Nano is my favorite pick for a CLI editor when using Linux.
Example for Centos 7:
yum install nano
Typically already installed. No harm in the above command, if already installed it will just give you the feedback ‘nothing to do’.
2) How to use
a) Open a file in the current directory:
b) Open a file in another directory:
3) Some relevant commands:
Save a file:
ctr - O
ctrl - X (it will prompt you for saving if necessary)