Emacs Chat: Tom Marble – Invoicing with Org and LaTeX; Clojure
Guest: Tom Marble
Tom Marble’s doing this pretty nifty thing with Org Mode, time tracking, LaTeX, and invoice generation. Also, Clojure + Emacs, and other good things. Enjoy!
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For the transcript, you may click here.
Hello, I’m Sacha Chua, and this is an Emacs Basics video on customizing Emacs. Emacs is incredibly flexible. You can tweak it to do much more than you might expect from a text editor. This week, we’re going to focus on learning how to tweak Emacs with M-x customize and by editing ~/.emacs.d/init.el.
You can change tons of options through the built-in customization interface. Explore the options by typing M-x customize. Remember, that’s Alt-x if you’re using a PC keyboard and Option-x if you’re on a Mac. So for me, that’s Alt-x customize <Enter>. In the future, I’ll just refer to this as the Meta key, so remember which key is equivalent to Meta on your keyboard. (Review – Emacs Basics: Call commands by name with M-x)
After you run
M-x customize, you’ll see different groups of options. Click on the links to explore a group.
For example, people often want to change the backup directory setting. This is the setting that controls where the backup files (the files ending in
~) are created. You’ve probably noticed that they clutter your current directory by default. To change this setting, select the Files > Backup group. Look for the entry that says Backup Directory Alist. Click on the arrow, or move your point to the arrow and press <Enter>. Click on INS, or move your point to INS and press <Enter>. Fill it in as follows:
Click on State and choose Save for future sessions. This will save your changes to
~/.emacs.d/init.el. When you’re done, type q to close the screen.
You can also jump straight to customizing a specific variable. For example, if you want to change the way Emacs handles case-sensitive search, you can use M-x customize-variable to set the case-fold-search variable. By default, case fold search is on, which means that searching for a lower-case “hello” will match an upper-case “HELLO” as well. If you would like to change this so that lowercase only matches lowercase and uppercase matches only uppercase, you can toggle this variable. I like leaving case fold search on because it’s more convenient for me. If you make lots of changes, you can use the Apply and Save button to save all the changes on your current screen.
Not sure what to customize? You can learn about options by browsing through M-x customize or reading the manual (Help > Read the Emacs Manual or M-x info-emacs-manual). You can also search for keywords using M-x customize-apropos.
The Customize interface lets you change lots of options, but not everything can be changed through Customize. That’s where your Emacs configuration file comes in. This used to be a file called
~/.emacs in your home directory, and you’ll still come across lots of pages that refer to a
.emacs file (or “dot emacs”). The new standard is to put configuration code in your
~/.emacs.d/init.el file, which you can create if it does not yet exist.
What goes into your
~/.emacs.d/init.el file? If you open it now, you’ll probably find the settings you saved using
M-x customize. You can also call functions, set variables, and even override the way Emacs works. As you learn more about Emacs, you’ll probably find Emacs Lisp snippets on web pages and in manuals. For example, the Org manual includes the following lines:
(global-set-key "\C-cl" 'org-store-link) (global-set-key "\C-cc" 'org-capture) (global-set-key "\C-ca" 'org-agenda) (global-set-key "\C-cb" 'org-iswitchb)
This code sets C-c l (that’s Control-c l) to run
org-store-link, C-c c to run
org-capture, C-c a to run
org-agenda, and C-c b to run
org-iswitchb. You can add those to the end of your
~/.emacs.d/init.el file. They’ll be loaded the next time you start Emacs. If you want to reload your
~/.emacs.d/init.el without restarting, use M-x eval-buffer.
Emacs Lisp may look strange. Don’t worry, you can get the hang of it even if you don’t think of yourself as a programmer. You can start by copying interesting snippets from other people’s configuration files. Start with small chunks instead of large ones, so you can test if things work the way you want them to. If you need help, StackOverflow and other Q&A resources may be useful.
As you experiment with configuring Emacs, you may run into mistakes or errors. You can find out whether it’s a problem with Emacs or with your configuration by loading Emacs with emacs -Q, which skips your configuration. If Emacs works fine with your configuration, check your
~/.emacs.d/init.el to see which code messed things up. You can comment out regions by selecting them and using M-x comment-region. That way, they won’t be evaluated when you start Emacs. You can uncomment them with M-x uncomment-region.
