Implementing a continuous "revert-buffer" aka Textpad - emacs

One of my colleagues uses TextPad, and one feature I found really useful is the Auto-Reload. (The feature has been described in this SO quesion: Alternative to TextPad's Prompt to Reload File). Basically, it keeps reloading the file without any prompt from the user, which is really helpful when monitoring log files that are updated in real-time. Is there something similar available for Emacs? If not, can anyone whip up the required elisp magic?

M-x auto-revert-mode
I should add that for log tails, there is the more specific auto-revert-tail-mode, and that if you like it as a general feature (my case), you can turn on global-auto-revert-mode, to revert all buffers. Beware of remote files in that case.

If you want auto-revert to apply everywhere you can also use global-auto-revert-mode. Add
(global-auto-revert-mode 1)
to your .emacs

Here's my preference, FWIW: I do not use auto-revert. Instead, I bind f5 to this command:
(defun revert-buffer-no-confirm ()
"Revert buffer without confirmation."
(interactive) (revert-buffer t t))
Sounds silly, but that simple change makes all of the difference. This is what f5 does anyway on MS Windows, so it's a habit that works in all applications (on Windows).
Note that I do not change (e.g. remap) any bindings for revert-buffer. I use this only when I explicitly want to revert without confirming (which is quite often, in practice).
HTH.

Related

reduce load time emacs [duplicate]

