title: Emacs date: 2020-12-17 16:21:49 background: bg-[#7752a9] tags: - editor - text - shortcut categories: - Toolkit intro: | Emacs is the extensible, customizable, self-documenting real time display text editor.
To enter Emacs, just type its name: ```shell script $ emacs
------
| - | - |
|-------------|------------------------|
| `C-z` | Suspend Emacs |
| `C-x` `C-c` | Exit Emacs permanently |
{.shortcuts}
### Global Description {.secondary}
| - | - |
|-----------|---------------------------------------------|
| `C-<key>` | Means hold the control, and press `<key>` |
| `M-<key>` | Means press the Esc once, and press `<key>` |
{.shortcuts}
NOTICE: This cheatsheet follows the above rules.
### Motion {.row-span-2}
| Backward | Forward | Entity to move over |
|-----------|-----------|--------------------------------|
| `C-b` | `C-f` | Haracter |
| `M-b` | `M-f` | Word |
| `C-p` | `C-n` | Line |
| `C-a` | `C-e` | Line beginning<br/>_(or end)_ |
| `M-a` | `M-e` | Sentence |
| `M-{` | `M-}` | Paragraph |
| `C-x` `[` | `C-x` `]` | Page |
| `C-M-b` | `C-M-f` | Sexp |
| `C-M-a` | `C-M-e` | Function |
| `M-<` | `M->` | Buffer beginning<br>_(or end)_ |
{.shortcuts .show-header}
### Case Change
| - | - |
|-------------|------------------|
| `M-u` | Uppercase word |
| `M-l` | Lowercase word |
| `M-c` | Capitalize word |
| `C-x` `C-u` | Uppercase region |
| `C-x` `C-l` | Lowercase region |
{.shortcuts}
### Files
| - | - |
|-------------|--------------------------------------------------|
| `C-x` `C-f` | Read a file into Emacs |
| `C-x` `C-s` | Save a file back to disk |
| `C-x` `s` | Save all files |
| `C-x` `i` | Insert contents of another file into this buffer |
| `C-x` `C-v` | Replace this file with your file |
| `C-x` `C-w` | Write buffer to a specified file |
| `C-x` `C-q` | Toggle read-only status of buffer |
{.shortcuts}
### Error Recovery
| - | - |
|-----------------------------|--------------------------------------------|
| `C-g` | Abort partially typed or executing command |
| `M-x` recover-session | Recover files lost by a system crash |
| `C-x` `u`<br>`C-_`<br>`C-/` | Undo an unwanted change |
| `M-x` revert-buffer | Restore a buffer to its original contents |
| `C-l` | Redraw garbaged screen |
{.shortcuts}
### Transposing {.row-span-2}
| - | - |
|-------------|----------------------|
| `C-t` | Transpose characters |
| `M-t` | Transpose words |
| `C-x` `C-t` | Transpose lines |
| `C-M-t` | Transpose sexps |
{.shortcuts}
#### Scroll
| - | - |
|-----------|--------------------------------------------------|
| `C-v` | Scroll to next screen |
| `M-v` | Scroll to previous screen |
| `C-x` `<` | Scroll left |
| `C-x` `>` | Scroll right |
| `C-l` | Scroll current line to <br>_center, top, bottom_ |
{.shortcuts}
#### Goto
| - | - |
|-----------|---------------------|
| `M-g` `g` | Goto line |
| `M-g` `c` | Goto char |
| `M-m` | Back to indentation |
{.shortcuts}
### Marking
| - | - |
|-------------------|-------------------------|
| `C-@`<br/>`C-SPC` | Uet mark here |
| `C-x` `C-x` | Exchange point and mark |
| `M-@` | Set mark arg words away |
| `M-h` | Mark paragraph |
| `C-x` `C-p` | Mark page |
| `C-M-@` | Mark sexp |
| `C-M-h` | Mark function |
| `C-x` `h` | Mark entire buffer |
{.shortcuts}
### Killing and Deleting {.row-span-2}
| Backward | Forward | Entity to kill |
|---------------|---------|--------------------------|
| `DEL` | `C-d` | Character <br>_(delete)_ |
| `M-DEL` | `M-d` | Word |
| `M-0` `C-k` | `C-k` | Line <br/> _(to end of)_ |
| `C-x` `DEL` | `M-k` | Sentence |
| `M--` `C-M-k` | `C-M-k` | Sexp |
{.shortcuts .show-header}
#### Killing
| - | - |
