# File lib/rubygems/commands/unpack_command.rb, line 10
10:   def initialize
11:     require 'fileutils'
12: 
13:     super 'unpack', 'Unpack an installed gem to the current directory',
14:           :version => Gem::Requirement.default,
15:           :target  => Dir.pwd
16: 
17:     add_option('--target=DIR',
18:                'target directory for unpacking') do |value, options|
19:       options[:target] = value
20:     end
21: 
22:     add_option('--spec', 'unpack the gem specification') do |value, options|
23:       options[:spec] = true
24:     end
25: 
26:     add_version_option
27:   end

    # File lib/rubygems/commands/unpack_command.rb, line 46
46:   def execute
47:     get_all_gem_names.each do |name|
48:       dependency = Gem::Dependency.new name, options[:version]
49:       path = get_path dependency
50: 
51:       unless path then
52:         alert_error "Gem '#{name}' not installed nor fetchable."
53:         next
54:       end
55: 
56:       if @options[:spec] then
57:         spec, metadata = get_metadata path
58: 
59:         if metadata.nil? then
60:           alert_error "--spec is unsupported on '#{name}' (old format gem)"
61:           next
62:         end
63: 
64:         open spec.spec_name, 'w' do |io|
65:           io.write metadata
66:         end
67:       else
68:         basename = File.basename path, '.gem'
69:         target_dir = File.expand_path basename, options[:target]
70:         FileUtils.mkdir_p target_dir
71:         Gem::Installer.new(path, :unpack => true).unpack target_dir
72:         say "Unpacked gem: '#{target_dir}'"
73:       end
74:     end
75:   end

    # File lib/rubygems/commands/unpack_command.rb, line 84
84:   def find_in_cache(filename)
85:     Gem.path.each do |path|
86:       this_path = Gem.cache_gem(filename, path)
87:       return this_path if File.exist? this_path
88:     end
89: 
90:     return nil
91:   end

     # File lib/rubygems/commands/unpack_command.rb, line 136
136:   def get_metadata path
137:     format = Gem::Format.from_file_by_path path
138:     spec = format.spec
139: 
140:     metadata = nil
141: 
142:     open path, Gem.binary_mode do |io|
143:       tar = Gem::Package::TarReader.new io
144:       tar.each_entry do |entry|
145:         case entry.full_name
146:         when 'metadata' then
147:           metadata = entry.read
148:         when 'metadata.gz' then
149:           metadata = Gem.gunzip entry.read
150:         end
151:       end
152:     end
153: 
154:     return spec, metadata
155:   end

     # File lib/rubygems/commands/unpack_command.rb, line 110
110:   def get_path dependency
111:     return dependency.name if dependency.name =~ /\.gem$/i
112: 
113:     specs = Gem.source_index.search dependency
114: 
115:     selected = specs.sort_by { |s| s.version }.last
116: 
117:     return Gem::RemoteFetcher.fetcher.download_to_cache(dependency) unless
118:       selected
119: 
120:     return unless dependency.name =~ /^#{selected.name}$/i
121: 
122:     # We expect to find (basename).gem in the 'cache' directory.  Furthermore,
123:     # the name match must be exact (ignoring case).
124: 
125:     path = find_in_cache selected.file_name
126: 
127:     return Gem::RemoteFetcher.fetcher.download_to_cache(dependency) unless path
128: 
129:     path
130:   end