class Gem::Installer

# File lib/rubygems/installer.rb, line 78
def exec_format
  @exec_format ||= Gem.default_exec_format
end

# File lib/rubygems/installer.rb, line 107
def initialize(gem, options={})
  require 'fileutils'

  @gem = gem
  @options = options
  @package = Gem::Package.new @gem

  process_options

  @package.security_policy = @security_policy

  if options[:user_install] and not options[:unpack] then
    @gem_home = Gem.user_dir
    @bin_dir = Gem.bindir gem_home unless options[:bin_dir]
    check_that_user_bin_dir_is_in_path
  end
end

# File lib/rubygems/installer.rb, line 627
  def app_script_text(bin_file_name)
    return <<-TEXT
#{shebang bin_file_name}
#
# This file was generated by RubyGems.
#
# The application '#{spec.name}' is installed as part of a gem, and
# this file is here to facilitate running it.
#

require 'rubygems'

version = "#{Gem::Requirement.default}"

if ARGV.first
  str = ARGV.first
  str = str.dup.force_encoding("BINARY") if str.respond_to? :force_encoding
  if str =~ /\\A_(.*)_\\z/ and Gem::Version.correct?($1) then
    version = $1
    ARGV.shift
  end
end

gem '#{spec.name}', version
load Gem.bin_path('#{spec.name}', '#{bin_file_name}', version)
TEXT
  end

# File lib/rubygems/installer.rb, line 674
def build_extensions
  builder = Gem::Ext::Builder.new spec, @build_args

  builder.build_extensions
end

# File lib/rubygems/installer.rb, line 598
def check_that_user_bin_dir_is_in_path
  user_bin_dir = @bin_dir || Gem.bindir(gem_home)
  user_bin_dir = user_bin_dir.gsub(File::SEPARATOR, File::ALT_SEPARATOR) if
    File::ALT_SEPARATOR

  path = ENV['PATH']
  if Gem.win_platform? then
    path = path.downcase
    user_bin_dir = user_bin_dir.downcase
  end

  unless path.split(File::PATH_SEPARATOR).include? user_bin_dir then
    unless self.class.path_warning then
      alert_warning "You don't have #{user_bin_dir} in your PATH,\n\t  gem executables will not run."
      self.class.path_warning = true
    end
  end
end

# File lib/rubygems/installer.rb, line 346
def default_spec_file
  File.join gem_home, "specifications/default", "#{spec.full_name}.gemspec"
end

# File lib/rubygems/installer.rb, line 726
def dir
  gem_dir.to_s
end

# File lib/rubygems/installer.rb, line 560
def ensure_dependencies_met
  deps = spec.runtime_dependencies
  deps |= spec.development_dependencies if @development

  deps.each do |dep_gem|
    ensure_dependency spec, dep_gem
  end
end

# File lib/rubygems/installer.rb, line 310
def ensure_dependency(spec, dependency)
  unless installation_satisfies_dependency? dependency then
    raise Gem::InstallError, "#{spec.name} requires #{dependency}"
  end
  true
end

# File lib/rubygems/installer.rb, line 527
def ensure_loadable_spec
  ruby = spec.to_ruby_for_cache
  ruby.untaint

  begin
    eval ruby
  rescue StandardError, SyntaxError => e
    raise Gem::InstallError,
          "The specification for #{spec.full_name} is corrupt (#{e.class})"
  end
end

# File lib/rubygems/installer.rb, line 540
def ensure_required_ruby_version_met
  if rrv = spec.required_ruby_version then
    unless rrv.satisfied_by? Gem.ruby_version then
      raise Gem::InstallError, "#{spec.name} requires Ruby version #{rrv}."
    end
  end
end

# File lib/rubygems/installer.rb, line 549
def ensure_required_rubygems_version_met
  if rrgv = spec.required_rubygems_version then
    unless rrgv.satisfied_by? Gem.rubygems_version then
      raise Gem::InstallError,
        "#{spec.name} requires RubyGems version #{rrgv}. " +
        "Try 'gem update --system' to update RubyGems itself."
    end
  end
end

# File lib/rubygems/installer.rb, line 705
def extract_bin
  @package.extract_files gem_dir, "bin/*"
end

# File lib/rubygems/installer.rb, line 696
def extract_files
  @package.extract_files gem_dir
end

# File lib/rubygems/installer.rb, line 712
def formatted_program_filename(filename)
  if @format_executable then
    self.class.exec_format % File.basename(filename)
  else
    filename
  end
end