|------------|--------------------------------------|
| `C-W` | Kill region C-w |
| `M-w` | Copy region to kill ring |
| `M-z` char | Kill through next occurrence of char |
| `C-y` | Yank back last thing killed |
| `M-y` | Replace last yank with previous kill |
{.shortcuts}
### Getting Help
| - | - |
|-----------|------------------------------------------|
| `C-x` `1` | Remove help window |
| `C-M-v` | Scroll help window |
| `C-h` `a` | Apropos: show commands matching a string |
| `C-h` `k` | Describe the function a key runs |
| `C-h` `f` | Describe a function |
| `C-h` `m` | Get mode-specific information |
{.shortcuts}
The help system is simple. Type `C-h` (or `F1`) and follow the directions. If you are a first-time user, type `C-h` `t` for a tutorial.
### Multiple Windows {.col-span-2}
When two commands are shown, the second is a similar command for a frame instead of a window.
| - | - | - |
|---------------|-----------|-------------------------------|
| `C-x` `5` `1` | `C-x` `1` | Delete all other windows |
| `C-x` `5` `2` | `C-x` `2` | Split window, above and below |
| `C-x` `5` `0` | `C-x` `0` | Delete this window |
| `C-x` `3` || Split window, side by side |
| `C-M-v` || Scroll other window |
| `C-x` `5` `o` | `C-x` `o` | Switch cursor to another window |
| `C-x` `5` `b` | `C-x` `4` `b` | Select buffer in other window |
| `C-x` `5` `C-o` | `C-x` `4` `C-o` | Display buffer in other window |
| `C-x` `5` `f` | `C-x` `4` `f` | Find file in other window |
| `C-x` `5` `r` | `C-x` `4` `r` | Find file read-only in other window |
| `C-x` `5` `d` | `C-x` `4` `d` | Run Dired in other window |
| `C-x` `5` `.` | `C-x` `4` `.` | Find tag in other window |
| `C-x` `^` || Grow window taller |
| `C-x` `{` || Shrink window narrower |
| `C-x` `}` || Grow window wider |
{.shortcuts}
### Formatting
| - | - |
|-------------|------------------------------------------|
| `TAB` | Indent current line (mode-dependent) |
| `C-M-\` | Indent region (mode-dependent) |
| `C-M-q` | Indent sexp (mode-dependent) |
| `C-x` `TAB` | Indent region rigidly arg columns |
| `M-;` | Indent for comment |
| `C-o` | Insert newline after point |
| `C-M-o` | Move rest of line vertically down |
| `C-x` `C-o` | Delete blank lines around point |
| `M-^` | Join line with previous (with arg, next) |
| `M-\` | Delete all white space around point |
| `M-SPC` | Put exactly one space at point |
| `M-q` | Fill paragraph |
| `C-x` `f` | Set fill column to arg |
| `C-x` `.` | Set prefix each line starts with |
| `M-o` | Set face |
{.shortcuts}
### Info {.row-span-2}
| - | - |
|-----------|---------------------------------------------|
| `C-h` `i` | Enter the Info documentation reader |
| `C-h` `S` | Find specified function or variable in Info |
{.shortcuts}
#### Moving within a node
| - | - |
|-------|-------------------|
| `SPC` | Scroll forward |
| `DEL` | Scroll reverse |
| `b` | Beginning of node |
{.shortcuts}
#### Moving between nodes
| - | - |
|-----|----------------------------------------|
| `n` | Next node |
| `p` | Previous node |
| `u` | Move up |
| `m` | Select menu item by name |
| `n` | Select nth menu item by number (1–9) |
| `f` | Follow cross reference (return with l) |
| `l` | Return to last node you saw |
| `d` | Return to directory node |
| `t` | Go to top node of Info file |
| `g` | Go to any node by name |
{.shortcuts}
#### Other
| - | - |
|-----|----------------------------------|
| `h` | Run Info tutorial |
| `i` | Look up a subject in the indices |
| `s` | Search nodes for regexp |
| `q` | Quit Info |
{.shortcuts}
### Minibuffer
The following keys are defined in the minibuffer.
