README.md

Documentation

Be consistent with POSIX tools.
CLI success comes from ease and predictability of use so be consistent.
Support Piping and output direction to chain commands together.
Work with GREP, AWK, JQ and other common tools and commands.
Support productivity features like tab completion and parameter value completion.

Commands should follow a "[noun] [noun] [verb]" pattern.
- For nouns that only support a single verb, the command should be named as a single hyphenated verb-noun pair.
Commands should support all output types (be consistent).
- Exceptions are okay if only a 'raw' format makes sense e.g. XML.
Commands and arguments should have descriptions.
- Include examples for the less straightforward commands.
Commands should return an object or dictionary, not strings/bools/etc.; logging.info(“Upload of myfile.txt successful”) NOT return “Upload successful”.

Log to ERROR or WARNING for user messages; don't use print() function (by default it goes to STDOUT).
STDOUT vs. STDERR: STDOUT is used for actual command output. Everything else to STDERR (e.g. log/status/error messages).

CLI - Provides the entry point.
Commands - Provides logic to register and load commands.
Arguments - Provides logic to register and load command arguments.
Validators - Provides logic to valid or transform command arguments.
Events - Provides an extensible events module that you can hook into.
Config - Provides user-configurable options back by environment variables or config files.
Logging - Provides consistent logging.
Completion - Provides tab completion support.
Prompting - Provides a consistent user-prompting experience.
Help - Provides command/argument help.
Output - Provides output options and displays command output.
Query - Provides JMESPath query support.
Testing - Provides a framework to test your commands.