import Mapping from '../domain/Mapping';
/**
 * Expands the environment variables present in the string.
 * Returns the string as is, if no variables were present. And,
 * in case the variable used in the string isn't defined it is
 * substituted with an empty string ('').
 *
 *  Example:
 *    Input: 'Current user is ${USER} at ${HOST}.'
 *    Output: 'Current user is kabir at leapfrog.'
 *
 * @param {string} value
 * @returns {string}
 */
export declare function expandEnvVars(value: string): string;
/**
 * Expand environment variables to be expanded that are
 * found in the values of the given map (key => value pairs).
 *
 * @param {Mapping<string>} vars
 * @returns {Mapping<string>}
 */
export declare function expandEnvVarsInMap(vars: Mapping<string>): Mapping<string>;