| - | - |
|-------|-----------------------------------------|
| `TAB` | Complete as much as possible |
| `SPC` | Complete up to one word |
| `RET` | Complete and execute |
| `?` | Show possible completions |
| `M-p` | Fetch previous minibuffer input |
| `M-n` | Fetch later minibuffer input or default |
| `M-r` | Regexp search backward through history |
| `M-s` | Regexp search forward through history |
| `C-g` | Abort command |
{.shortcuts}
Type `C-x` `ESC` `ESC` to edit and repeat the last command that used the minibuffer. Type `F10` to activate menu bar items on text terminals.
### Tags
| - | - |
|--------------------------|--------------------------------------------|
| `M-.` | Find a tag (a definition) |
| `C-u` `M-.` | Find next occurrence of tag |
| `M-x` visit-tags-table | Specify a new tags file |
| `M-x` tags-search | Regexp search on all files in tags table |
| `M-x` tags-query-replace | Run query-replace on all the files |
| `M-,` | Continue last tags search or query-replace |
{.shortcuts}
### Rectangles
| - | - |
|---------------|-------------------------------------|
| `C-x` `r` `r` | Copy rectangle to register |
| `C-x` `r` `k` | Kill rectangle |
| `C-x` `r` `y` | Yank rectangle |
| `C-x` `r` `o` | Open rectangle, shifting text right |
| `C-x` `r` `c` | Blank out rectangle |
| `C-x` `r` `t` | Prefix each line with a string |
{.shortcuts}
### Keyboard Macros
| - | - |
|---------------------------|-------------------------------------|
| `C-x` `(` | Start defining a keyboard macro |
| `C-x` `)` | End keyboard macro definition |
| `C-x` `e` | Execute last-defined keyboard macro |
| `C-u` `C-x` `(` | Append to last keyboard macro |
| `M-x` name-last-kbd-macro | Name last keyboard macro |
| `M-x` insert-kbd-macro | Insert Lisp definition in buffer |
{.shortcuts}
### Buffers
| - | - |
|-------------|-----------------------|
| `C-x` `b` | Select another buffer |
| `C-x` `C-b` | List all buffers |
| `C-x` `k` | Kill a buffer |
{.shortcuts}
Emacs Search{.cols-3}
------
### Regex (common) {.row-span-2}
| - | - |
|---------------|----------------------------------------------|
| `.` `(dot)` | Any single character except a newline |
| `*` | Zero or more repeats |
| `+` | One or more repeats |
| `?` | Zero or one repeat |
| `\` | Quote special characters |
| `\c` | Quote regular expression special character c |
| `\|` | Alternative (“or”) |
| `\(...\)` | Grouping |
| `\(:?...\)` | Shy grouping |
| `\(:NUM...\)` | Explicit numbered grouping |
| `\n` | Same text as nth group |
| `\b` | At word break |
| `\B` | Not at word break |
### Regex (entry)
| Start | End | Entity |
|-------|-------|--------|
| `^` | `$` | Line |
| `\<` | `\>` | Word |
| `\_<` | `\_>` | Symbol |
| `\‘` | `\’` | Buffer |
{.show-header}
### Regex (conflict)
| These | Others | class |
|---------|----------|---------------------------|
| `[...]` | `[^...]` | Explicit set |
| `\w` | `\W` | Word-syntax character |
| `\sc` | `\Sc` | Character with syntax c |
| `\cc` | `\Cc` | Character with category c |
{.show-header}
### Incremental Search
| - | - |
|---------|-----------------------------------|
| `C-s` | Search forward |
| `C-r` | Search backward |
| `C-M-s` | Regular expression search |
| `C-M-r` | Reverse regular expression search |
| `M-p` | Select previous search string |
| `M-n` | Select next later search string |
| `RET` | Exit incremental search |
| `DEL` | Undo effect of last character |
| `C-g` | Abort current search |
{.shortcuts}
Use `C-s` or `C-r` again to repeat the search in either direction. If Emacs is still searching, `C-g` cancels only the part not matched.
