1 files changed, 41 insertions, 0 deletions
diff --git a/lib/optparse/version.rb b/lib/optparse/version.rb
new file mode 100644
index 0000000000..35152181b0
--- /dev/null
+++ b/lib/optparse/version.rb
@@ -0,0 +1,41 @@
+# OptionParser internal utility
+
+class << OptionParser
+  def show_version(*pkg)
+    progname = ARGV.options.program_name
+    show = proc do |klass, version|
+      version = version.join(".") if Array === version
+      str = "#{progname}: #{klass} version #{version}"
+      if klass.const_defined?(:Release)
+        str << " (#{klass.const_get(:Release)})"
+      end
+      puts str
+    end
+    if pkg.size == 1 and pkg[0] == "all"
+      self.search_const(::Object, "Version", &show)
+    else
+      pkg.each do |pkg|
+        /\A[A-Z]\w*((::|\/)[A-Z]\w*)*\z/ni =~ pkg or next
+        begin
+          pkg = eval(pkg)
+          show.call(pkg, pkg.const_defined?(:Version) ? pkg.const_get(:Version) : "unknown")
+        rescue NameError
+          puts "#{progname}: #$!"
+        end
+      end
+    end
+    exit
+  end
+
+  def search_const(klass, name)
+    klasses = [klass]
+    while klass = klasses.shift
+      klass.constants.each do |cname|
+        klass.const_defined?(cname) or next
+        const = klass.const_get(cname)
+        yield klass, const if cname == name
+        klasses << const if Module === const and const != ::Object
+      end
+    end
+  end
+end