declare const username: {
	/**
	Get the username of the current user.

	It first tries to get the username from the `SUDO_USER` `LOGNAME` `USER` `LNAME` `USERNAME` environment variables. Then falls back to `$ id -un` on macOS / Linux and `$ whoami` on Windows, in the rare case none of the environment variables are set. The result is cached.

	@returns The username.

	@example
	```
	import username = require('username');

	(async () => {
		console.log(await username());
		//=> 'sindresorhus'
	})();
	```
	*/
	(): Promise<string | undefined>;

	/**
	Synchronously get the username of the current user.

	It first tries to get the username from the `SUDO_USER` `LOGNAME` `USER` `LNAME` `USERNAME` environment variables. Then falls back to `$ id -un` on macOS / Linux and `$ whoami` on Windows, in the rare case none of the environment variables are set. The result is cached.

	@returns The username.

	@example
	```
	import username = require('username');

	console.log(username.sync());
	//=> 'sindresorhus'
	```
	*/
	sync(): string | undefined;
};

export = username;