When I start working on a project in emacs, I use M-x cd to get into the project root directory. But every time I use C-x C-f to open a file in one of the subdirectories (like app/model/Store.rb) emacs changes current directory to that of the file. Is there a way to make emacs stay at the root?
How about this? It replaces the regular find-file command with your own which always starts in some "root" directory (customize the find-file-root-dir variable):
(defvar find-file-root-dir "~/"
"Directory from which to start all find-file's")
(defun find-file-in-root ()
"Make find-file always start at some root directory."
(interactive)
(let ((default-directory find-file-root-dir))
(call-interactively 'find-file)))
(global-set-key (kbd "C-x C-f") 'find-file-in-root)
Assuming that you want the working directory of a file to be set to whatever the working directory was before you executed find-file, you could try the following:
(defmacro disallow-cd-in-function (fun)
"Prevent FUN (or any function that FUN calls) from changing directory."
`(defadvice ,fun (around dissallow-cd activate)
(let ((old-dir default-directory) ; Save old directory
(new-buf ad-do-it)) ; Capture new buffer
;; If FUN returns a buffer, operate in that buffer in addition
;; to current one.
(when (bufferp new-buf)
(set-buffer new-buf)
(setq default-directory old-dir))
;; Set default-directory in the current buffer
(setq default-directory old-dir))))
Armed with this macro, go search for operations that set the variable default-directory: M-x find-library files; M-x occur (setq default-directory. After some investigation, you discover that the desired function is called find-file-noselect-1. Also, it looks like set-visited-file-name is also a candidate. So:
(disallow-cd-in-function find-file-noselect-1)
(disallow-cd-in-function set-visited-file-name)
Note
Note that (disallow-cd-in-function find-file) would work just fine, but then if you switched to ido-mode, you'd be opening files with ido-find-file instead of find-file. Both of these functions ultimately use find-file-noselect-1, so hitting that with the macro is a more univeral solution.
Is there a way to make emacs stay at the root?
No, there isn't. C-x C-f always visits starting from the default directory of the buffer you are already vising. The default directory, by default, is the same directory as the file. You can change these (separately for every buffer) using M-x cd.
But that is not what you want. What you should do is C-x b to *scratch* (whose default directory is the same as where you launched Emacs from -- in your words "root"), and then visit a new file. And if you need to do this frequently, just open up a dired in there and work your way thru.
I appreciate I'm not answering your question directly, but I noticed you were more specific in your requirements in one of your comments: "I don't use compile or recompile, I just tend to close files I am not working on, since it takes fewer keystrokes to open a file again".
Have you got ido turned on for buffer switching? If you exclude the directory thing for a moment, switching files or buffers with ido is an identical number of keystrokes (C-x C-f vs C-x b, followed by a few characters in the file name). If you include the directory thing, switching files is more tricky for the precisely the reasons you mention. Sticking with buffers is much easier.
Going a step further, with the help of 'anything.el' it's quite easy to abstract away whether a given file is in a buffer or in a file using the file cache. For example, if you do the following:
(file-cache-add-directory-recursively "/my/ruby/project") ".*\\.rb$")
and run 'anything-for-files' (I have it bound to C-x f) all your open buffers are listed, along with all of the files you've just added to the file cache; isolating a given file usually only takes one or two more characters.
Any file in your project is thus 4 or 5 key presses away, and the directory they are in or whether or not they are in a buffer becomes irrelevant.
Hope that's helpful...
Sorry I haven't worked out the details, but you might be able to add a function to find-file-hook that resets the default directory to whatever you want.
Related
How can I open multiple different instances of file in Emacs? That is to say, the instances are totally independent of each other but write to the same file.
I actually want to have a reference to the original file in one buffers side-by-side with the buffer in which I will be editing while referring to the original content. I don't find opening a temporary buffer, yanking the entire original content into it and have it side-by-side, as an elegant solution.
Other solutions are welcome as well.
I have tried using clone-indirect-buffer and C-x C-v but it doesn't server the purpose.
You can create a new buffer (C-xb*new*) and insert the content of the file to it with C-xifilename.
As I read through the find-file code, I see this warning coded into it:
"The file %s is already visited normally.
You have asked to visit it literally,
meaning no coding system decoding, format conversion, or local variables.
But Emacs can only visit a file in one way at a time.
Do you want to revisit the file literally now? "
Something that would imply that Emacs' code specifically tries to protect against the situation when the same file is visited multiple times, but the buffers are out of sync with each other. However... you could open two copies of Emacs, in which case they would not know about each other visiting the same file and so would allow this situation to happen.
I can understand that the above isn't a very nice option, but it looks like adding that kind of functionality will require some time understanding the reasons behind it being specifically prevented in the first place.
