How to interrupt the infinite loop & resume command prompt in emacs, ielm buffer
(loop () (print 1))
presently, to come out of this mess, i kill emacs & restart it...
Use the quit command, bound to C-g (Ctrl-G for the uninitiated).
Related
I have a block of code like this:
ec2_shell_exec(tag: "ls /
ec2_shell_exec(tag: "sudo yum install git-core
ec2_shell_exec(tag: "pwd
Whats the easiest way to add a ") to this block of code?
Please note, emacs runs in terminal mode aka -nw mode.
Interactively
C-M-% $ RET ") RET
don't forget to press 4 keys at the same time: Ctrl for C, Alt for M, and Shift-5 for %
if the above still does not work (e.g., you are in a terminal with emacs -nw), you can do M-x query-replace-regexp RET $ RET ") RET
Programmatically
(while (not (eobp)) ; you have to edit the condition!
(goto-char (line-end-position))
(insert "\")")
(forward-line))
A keyboard macro should be easy to type on most terminals:
Move to your first line
Start recording a keyboard macro with C-x (
Go to end of line with C-e
Type ")
Move down with C-n
Stop recording macro with C-x )
Type C-x e to replay once
Type e for each successive time you need to repeat it
Summarizing the two solutions here (for folks running emacs in terminal):
M-x query-replace-regexp RET $ RET ") RET
And
first highlight ec2_shell_exec(tag. And call mc/mark-all-like-this which is from multiple-cursor. You will see all ec2_shell_exec(tag being hightlighted. Now call end-of-line to move every cursor to the end. Finally, you can insert anything you want. Press C-g to end operation
video demo: https://www.youtube.com/watch?v=jNa3axo40qM
Thanks adobe and tom!
How to kill an internal process in Emacs? For example I run M-x shell.
I can check running processes with M-x list-processes but how can I kill a process from this list?
There is no default key binding for this; however see pjammer's answer -- list-processes+ includes (among other things) a kill binding on C-k -- and also Joao Tavora's answer -- which provides just a kill binding (for the same key).
event_jr points out in the comments that you can use M-: (kill-process) RET to kill the current buffer's process.
More generally: You can use M-: (kill-process PROCESS) RET, where PROCESS "may be a process, a buffer, or the name of a process or buffer", with those names being as they appear in the output of list-processes. Process names take precedence over buffer names, should you happen to have a conflict; so it's probably best to be in the habit of supplying the process name.
Alternatively, Emacs 23+ has a general system process manager (M-x proced) which is more akin to running top, and which does have a default binding for sending (arbitrary) signals (k). Of course it may be far less obvious in that listing which process you're interested in.
Edit: Better late than never :) The following enables M-x kill-process RET to be used (tested in Emacs 26.1):
;; Enable M-x kill-process (to kill the current buffer's process).
(put 'kill-process 'interactive-form
'(interactive
(let ((proc (get-buffer-process (current-buffer))))
(if (process-live-p proc)
(unless (yes-or-no-p (format "Kill %S? " proc))
(error "Process not killed"))
(error (format "Buffer %s has no process" (buffer-name))))
nil)))
This thread is ancient but here's a very quick hack that works perfectly for me
(define-key process-menu-mode-map (kbd "C-k") 'joaot/delete-process-at-point)
(defun joaot/delete-process-at-point ()
(interactive)
(let ((process (get-text-property (point) 'tabulated-list-id)))
(cond ((and process
(processp process))
(delete-process process)
(revert-buffer))
(t
(error "no process at point!")))))
An alternative way:
You can use M-x eval-expression RET
Then type: (delete-process "<name-of-the-process>") RET
(where "name-of-the-process" was previously obtained from M-x list-processes RET).
Confirm that the process was killed by repeating M-x list-processes RET).
And that's it.
it looks like there is a new mode or add on you can use instead called list process +
If you use counsel you can run M-x counsel-list-processes. You can then type M-o to bring up actions, one of which is kill.
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)
I am an hour new into programming in Emacs lisp. I have a little experience with scheme so I understand the big picture of lisps in general. However, I have only used the "pure functional" subset of scheme and do not know how to do practical tasks.
Write now, I know that C-x C-e will evaluate the code enclosed by the parentheses' by the current cursor position.
I wish to loop from i = 1 to 10 and print the values of i out. How is this done? I tried the following:
(defvar i 1)
(while (< i 11)
(print "i: " i)
(setq i (+ i 1)))
Emacs tells me: invalid function 0.
How do I do this correctly?
Why is emacs telling me invalid function 0
Feel free to give me tips about how to use the scratch buffer (all I know is C-x C-e evaluates) in emacs. Thanks for all the help!
EDIT1: Could someone tell me how to print out sequential values of i using a while loop?
