Notes of Efficient Editing in Emacs

Move cursor to the top/middle/bottom of the current window: M-r

Make words in upper case/lower case/capitalized: M-u, M-l, M-c

Swap words: M-t

Open lines:

• move to the next line and then opens a line: open-next-line C-o

• open a new line before the current one: open-previous-line M-o

Vertical editing:

• use set-goal-column to do vertical editing: C-x C-n

• remove vertical mark: C-u C-x C-n

Move point to the first non-whitespace character on this line: back-to-indenentation M-m

Default in undo-tree:

• undo: C-/, C-_

• redo: C-?, M-_

Mark regions:

• expand region: C-=

• mark the whole buffer: C-x h

Kill texts/region/buffers:

• kills from the current point to a character: zap-to-char M-z [e]

• kill line backwards: M-0 C-k (built-in) OR C-<backspace>

• kill one sentence backwards: C-x Backspace

• kill/yank to kill-ring:

  • C-w / M-w to kill or copy the mark region or the current line

  • C-y to yank

  • list contents in kill-ring and select to yank: M-y

Join the current line to the above one: M-^

Fill/unfill paragraph/region/buffer:

• fill/unfill paragraph/region: M-q=/=M-Q

• set fill-column: C-x f

• automatically split long lines up to a prefixed length: use auto-fill mode

• set fill-column: C-x f

Insert contents of file FILENAME into buffer: insert-file C-x i

Write current buffer into file FILENAME (equiv. "Save As"): write-file C-x C-w

Reload the file from the disk: s-u (s: super/command); C-x C-v

Open file in the read-only mode: C-x C-r

Toggle overwrite mode: M-x overwrite-mode

Count words in region: M-=

Automatic correct word by flyspell: flyspell-auto-correct-word C-.

Toggle window split (horizontal <-> vertical) :: C-x |

Open the Messages buffer :: C-h e

Insert TAB: C-q TAB (TAB trigger complete or insert 4 spaces)

Insert 4-spaced TAB: tab-to-tab-stop or M-i

Converting TAB and 4-spaces of regions: tabify and untabify

Enable whitespace-mode to show white spaces as dots or colourised blocks.

Remove all except 1 trailing whitespaces: M-x SPC or Esc SPC, to call just-one-space

Delete all trailing whitespaces in the whole buffer: M-s k to call delete-trailing-whitespace

Remove all following blank lines: C-x C-o to call delete-blank-lines

Encoding: use utf-8-unix by default

• open a file with specific coding system: revert-buffer-with-coding-system

• set a encoding system for saving file: set-buffer-file-coding-system

• find out the current coding system used for opening and saving files: describe-current-coding-system

• find out what encoding system was used to decode current file: describe-variable buffer-file-coding-system

• list all available encodings with M-x list-coding-systems

• declare a file with a particular character encoding: add the following line in the first line of your files:

  -- coding: utf-8 --

Typical procedure on converting other encoded files to UTF-8:

1. reload the buffer with an alternative encoding to confirm the right one to choose: C-x RET r, e.g. gbk;

2. two ways to change encoding to UTF-8, then save as a new file:

   • change when saving using C-x RET f, e.g., utf-8-unix, then C-x C-s;

   • load it immediately by using C-x RET c, e.g. utf-8-emacs-unix, and then write to a new file C-x C-w RET.

Change End-of-Line:

• M-x set-buffer-file-coding-system utf-8-unix or use C-x RET f

Use register to copy/paste:

• C-x r s [R] to copy the region in register

• C-x r r [R] to copy the rectangle to register

• C-x r g [R] to (paste) insert text saved in register

Rectangle editing:

• mark rectangle: C-x SPC

• kill rectangle: C-x r k

• copy rectangle: C-x r M-w

• yank the last killed rectangle: C-x r y

• delete the region-rectangle: C-x r d

• open rectangle, shifting text right: C-x r o

• blank out rectangle: C-x r c

• prefix each line with a string: C-x r t

Use multiple-cursors:

• select one word C->, then hit C-g to place multiple cursors

• to place cursors in front of each lines: select multiple lines, then hit C-S-l C-S-l to place cursors OR select nothing and hit C->, then edit

• (disabled) use C-S-SPC to mark rectangular region

Add incremental numbers to lines: C-x r N

Comment line or region: C-\; uncomment: C-|, M-\

Align comments: M-x align; M-x align-regexp (C-x M-a) (prefix C-u for options)

Use iedit: C-;

Indent region in python-mode:

• python-indent-shift-right C-c >

• python-indent-shift-left C-c <

• set mark: C-SPC C-SPC

• jump to previous mark: C-u C-SPC after it, just C-SPC to continue jumping

• jump to mark saved in global-mark ring: C-x C-SPC

• exchange the cursor and the previous mark: C-x C-x

• use counsel-mark-ring to show mark ring: M-g SPC

• record the position of point in register [x]: C-x r SPC [x] (where [x] denotes any single letter)

• jump to the position saved in register [x]: C-x r j [x]

• use counsel-register to show the list: M-g r

Most frequently used:

• M-g b (or C-x r b): call counsel-bookmark to create or jump to bookmarks from a list

• C-x r l: list all bookmarks (list-bookmarks). In this temporary buffer, you can manage bookmarks like in Dired.

More operations:

• C-x r m RET to set the bookmark for the visited file, at point

• C-x r m NAME RET to set the bookmark named NAME at point (bookmark-set)

• C-x r b NAME RET to jump to the bookmark named NAME (bookmark-jump)

• M-x bookmark-save to save all bookmark values in the default bookmark file

From abo-abo's blog (or emacs irrelevant:

• https://oremacs.com/2017/11/18/dired-occur

• https://oremacs.com/2015/11/04/ivy-occur

• https://oremacs.com/2015/01/27/my-refactoring-workflow

From emacs-china.org:

• https://emacs-china.org/t/topic/16439

• https://emacs-china.org/t/emacs/16537

• https://emacs-china.org/t/counsel-rg/14385

1. Search by counsel-rg (or any others), which lists results in the minibuffer.

2. Call ivy-occur by C-c C-o, which freezes the minibuffer like a buffer to keep the results. You may use C-x 1 to view in a full window. In this mini-buffer window, you are allowed with second search and editing. Use w h or C-x C-q to call ivy-wgrep-change-to-wgrep-mode to allow editing the search results.

3. In the editing mode, you may do replace or other operations. After C-c C-c to save your editing, all operations will be applied to and in effect in these original files.

1. Open this folder in Dired, then M-x dired-toggle-read-only.

2. Edit file name in whatever way you prefer.

3. C-x C-s (or C-c C-c) to save.

Example: We like to change all files names like "abc20201003.mp4" to "20201003abc.mp4". Follow the above procedure, and, during editing, use M-x query-replace-regexp with ^\([^0-9]*\)\([0-9]*\)\.mp4, then type \2\1.mp4.