The Cmd class provides a simple framework for writing line-oriented command interpreters. These are often useful for test harnesses, administrative tools, and prototypes that will later be wrapped in a more sophisticated interface.
The optional argument completekey is the readline name
of a completion key; it defaults to Tab. If completekey is
None and readline is available, command completion
is done automatically.
The optional arguments stdin and stdout specify the input and output file objects that the Cmd instance or subclass instance will use for input and output. If not specified, they will default to sys.stdin and sys.stdout.
Changed in version 2.3: The stdin and stdout parameters were added..