# frozen_string_literal: true
require_relative "../command"
require_relative "../version_option"
require_relative "../security_option"
require_relative "../remote_fetcher"
require_relative "../package"
# forward-declare
module Gem::Security # :nodoc:
class Policy # :nodoc:
end
end
class Gem::Commands::UnpackCommand < Gem::Command
include Gem::VersionOption
include Gem::SecurityOption
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_security_option
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
security_policy = options[:security_policy]
get_all_gem_names.each do |name|
dependency = Gem::Dependency.new name, options[:version]
path = get_path dependency
unless path
alert_error "Gem '#{name}' not installed nor fetchable."
next
end
if @options[:spec]
spec, metadata = Gem::Package.raw_spec(path, security_policy)
if metadata.nil?
alert_error "--spec is unsupported on '#{name}' (old format gem)"
next
end
spec_file = File.basename spec.spec_file
FileUtils.mkdir_p @options[:target] if @options[:target]
destination = if @options[:target]
File.join @options[:target], spec_file
else
spec_file
end
File.open destination, "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, security_policy
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
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)
#--
def get_path(dependency)
return dependency.name if /\.gem$/i.match?(dependency.name)
specs = dependency.matching_specs
selected = specs.max_by(&:version)
return Gem::RemoteFetcher.fetcher.download_to_cache(dependency) unless
selected
return unless /^#{selected.name}$/i.match?(dependency.name)
# 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
end
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