CPSC120B - Emacs Commands

Buffers and Windows

C-x C-f find file (open in current buffer)
C-x C-s save contents of current buffer
C-x C-c kill (close) Emacs
C-x s save all buffers
C-x C-w save current buffer with specified name
C-x k kill (close) current buffer
C-x C-b list existing buffers
C-x b select buffer by name
C-x 2 split current window in two vertically
C-x 3 split current window in two horizontally
C-x 0 delete the current window
C-x 1 delete all windows but the current
C-x o switch to other window
C-M-v scroll other window down
M-: (set-frame-width (selected-frame) n) set frame width to n characters
M-: (set-frame-height (selected-frame) n) set frame height to n characters
M-x customize-themes interactively choose color scheme

Navigating

C-f move cursor forward
C-b move cursor backward
C-n move cursor to next line
C-p move cursor to previous line
M-f move cursor forward one token
M-b move cursor backward one token
C-l center screen on cursor
C-a move cursor to beginning of line
C-e move cursor to end of line
C-v move down one screenful
M-v move cursor up one screenful
M-< move cursor to beginning of buffer
M-> move cursor to end of buffer
M-x goto-line go to line
M-a move cursor to beginning of statement
M-e move cursor to end of statement
M C-a move cursor to beginning of function
M C-e move cursor to end of function

Editing

C-<SPC> set mark (mark is the beggining of region; cursor is end of region)
C-x C-p set region to entire buffer
C-k kill (cut) from cursor to end of line
C-w kill (cut) region
M-w save (copy) region
C-y yank (paste) what was most recently killed
M-y yank-pop (cycle though) earlier kills, after yanking
<Backspace> delete character before cursor
C-d delete character at cursor
M-<Backspace> delete from cursor to beginning of token
M-d delete from cursor to end of token
M-\ delete horizontal space
M-; comment/un-comment region
<TAB> indent line
C-c > indent region
C-c < exdent region
C-/ undo
M-/ auto complete
M-q fill paragraph (useful for wrapping lines in comments)

Searching

C-s forward incremental search
C-r reverse incremental search
<RET> (when in search mode) stop searching
C-g (when in search mode) cancel search and return to where search started
M-y (when in search mode) yank most recent kill into seach string
M-% search_string replace_string query replace occurances of search_string with replace_string
y (when in query replace mode) replace highlighted search_string
(when in query replace mode) do not replace highlighted search_string
q (when in query replace mode) exit query replace mode
M-x grep search_string file_name1 file_name2 … search for search_string in the specified files (note the files do not have to be currently open)
M-x grep search_string * search for search_string in all files in the current directory
C-x ` select next search_string in grep buffer

Running

Add the following to the ~/.emacs.d/init.el file:

(require 'compile)
(add-hook 'python-mode-hook (lambda ()
  (set (make-local-variable 'compile-command)
     (format "python3 %s" (file-name-nondirectory buffer-file-name)))))
(defun compile-comint ()
  (interactive)
  (save-window-excursion (compile (eval compile-command) t))
  (pop-to-buffer (get-buffer "*compilation*"))
  (goto-char (point-max)))
(define-key global-map [?\s-r] 'compile-comint)
(setq compilation-ask-about-save nil)
(setq compilation-read-command nil)

S-r run current program
C-x ` select next error
M-x shell open shell in this window
M-p previous command (while cursor is at the command prompt in the shell)
C-c C-c kill currently running program (while in the shell)

Configuring

The following can be put in the ~/.emacs.d/init.el file to configure Emacs

On Windows, if the Emacs shell does not recognize the python command:
```
(setenv "PATH" (concat (getenv "PATH") ";C:\\path\\to\\python"))
```

On OS X, if the Emacs shell does not recognize the python command:

(setenv "PATH" (concat (getenv "PATH") ":/path/to/python"))
(setq exec-path (append exec-path '("/path/to/python")))

To set the initial font size of an Emacs window (FONT_SIZE is the initial font size times ten):
```
(set-face-attribute 'default nil :height FONT_SIZE)
```
To set the initial dimensions of an Emacs window (CHARS_WIDE and CHARS_HIGH are the number of characters that will fit in the window horizontally and vertically):
```
(setq default-frame-alist '((width . CHARS_WIDE) (height . CHARS_HIGH)))
```

To add run keyboard shortcut:

(require 'compile)
(add-hook 'python-mode-hook (lambda ()
  (set (make-local-variable 'compile-command)
    (format "python3 %s" (file-name-nondirectory buffer-file-name)))))
(define-key global-map [?\s-r] 'recompile)