Emacs gets even awesomer when you tailor it to the way you want to work. Enjoy customizing it!
Emacs has way too many keyboard shortcuts to memorize. Fortunately, you can call commands by name by typing M-x and the name of the command. M- stands for the Meta key. If your keyboard does not have a Meta key (and most don’t, these days), use Alt or Option. For example, on a PC keyboard, you can type Alt-x. Alternatively, you can replace Meta with ESC. M-x then becomes ESC x.
If you know the name of the command to execute, you can type it after M-x, and then press RET (the Return key, which is the same as the Enter key). For example, M-x find-file opens a file. M-x save-buffer saves the current file. You can use TAB to complete words. Use <up> and <down> to go through your command history.
What if you don’t know the name of the command to execute? You can use M-x apropos-command to search for the command using keywords. If you know the keyboard shortcut or you can find the command on a menu, you can also use M-x describe-key and then do the keyboard shortcut or select it from the menu.
If a command you execute has a keyboard shortcut, it will flash briefly at the bottom of your screen. For example:
You can run the command `find-file' with C-x C-f
Using TAB for completion can be a little slow. Here are two ways to make that and a whole lot of other things faster: ido and helm. To explore these approaches, you will need to add the MELPA package repository to your configuration. To set that up, add the following to the beginning of your
(package-initialize) (add-to-list 'package-archives '("melpa" . "http://melpa.milkbox.net/packages/") t)
Then use M-x eval-buffer to load the changes into your current Emacs, and use M-x package-refresh-contents to reload the list of packages.
This is what completion with Helm looks like:
Figure 2: Helm
Use M-x package-install to install the
helm package. Then you can try it out with M-x helm-mode . After you start Helm mode, try M-x again. You can type in multiple words to search for a command, and you can use <up> and <down> to go through completions. Use M-p and M-n to go through your command history.
If you like it, here’s some code that you can add to your
~/.emacs.d/init.el file to load it automatically next time, and to tweak it for more convenience.
(require 'helm-config) (helm-mode 1)
Use M-x eval-buffer to load your changes.
If you change your mind and want to disable
helm-mode, you can toggle it off with M-x helm-mode .
If you like how that works, you may want to
(global-set-key (kbd "M-x") 'helm-M-x). If you do, you’ll be able to see keybindings when you call commands with
M-x. Note that if you want to use a prefix argument (ex:
C-u), you will need to do that after calling
M-x instead of before.
Ido is like Helm, but it takes a different approach. Here’s what this combination will get you:
Figure 1: ido, smex, ido-vertical-mode, and flx-ido
If you want to give this a try, remove or comment out
(helm-mode 1) from your
~/.emacs.d/init.el (if you added it), and disable helm-mode if you still have it active from the previous section.
To set Ido up, use M-x package-install to install
After the packages are installed, add the following code to your
(ido-mode 1) (require 'ido-hacks nil t) (if (commandp 'ido-vertical-mode) (progn (ido-vertical-mode 1) (setq ido-vertical-define-keys 'C-n-C-p-up-down-left-right))) (if (commandp 'smex) (global-set-key (kbd "M-x") 'smex)) (if (commandp 'flx-ido-mode) (flx-ido-mode 1))
Use M-x eval-buffer to load your changes, then try M-x again. You should now have much better completion. You’ll be able to call commands by typing in part of their names. Use <up> and <down> to go through the completion options, and use <left> and <right> to go through your history.
Try it for a week. If you like it, keep it. If you don’t like it, try the Helm approach.
When you learn keyboard shortcuts, try to remember the names of the commands as well. You can do that with C-h k (
describe-key). For example, M-x calls the command
execute-extended-command. That way, even if you forget the keyboard shortcut, you can call the command by name.
If you forget the name of the command and you don’t know the keyboard shortcut for it, you can look for it in the menus or in the help file. You can open the help file with C-h i (
info). You can also use M-x apropos-command to search through the commands that you can call with M-x.
Make your own cheat sheet with frequently-used keyboard shortcuts and commands to help you learn more about Emacs. Good luck!