1 files changed, 40 insertions, 0 deletions
diff --git a/lib/rubygems/commands/stale_command.rb b/lib/rubygems/commands/stale_command.rb
new file mode 100644
index 0000000000..0be2b85159
--- /dev/null
+++ b/lib/rubygems/commands/stale_command.rb
@@ -0,0 +1,40 @@
+# frozen_string_literal: true
+
+require_relative "../command"
+
+class Gem::Commands::StaleCommand < Gem::Command
+  def initialize
+    super("stale", "List gems along with access times")
+  end
+
+  def description # :nodoc:
+    <<-EOF
+The stale command lists the latest access time for all the files in your
+installed gems.
+
+You can use this command to discover gems and gem versions you are no
+longer using.
+    EOF
+  end
+
+  def usage # :nodoc:
+    program_name.to_s
+  end
+
+  def execute
+    gem_to_atime = {}
+    Gem::Specification.each do |spec|
+      name = spec.full_name
+      Dir["#{spec.full_gem_path}/**/*.*"].each do |file|
+        next if File.directory?(file)
+        stat = File.stat(file)
+        gem_to_atime[name] ||= stat.atime
+        gem_to_atime[name] = stat.atime if gem_to_atime[name] < stat.atime
+      end
+    end
+
+    gem_to_atime.sort_by {|_, atime| atime }.each do |name, atime|
+      say "#{name} at #{atime.strftime "%c"}"
+    end
+  end
+end