import Arg from 'arg';
/**
 * format
 */
export declare function format(input?: string): string;
/**
 * Wrap arg to return an error instead of throwing
 */
export declare function arg<T extends Arg.Spec>(argv: string[], spec: T, stopAtPositional?: boolean, permissive?: boolean): Arg.Result<T> | Error;
/**
 * Check if result is an error
 */
export declare function isError(result: any): result is Error;