Whois is a protocol which runs on port no. 43 and it is use to get the information regarding internet resources like domain name and IP Address network blocks.
Mostly it is widely used for getting information about domain like owner of domain name,its registrar, Date of expiry etc.
To install whois in CentOS use the given below command.
yum install jwhois
vi is a full feature text editor but not everyone like it. Some may prefer to use NANO for quick configuration and crontab edits.
Before that, NANO installed in your system.
To change the Default Text Editor to NANO, edit the file as below
nano /etc/profile.d/nano.sh
add the following 2 lines
export VISUAL="nano" export EDITOR="nano"
Save it!
The changes made won’t take effect on the current session. Log out and log back in to activate the changes.