Strange Emacs behavior (produces garbage on the screen) - emacs

I'm trying to learn Emacs and eLisp by writing some simple macros. Here is one of them:
(global-set-key (kbd "C-c d") 'local-delete-line)
(defun local-delete-line ()
"deletes 1 line"
(interactive)
(beginning-of-line)
(set-mark-command)
(next-line)
(delete-region))
Unfortunately, after triggering C-c d (or any other hotkey that I set up by global-set-key), Emacs responds with this:
Any ideas what can cause this?
To troubleshoot, I've removed my whole .emacs file, created an empty one, and I've put only the definition of local-delete-line function, together with global-set-key command. Emacs still produces garbage when invoking the function.

Start by reading the doc of set-mark-command (C-h f set-mark-command). See what it says about not setting the mark in code you write. See how many arguments it requires.
Read the doc of delete-region: it requires two arguments.
Do M-: (setq debug-on-error t), and then try your recipe. The backtrace buffer will tell you what you have done wrong.
State what it is that you are trying to do. So far, it seems like you just want to delete or kill a line. If so, what's wrong with C-k?

Related

Emacs/AUCTeX prefix arguments

In LaTeX mode C-c C-c is bound to:
(TeX-command-master &optional OVERRIDE-CONFIRM)
Normally this interactive function runs a command, perhaps a LaTeX compilation, asking for confirmation.
In tex-buf.el it reads:
If a prefix argument OVERRIDE-CONFIRM is given, confirmation will
depend on it being positive instead of the entry in `TeX-command-list'.
This is a bit cryptic for me and reading C-h v TeX-command-list didn't help.
How can I pass the prefix argument to "TeX-command-master" so that I avoid all the confirmation requests?
Take a look at Emacs' documentation to find out about prefix arguments. In general, you can pass a command a prefix argument with C-u followed by a number. For one-digit numbers, you can also just type Meta followed by the digit. Thus to pass a positive prefix argument to TeX-command-master you could type:
M-1 C-c C-c
However, this will actually add another minibuffer confirmation, namely about the shell command to be used to compile the LaTeX source. Without the prefix argument, a command-dependent default is used for that.
If you want to avoid the question about the command to use, you can bind the undocumented variable TeX-command-force to "LaTeX" via:
(setq TeX-command-force "LaTeX")
However, this will have the downside that you're basically binding C-c C-c to the "latex" command, you cannot use any of the other commands such as "bibtex" or "view".
Other than that, LaTeX-mode does not allow for any customization of C-c C-c. Your best options are to either advise the function TeX-command-query or to bind C-c C-c to a wrapper function to set TeX-command-force dynamically. The latter would probably be the preferred option if you also want to auto-save the buffer.
It seems that the mystery of the OVERRIDE-CONFIRM continues. In the meantime a fellow suggests that, if we are unable to manage TeX-command-master, we can simply rewrite it.
In my version, based on his, if the buffer is not modified, the external viewer is launched; if the buffer is modified the compiler is run.
Everything with no confirmation for saving or running the given command.
(defun my-run-latex ()
(interactive)
(if (buffer-modified-p)
(progn
(setq TeX-save-query nil)
(TeX-save-document (TeX-master-file))
(TeX-command "LaTeX" 'TeX-master-file -1))
(TeX-view)))
Of course one can bind my-run-latex to whatever keybinding.
On the user's point of view this is a solution to my own question.
Do I click the close tag? Well, on the curious guy point of view I am still interested in understanding the mysterious TeX-command-master technicalities.
If someone should happen to know...
P.S.
Yes, TeX-save-query overrides the save-file request, also with TeX-command-master, that is C-c C-c. But you will still be asked to confirm the command action.
Build & view
Again, this solution, instead of modifying the behaviour of the TeX-command-master, rewrites it. The rewritten version of the command, named build-view, follows a rather straightforward logic.
If the LaTeX file buffer is not-modified, it runs the default viewer;
If the buffer is dirty, it runs the default LaTeX compiler and, after the build, opens the output in the default viewer.
Here's the code:
(defun build-view ()
(interactive)
(if (buffer-modified-p)
(progn
(let ((TeX-save-query nil))
(TeX-save-document (TeX-master-file)))
(setq build-proc (TeX-command "LaTeX" 'TeX-master-file -1))
(set-process-sentinel build-proc 'build-sentinel))
(TeX-view)))
(defun build-sentinel (process event)
(if (string= event "finished\n")
(TeX-view)
(message "Errors! Check with C-`")))
You can now type M-x build-view and start the told build-view process or associate it with a new keybinding such as “F2”:
(add-hook 'LaTeX-mode-hook '(lambda () (local-set-key (kbd "<f2>") 'build-view)))
Note: As suggested by Tyler, TeX-save-query variable is changed locally, therefore the old C-c C-c/ TeX-command-master is unaffected and will keep asking confirmations.
Do edit this code to make it better or easier to read!
I puzzled over the OVERRIDE-CONFIRM bit for a while, and couldn't figure out how it was supposed to work. If you want to automatically run Latex on your file, without being bothered about saving it first, or confirming that you want latex (rather than view, bibtex etc), you could use a function like this:
(defun my-run-latex ()
(interactive)
(TeX-save-document (TeX-master-file))
(TeX-command "LaTeX" 'TeX-master-file -1))
Bind this to something handy, and you'll still have C-c C-c for when you want to use the default processing commands. You may want to modify the TeX-command line if "Latex" isn't the processor you want to call.
If you are just looking to compile the latex source without a confirmation dialog, just add the following to your .emacs:
(setq TeX-command-force "")
You can then compile the source with C-c C-c and it won't ask to confirm. The only problem with this solution is that you can no longer change the command, but with most documents you won't want to. I might suggest that at the same time you can add this to your .emacs for even more flexibility, giving you a C-c C-c equivalent to the former behavior:
(define-key LaTeX-mode-map "\C-c\C-a"
;;; 'a' for ask, change to anything you want
(lambda (arg) (interactive "P")
(let ((TeX-command-force nil))
(TeX-command-master arg))))
You can then just work away at your document, do a C-x C-s, C-c C-c and then C-c C-v to see it. Like others have suggested you can also do the same for the save command and have it compile automatically on save, but some of my documents are in CVS and so I avoid putting hooks on that.
Credit to Ivan for some help on this one - don't know if he is on StackOverflow
I think the gist of this question is "how do I quickly compile my TeX document from AUCTeX without all the key presses and confirmations?"
My answer to that is to use the latexmk command rather than trying to coerce AUCTeX to do it.
latexmk -pdf -pvc myfile.tex
latexmk will monitor the file in question and rebuilt it as soon as you save it. If you use a good pdf viewer, it will notice the change in PDF and re-display it immediately. On OS X, skim works well for this.