I use Emacs v. 22 (the console version, either remotely with PuTTY or locally with Konsole) as my primary text editor on Linux. It takes a while to load up each time I start it though, probably almost a second, although I never timed it. I tend to open and close Emacs a lot, because I'm more comfortable using the Bash command-line for file/directory manipulation and compiling.
How can I speed up the start-up time?
Others have covered using gnuserve and emacsclient, and I'd suggest compiling within emacs (being able to jump to compilation errors is a win).
But, specifically speeding up the .emacs can be done by:
Byte compiling the .emacs file, which you can do automatically by using this snippet of code
Replacing as many of the (require 'package) statements with autoloaded functionality. This will delay loading of lisp until it's actually required. Using this technique allowed me to speed up my startup from >6 seconds to <1. This takes a little bit of work because not all libraries come properly marked autoload.
Removing code/functionality you no longer use.
Try running emacs with the option --no-site-file to avoid loading unnecessary packages in the site installation site-start.el.
If you are really serious, you can roll your own emacs with your favorite functionality already loaded. This, of course, means it's more involved to make changes to what you have in your .emacs because it's a part of the binary. Follow the link for information on how to use dump-emacs.
Buy a faster computer and/or faster disk.
How to determine what your .emacs loads
Now, how do you find out what your .emacs loads? With the goal to remove the functionality, or to delay it? Check your *Messages* buffer, which contains lines like:
Loading /home/tjackson/.emacs.tjackson.el (source)...
Loading /home/tjackson/installed/emacs/lisp/loaddefs.el (source)...done
Loading /user/tjackson/.elisp/source/loaddefs.el (source)...done
Loading autorevert...done
Loading /home/tjackson/.emacs.tjackson.el (source)...done
If you'll notice, the Loading statements can nest: the first .emacs.tjackson.el ends with ... and the last line shows the .emacs.tjackson.el load is ...done. All those other files are loaded from inside my .emacs.tjackson.el file. All the other loads are atomic.
Note: If you have a large .emacs, it's possible that the *Messages* buffer will lose some of the messages because it only keeps a fixed amount of information. You can add this setting early on to your .emacs to keep all the messages around:
(setq message-log-max t)
Note: It the 'load command will suppress the messages if its fourth argument nomessage is non-nil, so remove any such invocations (or, advise 'load and force the fourth argument to be nil).
In addition to Adam Rosenfield's solution, I recommend to use Emacs in server mode. You may add (server-start) to your dotemacs, and run emacsclient instead of emacs whenever you want to open file in Emacs. That way you have to pay the loading cost of Emacs only once, after then clients pop up immediately.
Edit
You're right, v22 does not create a new frame. Create a shell script that do the trick:
#!/bin/bash
# Argument: filename to open in new Emacs frame
/usr/bin/emacsclient -e '(let ((default-directory "`pwd`/")) (select-frame (make-frame)) (find-file "'$1'"))'
Edit 2
In v24+, you can do emacsclient -c to create a new frame.
Don't close Emacs every time you want to use the shell. Use Ctrl-Z to move Emacs to the background and the fg command in Bash to move it back to the foreground.
A couple of tips:
Use autoloads
Using autoload saves you from loading libraries until you use them.
For example:
(if (locate-library "ediff-trees")
(autoload 'ediff-trees "ediff-trees" "Start an tree ediff" t))
Compile your .emacs
Gives you a slight speed increase although there are pitfalls if you
work with version control and your .emacs is newer than .emacs.elc.
One common trick is:
(defun autocompile nil
"compile itself if ~/.emacs"
(interactive)
(require 'bytecomp)
(let ((dotemacs (file-truename user-init-file)))
(if (string= (buffer-file-name) (file-chase-links dotemacs))
(byte-compile-file dotemacs))))
(add-hook 'after-save-hook 'autocompile)
Learn to love emacs server.
Running emacs as a server means never having to close it down. However
I note your still using emacs22. emacs23 supports multi-tty which makes
it a lot easier to run emacs in one screen session and then bring up
new windows in another terminal. I use emacs to edit mail for my mail
client (mutt) and emacsclient is fantastic for these sort of quick edits.
One of
M-x shell
M-x eshell
M-x term
M-x ansi-term
should meet your command-line needs from within Emacs.
You can also use M-! (aka M-x shell-command) to execute a one-liner without dropping to the shell.
Check your .emacs file to see if you're loading unnecessary packages. Loading packages can take a significant amount of time. For example, you might only want to load the php-mode package if you're editing a PHP file. You can do that by installing a hook procedure, although I'm not certain of the details.
Also make sure that any packages you're loading are compiled (.elc files). You can compile an elisp file by running
emacs -batch -f batch-byte-compile thefile.el
Compiled packages load much faster than uncompiled packages.
"I tend to open and close emacs a lot, because I'm more comfortable using the bash command line for file/directory manipulation and compiling."
You're describing the way an editor like vim is used like. Shoot in&out. Emacs is usually kept open, and mostly all is done from "within it". hiena already answered what would be the correct approach here.
The fastest way is to profile your .emacs. I cut down my load time from >3s to 1s in 5 minutes after I found that 4 particular lines in my .emacs were taking up more than 80% of the load time.
One thing that helped me reduce the load time of my .emacs, in addition to autoload (as others have suggested), is eval-after-load. In the following example, delaying the call to sql-set-product saves you from having to load sql in your .emacs, making the exisiting sql autoloads more effective.
(eval-after-load "sql"
'(progn
(sql-set-product 'mysql)
(setq sql-mysql-options '("-C" "-t" "-f" "-n"))
(setq sql-sqlite-program "sqlite3")
))
Of course, for some packages there will be a hook available that you can do the same thing, but sometimes there isn't, or else this way just proves easier to think about.
Emacs is designed to run "all the time" (or at least for long periods of time), thus starting and stopping Emacs several times during a day is not recommended.
I would suggest using screen. Screen is a terminal multiplexer, giving you an unlimited virtual terminals in one terminal.
After installing simply write "screen emacs" in your terminal. Emacs will start as usual, but pressing "c-a c" (that is press ctrl-a and then c) will open a new virtual terminal. You can get back to emacs by pressing "c-a c-a" (that's two times ctrl-a).
You can even detach from the running screen session, the key sequence is "c-a d".
Re-attach to the session by issuing "screen -R" and you will be back where you left. This enables you to start an emacs session at work, detach, go home, and re-attach from home.
I've been running Emacs like this for months in a row.
Here's the official web site: http://www.gnu.org/software/screen/ but try googling for screen tutorials and howtos
You can use benchmark-init to profile your Emacs startup. It will keep track of what modules are being loaded and how much time is spent on each. The results can be presented either in a tabulated form or as a tree. The tree makes it easier to track who loads what, which can be helpful when you load a package with a lot of dependencies, and the tabulated form helps you quickly find where most of the time is being spent.
Once you have these results try to figure out if all of the modules have to be loaded all the time or if you can perhaps load some of them on-demand. For instance, in my configuration I only load Emacs extensions that are specific to certain modes when that mode is actually activated since most of the time I only use a small subset of them in a session. eval-after-load and mode hooks will be your friends here.
By applying this method my Emacs starts in 3-4 seconds and I have close to 200 extensions installed. Most of the time is spent loading Helm, which I always load since it replaces find-file and other core functions that are always needed, and CEDET, since I use the latest version and it has to be loaded before Emacs tries to load the older built-in version.
Try using the https://github.com/jwiegley/use-package macro to define your package loads and customizations. It handles deferred loading of packages for you, making it relatively easy to get good startup times even in the presence of large numbers of configured packages. I have almost 100 packages referenced in my .emacs, but my startup time is under 2 seconds on Linux, and 2.2s on the Mac.
One thing that others haven't mentioned is to include the elisp libraries you use as part of the dumped Emacs to move the library loading time from Emacs startup to Emacs build. It is not for the faint-hearted, but if you load several libraries in .emacs it could win you a few seconds of startup time.
I had around 120sec start time. I was able to find the fix installing this:
https://github.com/dholm/benchmark-init-el
put on top of your init.el
(let ((benchmark-init.el "~/.emacs.d/el-get/benchmark-init/benchmark-init.el"))
(when (file-exists-p benchmark-init.el)
(load benchmark-init.el)))
then once your emacs started, run:
M-x benchmark-init/show-durations-tree
On my side the problem was 127 secs in tramp-loaddefs
I fixed it by adding
127.0.0.1 host.does.not.exist
to /etc/hosts and that made my startup fast
see more here: https://github.com/emacs-helm/helm/issues/1045
another thing that maybe helpful to you: https://www.emacswiki.org/emacs/ProfileDotEmacs
This doesn't answer the question, but is kind of relevant
I don't know how to make it start faster, but there are a few things I could suggest:
for most things you do on the command line, you can do them in emacs:
compile: M-x compile, then type the command you use
my experience is only with C++, but with g++ you can press C-x ` to jump to lines that the compiler complains about
run shell commands: M-!, dumps output into a buffer
interactive shell: M-x shell
alternatively, you could run emacs like this:
emacs file.ext &
which opens emacs in the background so you can still use the shell ( this works best with putty and X forwarding with something like Xming)
I was trying to solve the same problem, when I came across this question here. I just wanted to add that the problem for me was not because of the load time of emacs lisp packages, but the fact that the host did not have a fully resolved hostname
To check your package load time do
M-x emacs-init-time
For me it was 0.3 seconds, and yet the load time was extremely high.
After changing my hostname correctly, it fixed the problem.
To configure your fully resolved hostname edit /etc/hostname, and /etc/hostsfile with:
127.0.0.1 localhost localhost.localdomain
192.168.0.2 hostname hostname.domain
I would have to check my customization, but there is a package called gnuserve or emacsclient. It migrates a lot so you will have to google for it.
It runs one emacs session in the background. Any further sessions of emacs are essentially just new frames of that session. One advatage is quick startup times for your later sessions.

