Linux Shell Scripting Cookbook - Third Edition

Opened port and services using netstat

netstat also returns network service statistics. It has many features beyond what is covered in this recipe.

Use netstat -tnp to list opened port and services:

$ netstat -tnp 
Proto Recv-Q Send-Q Local Address           Foreign Address         
    State       PID/Program name 

tcp        0      0 192.168.0.82:38163      192.168.0.2:3128        
    ESTABLISHED 2261/firefox-bin 

tcp        0      0 192.168.0.82:38164      192.168.0.2:3128        
    TIME_WAIT   -               

tcp        0      0 192.168.0.82:40414      193.107.206.24:422      
    ESTABLISHED 3836/ssh

tcp        0      0 127.0.0.1:42486         127.0.0.1:32955         
    ESTABLISHED 4022/GoogleTalkPlug

tcp        0      0 192.168.0.82:38152      192.168.0.2:3128        
    ESTABLISHED 2261/firefox-bin 

tcp6       0      0 ::1:22                  ::1:39263               
    ESTABLISHED -               

tcp6       0      0 ::1:39263               ::1:22                  
    ESTABLISHED 3570/ssh