Getoption

Getoption, often written as getOption, refers to a function or method used to retrieve the value of a named option from a set of configuration data, command-line arguments, or environmental sources. It is a common pattern in software that needs flexible configuration retrieval without requiring callers to know where the value comes from.

Typical features of a getOption utility include support for default values, type conversion or normalization, and a clear mechanism for handling missing or required options. Many implementations also apply a precedence order, such as explicit options provided at runtime taking priority over environment variables, which in turn override values from configuration files or defaults.

A common model is to supply a key and optionally a default value, with the function returning the corresponding value or the default if the key is not found. Some implementations allow specifying a type to cast the result, or a validation function to ensure the value meets constraints. In more advanced setups, getOption may merge multiple sources and cache results for performance.

Usage patterns vary by language and framework. For example, a simple getOption might look up a key in a provided options object and fall back to a default. In configuration-heavy systems, getOption can centralize access to settings, enabling consistent handling of missing values, environment-specific overrides, and error reporting for required options.

See also: configuration management, command-line argument parsing, environment variables, defaults.