I've tried this:
M-:(switch-to-buffer (find-file-noselect-1 (create-file-buffer (buffer-file-name)) (buffer-file-name) t nil (buffer-file-name) 1))
And it seems like it would work, but I'm not sure of consequences - maybe different major modes may rely on the original Emacs treatment of files and their editing history, so use with care. The last number 1 is the number to be displayed after the file name, as in Foo.bar<1> So, you'd need to change that, if you need more copies.
As mentioned, you might be able to use clone-buffer, although you'll have to let-bind buffer-file-name around the call since clone-buffer otherwise will refuse to clone it. Another option is to do:
M-x set-visited-file-name RET toto RET
C-x C-f thefile RET
C-x b RET
M-x set-visited-file-name RET thefile RET
the last set-visited-file-name should ask you if you really want to do that, but you can answer that you do and Emacs will accept your choice. Arguably, clone-buffer should not reject to do it, so you might like to submit a bug-report asking to make it behave similarly to what set-visited-file-name does.
You may have some luck with clone-buffer, depending on your mode. It has certain limitations that you can read about in the docs.
Otherwise, here's something quick and dirty:
(defun dodgy-clone-buffer ()
"Clone the current buffer. The clone will write to the original file."
(interactive)
(switch-to-buffer-other-window
(eval `(with-current-buffer
;; Create a new buffer or clear an existing one.
(get-buffer-create ,(format "*clone: %s*" (buffer-name)))
(delete-region (point-min) (point-max))
(insert ,(buffer-string))
(setq buffer-file-name ,(buffer-file-name))
(funcall ',major-mode)
(current-buffer)))))
I managed to make dired work in a single window, when I am navigating through the file system.
Improving ergonomics, I decided to create bookmarks for my most frequent dirs with short names like: 'lwt', 'eve', etc. But every time I open the bookmark, the new dired buffer is created, even if the old one exists.
How to make it open the bookmark in the existing dired buffer?
Edit:
The original answer was actually a non-answer. I apologise for not having tested it properly. I will leave it here so other potential answerers aren't misled like I was.
I have meanwhile taken a good look at the source code of bookmark.el and the dired+ modifications don't have any effect on it. By default the bookmark-jump function uses the switch-to-buffer function as its display function. bookmark-jump however has an optional display-func argument, so a possible solution (involving a bit of elisp hacking) would be to create a function that reuses the current dired buffer (based on the dired+ source code) and invoking bookmark-jump with it, and if the concept works, then bind that to a keyboard short-cut.
Original answer:
The behaviour you are observing is just a side effect of the general "create a new buffer when navigating" behaviour of dired. This fact makes this question an almost duplicate of How do I stop emacs dired mode from opening so many buffers?.
Of the solutions proposed there and at the Dired Reuse Directory Buffer Emacs Wiki page, probably the simplest one is installing the Dired+ package and toggling directory buffer reuse with:
(toggle-diredp-find-file-reuse-dir 1)
in your .emacs file.
If this can help - that's what I use to open my bookmarks in the same buffer.
(defun my-bookmarks-list-same-buffer ()
"Open *Bookmarks* in current buffer."
(interactive)
(bookmark-bmenu-list)
(switch-to-buffer "*Bookmark List*"))
(global-set-key (kbd "s-b") 'my-bookmarks-list-same-buffer)
With Bookmark+, at least, bookmark-jump (C-x j j) to a Dired bookmark does reuse the Dired buffer if it already exists.
How do I prevent Emacs from showing me all the files I'm not interested in (such as ~ backup files, .pyc files, or .orig files) when I: C-x C-f TAB ?
It is working in one respect: if I know the file I want to open begins with foo and I type foo TAB then the mini-buffer correctly autocompletes all the way to foo.py. It correctly ignored foo~ and foo.pyc, because both ~ and .pyc are in completion-ignored-extensions. It also correctly lets me open either ignored file if I really want to by typing in all the letters my self.
However, if I just hit TAB to to bring up the completion list buffer then that list includes files with extensions in completion-ignored-extensions, which makes it very difficult to find what I'm looking for.
Clearly the code to ignore uninteresting files is there and working. How do I get the completion list buffer to respect completion-ignored-extensions?
(by-the-by, can I make dired behave similarly?)
This piece of advice filters out files with extensions listed in 'completion-ignored-extensions:
(defadvice completion--file-name-table (after
ignoring-backups-f-n-completion
activate)
"Filter out results when they match `completion-ignored-extensions'."
(let ((res ad-return-value))
(if (and (listp res)
(stringp (car res))
(cdr res)) ; length > 1, don't ignore sole match
(setq ad-return-value
(completion-pcm--filename-try-filter res)))))
Note: This doesn't affect dired.
