/**
 * @file `onExit` — register a callback for process exit / signal. Triggers
 *   `load()` on first call. Returns a remover that unregisters the callback and
 *   calls `unload()` once both `exit` and `afterexit` listener lists empty
 *   out.
 */
import type { OnExitOptions } from './types';
/**
 * Register a callback to run on process exit or signal.
 *
 * @example
 *   ```typescript
 *   const remove = onExit((code, signal) => {
 *   console.log(`Exiting with code ${code}, signal ${signal}`)
 *   })
 *   // Later, to unregister:
 *   remove()
 *   ```
 */
export declare function onExit(cb: (code: number | null, signal: string | null) => void, options?: OnExitOptions | undefined): () => void;
