Linux 中如何查询端口被占用的情况

1、lsof -i:端口号 用于查看某一端口的占用情况，比如查看80端口使用情况，lsof -i:80

如果没有安装lsof 需要yum install lsof

[root@localhost ~]# lsof -i:80
COMMAND   PID USER   FD   TYPE DEVICE SIZE/OFF NODE NAME
nginx   22798 root   10u  IPv4 617071      0t0  TCP *:http (LISTEN)
nginx   22799  www   10u  IPv4 617071      0t0  TCP *:http (LISTEN)
nginx   22801  www   10u  IPv4 617071      0t0  TCP *:http (LISTEN)
nginx   22802  www   10u  IPv4 617071      0t0  TCP *:http (LISTEN)
nginx   22803  www   10u  IPv4 617071      0t0  TCP *:http (LISTEN)
[root@localhost ~]# yum install lsof

2:2、netstat -tunlp |grep 端口号，用于查看指定的端口号的进程情况，如查看80端口的情况，netstat -tunlp |grep 80

                                 -t (tcp) 仅显示tcp相关选项
                                 -u (udp)仅显示udp相关选项
                                 -n 拒绝显示别名，能显示数字的全部转化为数字
                                 -l 仅列出在Listen(监听)的服务状态
                                 -p 显示建立相关链接的程序名

[root@localhost ~]# netstat -tunlp
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program name    
tcp        0      0 0.0.0.0:139             0.0.0.0:*               LISTEN      32507/smbd          
tcp        0      0 0.0.0.0:80              0.0.0.0:*               LISTEN      22798/nginx: master 
tcp        0      0 0.0.0.0:22              0.0.0.0:*               LISTEN      4024/sshd           
tcp        0      0 0.0.0.0:443             0.0.0.0:*               LISTEN      22798/nginx: master 
tcp        0      0 0.0.0.0:445             0.0.0.0:*               LISTEN      32507/smbd          
tcp6       0      0 :::3306                 :::*                    LISTEN      23332/mysqld        
tcp6       0      0 :::139                  :::*                    LISTEN      32507/smbd          
tcp6       0      0 :::21                   :::*                    LISTEN      14459/vsftpd        
tcp6       0      0 :::22                   :::*                    LISTEN      4024/sshd           
tcp6       0      0 :::445                  :::*                    LISTEN      32507/smbd          
tcp6       0      0 :::33060                :::*                    LISTEN      23332/mysqld        
udp        0      0 0.0.0.0:68              0.0.0.0:*                           32682/dhclient      
udp        0      0 127.0.0.1:323           0.0.0.0:*                           3504/chronyd        
udp6       0      0 ::1:323                 :::*                                3504/chronyd        
[root@localhost ~]# 

[root@localhost ~]# netstat -tunlp | grep 80
tcp        0      0 0.0.0.0:80              0.0.0.0:*               LISTEN      22798/nginx: master 
[root@localhost ~]#