How to display only the firstname or lastname of current logged in user?

I want to appear the current firstname or last name of logged in user instead of full name.
How can i achieve this?

I know that i should change this line…

in file

any help?

Have you tried to split the $CURRENT_USER in php before passing it to the tpl file.

$pieces = explode(" ", $pizza);
echo $pieces[0]; // piece1
echo $pieces[1]; // piece2