nginx启动报错nginx: [emerg] bind() to 0.0.0.0:80 failed (98: Address already in use)

nginx启动报错，信息如下：

nginx: [emerg] bind() to 0.0.0.0:80 failed (98: Address already in use)

nginx: [emerg] bind() to 0.0.0.0:80 failed (98: Address already in use)

nginx: [emerg] bind() to 0.0.0.0:80 failed (98: Address already in use)

nginx: [emerg] bind() to 0.0.0.0:80 failed (98: Address already in use)

.....

使用ps ef|grep nginx，并未发现有nginx进程，有可能被其他进程占用，这时可以采用如下方式处理：

1. 查看80端口占用

   netstat -ntpl

2. 杀掉占用80端口的进程

kill -9 $pid