split-line

split-line is an interactive compiled Lisp function in `simple.el'.

It is bound to C-M-o.

(split-line &optional ARG)

Split current line, moving portion beyond point vertically down.
If the current line starts with `fill-prefix', insert it on the new
line as well. With prefix ARG, don't insert `fill-prefix' on new line.

When called from Lisp code, ARG may be a prefix string to copy.