Emacs command to Find and Open File similar to Eclipse

I've recently switched from using Eclipse to emacs. I'm trying to find a way to emulate eclipse's Ctrl-Shft-r functionality which lets you type in a file name and it begins showing all files in the current workspace that begin with the string you are typing.
C-x C-f seems to handle just tab-completion in the current directory, whereas Eclipse's functionality looked through all sub-directories to find matching files.
I'm looking for something (maybe there's a plugin that does this) that allows you to type the name of folder to look in, and then a partial file and returns back the results in a buffer. Possibly that uses auto-complete to list off matching files with their full paths.
First of all, steer clear of vanilla find-file function (that's the interactive function that is run when you hit C-x C-f). It is very limited, it forces you to hit TAB all the time, and the first thing most people do when switching to emacs is replace find-file with something more powefull.
There're a number of alternatives. ido-mode is one, helm is another. The former is light-weight, fast and comes built-in with emacs. The latter is immensely powerful and strives to be fast, too.
Second of all, there're two ways a recursive file search can usually be done:
directory search - that's when you just search a directory, no surprises here;
project search - that's when you setup a project your're working on, thus making emacs aware of which files are of interest to you right now.
For directory search, ido-find-file and helm-find-file are both viable options. Ido does its search automatically when you pause typing; helm uses (C-u) M-g s to activate grep. See this SO question for more info.
For project search, you need a library to manage your projects. Projectile is great for that. Set it up and use C-c p f or C-c p F to list files in current or all of your projects, respectively. Oh, and projectile uses ido by default, but there is helm support, too.
You're looking for projectile which indexes your project's files. I used it for a while but have recently switched to using helm-recentf
(global-set-key "\C-x\ \C-r" 'helm-recentf)
I have recent files set to a large number. Pretty much anything I've ever opened is a few keystrokes away. This even doubles up as a handy way to switch buffers.
(require 'recentf)
(setq recentf-auto-cleanup 'never)
(recentf-mode 1)
(setq recentf-max-saved-items 200)