# File lib/rubygems/installer.rb, line 188
def gem_dir
  @gem_dir ||= File.join(gem_home, "gems", spec.full_name)
end

# File lib/rubygems/installer.rb, line 390
def generate_bin
  return if spec.executables.nil? or spec.executables.empty?

  Dir.mkdir @bin_dir unless File.exist? @bin_dir
  raise Gem::FilePermissionError.new(@bin_dir) unless File.writable? @bin_dir

  spec.executables.each do |filename|
    filename.untaint
    bin_path = File.join gem_dir, spec.bindir, filename

    unless File.exist? bin_path then
      # TODO change this to a more useful warning
      warn "#{bin_path} maybe `gem pristine #{spec.name}` will fix it?"
      next
    end

    mode = File.stat(bin_path).mode | 0111
    FileUtils.chmod mode, bin_path

    check_executable_overwrite filename

    if @wrappers then
      generate_bin_script filename, @bin_dir
    else
      generate_bin_symlink filename, @bin_dir
    end

  end
end

# File lib/rubygems/installer.rb, line 427
def generate_bin_script(filename, bindir)
  bin_script_path = File.join bindir, formatted_program_filename(filename)

  FileUtils.rm_f bin_script_path # prior install may have been --no-wrappers

  File.open bin_script_path, 'wb', 0755 do |file|
    file.print app_script_text(filename)
  end

  say bin_script_path if Gem.configuration.really_verbose

  generate_windows_script filename, bindir
end

# File lib/rubygems/installer.rb, line 445
def generate_bin_symlink(filename, bindir)
  if Gem.win_platform? then
    alert_warning "Unable to use symlinks on Windows, installing wrapper"
    generate_bin_script filename, bindir
    return
  end

  src = File.join gem_dir, spec.bindir, filename
  dst = File.join bindir, formatted_program_filename(filename)

  if File.exist? dst then
    if File.symlink? dst then
      link = File.readlink(dst).split File::SEPARATOR
      cur_version = Gem::Version.create(link[-3].sub(/^.*-/, ''))
      return if spec.version < cur_version
    end
    File.unlink dst
  end

  FileUtils.symlink src, dst, :verbose => Gem.configuration.really_verbose
end

# File lib/rubygems/installer.rb, line 377
def generate_windows_script(filename, bindir)
  if Gem.win_platform? then
    script_name = filename + ".bat"
    script_path = File.join bindir, File.basename(script_name)
    File.open script_path, 'w' do |file|
      file.puts windows_stub_script(bindir, filename)
    end

    say script_path if Gem.configuration.really_verbose
  end
end

# File lib/rubygems/installer.rb, line 212
def install
  pre_install_checks

  FileUtils.rm_f File.join gem_home, 'specifications', @spec.spec_name

  run_pre_install_hooks

  # Completely remove any previous gem files
  FileUtils.rm_rf gem_dir

  FileUtils.mkdir_p gem_dir

  spec.loaded_from = spec_file

  if @options[:install_as_default]
    extract_bin
    write_default_spec
  else
    extract_files

    build_extensions
    write_build_info_file
    run_post_build_hooks

    generate_bin
    write_spec
    write_cache_file
  end

  say spec.post_install_message unless spec.post_install_message.nil?

  Gem::Specification.add_spec spec unless Gem::Specification.include? spec

  run_post_install_hooks

  spec

# TODO This rescue is in the wrong place. What is raising this exception?
# move this rescue to around the code that actually might raise it.
rescue Zlib::GzipFile::Error
  raise Gem::InstallError, "gzip error installing #{gem}"
end

# File lib/rubygems/installer.rb, line 320
def installation_satisfies_dependency?(dependency)
  return true if installed_specs.detect { |s| dependency.matches_spec? s }
  return false if @only_install_dir
  not dependency.matching_specs.empty?
end

# File lib/rubygems/installer.rb, line 290
def installed_specs
  @specs ||= begin
    specs = []

    Dir[File.join(gem_home, "specifications", "*.gemspec")].each do |path|
      spec = Gem::Specification.load path.untaint
      specs << spec if spec
    end

    specs
  end
end

# File lib/rubygems/installer.rb, line 739
def pre_install_checks
  verify_gem_home options[:unpack]

  # If we're forcing the install then disable security unless the security
  # policy says that we only install signed gems.
  @security_policy = nil if
    @force and @security_policy and not @security_policy.only_signed

  ensure_loadable_spec

  if options[:install_as_default]
    Gem.ensure_default_gem_subdirectories gem_home
  else
    Gem.ensure_gem_subdirectories gem_home
  end

  return true if @force

  ensure_required_ruby_version_met
  ensure_required_rubygems_version_met
  ensure_dependencies_met unless @ignore_dependencies

  true
end

# File lib/rubygems/installer.rb, line 570
def process_options
  @options = {
    :bin_dir      => nil,
    :env_shebang  => false,
    :force        => false,
    :only_install_dir => false
  }.merge options

