATH[load_path_insert_index..-1].map do |lp|
    expanded = File.expand_path(lp)
    next expanded unless File.exist?(expanded)

    File.realpath(expanded)
  end
end

# File lib/rubygems.rb, line 236
def self.find_and_activate_spec_for_exe(name, exec_name, requirements)
  spec = find_spec_for_exe name, exec_name, requirements
  Gem::LOADED_SPECS_MUTEX.synchronize do
    spec.activate
    finish_resolve
  end
  spec
end

# File lib/rubygems/defaults.rb, line 81
def self.find_home
  Dir.home.dup
rescue StandardError
  if Gem.win_platform?
    File.expand_path File.join(ENV["HOMEDRIVE"] || ENV["SystemDrive"], "/")
  else
    File.expand_path "/"
  end
end

# File lib/rubygems.rb, line 246
def self.find_spec_for_exe(name, exec_name, requirements)
  raise ArgumentError, "you must supply exec_name" unless exec_name

  dep = Gem::Dependency.new name, requirements

  loaded = Gem.loaded_specs[name]

  return loaded if loaded && dep.matches_spec?(loaded)

  specs = dep.matching_specs(true)

  specs = specs.find_all do |spec|
    spec.executables.include? exec_name
  end if exec_name

  unless spec = specs.first
    msg = "can't find gem #{dep} with executable #{exec_name}"
    raise Gem::GemNotFoundException, msg
  end

  spec
end