Class: Gem::Commands::UnpackCommand

Relationships & Source Files
Super Chains via Extension / Inclusion / Inheritance
Class Chain: self, ::Gem::Command
Instance Chain: self, ::Gem::VersionOption, ::Gem::Command, ::Gem::UserInteraction, ::Gem::DefaultUserInteraction
Inherits:	Gem::Command Object Gem::Command Gem::Commands::UnpackCommand
Defined in:	lib/rubygems/commands/unpack_command.rb

Class Attribute Summary

::Gem::Command - Inherited

.build_args	Arguments used when building gems.
.build_args=, .extra_args, .extra_args=

Class Method Summary

.new ⇒ UnpackCommand constructor

::Gem::Command - Inherited

.add_common_option,
.add_specific_extra_args	Add a list of extra arguments for the given command.
.common_options,
.new	Initializes a generic gem command named `command`.
.specific_extra_args	Return an array of extra arguments for the command.
.specific_extra_args_hash	Accessor for the specific extra args hash (self initializing).

Instance Attribute Summary

::Gem::Command - Inherited

#defaults	The default options for the command.
#program_name	The name of the command for command-line invocation.
#summary	A short description of the command.
#command	The name of the command.
#options	The options for the command.

::Gem::DefaultUserInteraction - Included

#ui	See DefaultUserInteraction.ui
#ui=	See DefaultUserInteraction.ui=

Instance Method Summary

#description
#execute
#find_in_cache(filename)

Find cached filename in Gem.path.
#get_metadata(path)

Extracts the ::Gem::Specification and raw metadata from the .gem file at Gem.path.
#get_path(dependency)

Return the full path to the cached gem file matching the given name and version requirement.

::Gem::VersionOption - Included

#add_platform_option	Add the –platform option to the option parser.
#add_prerelease_option	Add the –prerelease option to the option parser.
#add_version_option	Add the –version option to the option parser.

::Gem::Command - Inherited

#add_extra_args	Adds extra args from ~/.gemrc.
#add_option	Add a command-line option and handler to the command.
#arguments	Override to provide details of the arguments a command takes.
#begins?	True if `long` begins with the characters from `short`.
#defaults_str	Override to display the default values of the command options.
#description	Override to display a longer description of what this command does.
#execute	Override to provide command handling.
#get_all_gem_names	Get all gem names from the command line.
#get_all_gem_names_and_versions	Get all [gem, version] from the command line.
#get_one_gem_name	Get a single gem name from the command line.
#get_one_optional_argument	Get a single optional argument from the command line.
#handle_options	Handle the given list of arguments by parsing them and recording the results.
#handles?	True if the command handles the given argument list.
#invoke	Invoke the command with the given list of arguments.
#invoke_with_build_args	Invoke the command with the given list of normal arguments and additional build arguments.
#merge_options	Merge a set of command options with the set of default options (without modifying the default option hash).
#remove_option	Remove previously defined command-line argument `name`.
#show_help	Display the help message for the command.
#show_lookup_failure	Display to the user that a gem couldn't be found and reasons why.
#usage	Override to display the usage for an individual gem command.
#when_invoked	Call the given block when invoked.
#add_parser_run_info	Adds a section with `title` and `content` to the parser help view.
#configure_options,
#create_option_parser	Creates an option parser and fills it in with the help info for the command.
#parser	Create on demand parser.
#wrap	Wraps `text` to `width`

::Gem::UserInteraction - Included

#alert	Displays an alert `statement`.
#alert_error	Displays an error `statement` to the error output location.
#alert_warning	Displays a warning `statement` to the warning output location.
#ask	Asks a `question` and returns the answer.
#ask_for_password	Asks for a password with a `prompt`
#ask_yes_no	Asks a yes or no `question`.
#choose_from_list	Asks the user to answer `question` with an answer from the given `list`.
#say	Displays the given `statement` on the standard output (or equivalent).
#terminate_interaction	Terminates the RubyGems process with the given `exit_code`
#verbose	Calls `say` with `msg` or the results of the block if really_verbose is true.

