Emacs

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Emacs

Last time I compiled Emacs (Emacs 29.4): 

./configure --with-imagemagick --with-x-toolkit=gtk3 --with-modules --with-json --with-native-compilation --with-xwidgets

Code snippets

General

  • Disable Meta behavior in Emacs for right Option key

    Rif.: apple.stackexchange.com 

    (when (eq system-type 'darwin)
  (setq mac-right-option-modifier 'none))
  • Generic function to get JSON data from a URI
    (require 'json)
(defun get-json-data (url)
  (with-current-buffer
      (url-retrieve-synchronously url)
    (goto-char (+ 1 url-http-end-of-headers))
    (json-read-object)))
  • Org 2 Webjump list

    Convert a list of bookmarks (expressed in a org document) in a data structure suitable for webjump. 

    (require 'cl)
(defun get-webjump-sites ()
  "converts a org document in a data structure suitable for webjump"
  (let ((regex "\\[\\[\\(.*\\)\\]\\[\\(.*\\)\\]\\]"))
    (with-current-buffer (get-file-buffer "~/Dropbox/stefanorodighiero.net/links.org")
      (loop for i in (org-map-entries 'org-entry-properties nil 'file)
            for item-string = (cdr (assoc "ITEM" i))
            if (string-match regex item-string)
            collect `(,(match-string 2 item-string) . ,(match-string 1 item-string))))))

Elfeed

Download the image under the cursor 

(defun shr-download-image ()
  "Downloads the image under point"
  (interactive)
  (let ((url (get-text-property (point) 'image-url)))
    (if (not url)
        (message "No image under point!")
      (url-copy-file url (expand-file-name (url-file-nondirectory url)
                                           "~/Pictures/elfeed/")))))

(define-key elfeed-show-mode-map "D" #'shr-download-image)

Helm

An example of a custom-made Helm menu based on current buffer contents 

(defun helm-subroutines ()
  (interactive)
  (helm :sources '(((name . "Perl subroutines")
                    (volatile)
                    (headline "^sub ")))))

Switch theme

Disables all enabled themes before activating the new one: 

(defun switch-theme (theme)
  (interactive
   (list
    (intern (completing-read "Switch to custom theme: "
                             (mapcar 'symbol-name
                                     (custom-available-themes))))))
  (dolist (curr custom-enabled-themes) (disable-theme curr))
  (load-theme theme))

Increase text size

Increase text size for all the existing buffers matching a certain major-mode. 

(defun increase-text-scale-in-buffer-group (major-mode-name)
  "Increment text scale for all buffers matching a give major mode name"
  (interactive
   (list (intern (completing-read
                  "Select major mode from the list: "
                  (remove-duplicates (mapcar (lambda (b)
                                               (buffer-local-value
                                                'major-mode (get-buffer b)))
                                             (buffer-list)))))))
  (cl-loop for buffer in (buffer-list)
           when (string= (buffer-local-value
                          'major-mode (get-buffer buffer))
                         major-mode-name)
           do (with-current-buffer buffer
                (text-scale-increase 1))))

Create thumbnail

(defun create-thumbnail (filename)
  (let* ((dir (file-name-directory filename))
         (basename (file-name-base filename))
         (extension (downcase (file-name-extension filename)))
         (thumb-filename (concat dir basename "-thumb." extension)))
    (call-process "convert" nil nil nil
                  "-resize" "25%"
                  filename
                  thumb-filename)
    thumb-filename))

Clone indirect buffer in another frame

Rif.: Superuser 

(global-set-key [?\C-x ?5 ?c]
  '(lambda(newname display-flag)
    "Like `clone-indirect-buffer-other-window' but display in another frame."
    (interactive
      (progn
        (if (get major-mode 'no-clone-indirect)
          (error "Cannot indirectly clone a buffer in %s mode" mode-name))
        (list (if current-prefix-arg
          (read-buffer "Name of indirect buffer: " (current-buffer))) t)))
    (save-window-excursion
      (let ((newbuf (clone-indirect-buffer newname display-flag)))
      (switch-to-buffer-other-frame newbuf)))))

Dired

Rif.: Emacswiki 

(setq dired-dwim-target t)

org-babel: create a SQLite DB based on a table

In a sqlite src block: 

#+begin_src sqlite :db /tmp/test.db :var orgtable=log :colnames yes
drop table if exists sleep;
create table sleep (day text, up text, in_bed text);
.mode csv sleep
.import $orgtable sleep
#+end_src

Keys and commands

General

Key sequence Command Elisp function
C-x r t Rectangle: prefix  
C-c C-x C-v Toggle inline image mode  
M-g M-g Goto line…  
C-u C-x C-e Eval and insert output at point  
M-0 C-k Kill and yank backwards  
C-s C-w Appends the rest of the word under the cursor to the search pattern  
C-fx C-m f Set the file coding-system of the current buffer  
  • To search and replace across files in a project

    M-x counsel-projectile-ag. When we're ok with the list found, M-q. The user will be asked for the string to use to replace the occurrences, then guided through the places where the change will take place, for review. It can be useful to then use projectile-save-project-buffers.

Dired

Key sequence Command Elisp function
+ Create directory  
m/u Mark/Unmark for deletion  
Q Search&replace on marked files  
C-x C-q Edit mode  
C-c C-c (in edit mode) Apply changes  
C-c C-k (in edit mode) Cancel  
# Flag all auto-save files (files whose names start and end with ‘#’) for deletion  
~ Flag all backup files (files whose names end with ‘~’) for deletion  
% & Flag for deletion all files with certain kinds of names which suggest you could easily create those files again.  

Org-mode

Key sequence Command Elisp function
C-c c Capture  
C-c C-w Refile (org-refile)
C-c C-t Toggle state  
C-c C-d Add deadline  
C-c / Sparse tree (org-sparse-tree)
C-c C-x b Show the current subtree in an indirect buffer (org-tree-to-indirect-buffer)

Markdown mode

Key sequence Command Elisp function
C-c C-s b Insert blockquote (markdown-insert-blockquote)
C-c C-c p Preview  

eww

Key sequence Command Elisp function
H Show browsing history  
l   (eww-back-url)
w Copy current page URL (eww-copy-page-url)

Helm

Key sequence Command Elisp function
C-x c C-x C-f   (helm-find-files)
C-Space   Mark buffers in helm-mini
M-S-d   Delete marked buffers in helm-mini

SLIME

Slime cheat sheet

Key bindings

Key sequence Command Elisp function
C-M-i Complete symbol  
C-M-x Evaluate the current toplevel form slime-eval-defun
<Leader> !p Change package  

<Leader> is comma (,).

Snippets

This comes from #lisp IRC channel: "when you are in a slime repl window, slime-process will return that instance process", so 

(switch-to-buffer (process-buffer
                   (slime-process)))

Date: 2014-04-26 Sat 00:00

Author: Stefano Rodighiero

Created: 2024-10-29 Tue 14:58

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