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# Why cmd2

## cmd

cmd is the Python Standard Library's module for creating simple interactive command-line applications. cmd is an extremely bare-bones framework which leaves a lot to be desired. It doesn't even include a built-in way to exit from an application!

Since the API provided by cmd provides the foundation on which `cmd2` is based, understanding the use of cmd is the first step in learning the use of `cmd2`. Once you have read the cmd docs, return here to learn the ways that `cmd2` differs from cmd.

## cmd2

`cmd2` is a batteries-included extension of cmd, which provides a wealth of functionality to make it quicker and easier for developers to create feature-rich interactive command-line applications which delight customers.

`cmd2` can be used as a drop-in replacement for cmd with a few minor discrepancies as discussed in the Incompatibilities section. Simply importing `cmd2` in place of cmd will add many features to an application without any further modifications. Migrating to `cmd2` will also open many additional doors for making it possible for developers to provide a top-notch interactive command-line experience for their users.

Warning

As of version 4.0.0, `cmd2` does not have an actual dependency on `cmd`. `cmd2` is mostly API compatible with `cmd2`. See Incompatibilities for the few documented incompatibilities.

## Automatic Features

After switching from cmd to `cmd2`, your application will have the following new features and capabilities, without you having to do anything:

- More robust History. Both cmd and `cmd2` provide familiar readline-style history, but `cmd2` utilizes the powerful prompt-toolkit library for a pure Python, fully cross-platform experience. Additionally, `cmd2` has a robust `history` command which allows you to edit prior commands in a text editor of your choosing, re-run multiple commands at a time, save prior commands as a script to be executed later, and much more.
- Users can redirect output to a file or pipe it to some other operating system command. You did remember to use `self.stdout` instead of `sys.stdout` in all of your print functions, right? If you did, then this will work out of the box. If you didn't, you'll have to go back and fix them. Before you do, you should consider the various ways `cmd2` has of Generatoring Output.
- Users can load script files, which contain a series of commands to be executed.
- Users can create Shortcuts, Aliases, and Macros to reduce the typing required for repetitive commands.
- Embedded Python and/or IPython shells allow a user to execute Python code from within your `cmd2` app. How meta.
- Clipboard Integration allows you to save command output to the operating system clipboard.
- A built-in Timer can show how long it takes a command to execute

## Next Steps

In addition to the features you get with no additional work, `cmd2` offers a broad range of additional capabilities which can be easily added to your application. Next Steps has some ideas of where you can start, or you can dig in to all the Features.