::Gem::DefaultUserInteraction - Included

#use_ui

See DefaultUserInteraction.use_ui

Constructor Details

.new ⇒ `UnpackCommand`

[ GitHub ]

# File 'lib/rubygems/commands/unpack_command.rb', line 11


def initialize
  require 'fileutils'

  super 'unpack', 'Unpack an installed gem to the current directory',
        :version => Gem::Requirement.default,
        :target  => Dir.pwd

  add_option('--target=DIR',
             'target directory for unpacking') do |value, options|
    options[:target] = value
  end

  add_option('--spec', 'unpack the gem specification') do |value, options|
    options[:spec] = true
  end

  add_version_option
end

Instance Method Details

#description

[ GitHub ]

# File 'lib/rubygems/commands/unpack_command.rb', line 38


def description
  <<-EOF
The unpack command allows you to examine the contents of a gem or modify
them to help diagnose a bug.

You can add the contents of the unpacked gem to the load path using the
RUBYLIB environment variable or -I:

$ gem unpack my_gem
Unpacked gem: '.../my_gem-1.0'
[edit my_gem-1.0/lib/my_gem.rb]
$ ruby -Imy_gem-1.0/lib -S other_program

You can repackage an unpacked gem using the build command.  See the build
command help for an example.
  EOF
end

#execute

[ GitHub ]

# File 'lib/rubygems/commands/unpack_command.rb', line 65


def execute
  get_all_gem_names.each do |name|
    dependency = Gem::Dependency.new name, options[:version]
    path = get_path dependency

    unless path then
      alert_error "Gem '#{name}' not installed nor fetchable."
      next
    end

    if @options[:spec] then
      spec, metadata = get_metadata path

      if metadata.nil? then
        alert_error "--spec is unsupported on '#{name}' (old format gem)"
        next
      end

      spec_file = File.basename spec.spec_file

      open spec_file, 'w' do |io|
        io.write metadata
      end
    else
      basename = File.basename path, '.gem'
      target_dir = File.expand_path basename, options[:target]

      package = Gem::Package.new path
      package.extract_files target_dir

      say "Unpacked gem: '#{target_dir}'"
    end
  end
end

#find_in_cache(filename)

Find cached filename in Gem.path. Returns nil if the file cannot be found.

[ GitHub ]

# File 'lib/rubygems/commands/unpack_command.rb', line 107


def find_in_cache(filename)
  Gem.path.each do |path|
    this_path = File.join(path, "cache", filename)
    return this_path if File.exist? this_path
  end

  return nil
end

#get_metadata(path)

Extracts the ::Gem::Specification and raw metadata from the .gem file at Gem.path.

[ GitHub ]

# File 'lib/rubygems/commands/unpack_command.rb', line 161


def get_metadata path
  format = Gem::Package.new path
  spec = format.spec

  metadata = nil

  open path, Gem.binary_mode do |io|
    tar = Gem::Package::TarReader.new io
    tar.each_entry do |entry|
      case entry.full_name
      when 'metadata' then
        metadata = entry.read
      when 'metadata.gz' then
        metadata = Gem.gunzip entry.read
      end
    end
  end

  return spec, metadata
end

#get_path(dependency)

Return the full path to the cached gem file matching the given name and version requirement. Returns 'nil' if no match.

Example:

get_path 'rake', '> 0.4' # "/usr/lib/ruby/gems/1.8/cache/rake-0.4.2.gem"
get_path 'rake', '< 0.1' # nil
get_path 'rak'           # nil (exact name required)

[ GitHub ]

# File 'lib/rubygems/commands/unpack_command.rb', line 133


def get_path dependency
  return dependency.name if dependency.name =~ /\.gem$/i

  specs = dependency.matching_specs

  selected = specs.max_by { |s| s.version }

  return Gem::RemoteFetcher.fetcher.download_to_cache(dependency) unless
    selected

  return unless dependency.name =~ /^#{selected.name}$/i

  # We expect to find (basename).gem in the 'cache' directory.  Furthermore,
  # the name match must be exact (ignoring case).

  path = find_in_cache File.basename selected.cache_file

  return Gem::RemoteFetcher.fetcher.download_to_cache(dependency) unless path

  path
end

Class: Gem::Commands::UnpackCommand

Class Attribute Summary

::Gem::Command - Inherited

Class Method Summary

::Gem::Command - Inherited

Instance Attribute Summary

::Gem::Command - Inherited

::Gem::DefaultUserInteraction - Included

Instance Method Summary

::Gem::VersionOption - Included

::Gem::Command - Inherited

::Gem::UserInteraction - Included

::Gem::DefaultUserInteraction - Included

Constructor Details

.new ⇒ UnpackCommand

Instance Method Details

#description

#execute

#find_in_cache(filename)

#get_metadata(path)

#get_path(dependency)

.new ⇒ `UnpackCommand`