I'm using the most recent version of Emacs on Windows 7. Let's say I type the following code in my .emacs:
;test|
| means the cursor position. Now if I press Enter, the text will be moved to the right and it will look like:
;test
How to disable this feature?
This is done in accordance with the Emacs Lisp style guide:
Comments that start with a single semicolon, ';', should all be aligned to the same column on the right of the source code. Such comments usually explain how the code on that line does its job. For example:
(setq base-version-list ; There was a base
(assoc (substring fn 0 start-vn) ; version to which
file-version-assoc-list)) ; this looks like
; a subversion.
If you use two or more semicolons you will see other behaviour:
Comments that start with two semicolons, ';;', should be aligned to the same level of indentation as the code. Such comments usually describe the purpose of the following lines or the state of the program at that point.
...
Comments that start with three semicolons, ';;;', should start at the left margin. We use them for comments which should be considered a “heading” by Outline minor mode.
...
Comments that start with four semicolons, ';;;;', should be aligned to the left margin and are used for headings of major sections of a program.
The automatic indentation is done by electric-indent-mode. If you wish to disable it entirely, put something like
(electric-indent-mode -1)
in your init file. You could also disable it for specific modes using something like
(electric-indent-local-mode -1)
in the appropriate init hooks.
Simply using two semi-colons as suggested by the style guide should also prevent the behaviour, which will let you benefit from electric-indent-mode on other code.
Hi i have the following issue with my emacs:
When typing a long line, sometimes, when I type a space at the end of a line the line automatically gets split into multiple lines.
e.g. Line I am typing emacs: 'This is my line 1. This is my line 2. This is my line 3'%space%
emacs automatically formats this to:
'This is my line 1. %emacs adds new line%
This is my line 2. %emacs adds new line%
This is my line 3 %space%
Please help me fix this annoyance :)
What you are seeing is a feature (grin). "Auto Fill" mode is a buffer-local minor mode in
which lines are broken automatically when they become too wide. "Minor mode" means it is additional functionality which is associated with a buffer.
If you look at the emacs mode line, it will say "Auto Fill" if this is active. To turn it off for that buffer, M-x auto-fill-mode.
If for a particular major mode you would always like it on, you can turn it on by modifying the hook for that. For example, if every time you edit a text file, you would like auto-fill on, you can customize the variable text-mode-hook to turn it on.
M-x customize-variable
when prompted for the variable, say:text-mode-hook. You can use the same mechanism to turn it on (or off) for other modes.
Turn off auto-fill-mode: Put this in your init file, or do it for a particular mode on the mode hook: (auto-fill-mode).
Is there a key binding to quit a mode and return to the previous mode in emacs?
For example suppose I entered line number mode using the following command:
Alt+x linum-mode
How can I quickly disable this mode and return to the mode which I was in before (not using the same command again)?
Why wouldn't you want to use the same command again?
M-xM-pRET
It doesn't get much simpler than that.
Edit: You can repeat M-p in that sequence to step back further in the command history, and you can search the command history with M-xC-r.
Also, when you disable a minor mode you're not "returning to the mode you were in before"; you're just disabling one (of many) minor modes which are all active at the same time.
Tangentially, the concept of "returning to the mode you were in before" could apply to major modes (as there's only ever one active major mode in a given buffer), but strictly speaking there's no notion of 'disabling' a major mode -- only of 'enabling' the one you wish to change to -- so to 'toggle' between two major modes, you would need to call them alternately.
Just repeat the same command: M-x linum-mode. Such minor-mode commands are toggles: on/off.
C-x z calls repeat - repeat last command.
Repeatedly calling a minor-mode enables/disables it.
One more way to do it is with smex: the last command
that you called with M-x kinda sticks around.
So you can enable linum-mode with smex, do a bunch of editing
with usual shortcuts and then disable linum-mode with
M-x RET.
A solution might follow the path kill-ring-save works: store the modes being active as current-modes-listing in a previous-modes-ring.
