/** Find the actual key used for PATH (Windows may use `Path`). */
export declare function findPathKey(env: Record<string, string>): string;
export declare function normalizePathPrepend(entries?: string[]): string[];
export declare function mergePathPrepend(existing: string | undefined, prepend: string[]): string;
export declare function applyPathPrepend(env: Record<string, string>, prepend: string[] | undefined, options?: {
    requireExisting?: boolean;
}): void;