### Query Replace
| - | - |
|--------------|--------------------------------------|
| `M-%` | Interactively replace a text string |
| `M-x` regexp | Using regular expressions |
| `SPC` / `y` | Replace this one, go on to next |
| `,` | Replace this one, don’t move |
| `DEL` / `n` | Skip to next without replacing |
| `!` | Replace all remaining matches |
| `^` | Back up to the previous match |
| `RET` | Exit query-replace |
| `C-r` | Enter recursive edit (C-M-c to exit) |
{.shortcuts}
Misc
----
### Shells
| - | - |
|-------------|----------------------------------------|
| `M-!` | Execute a shell command |
| `M-&` | Execute a shell command asynchronously |
| `M-` | Run a shell command on the region |
| `C-u` `M-` | Filter region through a shell command |
| `M-x` shell | Start a shell in window shell |
{.shortcuts}
### International Character Sets {.col-span-2}
| - | - |
|----------------------------|------------------------------------|
| `C-x` `RET` `l` | specify principal language |
| `M-x` list-input-methods | show all input methods |
| `C-\` | enable or disable input method |
| `C-x` `RET` `c` | set coding system for next command |
| `M-x` list-coding-systems | show all coding systems |
| `M-x` prefer-coding-system | choose preferred coding system |
{.shortcuts}
### Registers
| - | - |
|-----------------|--------------------------------------|
| `C-x` `r` `s` | Save region in register |
| `C-x` `r` `i` | Insert register contents into buffer |
| `C-x` `r` `SPC` | Save value of point in register |
| `C-x` `r` `j` | Jump to point saved in register |
{.shortcuts}
### Miscellaneous
| - | - |
|------------|-------------------|
| `C-u` num | Numeric argument |
| `M--` | Negative argument |
| `C-q` char | Quoted insert |
{.shortcuts}
### Commands Dealing with Emacs Lisp
| - | - |
|--------------------|------------------------------------|
| `C-x` `C-e` | Eval sexp before point |
| `C-M-x` | Eval current defun |
| `M-x` eval-region | Eval region |
| `M-:` | Read and eval minibuffer |
| `M-x` load-library | Load a Lisp library from load-path |
{.shortcuts}
### Simple Customization
| - | - |
|-------------------|-------------------------------|
| `M-x` `customize` | customize variables and faces |
Making global key bindings in Emacs Lisp:
``` {.wrap}
(global-set-key (kbd "C-c g") ’search-forward)
(global-set-key (kbd "M-#") ’query-replace-regexp)
| ------------------- | ------------------------------------------ |
C-x a g |
Add global abbrev |
C-x a l |
Add mode-local abbrev |
C-x a i g |
Add global expansion for this abbrev |
C-x a i l |
Add mode-local expansion for this abbrev |
C-x a e |
Explicitly expand abbrev |
M-/ |
Expand previous word dynamically |
{.shortcuts}
| --------------------- | --------------------------------------- |
M-$ |
Check spelling of current word |
M-x ispell-region |
Check spelling of all words in region |
M-x ispell-buffer |
Check spelling of entire buffer |
M-x flyspell-mode |
Toggle on-the-fly spell checking |
{.shortcuts}
(defun command-name (args)
"documentation" (interactive "template")
body)
(defun this-line-to-top-of-window (line)
"Reposition current line to top of window.
With prefix argument LINE, put point on LINE."
(interactive "P")
(recenter (if (null line)
0
(prefix-numeric-value line))))
The interactive spec says how to read arguments interactively. Type C-h f interactive RET for more details.