Disable ido-mode for specific commands? - emacs

I've been using ido-mode for a few months, with ido-everywhere turned on, and am generally pretty happy with it. There's one thing I wish I could change, though. When I type C-u M-x shell to create a new shell buffer with a specific name, ido offers me a completion list of all of my open buffers. If I choose one, a new shell is launched in that buffer and it's put into shell-mode, no matter what it contains. It's hard to imagine a useful use case for this.
Is there a way to deactivate ido-mode for the shell command only? (As well as any other similar commands I may stumble across in the future, of course.)

Heh, it turns out you'll get the same completion choices whether or not you have ido-everywhere enabled.
There's no built-in way to do what you want. ido-mode only provides hooks for you to be able to override whether or not the find-file behavior is taken over by ido or not. The read-buffer is currently always overridden by ido-everywhere.
Luckily, a little Emacs lisp can get what you want:
(put 'shell 'ido 'ignore)
(defadvice ido-read-buffer (around ido-read-buffer-possibly-ignore activate)
"Check to see if use wanted to avoid using ido"
(if (eq (get this-command 'ido) 'ignore)
(let ((read-buffer-function nil))
(run-hook-with-args 'ido-before-fallback-functions 'read-buffer)
(setq ad-return-value (apply 'read-buffer (ad-get-args 0))))
ad-do-it))
And for any other command you don't want following ido-everywhere for buffer selection can be customized by simply adding a new expression to your .emacs:
(put 'other-command-i-want-untouched 'ido 'ignore)

Related

Prevent Emacs from exiting once the exit procedure has initiated?

Is there a way to prevent Emacs from exiting once I initiate the exit process?
I occasionally fat finger C-xC-s as C-xC-c. It isn't an awful process to get back up and running but I am curious if there is a way I can stop the exit process so that I can continue uninterrupted with all my files open.
Using GNU Emacs 24.3.1. Running on Cygwin under Window 7.
There is a built-in variable you can set to a function like so:
(setq confirm-kill-emacs 'y-or-n-p)
scottfrazer's answer's the more appropriate, to me, than what follows.
Enable Emacs Lock minor mode (emacs-lock-mode) on any of the buffers, to prevent Emacs from exiting in case you accidentally hit C-xC-c.
From the Emacs Wiki page:
Emacs cannot exit until the buffer is killed or unlocked
Add (emacs-lock-mode) to your .emacs/init.el file so that this lock is enabled in every Emacs session. Adding this will lock the *scratch* buffer which will have to be unlocked in case you really want to exit Emacs.
Another way/hack of doing this is to start a process in Emacs e.g. M-xshell or have an unsaved file associated to a buffer, doing this will prompt you for confirmations when Emacs is exiting.
Yes one more, unset C-xC-c using global-unset-key. And then if you want to exit Emacs M-xkill-emacs.
Using confirm-kill-emacs, as #scottfrazer suggested, is one approach.
More generally, you can use kill-emacs-query-functions to do whatever you want in this regard. (There was no real need for them to add confirm-kill-emacs, but they did.)
You probably do not want to use kill-emacs-hook in this regard (that's what kill-emacs-query-functions is for), but be aware of it, in case you come across it using apropos etc.
One advantage of kill-emacs-query-functions over justconfirm-kill-emacs is that you can require a better confirmation: yes instead of just hitting key y. For example:
(add-hook 'kill-emacs-query-functions
(lambda () (y-or-n-p "Do you really want to exit Emacs? "))
'append)
That is what I do. It is too easy to be hitting keys and accidentally hit C-x C-c y, especially since I have similar keys bound (e.g., C-x c, C-x C-x, C-x C-y).
If you're looking for a shorter answer, I've had this line at the bottom of all my .emacs files since the last century:
(shell)
I've added the following to my emacs configuration to prevent accidental closes. I didn't like having to confirm close emacs for something like a one off commit, but I hate losing my emacs session accidentally while deep in a problem.
This adds a global state flag to emacs describing whether or not it's locked. This flag is set either automatically after emacs is open for 5 minutes, or manually using the lock-emacs command. The lock can later be removed manually by using the unlock-emacs command.
If emacs is locked, and you attempt to close it (presumably accidentally), emacs will instead give you a message saying that emacs has been locked, and cannot be closed. If it's unlocked, close behaves exactly as it does by default.
;; don't close emacs on accident
(setq emacs-locked nil)
(setq confirm-kill-emacs
(lambda (&rest args)
(if emacs-locked
(progn
(message "%s" "Emacs is locked, and cannot be closed.")
nil)
t)
))
(defun lock-emacs-silently ()
(progn
(setq emacs-locked t))
)
(defun lock-emacs ()
"Prevent emacs from being closed."
(interactive)
(progn
(lock-emacs-silently)
(message "%s" "Emacs is now locked."))
)
(defun unlock-emacs ()
"Allow emacs to be closed."
(interactive)
(progn
(setq emacs-locked 'nil)
(message "%s" "Emacs can now be closed."))
)
(run-at-time "5 minutes" nil 'lock-emacs-silently)
(Open to suggestions on how to make the confirm-kill-emacs portion nicer, I'm a lisp novice :) ).
After using this for a couple of years, I ended up going to something much simpler:
;; Unbind the normal close
(global-unset-key (kbd "C-x C-c"))
;; Require C-c 3 times before closing
(global-set-key (kbd "C-x C-c C-c C-c") 'save-buffers-kill-terminal)

