My categories are basically authors, and I would like to create a function to list them according to their surname. For example I'd like to have something like:

E:

 - Heinz Erhardt
 - Albert Einstein
 - Eminem

The problem is, I also have authors with only one name (like "Eminem") which I would also like to be sorted according to the letter E.
The only way I know of to do this in wordpress is with the `get_terms` function and the `name__like`.

    function getAuthors(){
    $args = array(
        'name__like' => 'E',
    );
    return get_terms('category', $args );
    }

this creates the sql query which only lists categories with an "E" in it:

    AND t.name LIKE %E%;
I however need something like:

    AND t.name NOT LIKE '% %' AND t.name LIKE E% OR t.name LIKE '% E';
I tried to change the code in the get_terms function in the core file where the query is set up (taxonomies.php, line 1809). However I wasn't successfull and I wouldn't like to change something in the core files.

How can I customize the query passed by the `name__like`? Are there other better ways I can achieve my goal?