diff --git a/bin/example.rb b/bin/example.rb
index d1b8fbc..ab13bff 100755
--- a/bin/example.rb
+++ b/bin/example.rb
@@ -95,7 +95,62 @@ class Capture
 	end
 end
 
+cli.cmd( :args, "Expects and prints given arguments",
+	&lambda {|a, b, c:, d:, e:, f:, g:|
+		p a: a, b: b, c: c, d: d, e: e
+	}).
+	opt( :c, '-c=ForC', "Option c").
+	opt( :d, '-dForD', "Option d", default: "something").
+	opt( :e, '-e', "Toggle e", default: false).
+	opt( :f, '--[no-]f', "Toggle f", default: false).
+	opt( :g, '--long-option=sth', "Long option, no short option", default: "nothing").
+	opt( :h, '-hsth', "No long option, only short option", default: "nothing")
+
+cli.cmd( :example, "I have an example command") { $stderr.puts "This is an example" }
+cli.cmd( :help, "An example for help", aliases: [nil, '-h', '--help'], &lambda {|*commands, full:|
+	if full
+		cli.help_full *commands, output: $stderr
+	else
+		cli.help *commands, output: $stderr
+	end
+}).
+	opt( :full, '-f', '--[no-]full', "Print all commands and sub-commands.", default: false)
+
+cli.sub( :more, "Sub-Commands are also possible with a new cli") do |sub|
+	sub.cmd( :help, "", aliases: [nil, '-h', '--help']) {|*args| $stderr.puts sub.help(*args) }
+	sub.cmd( :example, "Here is an example, too") { $stderr.puts "This is an other example" }
+	sub.cmd( :foo, "BAR") { $stderr.puts "FOO bar"}
+
+	sub.cmd( :args, "Expects and prints given arguments", &lambda {|a, b=1, c:, d: 5, e:|
+			p a: a, b: b, c: c, d: d, e: e
+		}).
+		opt( :c, '-c=ForC', "Option c").
+		opt( :d, '-d=ForD', "Option d (implicit default)").
+		opt( :e, '-e', "Toggle e")
+
+	sub.sub( :deeper, "You want to have Sub-Sub-Commands?") do |sub2|
+		sub2.cmd( :help, "", aliases: [nil, '-h', '--help'], &lambda {|*commands| sub2.help( *commands, output: $stderr) })
+		sub2.cmd( :last, "The last example", &lambda { $stderr.puts "The last example" })
+
+		sub2.sub( :'sub-commands', "Endless Sub-Sub- ... with a special alias") do |sub3|
+			# h    -> help
+			# he   -> hehe
+			# hel  -> help
+			# help -> help
+			# heh  -> hehe
+			# hehe -> hehe
+			sub3.cmd( :help, "", min: 3, aliases: [nil, :h]) {|*args| $stderr.puts sub3.help( *args) }
+			sub3.cmd( :hehe, "The real last example", min: 2) { $stderr.puts "Trust me!" }
+		end
+	end
+end
+
+cli.cmd( :cli, "Interactive shell", min: 3, &lambda {||
+	cli.interactive( File.basename($0, '.rb')).run
+})
+
 cli.sub :tests, "Some tests", noshortaliases: true do |tcli|
+	tcli.cmd( :help, "", min: 4) {|*args| $stderr.puts tcli.help( *args) }
 	OptionParser.accept IPAddr do |arg|
 		begin
 			IPAddr.new arg
@@ -202,50 +257,6 @@ cli.sub :tests, "Some tests", noshortaliases: true do |tcli|
 	end.opt( :verbose, '-v', 'Prints additional information per test', default: false)
 end
 
