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

It is bound to C-k, <deleteline>.

(kill-line &optional ARG)

Kill the rest of the current line; if no nonblanks there, kill thru newline.
With prefix argument ARG, kill that many lines from point.
Negative arguments kill lines backward.
With zero argument, kills the text before point on the current line.

When calling from a program, nil means "no arg",
a number counts as a prefix arg.

To kill a whole line, when point is not at the beginning, type C-a C-k C-k.

If `show-trailing-whitespace' is non-nil, this command will just
kill the rest of the current line, even if there are only
nonblanks there.

If option `kill-whole-line' is non-nil, then this command kills the whole line
including its terminating newline, when used at the beginning of a line
with no argument. As a consequence, you can always kill a whole line
by typing C-a C-k.

If you want to append the killed line to the last killed text,
use C-M-w before C-k.

If the buffer is read-only, Emacs will beep and refrain from deleting
the line, but put the line in the kill ring anyway. This means that
you can use this command to copy text from a read-only buffer.
(If the variable `kill-read-only-ok' is non-nil, then this won't
even beep.)