Systemctl

启动、重启、停止、重载服务以及检查服务（如 httpd.service）状态

systemctl的start，restart，stop和reload命令时，我们不会从终端获取到任何输出内容，只有status命令可以打印输出。

1. # systemctl start httpd.service
2. # systemctl restart httpd.service
3. # systemctl stop httpd.service
4. # systemctl reload httpd.service
5. # systemctl status httpd.service

激活服务并在启动时启用或禁用服务（即系统启动时自动启动服务）

1. # systemctl is-active httpd.service
2. # systemctl enable httpd.service
3. # systemctl disable httpd.service