-cli.cmd( :args, "Expects and prints given arguments",
-	&lambda {|a, b, c:, d:, e:, f:, g:|
-		p a: a, b: b, c: c, d: d, e: e
-	}).
-	opt( :c, '-c=ForC', "Option c").
-	opt( :d, '-dForD', "Option d", default: "something").
-	opt( :e, '-e', "Toggle e", default: false).
-	opt( :f, '--[no-]f', "Toggle f", default: false).
-	opt( :g, '--long-option=sth', "Long option, no short option", default: "nothing").
-	opt( :h, '-hsth', "No long option, only short option", default: "nothing")
-
-cli.cmd( :example, "I have an example command") { $stderr.puts "This is an example" }
-cli.cmd( :help, "An example for help", aliases: [nil, '-h', '--help'], &lambda {|*commands, full:|
-	if full
-		cli.help_full *commands, output: $stderr
-	else
-		cli.help *commands, output: $stderr
-	end
-}).
-	opt( :full, '-f', '--[no-]full', "Print all commands and sub-commands.", default: false)
-
-cli.sub( :more, "Sub-Commands are also possible with a new cli") do |sub|
-	sub.cmd( :help, "", aliases: [nil, '-h', '--help']) {|*args| $stderr.puts sub.help(*args) }
-	sub.cmd( :example, "Here is an example, too") { $stderr.puts "This is an other example" }
-	sub.cmd( :foo, "BAR") { $stderr.puts "FOO bar"}
-
-	sub.cmd( :args, "Expects and prints given arguments", &lambda {|a, b=1, c:, d: 5, e:|
-			p a: a, b: b, c: c, d: d, e: e
-		}).
-		opt( :c, '-c=ForC', "Option c").
-		opt( :d, '-d=ForD', "Option d (implicit default)").
-		opt( :e, '-e', "Toggle e")
-
-	sub.sub( :deeper, "You want to have Sub-Sub-Commands?") do |sub2|
-		sub2.cmd( :help, "", aliases: [nil, '-h', '--help'], &lambda {|*commands| sub2.help( *commands, output: $stderr) })
-		sub2.cmd( :last, "The last example", &lambda { $stderr.puts "The last example" })
-
-		sub2.sub( :'sub-commands', "Endless Sub-Sub- ...") do |sub3|
-			sub3.cmd( :help, "") {|*args| $stderr.puts sub3.help( sub3, *args) }
-			sub3.cmd( :hehe, "The real last example", min: 2) { $stderr.puts "Trust me!" }
-		end
-	end
-end
-
 begin
 	cli.call *ARGV
 rescue DenCli::UsageError
diff --git a/lib/dencli.rb b/lib/dencli.rb
index 45a233e..26ee3ae 100755
--- a/lib/dencli.rb
+++ b/lib/dencli.rb
@@ -80,6 +80,9 @@ class DenCli
 		post
 	end
 
+	def []( k) @subs[k] end
+	def has?( k) @subs.has? k end
+
 	def sub *a, **o, &exe
 		@subs.sub *a, **o, &exe
 	end
@@ -110,10 +113,6 @@ class DenCli
 		Sub._help_commands output, subs.to_enum( :commands)
 	end
 
-	def [] k
-		@subs[k]
-	end
-
 	def interactive *args, **opts
 		Interactive.new self, *args, **opts
 	end
diff --git a/lib/dencli/interactive.rb b/lib/dencli/interactive.rb
index be778c2..8a75314 100644
--- a/lib/dencli/interactive.rb
+++ b/lib/dencli/interactive.rb
@@ -17,12 +17,15 @@ class DenCli::Interactive
 			end
 		read_history  if @histfile
 
-		Readline.vi_editing_mode  rescue NotImplementedError
+		begin
+			Readline.vi_editing_mode
+		rescue NotImplementedError
+		end
 		Readline.completion_append_character = " "
 		Readline.completion_proc = method :complete
 
 		prepare_sub cl.subs
-		cl.cmd :exit, "exit", min: 2 do
+		cl.cmd :exit, "exit", min: cl.has?(:ex) ? cl.has?(:exi) ? 4 : 3 : 2 do
 			exit 0
 		end
 		cl.subs.aliases['?'] = cl.subs.subs['help']
@@ -90,14 +93,16 @@ class DenCli::Interactive
 		c.subs.values.each do |n|
 			case n
 			when DenCli::Sub
-				n.cmd :exit, "<- #{n.parent.full_cmd.join ' '} - #{n.parent.description[3..-1]}", min: 2 do
-					@cur = n.parent
-				end
+				n.cmd :exit,
+						"<- #{n.parent.full_cmd.join ' '} - #{n.parent.description[3..-1]}",
+						min: n.has?(:ex) ? n.has?( :exi) ? 4 : 3 : 2,
+						&lambda {|| @cur = n.parent }
+				n.aliases.delete nil
+				n.subs.delete nil
 				n.cmd '', "", min: 2, aliases: [nil] do
 					@cur = n
 				end
-				n.subs.delete ''
-				n.aliases['?'] = n.subs['help']
+				n.aliases['?'] = n[:help]  if n.has? :help and not n.has? '?'
 				prepare_sub n
 			when DenCli::CMD
 			else raise "Unsupported sub-type: #{x}"
diff --git a/lib/dencli/sub.rb b/lib/dencli/sub.rb
index 19f9357..d8c34e6 100644
--- a/lib/dencli/sub.rb
+++ b/lib/dencli/sub.rb
@@ -13,7 +13,9 @@ class DenCli::Sub
 
 	def _full_cmd( post) parent._full_cmd [@name]+post end
 	def full_cmd() _full_cmd [] end
-	def []( k) @aliases[k] end
+	def []( name) @aliases[name&.to_s] end
+	def has?( name) @aliases.has_key? name&.to_s end
+
 
