1，启动 nginx报错

systemctl start nginx

[root@laoban yum.repos.d]# systemctl start nginx
Job for nginx.service failed because the control process exited with error code. See "systemctl status nginx.service" and "jetails.
[root@laoban yum.repos.d]# 

2，查看nginx状态

systemctl status nginx.service

报错提示： Failed to start The nginx HTTP and reverse proxy server.

3，看一下nginx端口号

netstat -anpt | grep nginx

nginx端口号是71816

4，杀死nginx进程

kill -QUIT 主进程号
kill -QUIT 71816

经过测试，kill -QUIT 该命令会自动 kill 掉 nginx 的父和子进程，推荐使用！如果 只用 kill -9 主进程，只有主进程被 kill，nginx 子进程还在！！！

5，重启

systemctl restart nginx
systemctl status nginx