The code needed therefor exists basically inside describe-mode, see upward from "Enabled minor modes" - respective for the major mode.
Then a hook should check if this-command has "-mode" in it's name. If yes, check, if current modes-listing equals car of previous-modes-ring. If not, add new setting.
Finally write a command which sets current modes according to selected listing from previous-modes-ring.
I edit .ml in Emacs. tab key indents well one line. But when I select a block of lines, tab key doesn't indent anything... Here is my .emacs, could anyone tell me what is wrong?
Also, tab doesn't indent comments at all, no matter whether it is 1 line or several lines... is it normal?
Complain to the author of your major mode: the default TAB binding is designed to tweakable by major-modes, but many major modes just override it locally instead and then often fail to reproduce the default behavior faithfully.
Try M-x indent-region RET.
The TAB key only indents the current line regardless if the region is active or not (but it would be a neat idea to implement a package to change the behavior).
When it comes to comments, it is up to the major mode. I don't know ml-mode, but major modes typically do indent comments.
I decided that I was ready to try something new, after a few years of using gEdit for most of my coding needs, and try to learn using Emacs. I knew this would be difficult, as I have heard how complex Emacs can be, but I was lured by its power. The hardest thing has been getting used to writing ELisp in the .emacs file to change things about the editor. I can't currently do it myself, but I have found a few helpful snippets here and there to change some options.
One thing I have been having a lot of problems with is getting Emacs to remember the text I have selected after a command. For instance, I commonly highlight a section of code to mass indent it. However, if I do this in Emacs, it will move the selected text only once before unselecting all of the text. Does anyone know a way around this?
Anyway, I apologize for what seems to me to be an easy question, but after an hour of Google searching and looking around here on SO, I thought it was worth asking. I have a few more questions about Emacs, but I will save them and ask separately after I get this straightened out. Thanks!
UPDATE
A few people have asked about what mod I am using and what type of text I am entering. While I don't know much about Emacs modes, I am editing a pure text file at the moment. Something like this:
Hello, I am a simple text file
that is made up of three separate
lines.
If I highlight all three lines and hit TAB, I get this:
Hello, I am a simple text file
that is made up of three separate
lines.
This is great, however, if I use C-x C-x like some suggest below to reselect the text and hit TAB again, I get this:
Hello, I am a simple text file
that is made up of three separate
lines.
I hope this helps!
FWIW, here is the reason for the behaviour of your newly-added example. (I'm not 'solving' the issue here, but I'm posting it to demystify what you're seeing.)
This was determined with emacs -q which disables my customisations, so the following is default behaviour for emacs 23.2.
You are in text-mode. You should see (Text) or similar in the mode line at the bottom of the screen, and C-h m will tell you (under the list of minor modes) "Text mode: Major mode for editing text written for humans to read." Emacs decides (by way of the auto-mode-alist variable) that it should switch to text-mode if you visit a filename matching certain extensions (such as .txt).
In text-mode pressing TAB with a region highlighted causes indent-according-to-mode to be called on each line of the region in sequence. The slightly convoluted path to finding this out starts at C-h k TAB, which tells us that TAB is bound to indent-for-tab-command, which in this instance calls indent-region -- that function name is not stated explicitly in the help, but can be seen in the code -- which checks the buffer-local indent-region-function variable, which is nil, and: "A value of nil means really run indent-according-to-mode on each line."
indent-according-to-mode checks the indent-line-function variable, which has the buffer-local value indent-relative.
Use C-h f indent-relative RET to see the help for this function. (Read this).
Although you probably won't yet have had the experience to know how to check all that (or necessarily even want to!), and fully understand everything it tells you, this is an example of how the self-documenting aspect of Emacs enables a user to figure out what is going on (which then makes it feasible to change things). I essentially just used C-h k (describe-key), C-h f (describe-function), and C-h v (describe-variable) to follow the documentation. Looking at the source code for indent-for-tab-command was as simple as clicking the file name shown as part of its help page.