EDIT2: When I evaluate the code, it opens up another tiny buffer showing each value of i one at a time. However, it is not a large buffer and only shows values of i from 13 to 19. When I try to get into that buffer, it closes immediately. How do I "scroll" through that tiny buffer? Note that I use emacs 24.3 through the terminal
EDIT3: I figured out that the tiny buffer is the Messages buffer. Is there a better way to view the output of my elisp code? The Messages buffer is full of other junk from evaluating things in emacs.
First and foremost, enable "Enter debugger on error" from the Options menu now and add (setq debug-on-error t) or (custom-set-variables '(debug-on-error t)) to your ~/.emacs.el.
Then you will get a *Backtrace* buffer on C-x C-e:
Debugger entered--Lisp error: (invalid-function 1)
1(10)
print("i: " 1)
(while (< i 11) (print "i: " i) (setq i (+ i 1)))
eval((while (< i 11) (print "i: " i) (setq i (+ i 1))) nil)
eval-last-sexp-1(nil)
eval-last-sexp(nil)
call-interactively(eval-last-sexp nil nil)
command-execute(eval-last-sexp)
which shows that the error comes from print.
C-h f print RET will tell you why, but the upshot is that you want to use insert instead of print here.
Just as an added note, since you mentioned knowing some scheme -- if you like the interactive REPL that you can use in typical scheme environment, you might like ielm -- I think it probably stands for Interactive Emacs Lisp mode. Not sure. Anyway, M-x ielm RET will open up an emacs lisp REPL. Sometimes it is actually useful -- for example, when you want to inspect the content of a variable with a lot of data in it, ielm will print the whole thing out. Ielm is built in to my Emacs. Not sure when it was added to the standard distribution, but the earliest copyright in the source says 1994, so it is probably in your Emacs.
You can evaluate Emacs-Lisp sexps in *scratch* or in any other buffer in the same mode or (my preference) in mode emacs-lisp-mode.
In *scratch* you need only hit C-j (newline) after a sexp to evaluate it. In an emacs-lisp-mode buffer you can, as you said, use C-x C-e after a sexp. Or you can use M-x evaluate-region after selecting one or more sexps. As always, C-h m in any mode tells you about it, and usually lists important key bindings.
You can also check a global variable value using C-h v SOME-VAR. And you can evaluate any sexp on the fly from the minibuffer, using M-:. For example: M-: (setq foo (+ 42 (length bar)))
Wrt the debugger:
As #sds mentioned, debug-on-error puts you in the debugger when an error is raised. You can also set debug-on-quit and then enter the debugger using C-g to quit (e.g., during a loop).
If you know the function you want to debug, you can use M-x debug-on-entry.
Step through the debugger using d, or skip to the end of a step using c. Use q to quit the debugger.
You can also insert calls to function debug in source code, as debugger entry points: (debug).
The backtrace in the debugger is always more informative if you load the relevant source file e.g., foo.el, instead of the byte-compiled file, e.g., foo.elc. So before you use M-x debug-on-entry use C-h f to find out which file the function is defined in, and then load that file using M-x load-file /path/to/the/file.el.
There is also another debugger, besides debug -- look for edebug in the Elisp manual. Some people prefer edebug; I prefer debug.
I'm currently running an asynchronous emacs command with a fair degree of regularity like this:
(save-window-excursion
(async-shell-command
cmd
(generate-new-buffer "async")))
This works well and all, but it clutters up my emacs instance with a whole ton of async<5> and async<11> buffers. How can I automatically kill these buffers when their corresponding asynchronous command finishes executing?
While it won't kill them when the command completes, you can have the buffers killed after a period of time - this assumes that the async commands are shotr-lived ( or have a fairly-known runtime). Something like:
(save-window-excursion
(let ((buf (generate-new-buffer "async")))
(async-shell-command cmd buf)
(run-with-timer 10 nil (lambda (buf) (kill-buffer buf)) buf)))
Please have a look at
http://news.gmane.org/find-root.php?message_id=%3cloom.20120517T145957%2d51%40post.gmane.org%3e
The second proposal there starts a sentinel along with the shell process.
When this sentinel detects the process status 'exit you can kill the process buffer right away or you can start dying-mode for the process buffer as it is proposed in the cited posting.
Within the dying time you can inspect the process output, cancel dying or prolong the life-time of the buffer.
Best regards,
Tobias
I'm assuming that (for this particular use-case) you are rarely interested in looking at the output that is put in the "async" buffer and that you just want to prevent the creation of the extraneous buffers. If so, you could do:
(save-window-excursion
(when (get-buffer "async")
(kill-buffer "async"))
(async-shell-command
cmd
(generate-new-buffer "async")))
This will kill the "async" buffer prior to running the "async-shell-command" and thus prevent the additional "async" buffers from being created.