What's in your .emacs?

Question

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My favorite snippet. The ultimate in Emacs eye candy:

;; real lisp hackers use the lambda character
;; courtesy of stefan monnier on c.l.l
(defun sm-lambda-mode-hook ()
  (font-lock-add-keywords
   nil `(("\\<lambda\\>"
   (0 (progn (compose-region (match-beginning 0) (match-end 0)
        ,(make-char 'greek-iso8859-7 107))
      nil))))))
(add-hook 'emacs-lisp-mode-hook 'sm-lambda-mode-hook)
(add-hook 'lisp-interactive-mode-hook 'sm-lamba-mode-hook)
(add-hook 'scheme-mode-hook 'sm-lambda-mode-hook)

So you see i.e. the following when editing lisp/scheme:

(global-set-key "^Cr" '(λ () (interactive) (revert-buffer t t nil)))

I have this to change yes or no prompt to y or n prompts:

(fset 'yes-or-no-p 'y-or-n-p)

I have these to start Emacs without so much "fanfare" which I got from this question.

(setq inhibit-startup-echo-area-message t)
(setq inhibit-startup-message t)

And Steve Yegge's function to rename a file that you're editing along with its corresponding buffer:

(defun rename-file-and-buffer (new-name)
  "Renames both current buffer and file it's visiting to NEW-NAME."
  (interactive "sNew name: ")
  (let ((name (buffer-name))
 (filename (buffer-file-name)))
    (if (not filename)
 (message "Buffer '%s' is not visiting a file!" name)
      (if (get-buffer new-name)
   (message "A buffer named '%s' already exists!" new-name)
 (progn
   (rename-file name new-name 1)
   (rename-buffer new-name)
   (set-visited-file-name new-name)
   (set-buffer-modified-p nil))))))

One thing that can prove very useful: Before it gets too big, try to split it into multiple files for various tasks: My .emacs just sets my load-path and the loads a bunch of files - I've got all my mode-specific settings in mode-configs.el, keybindings in keys.el, et cetera

My .emacs is only 127 lines, here are the most useful little snippets:

;; keep backup files neatly out of the way in .~/
(setq backup-directory-alist '(("." . ".~")))

This makes the *~ files which I find clutter up the directory go into a special directory, in this case .~

;; uniquify changes conflicting buffer names from file<2> etc
(require 'uniquify)
(setq uniquify-buffer-name-style 'reverse)
(setq uniquify-separator "/")
(setq uniquify-after-kill-buffer-p t) ; rename after killing uniquified
(setq uniquify-ignore-buffers-re "^\\*") ; don't muck with special buffers

This sets up uniquify which changes those ugly file<2> etc. buffer names you get when multiple files have the same name into a much neater unambiguous name using as much of the whole path of the file as it has to.

That's about it... the rest is pretty standard stuff that I'm sure everyone knows about.

This is not the whole kit and kaboodle, but it is some of the more useful snippets I've gathered:

(defadvice show-paren-function (after show-matching-paren-offscreen
                                      activate)
  "If the matching paren is offscreen, show the matching line in the                               
echo area. Has no effect if the character before point is not of                                   
the syntax class ')'."
  (interactive)
  (let ((matching-text nil))
    ;; Only call `blink-matching-open' if the character before point                               
    ;; is a close parentheses type character. Otherwise, there's not                               
    ;; really any point, and `blink-matching-open' would just echo                                 
    ;; "Mismatched parentheses", which gets really annoying.                                       
    (if (char-equal (char-syntax (char-before (point))) ?\))
        (setq matching-text (blink-matching-open)))
    (if (not (null matching-text))
        (message matching-text))))

;;;;;;;;;;;;;;;
;; UTF-8
;;;;;;;;;;;;;;;;;;;;
;; set up unicode
(prefer-coding-system       'utf-8)
(set-default-coding-systems 'utf-8)
(set-terminal-coding-system 'utf-8)
(set-keyboard-coding-system 'utf-8)
;; This from a japanese individual.  I hope it works.
(setq default-buffer-file-coding-system 'utf-8)
;; From Emacs wiki
(setq x-select-request-type '(UTF8_STRING COMPOUND_TEXT TEXT STRING))
;; Wwindows clipboard is UTF-16LE 
(set-clipboard-coding-system 'utf-16le-dos)