before defadvice not executing before the function?

[I apologize for the poor title, but couldn't come up with a better one.]
bin chen asked on Google+:
How to input relative path of (buffer-file-name) in minibuffer after M-! in #emacs?
I thought if the buffer-file-name is saved in a register, it should be accessible by invoking insert-register (C-x r i) while at the shell-command prompt.
(defun save-buffer-file-name-in-register ()
(set-register ?F (buffer-file-name))
(set-register ?D (file-name-directory buffer-file-name)))
(defadvice shell-command (before save-buffer-file-name)
"Save buffer-file-name to register F before running shell-command"
(save-buffer-file-name-in-register))
(ad-activate 'shell-command)
When I invoke shell-command (M-!) followed by insert-register (C-x r i), I get the error message: Register does not contain any text.
But when I run list-registers I do see that the registers F and D are set with the appropriate values. If I run the shell-command again, I can access the values from the registers previously saved.
Is it possible that the registers are being set too late for the first time? How can I fix the code to do what I want?
Edit: Changed around to before (Thanks to #phils)
n.b. You have defined around advice, not before advice.
Around advice acts as a wrapper, and must include the token ad-do-it to execute the code of the function it is wrapping.
You have effectively replaced the body of the shell-command function with a call to save-buffer-file-name-in-register
As to your main question, I'd need to check the documentation, but I suspect that because the arguments to the advised function are available to advice, the original function's interactive declaration probably executes before the advice does, which would explain why your register values are not visible at the interactive shell-command prompt.
(If the around in the above code is indeed what you were using, the fact that you were still being prompted for a shell command would seem to verify this sequence.)
When the interactive form runs, your advice hasn't executed yet. See: this question
You need to specify an interactive form in your advice that redefines the original if you want to stick with this approach. However, this approach is a little fancy-pants for the sake of fancy-pants-ness.
Just define your own interactive function which does what you want without registers.
(defun insert-cur-dir ()
(interactive)
(let ((dir-name (file-name-directory (buffer-file-name (window-buffer (minibuffer-selected-window))))))
(insert (or dir-name ""))))
(define-key minibuffer-local-map (kbd "C-c i") 'insert-cur-dir)
An alternative, but way awesomer approach is to use yasnippet.

