/**
 * Asynchronously checks if a command exists in the system.
 *
 * @remarks
 * This function will check if the command is available in the system's PATH and if it is executable.
 * @param commandName - The name of the command to check for existence
 * @returns A promise that resolves to `true` if the command exists and is executable, `false` otherwise
 */
export declare function commandExists(commandName: string): Promise<void>;
/**
 * Synchronously checks if a command exists in the system.
 *
 * @remarks
 * This function will check if the command is available in the system's PATH and if it is executable.
 * @param commandName - The name of the command to check for existence
 * @returns `true` if the command exists and is executable, `false` otherwise
 */
export declare function commandExistsSync(commandName: string): boolean;