 	def usage output: nil
 		output ||= ''
@@ -40,8 +42,8 @@ class DenCli::Sub
 		if n.nil?
 			output << "#{full_cmd.join ' '}: #{description}\n\n"
 			self.class._help_commands output, @subs
-		elsif @aliases.has_key? n
-			@aliases[n]._help output, *a
+		elsif has? n
+			self[n]._help output, *a
 		else
 			raise DenCli::UnknownCommand, "unknown command: #{_full_cmd( [n])[1..-1].join ' '}, available for #{full_cmd[1..-1].join' '}: #{@subs.keys.join ' '}"
 		end
@@ -96,8 +98,8 @@ class DenCli::Sub
 	def goto *a
 		return self  if a.empty?
 		n, *a = *a
-		if @aliases.has_key? n
-			@aliases[n].goto *a
+		if has? n
+			self[n].goto *a
 		else
 			raise DenCli::UnknownCommand, "unknown command: #{_full_cmd( [n])[1..-1].join ' '}, available for #{full_cmd[1..-1].join' '}: #{@subs.keys.join ' '}"
 		end
@@ -105,19 +107,19 @@ class DenCli::Sub
 
 	def call *a
 		n, *a = *a
-		if @aliases.has_key? n
-			@aliases[n].call *a
+		if has? n
+			self[n].call *a
 		else
 			raise DenCli::UnknownCommand, "unknown command: #{_full_cmd( [n])[1..-1].join ' '}, available for #{full_cmd[1..-1].join' '}: #{@subs.keys.join ' '}"
 		end
 	end
 
 	def _add name, min, obj, aliases
-		#DenCli::assert_type self, __method__, :name, name, Symbol, NilClass
+		#DenCli::assert_type self, __method__, :name, name, Symbol, String
 		#DenCli::assert_type self, __method__, :min, min, Integer, NilClass
 		#DenCli::assert_type self, __method__, :obj, obj, DenCli::Sub, DenCli::CMD
 		#DenCli::assert_type self, __method__, :aliases, aliases, Array, NilClass
-		name = name.to_s  unless name.nil?
+		name = name.to_s
 		@subs[name] = obj
 		if @noshortaliases
 			warn "Command/Alias for #{obj.full_cmd} defined in #{obj.defined_in} already exists: #{full_cmd.join ' '} #{name}.  Used by #{@aliases[name].full_cmd} defined in #{@aliases[name].defined_in}"  if @aliases.has_key? name
@@ -130,6 +132,7 @@ class DenCli::Sub
 		end
 		if aliases
 			[*aliases].each do |a|
+				a = a&.to_s
 				raise ArgumentError, "Alias for #{obj.full_cmd} defined in #{obj.defined_in} already exists: #{full_cmd.join ' '} #{a}.  Used by #{@aliases[a].full_cmd} defined in #{@aliases[a].defined_in}"  if @aliases.has_key? a
 				@aliases[a] = obj
 			end
@@ -138,11 +141,49 @@ class DenCli::Sub
 	end
 	private :_add
 
+	# Define a new sub-menu:
+	#
+	#   DenCli.new {|c|
+	#     c.sub( 'sub-command') {|s|
+	#       s.cmd( :hello, 'Greetings', &lambda {|| puts 'hello world' })
+	#     }
+	#   }
+	#
+	#   # ./prog sub-command hello
+	#
+	# name should be a string/symbol.  It will be converted to string.
+	# If provided, aliases must be a list of different aliases.  It will be converted to string.
 	def sub name, description, min: nil, aliases: nil, noshortaliases: nil, defined_in: nil, &exe
-		r = _add name, min, DenCli::Sub.new( self, name, description, noshortaliases: noshortaliases, defined_in: defined_in || Kernel.caller.first), aliases
+		r = _add name.to_s, min, DenCli::Sub.new( self, name, description, noshortaliases: noshortaliases, defined_in: defined_in || Kernel.caller.first), aliases
 		block_given? ? yield( r) : r
 	end
 
+	# Define a new command:
+	#
+	#   DenCli.new {|c|
+	#     c.cmd( :hello, 'Greetings', &lambda {|| puts 'hello world' })
+	#   }
+	#
+	#   # ./prog hello
+	#   hello world
+	#
+	# name should be a string/symbol.  It will be converted to string.
+	# If provided, aliases must be a list of different aliases.  Except of nil, any alias will be converted to string.
+	# nil is an alias for a default command for sub-commands, but interactive shells.
+	#
+	#   DenCli.new {|c|
+	#     c.sub( :greetings, 'Hello, Welcome, ...') do |s|
+	#       s.cmd( :hello, 'A simple Hello', aliases: %w[hello-world hello_world], &lambda {|| puts 'Hello World' })
+	#       s.cmd( :welcome, 'More gracefull', aliases: [nil, 'welcome-world', :hello_world], &lambda {|| puts 'Welcome World' })
+	#     }
+	#   }
+	#
+	#   # ./prog greetings
+	#   Welcome World
+	#   # ./prog greetings welcome
+	#   Welcome World
+	#   # ./prog greetings hello
+	#   Hello World
 	def cmd name, description, min: nil, aliases: nil, defined_in: nil, &exe
 		_add name, min, DenCli::CMD.new( self, name, description, exe, defined_in || Kernel.caller.first), aliases
 	end