8 Text Editors
Emacs is an extensible, customizable, free, text editor. 它有一个 IDE mode 能够使用 gdb and lldb. 掌握 Emacs 可以让你 edit code very quickly.
Reasons to learn Emacs:
- Endlessly customizable.
- key bindings 快速编辑代码.
- 具有 IDE 特性还 with zero project setup.
- 可选择 text-only mod, 适合 remote servers
- Emacs keyboard shortcuts work in many places: command line, GDB prompt, LLDB prompt, Xcode (optional), Visual Studio (optional)
8.1 Installation and Start & Quit
8.1.1 安装 emacs
安装
brew install --cask emacs # macOS
sudo apt install emacs # Windows/WSL, Linux
确认 compiler 版本
g++ --version # macOS
Apple clang version 13.1.6 (clang-1316.0.21.2.5)
$ lldb --version # macOS
Apple Swift version 5.6.1 (swiftlang-5.6.0.323.66 clang-1316.0.20.12)
$ g++ --version # WSL/Linux
g++ (GCC) 8.5.0 20210514
$ gdb --version # WSL/Linux
GNU gdb (GDB)
8.1.2 启动 emacs
启动 emacs:
emacs
在后台启动 Emacs，以便继续使用terminal:
emacs &
8.1.3 Short-cut 保存与关闭 emacs
保存：C-x C-s
C 表示 control 键. 这里的意思是按住 C ，而后按住 x 而松开，而后按住 s 而松开，最后松开 C.
关闭：C-x C-c
按住 C ，而后按住 x 而松开，而后按住 c 而松开，最后松开 C.
8.2 Customize Key binding 自定义按键
8.2.1 Basic: 编辑 init 文件
通过下面这个指令可以打开 emacs 的 init 文件.
emacs ~/.emacs.d/init.el
然后开始编辑 init.el 文件.
注意这个文本格式中 ; 就是注释的意思.
- 对于 Mac 而言，将 Command 映射到 Meta，将 Option 映射到 Super 更符合人体工程学.
;; macOS modifier keys
(setq mac-command-modifier 'meta) ; Command == Meta
(setq mac-option-modifier 'super) ; Option == Super
- basic customization
``` ;; Don't show a startup message (setq inhibit-startup-message t)
;; Show line and column numbers (setq line-number-mode t) (setq column-number-mode t)
;; Show syntax highlighting (global-font-lock-mode t)
;; Highlight marked regions (setq-default transient-mark-mode t)
;; Parentheses (electric-pair-mode 1) ; automatically close parentheses, etc. (show-paren-mode t) ; show matching parentheses
;; Smooth scrolling (one line at a time) (setq scroll-step 1)
;; Tab settings: 2 spaces. See also: language-specific customizations below. (setq-default indent-tabs-mode nil) (setq tab-width 2)
;; Easier buffer switching (global-set-key "\C-x\C-b" 'electric-buffer-list) ```
- package manager
automates package installation and configuration.
``` ;; Configure built in package manager (require 'package) (package-initialize) (add-to-list 'package-archives '("melpa" . "https://melpa.org/packages/")) (add-to-list 'package-archives '("gnu" . "https://elpa.gnu.org/packages/"))
;; Install use-package ;; https://github.com/jwiegley/use-package (when (not (package-installed-p 'use-package)) (package-refresh-contents) (package-install 'use-package)) (eval-when-compile (require 'use-package)) ```
- undo/redo
;; More intuitive undo/redo. M-_ undo, C-M-_ redo
(use-package undo-tree
:config
(global-undo-tree-mode)
(global-set-key "\C-\M-_" 'redo)
:ensure t
:defer t
)
- C/C++
``` ;; Intellisense syntax checking ;; http://www.flycheck.org/en/latest/ (use-package flycheck :config ;; enable in all modes (global-flycheck-mode) ;; C++17 (add-hook 'c++-mode-hook (lambda () (setq flycheck-clang-language-standard "c++17"))) :ensure t :defer t )
;; C and C++ programming. Build with C-c m. Rebuild with C-c c. Put ;; this in c-mode-base-map because c-mode-map, c++-mode-map, and so ;; on, inherit from it. (add-hook 'c-initialization-hook (lambda () (define-key c-mode-base-map (kbd "C-c m") 'compile))) (add-hook 'c-initialization-hook (lambda () (define-key c-mode-base-map (kbd "C-c c") 'recompile))) (setq-default c-basic-offset tab-width) ; indentation (add-to-list 'auto-mode-alist '("\.h$" . c++-mode)) ; assume C++ for .h files ```
- integrated debugging
如果是 wsl 则把这里的 lldb 换成 gdb
(use-package realgud
:ensure t
)
(use-package realgud-lldb
:ensure t
)
(使用debug: M-x gud-gdb for WSL/Linux, M-x realgud--lldb for mac)
8.2.2 重置所有configuration
重开命令：
rm -rf ~/.emacs ~/.emacs.d/
8.2.3 直接在 Emac 中创建文件
emacs 1.cpp
8.3 Pro-tips
8.3.1 Auto-Complete
M + / 可以提供 C++ 语句的 auto complete.
8.3.2 Company Mode
添加这个到 init.el
;; Autocomplete for code
;; Company docs: https://company-mode.github.io/
;; Company TNG: https://github.com/company-mode/company-mode/issues/526
(use-package company
:config
(company-tng-configure-default) ; use default configuration
(global-company-mode)
:ensure t
:defer t ; lazy loading
)
8.3.3 添加 Emacs Shortcut term
e ()
{
emacs "$@" &
}
添加这个到 ~/.bash_profile / ~/.zshrc，我们就可以直接用一个 e 来指代 emacs
e stats.cpp
8.3.4 Editing remotely with TRAMP
Emacs TRAMP mode lets you edit a file on a remote server using a local GUI window.
Configure Emacs TRAMP mode to use SSH multiplexing. Add this to your ~/.emacs.d/init.el.
(use-package tramp
:config
(setq tramp-default-method "ssh")
(setq tramp-ssh-controlmaster-options
(concat
"-o ControlMaster auto "
"-o ControlPath ~/.ssh/socket-%%C "
))
(setq tramp-use-ssh-controlmaster-options nil)
:defer 1 ; lazy loading
)
SSH into your remote server, CAEN Linux in this example. This will set up an SSH multiplexing connection.
ssh login.engin.umich.edu
...
In Emacs, open the file /ssh:login.engin.umich.edu:main.cpp. Recall C-x C-f is find-file. Tab completion works in the minibuffer. You’re now editing a file main.cpp on a remote server.
ssh login.engin.umich.edu
hostname
# ...caen-vnc-vm05.engin.umich.edu
cd p1-stats
tmux new -s shared
emacs -nw main.cpp
Bob connects to the same remote server that Alice did. He connects to Alice’s tmux session named shared. She’s already running Emacs, so he sees her Emacs session.
ssh caen-vnc-vm05.engin.umich.edu
tmux attach -t shared
8.3.5 Text-only mode
If you’re on a remote server without a GUI, you can use Emacs in text-only mode. The -nw option stands for “no window”.
emacs -nw