cli-development

Unix philosophy for CLIs emphasizes doing one thing well, composability, and predictable behavior. Structure commands with clear hierarchies, use flags for options and subcommands for distinct operations, provide meaningful exit codes, and ensure output works in pipelines. This Skill guides CLI design principles that balance usability with consistency across languages.

Use subcommands when you have distinct workflows or major operational modes—like git commit versus git push. Use flags for modifying behavior within a single command. This Skill covers decision frameworks for command hierarchy, helping you choose the structure that matches your tool's conceptual model and user workflows.

Argument parsing should follow a clear precedence: command-line flags override environment variables, which override config file defaults. This Skill addresses variable precedence patterns, config file integration, and argument parsing strategies to ensure predictable and user-friendly behavior across platforms.

Effective CLIs provide clear, contextual help (mycli --help, mycli init --help), use meaningful exit codes to signal success or failure types, and deliver readable error messages. This Skill covers output formatting, help text standards, error handling patterns, and testing strategies for reliable user experience.

Yes. This Skill applies CLI design principles across languages and platforms, addressing cross-platform considerations like path handling, output formatting, and colored output support. It guides you toward consistent UX regardless of operating system.

Built-in testing validates argument parsing, exit codes, output formatting, and help text consistency. Documentation should include usage examples and version info. This Skill covers testing strategies and documentation workflows to ensure maintainability and reliability of CLI tools.