• Namespace-Aware Configuration: One of Shell Smith's most powerful features is its ability to automatically use the current namespace as the default name for:
  • Configuration file naming (<name>.yml)
  • Environment variable prefix pattern
  • When no explicit :name option is provided
• Multi-source Configuration: Shell Smith manages configurations from:
  • Default values
  • YAML configuration files
  • Environment variables
  • Command-line arguments

The library uses a config macro that merges configuration values from different sources. Here's an example showing both explicit naming and namespace-based defaults:

;; With explicit naming
(def config-explicit
  (shell-smith/config usage
    :defaults {:port 3000}
    :name "mytool"))

;; Using namespace-based defaults
;; If your namespace is 'my.app.server'
;; - Will look for 'my.app.server.yml'
;; - Will match env vars starting with 'MY_APP_SERVER_'
(def config-from-ns
  (shell-smith/config usage
    :defaults {:port 3000}))

The configuration sources are merged in this order (from lowest to highest priority):

• Default values
• YAML configuration file (<name>.yml in current working directory)
• Environment variables (matching pattern <UPPERCASE_NAME>_*)
• Command-line arguments

For example, if your namespace is my.app.tool, Shell Smith will automatically:

• Look for my.app.tool.yml in the current directory
• Match environment variables starting with MY_APP_TOOL_

This convention-over-configuration approach makes it incredibly easy to organize your CLI tool's configuration while maintaining flexibility when needed.

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