emacs ( recompile -y )

Is it possible to pass a "-yes" flag to the 'recompile' command in emacs?
Excuse my complete lack of (e)lisp know-how. I got sick of going outside Emacs to compile my latex code, so i added the following key binding to my .emacs:
(global-set-key (kbd "<f12>") 'recompile);
Is it possible to automatically answer 'yes' to the following prompt that might appear:
"A compilation process is running; kill it? (yes or no)."
Also, is it possible to make the window that opens and shows the output to scroll to the bottom automatically. The interesting stuff is typically down there. Maybe its possible to chain the following command after recompile: "C-x o, end-of-buffer".
Thanks!
Here's some code to solve your first problem (interrupting the current compilation):
(defun interrupt-and-recompile ()
"Interrupt old compilation, if any, and recompile."
(interactive)
(ignore-errors (kill-compilation))
(recompile))
For your second problem (scrolling the compilation output), just customize the user setting compilation-scroll-output.
This behaviour is governed by the compilation-always-kill global variable. Customize it via customize-variable and set it to t.
Not sure which version of emacs first had this, but 26 and newer certainly does.
I somehow need to put kill-compilation into a ignore-errors with Emacs 23.2 to get it to work when no process is running. Otherwise works great.
(defun interrupt-and-recompile ()
"Interrupt old compilation, if any, and recompile."
(interactive)
(ignore-errors
(kill-compilation))
(recompile)
)
Whenever I tried using kill-compilation with latex/pdflatex it did not work. I assume it is because latex does not respond to SIGINT.
Instead I am using the following hack, which first sets the process-kill-without-query bit of the compilation-buffer and then closes it (which kills the running process).
(defun interrupt-and-recompile ()
"Interrupt old compilation, if any, and recompile."
(interactive)
(ignore-errors
(process-kill-without-query
(get-buffer-process
(get-buffer "*compilation*"))))
(ignore-errors
(kill-buffer "*compilation*"))
(recompile)
)
The other solutions didn't work for me for the same reason as sfeuz, but I didn't like the nuclear option of killing the hardcoded buffer by name.
Here's a short solution that autoanswers yes to that specific question by advising yes-or-no-p:
ftp://download.tuxfamily.org/user42/compilation-always-kill.el
(source: http://www.emacswiki.org/CompilationMode)

How can I easily reload Emacs lisp code as I am editing it?

