Nginx(engine x)的必会操作

环境： Ubuntu18.04LTS
业务： 易忘记，记录一下

安装

apt-get install nginx

启动

首先查看Nginx的文件的位置

$ whereis nginx
nginx: /usr/sbin/nginx /usr/lib/nginx /etc/nginx /usr/share/nginx /usr/share/man/man8/nginx.8.gz

配置目录/etc/nginx的配置文件nginx.conf，一般装好之后没有什么问题，可以使用命令检查一下：

toohoo@ubuntu:~$ sudo /usr/sbin/nginx  -t
nginx: the configuration file /etc/nginx/nginx.conf syntax is ok
nginx: configuration file /etc/nginx/nginx.conf test is successful

现在使用命令启动Nginx:
$ sudo /usr/sbin/nginx -c /etc/nginx/nginx.conf
没有消息就是好消息，启动时没有提示的。

如果被占用或者之前已经开启过会出现一下情况：

$ sudo /usr/sbin/nginx -c /etc/nginx/nginx.conf 
nginx: [emerg] bind() to 0.0.0.0:80 failed (98: Address already in use)
nginx: [emerg] bind() to [::]: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 [::]: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 [::]: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 [::]: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 [::]:80 failed (98: Address already in use)
nginx: [emerg] still could not bind()

这时候可以使用命令查看占用端口的程序：
sudo netstat -ntpl|grep 80
如果是之前已经开启了会出现下面的情况：

toohoo@ubuntu:~$ sudo netstat -ntpl|grep 80
tcp        0      0 0.0.0.0:80              0.0.0.0:*               LISTEN      92940/nginx: master 
tcp6       0      0 :::80                   :::*                    LISTEN      92940/nginx: master 

92940是pid，这是候可以先停止Nginx运行：
sudo nginx -s stop
如果是其他的程序占用，不知道停止的情况下，可以使用下面命令杀掉：
sudo kill 9 pid / sudo kill -QUIT pid

停止

两种方法：
sudo nginx -s stop 和 sudo kill 9 pid / sudo kill -QUIT pid
前提是知道进程的PID，下面是两种情况：
1、知道端口查看进程和pid命令：

~$ sudo netstat -ntpl|grep 80
tcp        0      0 0.0.0.0:80              0.0.0.0:*               LISTEN      94178/nginx: master 
tcp6       0      0 :::80                   :::*                    LISTEN      94178/nginx: master

2、知道进程(例如Nginx)查看PID命令

$ ps -ef|grep nginx
root      94178      1  0 21:33 ?        00:00:00 nginx: master process /usr/sbin/nginx -c /etc/nginx/nginx.conf
www-data  94179  94178  0 21:33 ?        00:00:00 nginx: worker process
www-data  94180  94178  0 21:33 ?        00:00:00 nginx: worker process
toohoo    94198  41731  0 21:33 pts/1    00:00:00 grep --color=auto nginx

root对应的第一个就是Nginx进程号

重启

1、重启，平滑操作，前后进场PID一样,方法
sudo kill -HUP 主进程号

toohoo@ubuntu:~$ sudo kill -HUP 94178
toohoo@ubuntu:~$ ps -ef|grep nginx
root      94178      1  0 21:33 ?        00:00:00 nginx: master process /usr/sbin/nginx -c /etc/nginx/nginx.conf
www-data  94179  94178  0 21:33 ?        00:00:00 nginx: worker process is shutting down
www-data  94258  94178  0 21:42 ?        00:00:00 nginx: worker process
www-data  94259  94178  0 21:42 ?        00:00:00 nginx: worker process
toohoo    94263  41731  0 21:43 pts/1    00:00:00 grep --color=auto nginx

2、关掉，再打开，进程PID不一样,方法:
关掉：sudo nginx -s stop 和 sudo kill 9 pid / sudo kill -QUIT pid
打开：$ sudo /usr/sbin/nginx -c /etc/nginx/nginx.conf