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 $pid  //这个$pid就是端口
转自http://genggeng.iteye.com/blog/1181665