On Thu, Dec 8, 2022 at 5:06 PM Stefan Kangas <stefankangas@gmail.com> wrote:

a.k.a.

    (add-to-list 'auto-mode-alist ("\\.[ch]\\'" . c-ts-mode))
 
a.k.a.

(push '("\\.[ch]\\'" . c-ts-mode) auto-mode-alist)