core-bundle/src/Resources/contao/controllers/FrontendShare.php
public function run()
	{
		switch (Input::get('p'))
		{
			case 'facebook':
				return new RedirectResponse(
					'https://www.facebook.com/sharer/sharer.php'
						. '?u=' . rawurlencode(Input::get('u', true))
				);

			case 'twitter':
				return new RedirectResponse(
					'https://twitter.com/intent/tweet'
						. '?url=' . rawurlencode(Input::get('u', true))
						. '&text=' . rawurlencode(Input::get('t', true))
				);

			case 'gplus':
				return new RedirectResponse(
					'https://plus.google.com/share'
						. '?url=' . rawurlencode(Input::get('u', true))
				);
		}

		return new RedirectResponse('../');
	}
public function run()
	{
		switch (Input::get('p'))
		{
			case 'facebook':
				return new RedirectResponse(
					'https://www.facebook.com/sharer/sharer.php'
						. '?u=' . rawurlencode(Input::get('u', true))
				);

			case 'twitter':
				return new RedirectResponse(
					'https://twitter.com/intent/tweet'
						. '?url=' . rawurlencode(Input::get('u', true))
						. '&text=' . rawurlencode(Input::get('t', true))
				);

			case 'gplus':
				return new RedirectResponse(
					'https://plus.google.com/share'
						. '?url=' . rawurlencode(Input::get('u', true))
				);
		}

		return new RedirectResponse('../');
	}
Run the controller

@return RedirectResponse