(defun jonnay-timestamp ()
  "Spit out the current time"
  (interactive)
  (insert (format-time-string "%Y-%m-%d")))

(defun jonnay-sign ()
  "spit out my name, email and the current time"
  (interactive)
  (insert "-- Jonathan Arkell ([email protected])")
  (jonnay-timestamp))


;; Cygwin requires some seriosu setting up to work the way i likes it
(message "Setting up Cygwin...")
(let* ((cygwin-root "c:")
       (cygwin-bin (concat cygwin-root "/bin"))
       (gambit-bin "/usr/local/Gambit-C/4.0b22/bin/")
       (snow-bin "/usr/local/snow/current/bin")
       (mysql-bin "/wamp/bin/mysql/mysql5.0.51a/bin/"))
   (setenv "PATH" (concat cygwin-bin ";" ;
                          snow-bin ";" 
                          gambit-bin ";"
                          mysql-bin ";"
                          ".;")  
           (getenv "PATH"))
   (setq exec-path (cons cygwin-bin exec-path)))

(setq shell-file-name "bash")
(setq explicit-shell-file-name "bash")

(require 'cygwin-mount)
(cygwin-mount-activate)
(message "Setting up Cygwin...Done")


; Completion isn't perfect, but close
(defun my-shell-setup ()
   "For Cygwin bash under Emacs 20+"
   (setq comint-scroll-show-maximum-output 'this)
   (setq comint-completion-addsuffix t)
   (setq comint-eol-on-send t)
   (setq w32-quote-process-args ?\")
   (make-variable-buffer-local 'comint-completion-addsuffix))

(setq shell-mode-hook 'my-shell-setup)
(add-hook 'emacs-startup-hook 'cygwin-shell)


; Change how home key works
(global-set-key [home] 'beginning-or-indentation)
(substitute-key-definition 'beginning-of-line 'beginning-or-indentation global-map)


(defun yank-and-down ()
  "Yank the text and go down a line."
  (interactive)
  (yank)
  (exchange-point-and-mark)
  (next-line))

(defun kill-syntax (&optional arg)
  "Kill ARG sets of syntax characters after point."
  (interactive "p")
  (let ((arg (or arg 1))
    (inc (if (and arg (< arg 0)) 1 -1))
    (opoint (point)))
    (while (not (= arg 0))
      (if (> arg 0)
      (skip-syntax-forward (string (char-syntax (char-after))))
    (skip-syntax-backward (string (char-syntax (char-before)))))
      (setq arg (+ arg inc)))
    (kill-region opoint (point))))

(defun kill-syntax-backward (&optional arg)
  "Kill ARG sets of syntax characters preceding point."
  (interactive "p")
  (kill-syntax (- 0 (or arg 1))))

(global-set-key [(control shift y)] 'yank-and-down)
(global-set-key [(shift backspace)] 'kill-syntax-backward)
(global-set-key [(shift delete)] 'kill-syntax)


(defun insert-file-name (arg filename)
  "Insert name of file FILENAME into buffer after point.
  Set mark after the inserted text.

  Prefixed with \\[universal-argument], expand the file name to
  its fully canocalized path.

  See `expand-file-name'."
  ;; Based on insert-file in Emacs -- ashawley 2008-09-26
  (interactive "*P\nfInsert file name: ")
  (if arg
      (insert (expand-file-name filename))
      (insert filename)))

(defun kill-ring-save-filename ()
  "Copy the current filename to the kill ring"
  (interactive)
  (kill-new (buffer-file-name)))

(defun insert-file-name ()
  "Insert the name of the current file."
  (interactive)
  (insert (buffer-file-name)))

(defun insert-directory-name ()
  "Insert the name of the current directory"
  (interactive)
  (insert (file-name-directory (buffer-file-name))))

(defun jonnay-toggle-debug ()
  "Toggle debugging by toggling icicles, and debug on error"
  (interactive)
  (toggle-debug-on-error)
  (icicle-mode))


(defvar programming-modes
  '(emacs-lisp-mode scheme-mode lisp-mode c-mode c++-mode 
    objc-mode latex-mode plain-tex-mode java-mode
    php-mode css-mode js2-mode nxml-mode nxhtml-mode)
  "List of modes related to programming")

; Text-mate style indenting
(defadvice yank (after indent-region activate)
  (if (member major-mode programming-modes)
      (indent-region (region-beginning) (region-end) nil)))