For the dired issue, add this to your .emacs
(eval-after-load "dired"
'(require 'dired-x))
(add-hook 'dired-mode-hook
(lambda ()
(dired-omit-mode 1)))
Read the documentation for dired-x to get an idea of what's available there.
I would recommend using ido-mode to ignore files; it comes with Emacs by default and adds many other useful enhancements that you'll quickly learn to love. The Ignorance is Bliss section from this Mastering Emacs blog post covers how to ignore files, directories, and buffers:
ido-ignore-buffers Takes a list of buffers to ignore in C-x b
ido-ignore-directories Takes a list of directories to ignore in C-x d and C-x C-f
ido-ignore-files Takes a list of files to ignore in C-x C-f
Icicles does what you expect by default. It always respects completion-ignored-extensions for file-name completion, including for buffer *Completions*. And you can toggle this ignoring on/off at anytime, by hitting C-. in the minibuffer.
In addition, if you use library completion-ignored-build.el by Kevin Ryde, then Icicles automatically takes advantage of that library's dynamic adjustment of ignored file extensions. (Just load completion-ignored-build.el -- do not enable its minor mode or advice.)
I don't know of an answer for completion, I'm afraid. I think this is by design - when you know the name you're looking for, you probably don't want e.g. the backup file. But when you don't know, it's probably better to have a list of all of the files.
However, for dired, you can load the 'dired-x' package on startup (in your .emacs), and this provides dired-omit-mode:
(load "dired-x")
You can use 'M-x customize-variable<RET>dired-omit-files' to set the actual patterns to ignore. Then when you are in dired mode you can use M-O (the letter, not the number) to toggle 'omission' on and off.
One problem that I have with emacs is that it doesn't seem to handle like-named files in different directories very well. For example, if I'm not careful, I'll end up with 20 __init__.py buffers open. What I've been doing is using M-x rename-buffer and renaming it to indicate what package it's within. However, doing this manually is somewhat tedious.
Does anyone have any strategies for attacking this problem?
I like uniquify, which comes with Emacs:
(require 'uniquify)
(setq uniquify-buffer-name-style 'reverse)
(setq uniquify-separator "/")
(setq uniquify-after-kill-buffer-p t) ; rename after killing uniquified
(setq uniquify-ignore-buffers-re "^\\*") ; don't muck with special buffers (or Gnus mail buffers)
With those settings, the directory gets added to the buffer name, giving you an indication of where the file is. For example, loading the files /some/path/to/Makefile and /some/path/to/different/Makefile would result in the following buffer names:
Makefile/to (which is /some/path/to/Makefile)
and
Makefile/different (which is /some/path/to/different/Makefile)
uniquify also handles updating the buffer names when buffers are deleted, so when one of the two Makefile buffers is deleted, the other gets renamed to simply Makefile.
If you want full control you can redefine create-file-buffer.
If you want the full filename it could be as simple as
(defun create-file-buffer (filename)
"Create a suitably named buffer for visiting FILENAME, and return it."
(generate-new-buffer filename))
See files.el for reference.
When I use Emacs I want to be able to easily display and navigate through a list of files I worked on from not just the current session but from previous sessions. (BTW, running Emacs 22.2 on Windows)
From Joe Grossberg's blog (no longer available):
But if you're using GNU Emacs 21.2
(the latest version, which includes
this as part of the standard distro),
you can just put the following lines
into your .emacs file
;; recentf stuff
(require 'recentf)
(recentf-mode 1)
(setq recentf-max-menu-items 25)
(global-set-key "\C-x\ \C-r" 'recentf-open-files)
Then, when you launch emacs, hit
CTRL-X CTRL-R. It will show a list of
the recently-opened files in a buffer.
Move the cursor to a line and press
ENTER. That will open the file in
question, and move it to the top of
your recent-file list.
(Note: Emacs records file names.
Therefore, if you move or rename a
file outside of Emacs, it won't
automatically update the list. You'll
have to open the renamed file with the
normal CTRL-X CTRL-F method.)
Jayakrishnan Varnam has a page
including screenshots of how this
package works.
Note: You don't need the (require 'recentf) line.
Even if you don't have recentf turned on, Emacs is saving a list of files entered via the minibuffer in the variable file-name-history. Also, executing (savehist-mode 1) in your .emacs file makes that variable persist across invocations of Emacs.
So here's a little function that displays the files that actually exist from that list (anyone is welcome to use/build on this):
(defun dir-of-recent-files ()
"See the list of recently entered files in a Dired buffer."
(interactive)
(dired (cons
"*Recent Files*"
(seq-filter
'file-exists-p
(delete-dups
(mapcar (lambda (s) (string-trim-right s "/*"))
file-name-history)
))))
)
I find this quite useful and have it bound to one of those little special function keys on my desktop keyboard. (And so I have not seen the point of turning on recentf...)