https://unix.cafe/wp/ar/2017/04/%d9%83%d9%8a%d9%81%d9%8a%d8%a9-%d8%a5%d8%af%d8%a7%d8%b1%d8%a9-%d8%a7%d9%84%d8%ae%d8%af%d9%85%d8%a9-%d9%81%d9%8a-systemd-%d9%88-sysvinit-%d9%88-upstart-%d9%88-runit-%d9%88-openrc/