User:Timothee Flutre/Notebook/Postdoc/2012/07/25

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About Emacs

  • Motivation: when analyzing data for any research project, it's essential to know well a good text editor. Indeed, it's very efficient to be able to program in several languages (eg. Python, C/C++, R), interact with the shell like in a terminal, manipulate data and plot exploratory analyzes in R, all this within the same editor! One such editor is Emacs, and is available on Linux, Mac OS and Windows. For Mac OS X users, I recommend this distribution.
  • Configuration: my own file ~/.emacs (versioned here):
  • Tips:
    • from the office computer (desktop), log interactively to a cluster node, launch emacs --daemon and keep the terminal open indefinitely; then access this session from any computer, e.g. a laptop, with emacsclient -t; and close it when needed via emacsclient -e "(kill-emacs)"
    • especially useful with PuTTY on Windows, launch emacs so that its window is the terminal itself, via emacs -nw
    • when updating org-mode, one may have to first comment all org-related lines in ~/.emacs, remove the dir ~/.emacs.d/elpa/org-*, re-open Emacs with option -Q, install the latest version of org-mode, close Emacs and re-open it without -Q, uncomment all org-related lines in ~/.emacs
  • Emacs Lisp: intro
    • see the content of a variable, C-h v, the enter the name of the variable, say load-path
    • go to the *scratch* buffer
    • write (+ 2 2)
    • put the cursor after the last parenthesis, and enter C-x C-e
    • one should see 4 in the mini-buffer
    • do the same with (concat "abc" "def")
    • here is an example of a function (interactive in this case)
(defun f (x y)
  (interactive "nx=\nny=")
  (message "%i" (+ x y))