Emacs can be used as a unified environment for software development under UNIX. If things are set up properly, you can use it for everything.

We'll assume you're using Emacs 19. On Athena:

		add emacs19; emacs19

Buffers and files and windows

C-x C-f

open file in a new buffer

C-x C-w

write file out with a different name

C-x C-s

save buffer under current name

C-x b

switch to buffer

C-x k

kill current buffer

C-g

cancel

C-x 2

split current window

C-x o

switch to other window

C-x 1

make current window only window

C-x 0

remove current window

C-x 5 2

make another X window

C-x 5 0

delete the current X window

.emacs file and elisp

• At the core of Emacs is an interpreter for elisp, a variant of LISP
• Emacs is configured by writing elisp code
• Single line commands can be entered with:
  ESC ESC
  enter elisp command

• .emacs file run on startup
• Add emacs19 specific things to .emacs with:

  	(defun startup19 () "startup for emacs19"
  		(...)
  		(...)   ; Stuff for emacs19 only
  		(...)
  		(cond (window system
  		(...)
  		(...)   ; Stuff for emacs19 and X only
  		(...)
  		))
  	)
  	(if (string-match "^19" emacs-version) (startup19))
  
  	

• Examples in dotfiles locker on Athena:

  		add dotfiles; cd /mit/dotfiles/Emacs
  	

• Enter more complicated commands in lisp-interaction-mode:
  M-x lisp-interaction-mode
  enters lisp-interaction-mode
  C-j
  executes commands in lisp-interaction-mode

Regions

• Used to select regions of text on which to perform an operation
• Select with C-SPACE then move to end
• Also select with mouse button 1 and drag

Editing C code in c-mode

• C-mode allows you to edit C code more easily
  M-x c-mode
  enters C mode

• Indentation of code: press TAB anwhere on line

• Indent current region with M-C-\
• Make return auto-indent:

  		(define-key c-mode-map "\C-m" 'newline-and-indent)
  	

• Turning on auto parentheses matching (region face defines color)

  		(load-library "paren")
  	

• Other useful commands:

  M-;

  indents and inserts /* */ for adding comments

  M-x comment-region

  comments out regions

  M-/

  does dynamic expansion of words (finds closest match in buffer)

  M-C-e

  move to end of function

  M-C-h

  selects current function

  M-x c-macro-expand-region

  runs cpp on region

  C-_

  undo

  M-x line-number-mode
  prints line number at bottom of buffer
  M-x goto-line
  goes to a specified line

M-x compile

• In c-mode, M-x compile runs make for you
• To make C-c C-c do a compile in c-mode:

  	;; Use C-c C-c in c-mode to do a compile
  	(defun my-save-and-compile ()
  	  (interactive "")
  	  (save-buffer 0)
  	  (compile "make -k"))  
  	(define-key c-mode-map "\C-c\C-c" 'my-save-and-compile)
  	

• Middle button over an error goes to it in the source
• M-n goes to next error with:

  		(define-key c-mode-map "\M-n" 'next-error)
  	

Tags

• Keeps track of what is defined where
• Generate TAGS file with:

  	etags *.[ch]
  	

• To go to where a function is defined, do M-. over the function call
• To do a query replace over all files, do M-x tags-query-replace
• To search for something across all files, M-x tags-search
• To go to next occurance of search string, M-,

Faces and colorization

• List faces with M-x list-faces-display
• (set-face-foreground 'face "color")
• (set-face-background 'face "color")
• Use font-lock minor mode to enable hilighting

  	(require 'hilit19)
  	(font-lock-mode 1)	
  	

• Highlight active region with:

  	(transient-mark-mode 1)	
  	

• Example of setting C coloring:

          ;; comments
          (hilit-translate comment 'pink)
          ;; string constants
          (hilit-translate string 'lightsalmon)
          ;; "#include"
          (hilit-translate include 'yellow)
          ;; keywords (if, for, ...)
          (hilit-translate keyword 'green)
          ;; function definitions
          (hilit-translate defun 'aquamarine2)
          ;; "#define"
          (hilit-translate define 'yellow)
          ;; struct definitions
          (hilit-translate decl 'gray80)
  	

• Colorize on file writes:

  	
  	;;; colorize on file writes
  	(if (not (memq 'hilit-rehighlight-buffer write-file-hooks))
  	    (setq write-file-hooks
  	                  (cons 'hilit-rehighlight-buffer write-file-hooks)))
  	

Using the shell within emacs

• Start shell with M-x shell
• For command line history, use M-p and M-n

Using GDB within emacs

• Start with M-x gdb
• For command line history, use M-p and M-n
• Some other commands:
  C-c TAB
  step one statement
  C-x C-a C-b
  in c file will set a break point at that line