Emacs

I use Emacs for almost everything: coding, writing, taking notes, managing tasks, using version control, preparing presentations. I’m using it right now! Well I mean, I’m writing this in Emacs. There is also a good chance I’m using it now now. The two main reasons why I like it and would recommend it:

Universal: I can use the same customized/familiar/efficient editor for everything. No need to learn how to use multiple editors.
It can be used in the terminal (super useful to work remotely on servers).

If I couldn’t use Emacs, I would definitely learn vim for these same reasons.

Emacs Manual

Basic configuration

Some of the basic tweaks in my .emacs file:

;; Disable startup screen
(setq inhibit-splash-screen t)
;; Turn the blinking off
(blink-cursor-mode 0)
;; Turn off the tool bar
(tool-bar-mode 0)
;; Change the font
;; (set-default-font "DejaVu Sans Mono 12") ;; (deprecated?)
(set-frame-font "DejaVu Sans Mono 12" nil t)
;; Show column number
(setq column-number-mode t)
;; turn off alarm bell
(setq ring-bell-function 'ignore)

General commands

Some miscellaneous commands that could be useful:

Counting words: select a region and press M-=. There are other ways for LaTeX.
In a console (R, Shell), previous/next line in the history is accessed by M-p/M-n. (Useful when ssh-tunneling with broken key-bindings).
Search for a regular expression in files using M-x lgrep command.
Evaluate lisp commands: C-M-x.
List key bindings currently available: C-h b.
Search Emacs documentation: C-h a.
List key bindings currently available starting with C-c: C-c C-h.
Narrow down to a region with C-x n n (e.g. when refactoring).
- Widen back to the entire buffer with C-x n w.
Accents with C-x 8 (C-x 8 C-h for list).
Shift a selected chunk with spaces: C-x TAB or C-4 C-x TAB to add a specific number of spaces (here 4).
To insert a tab: C-q <tab>
Go to line M-g g
Line wrapping
- Don’t wrap lines: M-x toggle-truncate-lines
- Wrap line but don’t cut words: M-x visual-line-mode

Regexp replace :

Command: C-M-%.
$ and $ to define groups.
\1 to refer to the first group.

Windows:

C-x 1 remove other windows.
C-x 2 split window horizontally.
C-x 3 split window vertically.
C-x + balance windows.

Kill ring

The kill ring is the equivalent of the clipboard, used to copy(kill) and paste(yank) stuff. Of note, deleting stuff also adds it to the kill ring.

Copy a selection to clipboard/kill ring with M-w.
Cut/kill a selection with C-w.
Paste(yank) the last kill C-y.
Yank a specific position in the kill ring, e.g. second-to-last with M-2 C-y.
After yanking (C-y), cycle through earlier kills with M-y (useful if you don’t remember when you copied something).

Calculator

Call the quick interface of the calculator with C-x * q (or M-x quick-calc). The result of the calculation will be shown and saved in the clipboard.

You can also evaluate a calculation in a buffer (make sure it’s flanked but empty lines) with C-x * e, then q to quit the calc mode.

For the standard interface, type C-x * c (or M-x calc).

By default it works in stack mode:

<ENTER> adds a number to the stack.
+, -, *, /, ^ performs an basic operations between the last 2 numbers.
<TAB> swaps the last 2 numbers.
<BACKSPC> removes last number in stack.
M-0 <BACKSPC> removes all numbers in stack.

To use the more conventional algebraic mode, start with an apostrophe '.

There’s a lot more to it (see manual). For example it can convert different units with u c, e.g. :

' 10 mi/h, then u c m/s
' 1.80 m, then u c mfi
' 23425 s, then u c hms

Display the list of units with u v.

Console-size split screen

I put this function and key binding in my .emacs:

(defun consoleSplit ()
  (interactive)
  (save-excursion
    (split-window-below)
    (enlarge-window 15)))
(global-set-key (kbd "C-x 9") 'consoleSplit)

It splits the buffer in two and reduce the bottom buffer by 15 lines resulting in a large and a small buffer for example for a script and the console.

MELPA package repository

Usually packages are just .el files to download and add in the folder defined in .emacs (e.g. (add-to-list 'load-path "~/.emacs.d/lisp/")). However, there is easier way: MELPA package manager!

