diff --git a/lib/dencli.rb b/lib/dencli.rb
index 0c09257..4f25347 100755
--- a/lib/dencli.rb
+++ b/lib/dencli.rb
@@ -1,3 +1,5 @@
+require 'optparse'
+
 class DenCli
 	class UsageError < ::RuntimeError
 	end
@@ -54,8 +56,8 @@ class DenCli
 
 	attr_reader :subs
 
-	def initialize progname, desc
-		@subs = Sub.new self, progname, desc
+	def initialize progname, description
+		@subs = Sub.new self, progname, description
 	end
 
 	def full_cmd
diff --git a/lib/dencli/cmd.rb b/lib/dencli/cmd.rb
index 0633bfb..de0cf59 100644
--- a/lib/dencli/cmd.rb
+++ b/lib/dencli/cmd.rb
@@ -1,18 +1,33 @@
 require_relative '../dencli'
 
 class DenCli::CMD
-	attr_reader :parent, :name, :desc, :exe, :completion
+	attr_reader :parent, :name, :description, :exe, :completion, :arguments
 
-	def initialize parent, name, desc, exe
+	def initialize parent, name, description, exe
 		raise "Proc expected, instead of: #{exe.inspect}"  unless Proc === exe
-		@parent, @name, @desc, @exe = parent, name, desc, exe
+		@parent, @name, @description, @exe = parent, name, description, exe
+		@arguments = []
 		completion {|*a| [] }
 	end
 
 	def _full_cmd( post) parent._full_cmd [@name]+post end
 	def full_cmd() _full_cmd [] end
-	def call( *a) @exe.call *a end
-	def help() "#{parent.full_cmd.join ' '} #{name}\n#{    desc}" end
+	def call( *as)
+		if @arguments.empty?
+			@exe.call *as
+		else
+			os = {}
+			options = OptionParser.new
+			options.banner = "#{full_cmd.join ' '}"
+			@arguments.each do |(aname, aas, aos, aexe)|
+				os[aname] = aos[aname]  if aos.has_key? :default
+				options.on( *aas) {|val| os[aname] = aexe[val] }
+			end
+			as = options.parse! as
+			@exe.call *as, **os
+		end
+	end
+	def help() "#{parent.full_cmd.join ' '} #{name}\n#{description}" end
 
 	def complete( *pre, str) @completion.call *pre, str end
 
@@ -21,10 +36,15 @@ class DenCli::CMD
 		self
 	end
 
+	def arg name, *as, **os, &exe
+		@arguments.push [name.to_s.to_sym, as, os, exe || lambda{|*a|a} ]
+		self
+	end
+
 	def inspect
-		"#<%s:0x%x %s @name=%p @desc=%p @parent=<%s:0x%x %s> @exe=<arity=%d>>" % [
+		"#<%s:0x%x %s @name=%p @description=%p @parent=<%s:0x%x %s> @exe=<arity=%d>>" % [
 			self.class.name, self.object_id, self.full_cmd,
-			@name, @desc, @parent.class.name, @parent.class.object_id, @parent.full_cmd,
+			@name, @description, @parent.class.name, @parent.class.object_id, @parent.full_cmd,
 			@exe.arity
 		]
 	end
diff --git a/lib/dencli/interactive.rb b/lib/dencli/interactive.rb
index e0016a8..d03b482 100644
--- a/lib/dencli/interactive.rb
+++ b/lib/dencli/interactive.rb
@@ -90,7 +90,7 @@ class DenCli::Interactive
 		c.subs.values.each do |n|
 			case n
 			when DenCli::Sub
-				n.cmd :exit, "<- #{n.parent.full_cmd.join ' '} - #{n.parent.desc[3..-1]}", min: 2 do
+				n.cmd :exit, "<- #{n.parent.full_cmd.join ' '} - #{n.parent.description[3..-1]}", min: 2 do
 					@cur = n.parent
 				end
 				n.cmd '', "", min: 2, aliases: [nil] do
diff --git a/lib/dencli/sub.rb b/lib/dencli/sub.rb
index 8e2ec74..0d06fea 100644
--- a/lib/dencli/sub.rb
+++ b/lib/dencli/sub.rb
@@ -1,10 +1,10 @@
 require_relative '../dencli'
 
 class DenCli::Sub
-	attr_reader :parent, :name, :desc, :subs, :aliases
+	attr_reader :parent, :name, :description, :subs, :aliases
 
-	def initialize parent, name, desc
-		@parent, @name, @desc, @subs, @aliases = parent, name, "-> #{desc}", {}, {}
+	def initialize parent, name, description
+		@parent, @name, @description, @subs, @aliases = parent, name, "-> #{description}", {}, {}
 	end
 
 	def _full_cmd( post) parent._full_cmd [@name]+post end
@@ -13,10 +13,10 @@ class DenCli::Sub
 
 	def help n = nil, *a
 		if n.nil?
-			r = "#{full_cmd.join ' '}: #{desc}\n\n"
+			r = "#{full_cmd.join ' '}: #{description}\n\n"
 			m = @subs.map {|k,_| k.length }.max
 			@subs.each do |k, c|
-				r += "  % -#{m}s  %s\n" % [k, c.desc]  unless k.nil?
+				r += "  % -#{m}s  %s\n" % [k, c.description]  unless k.nil?
 			end
 			r
 		elsif @aliases.has_key? n
@@ -46,13 +46,13 @@ class DenCli::Sub
 	end
 	private :_add
 
-	def sub name, desc, min: nil, aliases: nil, &exe
-		r = _add name, min, DenCli::Sub.new( self, name, desc), aliases
+	def sub name, description, min: nil, aliases: nil, &exe
+		r = _add name, min, DenCli::Sub.new( self, name, description), aliases
 		block_given? ? yield( r) : r
 	end
 
-	def cmd name, desc, min: nil, aliases: nil, &exe
-		_add name, min, DenCli::CMD.new( self, name, desc, exe), aliases
+	def cmd name, description, min: nil, aliases: nil, &exe
+		_add name, min, DenCli::CMD.new( self, name, description, exe), aliases
 	end
 
 	def complete *pre, str
@@ -66,9 +66,9 @@ class DenCli::Sub
 	end
 
 	def inspect
-		"#<%s:0x%x %s @name=%p @desc=%p @subs={%s} @aliases={%s} @parent=<%s:0x%x %s>>" % [
+		"#<%s:0x%x %s @name=%p @description=%p @subs={%s} @aliases={%s} @parent=<%s:0x%x %s>>" % [
 			self.class.name, self.object_id, self.full_cmd,
-			@name, @desc, @subs.keys.join(', '), @aliases.keys.join(', '), @parent.class.name, @parent.class.object_id, @parent.full_cmd
+			@name, @description, @subs.keys.join(', '), @aliases.keys.join(', '), @parent.class.name, @parent.class.object_id, @parent.full_cmd
 		]
 	end
 end
diff --git a/lib/dencli/version.rb b/lib/dencli/version.rb
index 3521c05..8102ea7 100644
--- a/lib/dencli/version.rb
+++ b/lib/dencli/version.rb
@@ -1,3 +1,3 @@
 class DenCli
-	VERSION = '0.2.1'
+	VERSION = '0.3.0'
 end