What are the best practices for designing a command line interface (CLI) using development tools?

1 Choose a framework

One of the first steps to design a CLI is to choose a framework that suits your needs and preferences. A framework is a library or a tool that provides you with features and functionalities to build and run your CLI, such as parsing arguments, generating help messages, validating inputs, and handling errors. There are many frameworks available for different programming languages, such as Click for Python, Commander for Node.js, Thor for Ruby, and Cobra for Go. You should compare the features, documentation, and community support of different frameworks before deciding which one to use.

2 Define your commands

The next step is to define the commands that your CLI will offer to the users. Commands are the actions that your CLI can perform, such as creating, deleting, updating, or listing resources. When designing your commands, you should use verbs to name them and nouns to name the resources; for example, create-user , delete-project , or list-files . Additionally, use consistent and intuitive naming conventions and avoid abbreviations or aliases that might confuse the users. Utilize subcommands to group related commands and provide a hierarchical structure for your CLI; for instance, user create , user delete , or user list . Finally, use flags and options to modify the behavior or the output of your commands in order to give users more flexibility. Examples of this include --verbose , --force , or --format .

3 Design your interface

Designing the interface of your CLI should be done with usability and clarity in mind. Your commands, flags, and options should have clear and concise help messages that explain what they do and how to use them. You can use the features of your framework to generate help messages automatically or customize them manually. Additionally, feedback and confirmation messages should be provided for commands to show the progress, status, and results of your actions. Colors, symbols, or animations can be used to enhance these messages and make them more readable and engaging. Error and exception handling should also be included for commands, showing meaningful and helpful messages when something goes wrong. The features of your framework can handle common errors or exceptions, or you can write your own logic to handle specific cases.

4 Test and debug your CLI

The final step is to test and debug your CLI and ensure that it works as expected and meets the requirements and expectations of the users. To do this, you should use unit testing and integration testing tools to verify the functionality and performance of your commands, flags, and options and check for any errors or bugs. Additionally, code analysis and code quality tools can be used to check the style, syntax, and structure of your code. Finally, documentation and code generation tools should be used to create and update the documentation and the code of your CLI. Examples of such tools include Pytest for Python, Mocha for Node.js, RSpec for Ruby, Go Test for Go, Pylint for Python, ESLint for Node.js, RuboCop for Ruby, or Go Lint for Go.

5 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?