C-w/C-x w

init.el

(defun delete-line-or-region-or-buffer ()
  "Delete current line, or text selection.
When `universal-argument' is called first, delete whole buffer (respects `narrow-to-region')."
  (interactive)
  (if current-prefix-arg
          (delete-region (point-min) (point-max))
        (progn (if (use-region-p)
                           (delete-region (region-beginning) (region-end))
                         (progn
                           (if (current-line-empty-p)
                                   (delete-blank-lines)
                                 (progn
                                   (kill-region (line-beginning-position) (line-end-position))
                                   (delete-char 1))))))))

(defun cut-line-or-region-or-buffer ()
  "Cut current line, or text selection.
When `universal-argument' is called first, cut whole buffer (respects `narrow-to-region').
URL `http://ergoemacs.org/emacs/emacs_copy_cut_current_line.html'
Version 2015-06-10"
  (interactive)
  (if current-prefix-arg
          (progn ; not using kill-region because we don't want to include previous kill
                (kill-new (buffer-string))
                (delete-region (point-min) (point-max)))
        (progn (if (use-region-p)
                           (kill-region (region-beginning) (region-end) t)
                         (progn
                           (if (current-line-empty-p)
                                   (delete-blank-lines)
                                 (progn
                                   (kill-region (line-beginning-position) (line-end-position))
                                   (delete-char 1))))))))