Linux Interview questions

Let's start right away:

1. How do you check if the kernel system is running? uname -a
   

2.-How to check the current ip address?   ifconfig

ip addr show

3.-How to find free  extra disk space?    df -ah

4.-How to manage service on a system?    service udev status  or systemctl status udev

5.- How to check for open ports in Linux machine?   netstat -tupln

6.-How to check cpu usage?    top or htop

7.-How to look for something you don't know in linux?  man