As an Emacs beginner, I am working on writing a minor mode. My current (naive) method of programming elisp consists of making a change, closing out Emacs, restarting Emacs, and observing the change. How can I streamline this process? Is there a command to refresh everything?
You might try using M-C-x (eval-defun), which will re-evaluate the top-level form around point. Unlike M-x eval-buffer or C-x C-e (exal-last-sexp), this will reset variables declared with defvar and defcustom to their initial values, which might be what's tripping you up.
Also try out C-u C-M-x which evaluates the definition at point and sets a breakpoint there, so you get dropped into the debugger when you hit that function.
M-x ielm is also very useful as a more feature-rich Lisp REPL when developing Emacs code.
M-x eval-buffer should do it.
What Sean said. In addition, I have (eval-defun) bound to a key, along with a test. The development loop then becomes: 1) edit function, 2) press eval-and-test key, 3) observe results, 4) repeat. This is extremely fast.
During development I write a test, bind it to jmc-test, then use the above key to run it on my just-edited function. I edit more, then press key again, testing it again. When the function works, I zap jmc-test, edit another function, and write another jmc-test function. They're nearly always one line of code, so easy to just bang out.
(defun jmc-eval-and-test ()
(interactive)
(eval-defun nil)
(jmc-test))
(define-key emacs-lisp-mode-map (kbd "<kp-enter>") 'jmc-eval-and-test)
(when t
(defun myfunc (beer yum)
(+ beer yum))
(defun jmc-test () (message "out: %s" (myfunc 1 2))))
When editing "myfunc", if I hit keypad enter, it prints "out: 3".
It all depends on what you're writing and how you've written it. Toggling the mode should get you the new behavior. If you're using [define-minor-mode][1], you can add code in the body of the macro that keys off the mode variable:
(define-minor-mode my-minor-mode
"doc string"
nil
""
nil
(if my-minor-mode
(progn
;; do something when minor mode is on
)
;; do something when minor mode is off
)
But, another way to check it quickly would be to spawn a new Emacs from your existing one:
M-x shell-command emacs&
I just define a function called ldf (short for load-file) in my .emacs file,
like this:
(defun ldf (arg) (interactive "P") (load-file (buffer-file-name)))
As you can see, this little function looks up the filename of the current buffer and then loads the file. Whenever I need to reload the current buffer elisp file, just type "M-x ldf"

How to do use C-x k to kill an Emacs buffer opened in server mode?

I use windows batch file to open files in an already-running instance of Emacs using emacsclientw.exe. However, any file opened that way is opened in server mode, which means that I have to use C-x # to kill it, instead of the usual C-x k. How do I change this behavior?
My solution was to rebind it (well M-w actually) to:
(lambda ()
(interactive)
(if server-buffer-clients
(server-edit)
(kill-this-buffer)))
[edit: having now read the code for server-edit, it might be better to use server-done (depending on what you want). server-edit will switch you to a server-edited buffer (if any still exist) but server-done will simply switch you to the next buffer. You could also use the output of server-done to see if the buffer was actually killed (not the case if the file was open before invoking emacsclient) and then kill it if not. Or use server-kill-buffer as suggested elsewhere.]
Here is what i put in my .emacs to do this :
(add-hook 'server-switch-hook
(lambda ()
(local-set-key (kbd "C-x k") '(lambda ()
(interactive)
(if server-buffer-clients
(server-edit)
(ido-kill-buffer))))))
Like this C-x k work the usual way when i'm not finding a file from emacsclient (which for me is ido-kill-buffer), and if i'm using emacsclient, C-x k does server-edit if the client is waiting, or run ido-kill-buffer otherwise (if i used emacsclient -n).
use:
D:\> emacsclientw -n foo.txt
the -n says "no wait". This is in GNU Emacs 22.2.1 (i386-mingw-nt5.1.2600) of 2008-03-26 on RELEASE (and many prior versions, IIRC).
You know, I hate to suggest workarounds instead of a real solution... but after reading the server code, I am confused as to how emacs even determines that a buffer is a server buffer.
With that in mind, why not open up files like:
emacsclient --eval '(find-file "/path/to/file")'
This way emacs doesn't know that your buffer was opened via emacsclient, which sounds like what you really want.
Edit:
I'm not really happy with this, but it seems to work:
(global-set-key (kbd "C-x k") (lambda () (interactive) (server-kill-buffer (current-buffer))))
Okay, THIS did work for me:
(global-set-key (kbd "C-x k") '(lambda ()
(interactive)
(if server-buffer-clients
(server-done)
(kill-this-buffer))))
(this is the code from IvanAndrus's answer with the explicit changes from edits and comments, and using jrockway's keybinding.)
And, yes -- I am rebinding a standard keybinding. BUT it's a functional replacement NOT something completely different (eg, replacing kill-ring-save with kill-buffer stuff).
BTW, EmacsWiki has a couple of pages on this topic-- KillKey and KillingBuffer -- neither of which shed better light for me than the above (although the first-function on KillKey also used "server-edit"...).
I am not sure if that will work on windows, but on linux, emacs -daemon is just great.
With it, you don't have to run a different program, and your bindings are the same. I guess there are other advantages, but since I could never learn those emacsclient bindings, I never really used it, and can't say.
I don't think -daemon had been released yet, I am using 23.0.60.1 from CVS.