复制当前行

复制当前行

这是个常常要用到的操做，之前要么老老实实 Mark 当前行的行首和行尾，而后复制。整个按键流程是：

1. Ctrl-a 光标到行首
2. Ctrl-Shift-Space 设置标记
3. Ctrl-e 光标到行尾。如此这一行就被选为激活的区域了
4. Alt-w 复制当前激活的区域

要么按我比较习惯的操做先剪切当前行，再撤消上一次的剪切操做

1. Ctrl-a 光标到行首
2. Ctrl-k 剪切至行屋，该行消失
3. Ctrl-/ 撤消上一次的操做，该行重现

能够看到，方案二比方案一省一次按键，并且 Ctrl 键不用松开。不过，如此基本的操做要按三个键仍是太麻烦了，并且方案二会让文件变成被编辑过的状态。其实，能够发挥一下“按我说的作”的精神。为何不把 Alt-w 变的更聪明一些，当没有激活的区域时就复制当前的一整行呢？ 说作就作:

;; Smart copy, if no region active, it simply copy the current whole line
(defadvice kill-line (before check-position activate)
  (if (member major-mode
              '(emacs-lisp-mode scheme-mode lisp-mode
                                c-mode c++-mode objc-mode js-mode
                                latex-mode plain-tex-mode))
      (if (and (eolp) (not (bolp)))
          (progn (forward-char 1)
                 (just-one-space 0)
                 (backward-char 1)))))
 
(defadvice kill-ring-save (before slick-copy activate compile)
  "When called interactively with no active region, copy a single line instead."
  (interactive (if mark-active (list (region-beginning) (region-end))
                 (message "Copied line")
                 (list (line-beginning-position)
                       (line-beginning-position 2)))))
 
(defadvice kill-region (before slick-cut activate compile)
  "When called interactively with no active region, kill a single line instead."
  (interactive
   (if mark-active (list (region-beginning) (region-end))
     (list (line-beginning-position)
           (line-beginning-position 2)))))
 
;; Copy line from point to the end, exclude the line break
(defun qiang-copy-line (arg)
  "Copy lines (as many as prefix argument) in the kill ring"
  (interactive "p")
  (kill-ring-save (point)
                  (line-end-position))
                  ;; (line-beginning-position (+ 1 arg)))
  (message "%d line%s copied" arg (if (= 1 arg) "" "s")))
 
(global-set-key (kbd "M-k") 'qiang-copy-line)

上面还多加了一个配置，就是把 Alt-k 设成复制光标所在处到行尾。与 kill-line 的 Ctrl-k 对应。这样一来，若是是要拷贝一整行的话，只要将光标移动到该行任意位置，按下 Alt-w 就好了。若是是复制某个位置到行尾的文字的话，就把光标移到起始位置处，按 Alt-k 。比默认的操做简化了不少。