import * as childProcess from 'child_process';
/**
 * open a file or uri using the default application for the file type.
 *
 * @return {ChildProcess} - the child process object.
 * @param {string} target - the file/uri to open.
 * @param {string} appName - (optional) the application to be used to open the
 *      file (for example, "chrome", "firefox")
 * @param {function(Error)} callback - called with null on success, or
 *      an error object that contains a property 'code' with the exit
 *      code of the process.
 */
export default function (target: string, appName: string | Function, callback?: any): childProcess.ChildProcess;