I want to write a little function to enter a fixed comment string such as the following on a new line, respecting the mode, e.g. in elisp I would like it to write
;; this is a comment
on the next line; and in C I would like it to write
/* this is a comment */
on the next line, and so on. How to do this? Maybe comment-dwim is useful but I don't know how to do it. Thank you.