export interface LockOptions {
    lockTimeout?: number;
    waitTimeout?: number;
}
export declare class LockError extends Error {
}
export type UnlockFunction = (file?: string) => Promise<void>;
/**
 * Creates a cross-process lock for the given file, for the actual process.
 *
 * Note, that it will be only a soft-lock, the file will be locked for other
 * instances of cross-process-lock, or processes using the same API for locking.
 *
 * @param file The path of the file to lock.
 * @param options The lock options/timeout.
 * @returns The function to unlock the file.
 */
export declare function lock(file: string, options?: LockOptions): Promise<UnlockFunction>;