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Class: Gem::Commands::UnpackCommand

Relationships & Source Files
Super Chains via Extension / Inclusion / Inheritance
Class Chain:
Instance Chain:
Inherits: Gem::Command
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

::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

Instance Method Summary

::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

Constructor Details

.newUnpackCommand

[ 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,  =  path

      if .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 
      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  path
  format = Gem::Package.new path
  spec = format.spec

   = 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
         = entry.read
      when 'metadata.gz' then
         = Gem.gunzip entry.read
      end
    end
  end

  return spec, 
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