linux系统使用lsof命令"-bash: lsof: command not found"

在redhat系统下想使用lsof命令查看应用端口占用情况

[root@photo720 ~]# uname -a
Linux photo720 3.10.0-514.26.2.el7.x86_64 #1 SMP Tue Jul 4 15:04:05 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux
[root@photo720 ~]# lsof -i:80
-bash: lsof: command not found
[root@photo720 ~]# 

发现lsof命令使用不了，因为没有安装lsof
安装命令如下：
yum install -y lsof

[root@photo720 ~]# yum install -y lsof
Loaded plugins: fastestmirror
Repodata is over 2 weeks old. Install yum-cron? Or run: yum makecache fast
base                                                                            | 3.6 kB  00:00:00     
epel                                                                            | 4.7 kB  00:00:00     
extras                                                                          | 3.4 kB  00:00:00     
updates                                                                         | 3.4 kB  00:00:00     
(1/4): extras/7/x86_64/primary_db                                               | 201 kB  00:00:00     
(2/4): epel/x86_64/updateinfo                                                   | 992 kB  00:00:00     
(3/4): epel/x86_64/primary_db                                                   | 6.7 MB  00:00:00     
(4/4): updates/7/x86_64/primary_db                                              | 4.2 MB  00:00:00     
Determining fastest mirrors
Resolving Dependencies
--> Running transaction check
---> Package lsof.x86_64 0:4.87-6.el7 will be installed
--> Finished Dependency Resolution

Dependencies Resolved

=======================================================================================================
 Package               Arch                    Version                     Repository             Size
=======================================================================================================
Installing:
 lsof                  x86_64                  4.87-6.el7                  base                  331 k

Transaction Summary
=======================================================================================================
Install  1 Package

Total download size: 331 k
Installed size: 927 k
Downloading packages:
lsof-4.87-6.el7.x86_64.rpm                                                      | 331 kB  00:00:00     
Running transaction check
Running transaction test
Transaction test succeeded
Running transaction
  Installing : lsof-4.87-6.el7.x86_64                                                              1/1 
  Verifying  : lsof-4.87-6.el7.x86_64                                                              1/1 

Installed:
  lsof.x86_64 0:4.87-6.el7                                                                             

Complete!

测试

[root@photo720 ~]# lsof -i:80
COMMAND     PID USER   FD   TYPE  DEVICE SIZE/OFF NODE NAME
AliYunDun  3598 root   22u  IPv4 3670184      0t0  TCP photo720:34692->100.100.30.25:http (ESTABLISHED)
nginx     14912 root   10u  IPv4 2972890      0t0  TCP *:http (LISTEN)
nginx     14912 root   13u  IPv4 3691002      0t0  TCP photo720:http->116.24.67.35:eli (ESTABLISHED)
nginx     23692 root   10u  IPv4 2972890      0t0  TCP *:http (LISTEN)