Function: kill-whole-line

Kill current line.
With prefix ARG, kill that many lines starting from the current line.
If ARG is negative, kill backward. Also kill the preceding newline.
(This is meant to make C-x z work well with negative arguments.)
If ARG is zero, kill current line but exclude the trailing newline.

Variable: kill-whole-line

If non-nil, `kill-line' with no arg at start of line kills the whole line.