diff-buffer-against-file.el

   1 (defun diff-buffer-against-file (context)
   2   "diff the current (edited) buffer against the file of the same name"
   3   (interactive "P")
   4   (let (($file (concat "\"" buffer-file-name "\""))
   5         ($temp_buffer "emacs.diff")
   6         ($temp_file "/tmp/emacs.diff"))
   7
   8     (delete-other-windows)
   9     (push-mark (point) t)
  10     (generate-new-buffer $temp_file)
  11     (copy-to-buffer $temp_buffer (point-min) (point-max))
  12     (set-buffer $temp_buffer)
  13     (write-file $temp_file)
  14     (shell-command (concat (if context "diff -c " "diff ") $file " " $temp_file))
  15     (kill-buffer $temp_file)
  16     (pop-mark)
  17     )
  18   )