require 'rubygems/command' require 'rubygems/installer' require 'rubygems/version_option' require 'rubygems/remote_fetcher' class Gem::Commands::UnpackCommand < Gem::Command include Gem::VersionOption 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 def arguments # :nodoc: "GEMNAME name of gem to unpack" end def defaults_str # :nodoc: "--version '#{Gem::Requirement.default}'" end 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 def usage # :nodoc: "#{program_name} GEMNAME" end #-- # TODO: allow, e.g., 'gem unpack rake-0.3.1'. Find a general solution for # this, so that it works for uninstall as well. (And check other commands # at the same time.) 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 cached filename in Gem.path. Returns nil if the file cannot be found. # #-- # TODO: see comments in get_path() about general service. 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 ## # 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) #-- # TODO: This should be refactored so that it's a general service. I don't # think any of our existing classes are the right place though. Just maybe # 'Cache'? # # TODO: It just uses Gem.dir for now. What's an easy way to get the list of # source directories? 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 ## # Extracts the Gem::Specification and raw metadata from the .gem file at # +path+. #-- # TODO move to Gem::Package as #raw_spec or something 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 end