  @env_shebang         = options[:env_shebang]
  @force               = options[:force]
  @install_dir         = options[:install_dir]
  @gem_home            = options[:install_dir] || Gem.dir
  @ignore_dependencies = options[:ignore_dependencies]
  @format_executable   = options[:format_executable]
  @security_policy     = options[:security_policy]
  @wrappers            = options[:wrappers]
  @only_install_dir    = options[:only_install_dir]

  # If the user has asked for the gem to be installed in a directory that is
  # the system gem directory, then use the system bin directory, else create
  # (or use) a new bin dir under the gem_home.
  @bin_dir             = options[:bin_dir] || Gem.bindir(gem_home)
  @development         = options[:development]

  @build_args          = options[:build_args] || Gem::Command.build_args
end

# File lib/rubygems/installer.rb, line 482
def shebang(bin_file_name)
  ruby_name = RbConfig::CONFIG['ruby_install_name'] if @env_shebang
  path = File.join gem_dir, spec.bindir, bin_file_name
  first_line = File.open(path, "rb") {|file| file.gets}

  if /\A#!/ =~ first_line then
    # Preserve extra words on shebang line, like "-w".  Thanks RPA.
    shebang = first_line.sub(/\A\#!.*?ruby\S*((\s+\S+)+)/, "#!#{Gem.ruby}")
    opts = $1
    shebang.strip! # Avoid nasty ^M issues.
  end

  if which = Gem.configuration[:custom_shebang]
    # replace bin_file_name with "ruby" to avoid endless loops
    which = which.gsub(/ #{bin_file_name}$/," #{RbConfig::CONFIG['ruby_install_name']}")

    which = which.gsub(/\$(\w+)/) do
      case $1
      when "env"
        @env_path ||= ENV_PATHS.find {|env_path| File.executable? env_path }
      when "ruby"
        "#{Gem.ruby}#{opts}"
      when "exec"
        bin_file_name
      when "name"
        spec.name
      end
    end

    "#!#{which}"
  elsif not ruby_name then
    "#!#{Gem.ruby}#{opts}"
  elsif opts then
    "#!/bin/sh\n'exec' #{ruby_name.dump} '-x' \"$0\" \"$@\"\n#{shebang}"
  else
    # Create a plain shebang line.
    @env_path ||= ENV_PATHS.find {|env_path| File.executable? env_path }
    "#!#{@env_path} #{ruby_name}"
  end
end

# File lib/rubygems/installer.rb, line 195
def spec
  @spec ||= @package.spec
rescue Gem::Package::Error => e
  raise Gem::InstallError, "invalid gem: #{e.message}"
end

# File lib/rubygems/installer.rb, line 338
def spec_file
  File.join gem_home, "specifications", "#{spec.full_name}.gemspec"
end

# File lib/rubygems/installer.rb, line 329
def unpack(directory)
  @gem_dir = directory
  extract_files
end

# File lib/rubygems/installer.rb, line 618
def verify_gem_home(unpack = false)
  FileUtils.mkdir_p gem_home
  raise Gem::FilePermissionError, gem_home unless
    unpack or File.writable?(gem_home)
end

# File lib/rubygems/installer.rb, line 658
  def windows_stub_script(bindir, bin_file_name)
    ruby = File.basename(Gem.ruby).chomp('"')
    return <<-TEXT
@ECHO OFF
IF NOT "%~f0" == "~f0" GOTO :WinNT
@"#{ruby}" "#{File.join(bindir, bin_file_name)}" %1 %2 %3 %4 %5 %6 %7 %8 %9
GOTO :EOF
:WinNT
@"#{ruby}" "%~dpn0" %*
TEXT
  end

# File lib/rubygems/installer.rb, line 768
def write_build_info_file
  return if @build_args.empty?

  build_info_dir = File.join gem_home, 'build_info'

  FileUtils.mkdir_p build_info_dir

  build_info_file = File.join build_info_dir, "#{spec.full_name}.info"

  open build_info_file, 'w' do |io|
    @build_args.each do |arg|
      io.puts arg
    end
  end
end

# File lib/rubygems/installer.rb, line 787
def write_cache_file
  cache_file = File.join gem_home, 'cache', spec.file_name

  FileUtils.cp @gem, cache_file unless File.exist? cache_file
end

# File lib/rubygems/installer.rb, line 368
def write_default_spec
  File.open(default_spec_file, "w") do |file|
    file.puts spec.to_ruby
  end
end

# File lib/rubygems/installer.rb, line 354
def write_spec
  open spec_file, 'w' do |file|
    spec.installed_by_version = Gem.rubygems_version

    file.puts spec.to_ruby_for_cache

    file.fsync rescue nil # for filesystems without fsync(2)
  end
end