Copyright for epoll_ctl.2:
Copyright (C) 2003 Davide Libenzi Davide Libenzi <firstname.lastname@example.org> and Copyright 2009, 2014, 2016, 2018, 2019 Michael Kerrisk <email@example.com>
License for epoll_ctl.2:
This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this manual; if not, see <http://www.gnu.org/licenses/>.