/**
 * Classify an in-memory byte header as binary (non-UTF-8-text).
 *
 * Binary when the header contains a NUL byte (true binary, plus UTF-16/UTF-32
 * text whose ASCII range is NUL-padded) or when it is not valid UTF-8. The
 * decode runs in streaming mode so a multibyte sequence truncated at the header
 * boundary is tolerated, while any genuinely invalid byte still fails — matching
 * the strict `fatal` decode the `local://`/`ssh://` read paths already use.
 */
export declare function isProbablyBinaryHeader(header: Uint8Array): boolean;
/**
 * Sniff the first {@link BINARY_SNIFF_BYTES} of `filePath` and report whether it
 * is binary (non-UTF-8-text). See {@link isProbablyBinaryHeader} for the rule.
 */
export declare function isProbablyBinary(filePath: string, maxBytes?: number): Promise<boolean>;
/** Synchronous {@link isProbablyBinary}. */
export declare function isProbablyBinarySync(filePath: string, maxBytes?: number): boolean;