How to configure emacs to have it complete the path automatically like vim?

Question

I have been a vim user for several years. Now I want to try Emacs for some reasons. I use the path auto-completition functionality(C-c, C-f) a lot in Vim. So I am wondering

Answer 1

Here's an implementation using hippie-expand, and utilising ido for the selection menu.

This gives us my-ido-hippie-expand (which I'm binding to C-c e) as the ido equivalent of hippie-expand, and also makes it easy to generate other targeted expansion utilities using particular expansion functions (typically some sub-set of hippie-expand-try-functions-list) which facilitates a filename-only version.

(defun my-hippie-expand-completions (&optional hippie-expand-function)
  "Return the full list of possible completions generated by `hippie-expand'.
The optional argument can be generated with `make-hippie-expand-function'."
  (require 'cl)
  (let ((this-command 'my-hippie-expand-completions)
        (last-command last-command)
        (buffer-modified (buffer-modified-p))
        (hippie-expand-function (or hippie-expand-function 'hippie-expand)))
    (flet ((ding)) ; avoid the (ding) when hippie-expand exhausts its options.
      (while (progn
               (funcall hippie-expand-function nil)
               (setq last-command 'my-hippie-expand-completions)
               (not (equal he-num -1)))))
    ;; Evaluating the completions modifies the buffer, however we will finish
    ;; up in the same state that we began.
    (set-buffer-modified-p buffer-modified)
    ;; Provide the options in the order in which they are normally generated.
    (delete he-search-string (reverse he-tried-table))))

(defmacro my-ido-hippie-expand-with (hippie-expand-function)
  "Generate an interactively-callable function that offers ido-based completion
using the specified hippie-expand function."
  `(call-interactively
    (lambda (&optional selection)
      (interactive
       (let ((options (my-hippie-expand-completions ,hippie-expand-function)))
         (if options
             (list (ido-completing-read "Completions: " options)))))
      (if selection
          (he-substitute-string selection t)
        (message "No expansion found")))))

(defun my-ido-hippie-expand ()
  "Offer ido-based completion for the word at point."
  (interactive)
  (my-ido-hippie-expand-with 'hippie-expand))

(global-set-key (kbd "C-c e") 'my-ido-hippie-expand)

And the extension of this for just completing filenames:

(defun my-ido-hippie-expand-filename ()
  "Offer ido-based completion for the filename at point."
  (interactive)
  (my-ido-hippie-expand-with
   (make-hippie-expand-function '(try-complete-file-name))))

(global-set-key (kbd "C-c f") 'my-ido-hippie-expand-filename)

Answer 2

Notes of interest:

;;  For the real hippie-expand enthusiast: A macro that makes it
;;  possible to use many functions like hippie-expand, but with
;;  different try-functions-lists.
;;  Usage is for example:
;;    (fset 'my-complete-file (make-hippie-expand-function
;;                             '(try-complete-file-name-partially
;;                               try-complete-file-name)))
;;    (fset 'my-complete-line (make-hippie-expand-function
;;                             '(try-expand-line
;;                               try-expand-line-all-buffers)))
;;
;;;###autoload
(defmacro make-hippie-expand-function (try-list &optional verbose)
  "Construct a function similar to `hippie-expand'.
Make it use the expansion functions in TRY-LIST.  An optional second
argument VERBOSE non-nil makes the function verbose."

You could presumably utilise this to generate a list of possible filename completions.

edit: Actually, that doesn't get you any further than the other question. I'll keep it here, as it seems a slightly nicer approach.

Answer 3

I'm not sure how to customize HippieExpand to do this, but you might want to take a look at the auto-complete package. It's fairly easy to set up and offers completion as a drop-down list. It's also very customizable so you can tweak it to behave exactly like you'd prefer. Hope you find it useful!

Edit: I just realized you were looking just for path completion not auto-completion in general. In that case auto-complete.el might be overkill. Still I do suggest that you take a look at it as it offers a lot of added utility. I second taking a look at ido for path-completion.