call emacs commande automatically

I would find a way to execute the commands in the file emacs. Emacs and therefore automatically.
For example I often use: highlight-80
So I'm forced to type every time: Meta key + highlight-80 +-fashion
it's the same with linum-mode and plenty of other.
I have been trying to put in the file emacs.:
(highlight-80 +-mode)
But the option is not enabled.
Thank you in advance for your help. I am looking desperately for a moment, emacs is my working tool quotidient.
Regards
Use C-h f or C-h v, and read the Emacs manual about such choices.
Some of them are user options (variables), whose values you can customize, using M-x customize-option, so the default setting becomes what you want.
Others are modes, which you can call/set in your init file (~/.emacs) --- see the Emacs manual for how to do that. Typically, you use a positive number to turn a mode on and a negative number to turn it off. E.g.: (menu-bar-mode -1) in your init file turns off the use of a menu bar.
In sum, the Emacs manual (C-x r) is your friend. Sit down and have a first chat with it.
You seem generally a bit unsure about how customising Emacs works, so reading the manual on this topic should probably be your next step:
http://www.gnu.org/software/emacs/manual/html_node/emacs/Customization.html
If you are not using the current stable release (Emacs 24.3 at the moment), there's a chance that some of that information will not apply. The in-built manual is, of course, always correct for the version you are running:
C-hig (emacs) Customization RET

Add content to Emacs minibuffer as the user types in it?

I'm probably going down the wrong path here, so let me know if I am. I'm trying to build a similar user interface to that which Vim's ctrlp and other plugins use, whereby the user is given a prompt, and as they type, results are shown above the minibuffer prompt line.
I've gotten the minibuffer command handling part working fine with minibuffer-with-setup-hook and a local post-command-hook (easy) and can get the results I want to display (verified by just (message)ing them for now).
If I want to show, say, 10 lines of results above that minibuffer prompt line, should I be somehow prepending text to the minibuffer, or using a separate buffer that I'll close once the command finishes? Any pointers to parts of the manual I should be reading to be on the right track with this?
The "minibuffer" is a normal buffer, so you can modify it by inserting/deleting text into it in the normal way. This said, adding text "before" means basically modifying the prompt which might lead to problems down the line. You'll probably be much better off doing something like
(let ((ol (make-overlay (point-min) (point-min))))
(overlay-put ol 'before-string (format "%s\n" myresults)))
I started to write this as a comment, but it got a bit too long ...
TBH, I feel there is room for a lighter weight version of helm. But the reality is helm is good enough, and someone else has already written it.
Neither I nor anyone else (so far) is motivated enough to rewrite it. What you describe as "God" aspect of it is indeed unappealing. But it is possible to load it (huge as it is, with modern computers, it really isn't an issue), and change settings so it is minimalistic.
ido is a simpler alternative, but the style of UI is not exactly how you described.

Why isn't return bound to newline-and-indent by default on emacs

I have tried emacs on and off for a while now and every time I start emacs, I go through the same routine. Customizing. The first one is binding return to newline-and-indent. (g)Vim does this by default. Showing matching parenthesis is also done by default on (g)Vim. It is grea that I can customize emacs to my heart's content but why doesn't emacs have nice and easy defaults? For reference, I am now using Emacs 23 on a RHEL5 box.
Probably because RMS didn't want it, that and because changing long-standing defaults is just an issue of politics. Like vi, Emacs has a hard-core following and basic changes like these are minefields.
Note: if you saved your customizations, then you wouldn't have to re-do them every time...
To have those nice and easy defaults, install Emacs Starter Kit. It enables by default a bunch of useful and convenient features make even the advanced Emacs users more productive.
Otherwise, as TJ pointed out, Emacs Customization Mode (type M-x customize) allows you to save permanently any of the settings. You can even store them in a separate file from your dotemacs―(setq custom-file "~/.emacs-custom.el")―so you can use it in every computer you work on.
The title of your question doesn't really reflect what your question is (and has been answered by Trey and Torok), but I'll tell you why I like it being bound to just newline: useless whitespace. Say you are nested inside a conditional in a function etc. and hit return a couple times to leave a blank line. The blank line now has a bunch of space chars on it. Yes, you can (and I do) remove trailing whitespace before saving, but I also have visual whitespace mode on and I can see it there taunting me.