cleanenv

Reads from both files (YAML, JSON, TOML, etc.) and environment variables into a single struct, with environment variables automatically overriding file values, as demonstrated in the ReadConfig example.

Uses Go struct tags like env and env-default to define configuration mapping, making it clear and type-safe without external dependencies, aligning with its simplicity philosophy.

Allows marking fields with env-upd to refresh values from environment variables during runtime using UpdateEnv, useful for dynamic systems like distributed architectures.

Generates environment variable descriptions via env-description tags and GetDescription function, aiding in CLI help generation and documentation.