To install it, add to .emacs:

(require 'package)
(add-to-list 'package-archives '("melpa" . "https://melpa.org/packages/") t)
(package-initialize)

Then to find and install a new package, use M-x list-packages, find the package in the list and click on Install.

Solarized theme

I use Solarized theme palette. I installed the color-theme-sanityinc-solarized pacakge directly from MELPA. Then I added the dark version as default with (load-theme 'sanityinc-solarized-dark t). To change it interactively I run M-x load-theme and then for example sanityinc-solarized-light.

I also have an alias in my .bashrc to open emacs directly in light mode:

alias emacsl="emacs --eval \"(load-theme 'sanityinc-solarized-light t)\""

Note: a theme can be “unloaded” using M-x disable-theme.

I’ve also created some keybindings to switch between light and dark themes:

(defun lighten ()
  (interactive)
  (load-theme 'sanityinc-solarized-light t))
(global-set-key (kbd "C-c b l") 'lighten)
(defun darken ()
  (interactive)
  (load-theme 'sanityinc-solarized-dark t))
(global-set-key (kbd "C-c b d") 'darken)

For R

Emacs Speaks Statistics

The easiest is to install ESS through MELPA. Otherwise, see below (potentially outdated).

To install ESS, without needing the admin rights, the easiest way is to download and compile it in a dedicated folder (e.g. .emacs.d/lisp/ess):

git clone https://github.com/emacs-ess/ESS.git .emacs.d/lisp/ess
cd .emacs.d/lisp/ess
make

Then add these lines to ~/.emacs:

(add-to-list 'load-path "~/.emacs.d/lisp/ess/lisp/")
(load "ess-site")

I also have these ESS config:

(setq ess-default-style 'DEFAULT)
(setq ess-indent-level 2)
(setq ess-ask-for-ess-directory nil)
(setq ess-r-package-auto-set-evaluation-env nil)

The last one took me some times to figure out: when developing a R package, commands were evaluated in another environment so the objects didn’t exist in the usual R buffer (which was driving me crazy).

Recently I had an issue where the startup directory was not the buffer’s directory but the root of the git repo. The solution was to define a ess-directory-function like so:

(defun my-ess-directory-function ()
  default-directory)
(setq ess-directory-function #'my-ess-directory-function)

Auto-complete

To get auto-completion (with objects, functions or parameters) I use auto-complete. It’s also available through MELPA.

Then I configure it in my .emacs:

(require 'auto-complete-config)
(add-to-list 'ac-dictionary-directories "~/.emacs.d/lisp/ac-dict")
(ac-config-default)
(setq ac-auto-start nil)
(define-key ac-mode-map [C-tab] 'auto-complete)
(define-key ac-completing-map "\t" 'ac-complete)
(define-key ac-completing-map "\r" nil)
(setq ac-quick-help-delay 0.1)

Smart underscores

By default, pressing underscore will insert a <- instead of a _. This was supposed to ease the pain of writing assignments with the arrow. However, now we actually want a _ most of the time (e.g. for ggplot2 functions). Using smart underscores, <- will be inserted only when following a space.

It’s available in MELPA. Otherwise simply put this .el file in the load path and add these lines to ~/.emacs:

(require 'ess-smart-underscore)
(setq ess-S-underscore-when-last-character-is-a-space t)

Poly-mode for R + Markdown

With polymode (MELPA), the mode depends on the position of the cursor in the document. For R + Markdown it means that we can edit the Markdown part in markdown-mode and run the R code as if in a R script.

I added this to my .emacs:

(require 'poly-R)
(require 'poly-markdown)
(add-to-list 'auto-mode-alist '("\\.Rmd\\'" . poly-markdown+r-mode))

Custom keyboard shortcuts

Some keybindings I set up but don’t end up using that much…

To render RMarkdown

I tweaked a function to run rmarkdown::render on the current buffer and bound it to C-c C-e.

In .emacs:

(defun renderRmd ()
  (interactive)
  (save-window-excursion
    (message "Rendering %S" (buffer-file-name))
    (shell-command (format "Rscript -e 'rmarkdown::render(%S)'" (buffer-file-name)))
    (message "Done")))
(add-hook 'markdown-mode-hook
          (lambda ()
            (local-set-key (kbd "C-c C-e") 'renderRmd)))
(add-hook 'ess-mode-hook
          (lambda ()
            (local-set-key (kbd "C-c C-e") 'renderRmd)))

The key binding is active in markdown documents or R scripts (and so anywhere in a R-Markdown document).

