export type IOFormat = 'yaml' | 'json' | 'common';
export declare function formatFromFilename(filename: string): IOFormat;
export declare function parseJSONOrYAML<T>(rawInputData: string, source: string): T;
export declare function readDataFromStdin(): Promise<string>;
/**
 * Simple function to test for TTY input. Use this instead of directly calling `process` if you want
 * to mock in unit tests.
 */
export declare function stdinIsTTY(): boolean;
/**
 * Simple function to test for TTY output. Use this instead of directly calling `process` if you want
 * to mock in unit tests.
 */
export declare function stdoutIsTTY(): boolean;
/**
 * Check for existence of YAML file.
 * Enforces official file extension and warns user if incorrect file detected.
 */
export declare function yamlExists(filepath: string): boolean;
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