I suggest doing the following to help see what is happening when indent-relative runs on each line:
M-x set-variable x-stretch-cursor t
M-x set-variable ruler-mode-show-tab-stops t
M-x ruler-mode
Now for each line in turn, put the cursor at the very start of the line and press TAB. You'll end up with all three lines indented to the first tab-stop ('T' in the ruler).
Now repeat this -- again, ensure you are at the very start of each line, in front of the existing indentation.
The first character of the first line (which is currently a tab) is once again indented to the first tab-stop, as there is no preceding line for it to examine.
Next, the first character of the second line is indented to match the position of the first non-white-space character of the preceding line. Because the first character of the second line is also a tab, the actual text of the second line is pushed one tab further along.
The third line follows suit. Its first tab character is lined up with the first non-white-space character of the second line, with the same relative effect as before, giving you the final state in your example.
To emphasise, note what happens if you now put enter the line "a b c" above the existing lines, then move back to the start of the next line (what was previously the first line) and press TAB. The first tab character will now be indented in line with the 'b'. Provided that the indent-tabs-mode variable is true (meaning you have actual tab characters), then this will have no practical effect on the position of the words in the line, as 'indenting' a tab with spaces will not have an effect until the number of spaces exceeds the width of the tab (but that's another kettle of fish entirely!)
All this really means is that text-mode in Emacs doesn't behave the way you'd like it to in this situation. Other major modes can do completely different things when you press TAB, of course.
As is invariably the case with Emacs, things you don't like can be changed or circumvented with elisp. Some searching (especially at the Emacs Wiki) will frequently turn up useful solutions to problems you encounter.
Try typing C-x C-x after Emacs unselects it.
Then, instead of hitting tab (I never knew that tab does what you said! That's totally whacked.), do M-8 C-x C-i. Pity it's so many keys, but it ought to do what you want -- namely, shove everything over 8 columns. Obviously replace the M-8 with something else if you want some other number of columns.
What I usually do is simply type C-x C-x (exchange-point-and-mark) after a command that deactives the region.
How are you indenting, and in which mode?
The indentation rules in any programming mode should generally just get it right. (If they don't, that's probably more indicative that you want to configure the rules for that mode differently, but I suspect that's a different question which has been asked already).
If you're in text-mode or similar and just using TAB, then I can see the problem.
Note that if you're using indent-rigidly (C-x C-i, or C-x TAB which is the same thing) then you can repeatedly indent the same region simply by repeating the command, even if the highlighting has disappeared from view.
You can also use a prefix arg to indent-rigidly to make it indent many times. e.g. C-u C-u C-x C-i (easier to type than it looks) will indent 16 spaces (4 x 4, as the prefix arg defaults to 4, and it multiplies on each repeat). Similarly, M-8 C-x C-i indents 8 spaces. This is fine in some circumstances, and way too cumbersome in others.
Personally I suggest putting (cua-selection-mode 1) into your .emacs and using that for rigid indentation. Trey Jackson made a handy blog about it. With this, you can C-RET to start rectangle selection, down as many lines as you need, TAB repeatedly to indent the lines, and C-RET to exit the mode.
While the rectangle is active, RET cycles through the corners. For left-hand corners, typing inserts in front. For right-hand corners, typing inserts after. For the single-column rectangle, bottom counts as 'left' and top counts as 'right' for this purpose.
Trey's blog lists all the available features (or look in the source file: cua-base.el)
Be warned that indentation in Emacs is generally an unexpectedly complicated topic.
You can do this with something like the following:
(add-hook 'text-mode-hook (lambda ()
(set (make-local-variable 'indent-region-function)
(lambda (s e)
(indent-rigidly s e tab-width)))))
Then selecting a region and hitting TAB. will indent the region by a tab-width. You can then exchange point and mark with C-x C-x and hit TAB again to repeat.
I do, however, agree with the previous answers that suggest using indent-rigidly directly.