To send a `dev.off()`

When working remotely, I send dev.off() to the R buffer using C-c C-d C-d to “update” the PDF opened from a mounted server.

In .emacs:

(defun devoff ()
  (interactive)
  (save-excursion
    (message "Closing device")
    (setq ess-command "dev.off()")
    (ess-execute ess-command 'buffer nil nil)))
(add-hook 'ess-mode-hook
          (lambda ()
            (local-set-key (kbd "C-c C-d C-d") 'devoff)))

Note: I use options(device=function() pdf(width=9, height=7)) to specify the dimensions of the default Rplots.pdf created.

Jumping to function definitions

When developping a package, use the typical commands:

M-. jump to a definition
M-, jump back.

Build the TAGS file with M-x ess-build-tags-for-directory.

To use, activating the mode M-x xref-etags-mode might be necessary. I added this to my .emacs:

(add-hook 'ess-mode-hook (lambda () (xref-etags-mode)))

For writing

When writing I prefer when long lines are wrapped without cutting a word: M-x visual-line-mode

Spell checking

I use ispell and flyspell.

To turn on the live spell check automatically for Latex and markdown documents:

(add-hook 'LaTeX-mode-hook 'flyspell-mode)
(add-hook 'markdown-mode-hook 'flyspell-mode)

I use the american dictionary by default:

(setq ispell-dictionary "american")
(setq ispell-local-dictionary "american")

Most useful key binding (more at Emacs Manual):

M-$ to trigger spell checking on a word (for example flagged by flyspell).
M-x ispell-buffer to launch spell checking. See also ispell-region or ispell-continue.

In the ispell interface, select a correction (0..9), skip (SPC) or update the dictionary (accept/insert).

If using a GUI, flyspell-popup (available on MELPA) provides a convenient pop-up interface that I bound to C-; with:

(require 'flyspell)
(define-key flyspell-mode-map (kbd "C-;") 'flyspell-popup-correct)

On Ubuntu, more dictionaries are installed using aspell packages, for example the aspell-fr for the French dictionary.

Thesaurus and synonyms

I tested the synosaurus package a few times (available in MELPA). It’s not as user friendly as some online resources but a good offline alternative. It uses the WordNet database through the wn command line. The shortcut to list synonyms is C-c C-s l.

In my .emacs I added the synosaurus-mode minor mode:

(add-hook 'LaTeX-mode-hook 'synosaurus-mode)
(add-hook 'markdown-mode-hook 'synosaurus-mode)
;; disable keybinding conflicting with markdown's
(eval-after-load "synosaurus"
  '(define-key synosaurus-mode-map (kbd "C-c C-s i") nil))
(eval-after-load "synosaurus"
  '(define-key synosaurus-mode-map (kbd "C-c C-s l") nil))

Grammar checking

The langtool package is available in MELPA. It uses the LanguageTool JAR to highlight potential grammar problems (downloaded from here). In my .emacs:

(require 'langtool)
(setq langtool-language-tool-jar "/usr/local/Cellar/languagetool/3.8/libexec/languagetool-commandline.jar")
(setq langtool-default-language "en-US")
(setq langtool-mother-tongue "fr")
;; (setq langtool-disabled-rules '("WHITESPACE_RULE")) ;; optional

Specific rules can be disabled, see list of rules here. For example, WHITESPACE_RULE for LaTeX.

Then:

M-x langtool-check to highlight problems.
M-x langtool-check-done to remove highlighting.
M-x langtool-switch-default-language to switch to another language, e.g. fr

For LaTeX

I put some Emacs tricks (e.g. for table manipulation) on the LaTeX page.