Execute a particular command on multiple emacs buffers

Is there a way to execute emacs command on multiple buffers without having to selecting them individually and executing it on each individual buffer.
I usually open multiple files matching a particular regex, e.g. ~/*.py and wish to enable a particular mode, say hs-minor-mode or glasses-mode on each, or say execute C-c # C-M-h on each. Currently I have to select each one of them and do it individually. So is there a hack or a loop to automate the task.
Lets say I mark the buffers from the buffer-list and then run the command for all those marked.
I tried this but after executing the commands in eval-expression I completely lost access to my minibuffer, meaning whenever I typed M-x the minibuffer returned this
unable to access the minibuffer emacs error "Process Menu Mode doesn't support Hideshow Minor Mode"
and I was forced to actually kill the entire emacs process because the C-x C-s wasn't working neither was the End Task.
PS: I have no experience in elisp
You can use ibuffer mode for this (It is part of the default Emacs distribution).
(global-set-key "\C-x\C-b" 'ibuffer) ;; make ibuffer the default
In *Ibuffer* you can mark the required buffers with m and then
execute a form in each with E.
Generally, ibuffer is a lot more flexible then the usual buffer list and I think ibuffer should really be the default buffer-list in Emacs.
If you do this often, you might want to switch those particular modes on every time you enter python mode by attaching them to the mode-hook:
(add-hook 'python-mode-hook 'hs-minor-mode)
(add-hook 'python-mode-hook 'glasses-mode)
I didn't know ibuffer had that feature!
Anyway, for those who are more familiar with dired, here is a command that do the same. Select the files in dired with m or any other more powerful method. Then do, M-xdired-do-command and write a form or a command just as in M-x.
(defun dired-do-command (command)
"Run COMMAND on marked files. Any files not already open will be opened.
After this command has been run, any buffers it's modified will remain
open and unsaved."
(interactive
(list
(let ((print-level nil)
(minibuffer-history-position 0)
(minibuffer-history-sexp-flag (1+ (minibuffer-depth))))
(unwind-protect
(read-from-minibuffer
"Command: " (prin1-to-string (nth 0 command-history))
read-expression-map t
(cons 'command-history 0))
;; If command was added to command-history as a
;; string, get rid of that. We want only
;; evaluable expressions there.
(if (stringp (car command-history))
(setq command-history (cdr command-history)))))))
(dolist (filename (dired-get-marked-files))
(with-current-buffer (find-file-noselect filename)
(if (symbolp command)
(call-interactively command)
(eval command)))))

Create "M-x" command shortcuts in emacs?

Some of the commands in emacs are so long to type.
Still, I'd like them as M-x commands (not keyboard shortcuts) as I have so many, I'd start stumble on them.
And, the old ones should not be removed. It'll take a while getting used to the new ones.
Only way I could think of, doing it one by one like this. Better way?
(defun icd (dict) "Alias for ispell-change-dictionary"
(interactive "sDictionary: ")
(ispell-change-dictionary (downcase dict)))
Use defalias:
(defalias 'bc 'emacs-lisp-byte-compile)
Before defining aliases for every command, you should use ido-mode
See here: EmacsWiki
If you put
(setq completion-styles (append completion-styles '(initials)))
(define-key minibuffer-local-completion-map
[?\M-\t] 'minibuffer-force-complete)
in your .emacs, then M-x icd M-TAB M-TAB will get you ispell-change-directory. And next time around, a single M-TAB will be sufficient (because the cycling prefers entries that are found in the history).

Can I use ido-completing-read instead of completing-read everywhere?

