Register Shutdown Function

:::info[Note] This is a point-in-time snapshot of the API documentation from January 2026. Going forward, we will not be maintaining a public copy of these references, and recommend users to refer to the built-in signature helpers available in the Hack LSP instead for complete and up-to-date information. :::

Register a function for execution on shutdown

function register_shutdown_function<T>(
  (function(): T) $function,
): void;

Parameters

• (function(): T) $function

Returns

• void