Reads the file index and extracts each file into the gem directory.
Ensures that files can’t be installed outside the gem directory.
# File lib/rubygems/installer.rb, line 562
def extract_files
raise ArgumentError, "format required to extract from" if @format.nil?
@format.file_entries.each do |entry, file_data|
path = entry['path'].untaint
if path.start_with? "/" then # for extra sanity
raise Gem::InstallError, "attempt to install file into #{entry['path']}"
end
path = File.expand_path File.join(gem_dir, path)
unless path.start_with? gem_dir then
msg = "attempt to install file into %p under %s" %
[entry['path'], gem_dir]
raise Gem::InstallError, msg
end
FileUtils.rm_rf(path) if File.exist? path
dir = File.dirname path
FileUtils.mkdir_p dir unless File.exist? dir
File.open(path, "wb") do |out|
out.write file_data
end
FileUtils.chmod entry['mode'], path
say path if Gem.configuration.really_verbose
end
end