Emacs

The Thermonuclear Word Processor Text Editor

Emacs

Summary

• What is Emacs?
• History of Emacs
• General Use
• The "Extensible" Editor
• Further Reading

What is Emacs?

The Thermonuclear Word Processor

I use emacs, which might be thought of as a thermonuclear word processor... If you are a professional writer... emacs outshines all other editing software in approximately the same way that the noonday sun does the stars. It is not just bigger and brighter; it simply makes everything else vanish.

What is Emacs?

Emacs is mind-blowing!

What is Emacs?

• Emacs is a family of 'extensible' text editors
• The most popular is GNU Emacs (latest: 24.2)
  • GNU Emacs is available on a variety of platforms including Windows, Mac OS X, and GNU/Linux
• Features include:
  • deep customizability
  • infinite extensibility
  • editing modes for different file types (e.g. HTML, JavaScript, Perl, etc.)

What is Emacs?

Getting emacs on Ubuntu 12.04

Can be as simple as: apt-get install emacs

But to get the latest, add the following to your sources.list:

What is Emacs?

DEMO: running emacs

What is Emacs?

EMACS could stand for

• Eight Megabytes And Constantly Swapping
• Emacs Makes A Computer Slow
• Eventually malloc()s All Computer Storage
• Eventually Makes All Computers Sick
• Eternally Modifying All Configuration Settings
• Escape, Meta, Alt, Control, Shift

History of emacs

or 35+ years in 5 minutes

• Emacs is old. Like, really old.
• Originally written in 1976 by Richard Stallman and Guy L. Steele as a set of Editor MACroS for the TECO editor
• Between 1976 and 1984, many Emacs-like editors were developed
• The first Unix port was Gosling Emacs, created by James Gosling

History of Emacs

Richard Stallman

History of Emacs

or 35+ years in 5 minutes

• GNU Emacs, one of GNU's first projects, was created in 1984 (starting @ v13) as a free (as in freedom) alternative to the proprietary Gosling Emacs
• In 1991, Emacs was forked with the development of Lucid Emacs (now XEmacs) after frustration with the slow development process
• Development is active. Latest release adds package management, right-to-left scripts (e.g. Hebrew), improvements to themes.

General Use

General Use

Buffers, Major & Minor Modes

• Technically, you don't edit files, but buffers
• Buffers can be attached to actual files, but need not be
• Certain buffers are created at startup (e.g. *scratch*); others hold output (e.g. *Messages*)
• Each buffer has only one major mode which allows emacs to adapt to the type of file you are writing
• Example: html-mode
• 1. Performs syntax highlighting of HTML tags
  2. Indents <tags> using tab
  3. Binds the command sgml-close-tag to C‑c C‑e

General Use

Buffers, Major & Minor Modes

• There may be many minor modes applied to a buffer.
• Minor modes should not interfere with the function of major mode
• Example: M-x yas/minor-mode: binds the yas-expand function to tab

General Use

DEMO: Major & Minor modes

General Use

Keybindings

General Use

Keybindings

General Use

Keybindings

• Emacs is notorious for its sometimes complex keybindings
• Many commands are accomplished by a series of keyboard combinations (called chords)
• Meta (abbreviated M) is on most keyboards the Alt key
• Control (abbreviated C) is the Ctrl key

General Use

Keybindings

The "Extensible" Editor

or: It's a great OS; all it needs is a text editor

• The core of Emacs is written in C, but nearly all text-manipulation functions are implemented through Emacs Lisp
• The configuration file for emacs is .emacs and is written in Emacs Lisp (eval'd at startup)

	    
	      (progn
	      (setq inhibit-startup-screen)
	      (set-foreground-color "white")
	      (set-background-color "black")
	      (set-cursor-color "white"))
	    
	  

The "Extensible" Editor

*scratch*

• Emacs is LISP machine
• Emacs starts with a buffer that evaluates LISP expressions
• Expressions evaluated in *scratch* become part of runtime environment

The "Extensible" Editor

Really important applications run on top of Emacs

• M-x snake
• M-x tetris
• M-x doctor
• M-x butterfly

The "Extensible" Editor

DEMO: M-x org-mode

Further Reading

Emacs

• A Guided Tour of Emacs (gnu.org)
• EmacsWiki (emacswiki.org)
• GNU Emacs Manual (gnu.org)
• OrgMode (orgmode.org)
• C-h t (tutorial within emacs)

FIN

Daniel Fowler

• e-mail: me@danfowler.net
• twitter: @danfowler
• url: danfowler.net