diff --git a/Lib/cmd.py b/Lib/cmd.py
new file mode 100644
index 0000000..d28e393
--- /dev/null
+++ b/Lib/cmd.py
@@ -0,0 +1,65 @@
+# A generic class to build line-oriented command interpreters
+
+import string
+import sys
+import linecache
+
+PROMPT = '(Cmd) '
+IDENTCHARS = string.letters + string.digits + '_'
+
+class Cmd:
+	
+	def init(self):
+		self.prompt = PROMPT
+		self.identchars = IDENTCHARS
+		self.lastcmd = ''
+		return self
+
+	def cmdloop(self):
+		stop = None
+		while not stop:
+			try:
+				line = raw_input(self.prompt)
+			except EOFError:
+				line = 'EOF'
+			stop = self.onecmd(line)
+
+	def onecmd(self, line):
+		line = string.strip(line)
+		if not line:
+			line = self.lastcmd
+			print line
+		else:
+			self.lastcmd = line
+		i, n = 0, len(line)
+		while i < n and line[i] in self.identchars: i = i+1
+		cmd, arg = line[:i], string.strip(line[i:])
+		if cmd == '':
+			return self.default(line)
+		else:
+			try:
+				func = eval('self.do_' + cmd)
+			except AttributeError:
+				return self.default(line)
+			return func(arg)
+
+	def default(self, line):
+		print '*** Unknown syntax:', line
+
+	def do_help(self, arg):
+		if arg:
+			# XXX check arg syntax
+			try:
+				func = eval('self.help_' + arg)
+			except:
+				print '*** No help on', `arg`
+				return
+			func()
+		else:
+			import getattr
+			names = getattr.dir(self)
+			cmds = []
+			for name in names:
+				if name[:3] == 'do_':
+					cmds.append(name[3:])
+			print cmds