I'm a big fan of ido-mode, so much so that I would like to use it for things like describe-function or find-tag and so on, without having to write something like in "Can I get ido-mode-style completion for searching tags in Emacs?" for each one.
Both
(defalias completing-read ido-completing-read)
and
(setf 'completing-read 'ido-completing-read)
don't work, at least partly because ido-completing-read calls completing-read in its body, so any simple redefinition would result in infinite recursion.
In theory, it should be possible, since the first line of the docstring for ido-completing-read is "Ido replacement for the built-in completing-read." I've looked around a bit and can't seem to find anyone else who has attempted or succeeded at it.
I realize that Icicles probably provides something like this, and I may end up going with that anyway, but it is a bit more of a plunge than I care to take right now.
Thanks for any help.
Edit: This is now an Emacs package available from MELPA. It has been expanded into a full-fledged minor mode. Development happens on GitHub.
Original post:
Here is my refinement of Jacobo's answer. Credit to him for the original magic. I've added an override variable, which you can use to prevent the use of ido-completing-read in specific functions. I have also added a check that uses the original completing-read if there are no completions (This happens occasionally, for example in org-remember-apply-template from org-mode, which breaks with Jacobo's original advice).
(defvar ido-enable-replace-completing-read t
"If t, use ido-completing-read instead of completing-read if possible.
Set it to nil using let in around-advice for functions where the
original completing-read is required. For example, if a function
foo absolutely must use the original completing-read, define some
advice like this:
(defadvice foo (around original-completing-read-only activate)
(let (ido-enable-replace-completing-read) ad-do-it))")
;; Replace completing-read wherever possible, unless directed otherwise
(defadvice completing-read
(around use-ido-when-possible activate)
(if (or (not ido-enable-replace-completing-read) ; Manual override disable ido
(boundp 'ido-cur-list)) ; Avoid infinite loop from ido calling this
ad-do-it
(let ((allcomp (all-completions "" collection predicate)))
(if allcomp
(setq ad-return-value
(ido-completing-read prompt
allcomp
nil require-match initial-input hist def))
ad-do-it))))
Oh, and for using ido in M-x, use amx.
Hocus pocus, abracadabra, presto!
(defadvice completing-read
(around foo activate)
(if (boundp 'ido-cur-list)
ad-do-it
(setq ad-return-value
(ido-completing-read
prompt
(all-completions "" collection predicate)
nil require-match initial-input hist def))))
That works with everything but subr's, from which execute-extended-command is the one that matters (what is binded to M-x). But we can get what we want from M-x
(global-set-key
"\M-x"
(lambda ()
(interactive)
(call-interactively
(intern
(ido-completing-read
"M-x "
(all-completions "" obarray 'commandp))))))
I don't think ido-mode is ready for this quite yet. In particular, ido-completing-read currently only works with strings, while completing-read supports alists as well. This is very important once you want to have a different user-level description of the items you want to complete on.
Therefore I am not surprised that it doesn't work out of the box, yet. Short of modifying the code yourself your best bet is probably to just file a bug report/feature request.
Ido comes with a function that should do this, so just call it in your .emacs file:
(ido-everywhere t)
Using Emacs 24.3, ido-ubiquitous didn't work for me. So tried this and it is working fine so far:
(defun my-completing-read (prompt collection &optional predicate
require-match initial-input
hist def inherit-input-method)
(if (listp collection)
(ido-completing-read prompt collection predicate require-match
initial-input hist def inherit-input-method)
(completing-read-default prompt collection predicate require-match
initial-input hist def inherit-input-method)))
(setq completing-read-function 'my-completing-read)
Just a thought: have you tried editing ido-completing-read to call original-completing-read instead of completing-read, defining original-completing-read to be the current completing-read and then doing your defalias or setf thing?

How to accomplish equivalent of Vim's Ctrl-n in GNU Emacs?

Vim's Ctrl+N generally works like this: I type few letters, hit Ctrl+N, and Vim provides me with completions based on words in my all opened buffers.
Solution for Emacs doesn't have to be identical. I mainly use it like this: declare variable, then use it in later code. But I like the lightweight approach of not parsing the source code.
You want dabbrev-expand, bound to M-/ by default. I haven't used Vim, but from your description, it does the exact same thing.
try hippie-expand, bound to your favorite key
(global-set-key (kbd "M-/") 'hippie-expand)
Instead of presenting a completion-list, repeatedly hitting the bound-key cycles through the completions in-place.
Why "hippie"-expand? I have no idea, and I actually avoided looking at the function because the name was uninformative and off-putting, until I read the write-up at 'Life Is Too Short For Bad Code'. (The EmacsWiki entry on hippie-expand also asks "why 'hippie?'" but can't answer it, either.)
I personally use AutoComplete It gives you a nice dropdown box. You can select how many letters you want to type before it activates and customise what you want to show up, including stuff in dabbrev-expand.
;; Allow tab to autocomplete
(defun indent-or-expand (arg)
"Either indent according to mode, or expand the word preceding point."
(interactive "*P")
(if (and
(or (bobp) (= ?w (char-syntax (char-before))))
(or (eobp) (not (= ?w (char-syntax (char-after))))))
(dabbrev-expand arg)
(tab-to-tab-stop)))
(defun my-tab-fix ()
(local-set-key [tab] 'indent-or-expand))
(add-hook 'as-mode-hook 'my-tab-fix)
(add-hook 'java-mode-hook 'my-tab-fix)
(add-hook 'c-mode-hook 'my-tab-fix)
(add-hook 'sh-mode-hook 'my-tab-fix)
(add-hook 'emacs-lisp-mode-hook 'my-tab-fix)
The matter, in my opinion is that emacs completion I tryed doesn't complete regarding the context.
For instance, if you write some OOP with a method foobar() and an argument foo, M-/ will suggest you both foo and foobar.
But it would be great if you are calling an object method, not to provide just "foo" completion.
Has anyone a solution?
Aif> This requires much more than what "hippie expand" has to offer. If you code C/C++ you COULD use ECB http://ecb.sourceforge.net/ but frankly, the project is quite dead and this addon is not very reliable. If you need really good intelligent completion you should try Eclipse (CDT). But if you code python then Emacs (rope + flymake) is just as fine as Eclipse (PyDev).