root@user:# nano galfit.feedme
root@user:# vi galfit.feedme
For editing use
vi galfit.feedme //if user has file editing permissions
or
sudo vi galfit.feedme //if user doesn't have file editing permissions
For inserting
Press i //Do required editing
For exiting
Press Esc
:wq //for exiting and saving
:q! //for exiting without saving