I general I prefer to use AUCTeX (available through MELPA). It handles multi-file documents and keeps the annoying compilation buffer closed. My configuration is:

(setq TeX-PDF-mode t)
(setq-default TeX-master nil)
(setq LaTeX-verbatim-environments-local '("lstlisting"))

Word count

To count the full document, including \include/\input documents, I call texcount with M-x latex-word-count after adding this to the .emacs configuration:

(defun latex-word-count ()
  (interactive)
  (shell-command (concat "texcount " "-sum -inc -sub=section " (buffer-file-name))))

To count words in a selected region, I use detex to strip LaTeX commands and wc to count words:

(defun latex-wc-region (&optional b e) 
  (interactive "r")
  (shell-command-on-region b e "detex | wc -w"))

Chunk folding

Sometimes I like to fold chunk of the document to improve clarity, e.g. frames in beamer document or figure/table in a manuscript. I added to my .emacs:

(add-hook 'LaTeX-mode-hook (lambda ()
			     (add-to-list 'LaTeX-fold-env-spec-list '("[frame]" ("frame")))
			     (setq TeX-fold-macro-spec-list (list ()))
			     (TeX-fold-mode 1)))

Then the main key bindings are:

C-c C-o C-e folds an environment.
C-c C-o C-r folds a region.
C-c C-o i unfold an item.
C-c C-o C-f to switch the fold-mode on/off

Because I added frame in the list, I can select a bunch of frames, press C-c C-o C-r and they all get folded (but not the rest). Otherwise, I manually fold the frames/figures/tables that are distracting.

For Markdown

C-c C-s s bold (strong).
C-c C-s e italic (emphasis).
C-c C-s s code (code).
C-c C-o follow a link.
C-c C-x C-l to toggle the hide-url mode to get shorter links.
C-c C-p/C-c C-n jump to previous/next outline.

Table formatting

Pressing TAB when the cursor is in a heading will cycle through heading-only/full view.

M-x orgtbl-mode to format markdown tables like org-tables.

Markdown live preview

markdown-preview-mode opens a page on the web browser and update it every time the buffer is saved.

For Python

Elpy python mode

Elpy combines several packages to provide a lot of nice features, e.g. code coloring, completion, syntax checks, formatting recommendations.

To install the dependencies for elpy:

pip install jedi autopep8 flake8

Then I have in my .emacs:

(package-initialize) ;; if not present already
(elpy-enable)
(setq elpy-company-add-completion-from-shell t)
(setq elpy-shell-use-project-root nil)
(setq elpy-shell-display-buffer-after-send t)
(setq elpy-shell-starting-directory 'current-directory)

Keybindings that I use:

C-RET or C-c C-y C-e to send line to python and step.
C-c C-y r sends region to python. Same for function, class or buffer.
C-up/C-down navigates between lines with same indentation as the current line.
C-c C-d open doc for symbol on point.
C-c C-z switch to Python shell (or start one).
C-c C-n go to next flymake error (previous with p).
C-c C-e edit all occurrences of symbol on point for refactoring (narrow if needed).

Of note, I use the Jupyter console instead of the default interpreter. So pip install jupyter and in my .emacs:

(setq python-shell-interpreter "jupyter"
      python-shell-interpreter-args "console --simple-prompt"
      python-shell-prompt-detect-failure-warning nil)
(add-to-list 'python-shell-completion-native-disabled-interpreters
             "jupyter")

Send commands to a specific buffer

Sometimes I want to send the commands to a specific buffer. For example, when testing new packages within a Docker container, I start a shell buffer, run docker and python.

I installed isend from MELPA. Then I simply go to the code buffer and run M-x isend-associate RET *shell* RET. At this point C-Enter will send the command to the shell buffer.

For C/CPP

Set the default indentation level with the c-basic-offset (e.g. setting it with M-x set-variable).
To jump to the matching {/}: C-M-f/C-M-b

I’m following this tutorial.

The speedbar is nice to get an overview of the files. M-x speedbar.
A better speedbar is provided by sr-speedbar and toogled with M-x sr-speedbar-toggle.

For Shell

To open a shell buffer, type M-x shell.

Then I use the Emacs Speaks SHELL package, that adds all the nice commands to send lines/regions from a script to a Shell buffer. In my .emacs I added:

(require 'essh)
(defun essh-sh-hook ()
  (define-key sh-mode-map "\C-c\C-r" 'pipe-region-to-shell)
  (define-key sh-mode-map "\C-c\C-b" 'pipe-buffer-to-shell)
  (define-key sh-mode-map "\C-c\C-j" 'pipe-line-to-shell)
  (define-key sh-mode-map "\C-c\C-n" 'pipe-line-to-shell-and-step)
  (define-key sh-mode-map "\C-c\C-f" 'pipe-function-to-shell)
  (define-key sh-mode-map "\C-c\C-d" 'shell-cd-current-directory))
(add-hook 'sh-mode-hook 'essh-sh-hook)

The shortcuts are self-explanatory.

