systemctl
man - 控制systemd系統和服務管理程序
實例：
啓動服務
systemctl start network.service關閉服務
systemctl stop network.service重啓服務
systemctl restart network.service查看服務狀態
systemctl status network.service開機自啓動
systemctl enable network.service關閉開機自啓動
systemctl disable network.service查看已有服務
systemctl list-units -type=service
systemctl list-units -t service