For WDL workflows

Install through MELPA:

wdl-mode for syntax highlighting and indentation.
poly-wdl to switch to “shell” mode within command chunks.

In my .emacs file:

(setq wdl-indent-level 4) to change the indentation size.
(setq-default indent-tabs-mode nil) to make sure tabs are made of spaces (WDL doesn’t like mixing spaces and tabs).

Eventually the minor mode whitespace-mode is useful to explicitly show spaces and double-check that none of the indentations are made of tabs.

There is also an LSP implementation for WDL that can be used by Emacs to provide syntax validation and (some) auto-completion.

Install through MELPA: lsp-mode, lsp-ui and company-lsp.
Install the LSP server for WDL: pip install wdl-lsp (or pip3).
Add to .emacs file:

(require 'lsp-mode)
(add-to-list 'lsp-language-id-configuration '(wdl-mode . "wdl"))
(defgroup lsp-wdl nil
  "LSP support for WDL."
  :group 'lsp-mode
  :link '(url-link "https://github.com/broadinstitute/wdl-ide"))
(defcustom lsp-wdl-server-command "wdl-lsp"
  "Command to start wdl-lsp."
  :group 'lsp-wdl
  :risky t
  :type 'file)
(lsp-register-client
 (make-lsp-client :new-connection (lsp-stdio-connection
                                   (lambda () lsp-wdl-server-command))
                  :major-modes '(wdl-mode)
                  :priority -1
                  :server-id 'wdl))
(add-hook 'wdl-mode-hook #'lsp)
;; Syntax validation interface
(require 'lsp-ui)
(add-hook 'lsp-mode-hook 'lsp-ui-mode)
(setq lsp-ui-sideline-enable nil)
;; To get some auto-completion
(require 'company-lsp)
(push 'company-lsp company-backends)

The first time a file is opened, lsp will ask what is the root of the project. This can be changed later using M-x lsp-workspace-folders-remove and M-x lsp-workspace-folders-add.

For file manipulation

To visualize blanks (tabs, spaces, new lines) I use the minor mode whitespace-mode.

To disable line wrapping: M-x toggle-truncate-lines

To insert a tab: C-q <tab>

Compare two files (diff)

To compare and merge two files, use Ediff mode by calling M-x ediff (or M-x ediff-buffers when diff should be done between existing buffers). Once launched press:

| to change the split mode (vertical/horizontal).
n/p to go to the next/previous difference.
a to put A’s version to B.
b to put B’s version to A.
q to quit.
? to get the full list of shortcuts.

CSV/TSV

I use the csv-mode and the command c-c c-a to align columns. By default it understand ,, ; and \t as separator. If not I think the variable to customize is csv-separators.

Dired mode

When opening a directory (C-x C-f), Emacs shows the files in Dired mode:

d/u mark/unmark files for deletion.
x deletes files marked for deletion.
% d regexp <RET> flags file matching a regexp.
R rename a file.
C copy a file.

Added to my .emacs to show human-readable sizes:

(setq dired-listing-switches "-aBhl")

For Version Control

The built-in interface supports Git:

C-x v + to pull.
C-x v d to show the status.
C-x v v to commit.
C-x v P to push.
C-x v i to add.
C-x v = to see differences.

A more popular Git interface is Magit. After installing magit using MELPA, invoke the main buffer with M-x magit-status (or C-x g) and then:

? to list keystroke/commands.
F u to pull.
g to refresh.
s to stage file.
c c to commit.
P u to push.

Magit configuration in my .emacs:

(setq vc-handled-backends (delq 'Git vc-handled-backends))
(global-set-key (kbd "C-x g") 'magit-status)

File encryption

Encryption is integrated directly. Just add the extension .gpg to a file.

On HPCs

See how to setup GNU screen to avoid visual glitches in the Shell section.
M-x ess-remote to use a shell buffer as R buffer to send commands to. For example to send commands from a local R script to an R session on a server (connected through ssh in the shell buffer), or on an interactive job (launched in the shell buffer).

Remote files can be accessed/edited by opening them with /ssh:USER@SERVER:/path/to/file. A shortcut to connect to a server might be, in the .emacs:

(defun connect-SERVER ()
  (interactive)
  (dired "/ssh:USER@SERVER:/path/to/root"))

For online notes

Update: I don’t use this anymore. I take temporary notes in Simplenote, some of which I save in org-mode if I want to keep them.

Evernote

I use Evernote for easily keep notes synchronized across computer, tablet and smartphone. And there is a Emacs mode for it (of course!).

To install it, first run:

gem install evernote_oauth
git clone https://github.com/pymander/evernote-mode
cd evernote-mode/ruby
ruby setup.rb

I had an error with the last command and fixed it by changing ::Config::CONFIG with ::RbConfig::CONFIG in setup.rb.

Then, copy evernote-mode.el to the load path and add to .emacs:

(require 'evernote-mode)
(setq evernote-developer-token "<MYTOKEN>")
(setq evernote-username "<MYUSERNAME>")
(setq evernote-enml-formatter-command '("w3m" "-dump" "-I" "UTF8" "-O" "UTF8"))
(global-set-key "\C-cec" 'evernote-create-note)
(global-set-key "\C-ceo" 'evernote-open-note)
(global-set-key "\C-ces" 'evernote-search-notes)
(global-set-key "\C-ceS" 'evernote-do-saved-search)
(global-set-key "\C-cew" 'evernote-write-note)
(global-set-key "\C-cep" 'evernote-post-region)
(global-set-key "\C-ceb" 'evernote-browser)

I retrieved my developer token (to use instead of <MYTOKEN>) there.

Side notes:

I also had to install w3m software.
By default the notes are in read-only XHTML mode, I use M-x evernote-change-edit-mode TEXT to change the edit mode to text.

Simplenote

I now use Simplenote instead of Evernote, in order to make sure that I have an offline version of my notes at all time. Moreover it integrates (almost completely) the Markdown format. It makes it easy to take notes and to transfer them in our wiki (e.g. for conference notes). It’s also easier to clean the notes through emacs compared to the online page or apps.

There is a Emacs package that can be installed using MELPA: M-x package-install [RET] simplenote2 [RET].

The Simplenote buffer can be summoned by M-x simplenote2-browse or M-x simplenote2-list.

In list mode, the relevant commands are:

g: sync with the server.
a: create a new note
d: mark note on the current line for deletion
u: unmark note on the current line for deletion
t: set tags for filtering
^: toggle tags filtering condition between “AND” and “OR”

Other general commands include:

simplenote2-add-tag and simplenote2-delete-tag
simplenote2-set-markdown

For OSX

Update: I don’t use macs anymore so this section might be more outdated than the rest.

Here are some bits of configuration specific to OSX.

Maximize window at opening

Using the maxframe elisp from Ryan McGeary. I’ll copy the maxframe.el in the master branch of this repo in case it disappears.

(require 'maxframe)
(add-hook 'window-setup-hook 'maximize-frame t)

Keybindings

To change the annoying OSX bindings: paragraph jumping, home/end for line not page.

(define-key function-key-map (kbd "M-<down>") 'forward-paragraph)
(define-key function-key-map (kbd "M-<up>") 'backward-paragraph)
(global-set-key (kbd "<home>") 'beginning-of-line)
(global-set-key (kbd "<end>") 'end-of-line)

Ispell

To specify where is ispell located.

(setq ispell-program-name "/usr/local/Cellar/ispell/3.4.00/bin/ispell")

Also something about the right-click (I don’t remember why I have that).

(eval-after-load "flyspell"
    '(progn
       (define-key flyspell-mouse-map [down-mouse-3] #'flyspell-correct-word)
       (define-key flyspell-mouse-map [mouse-3] #'undefined)))

Explicit path definition

For LaTeX, I specified the PATH in .emacs:

(setenv "PATH" (concat (getenv "PATH") ":/usr/texbin"))
(setq exec-path (append exec-path '("/usr/texbin")))

For pandoc and ESS, I defined a RSTUDIO_PANDOC in .emacs:

(setenv "RSTUDIO_PANDOCPATH" (concat (getenv "RSTUDIO_PANDOC") ":/usr/local/bin"))

Hippocamplus My Second Memory