Install Emacs

2025-02-08, Sat

Install Emacs tends out to be more complicated than I thought. This log file intends to record huccups I've encountered.

1. on Debian GNU/Linux

Debian packages are provided in separate sections¹, and emacs is available in the main section. However, this package lacks all the built-in documentation, which is somehow provided in the non-free section through package emacs-common-non-dfsg. Without documentation, the claim of "self-documenting editor" doesn't stand, so a bit tweak is needed.

Open /etc/apt/sources.list and add "non-free" section after "main"
Run "apt-get update", as usual
Run "apt-get install emacs emacs-common-non-dfsg"

2. on macOS

The GNU site already provides instructions to install pre-built binaries of Emacs on macOS ²^,³. Follow any one would be sufficient.

However, things became tricker when I tried to compile from source.

First, install libraries required, in reverse order:

gnutls
nettle
gmp
libtasn1
help2man

The process was straightforward when I compiled these libraries from source one by one, …until gnutls-3.7.11, which is the current stable version provided on the official site⁴. When compiling from the source file downloaded, there was error thrown for file lib/system/certs.c. Turns out there is a one line change needed in the declaration of osstatus_error, like this:

static int osstatus_error(OSStatus status)

This problem was resolved long time ago in the master branch⁵. So it's not like a big issue anymore. Nevertheless, the experience worths a note.

Key Takeways

When there is error thrown while compiling source code from renowned resource, take a closer look at the error message. No need to get panic, upset, or scared.
If a solution is found for the error, consider to submit a patch to the source repo in order to give something back to the community.

3. Notes on Common Commands

This section records common commands & keybindings for some modes, major or minor.

3.1. Major mode c-mode

Key	Binding	Description
C-c C-e	c-macro-expand	Expand C macros in the region, using the C preprocessor

3.2. Major mode org-mode

Key	Binding	Description
C-c C-c	org-ctrl-c-ctrl-c	Multi-purpose command that does things depending on context

3.3. Major mode emacs-lisp-mode

Key	Binding	Description
C-c C-e	elisp-eval-region-or-buffer	Evaluate forms in the active region or whole buffer
C-M-i	completion-at-point	Perform completion on the text around point

3.4. Major mode lisp-interaction-mode (for `scratch`)

Key	Binding	Description
C-j	eval-print-last-sexp	Evalute sexp before point

4. Notes on Common Practices

4.1. `sudo` edit file

Use TRAMP mode⁶ to sudo open and edit file by append /sudo:: at the beginning of the file name, e.g.

find-file (C-x C-f)
/sudo::/path/to-file

4.2. Sample Init Config

Sample init config could be found in the Emacs manual⁷ or online⁸. Nevertheless, I'll put another snippet below for reference:

;; ref: ~/.emacs.d/init.el
;;
;; save & restore desktop-session
(desktop-save-mode 1)
;; enable display of line number across all windows
(global-display-line-numbers-mode)

;; show column number in the mode line
(column-number-mode)
;; disable tool-bar
(tool-bar-mode 0)

;;; ============================================================
;;; configs that applies to speicifc mode or
;;; depends on external program
;;; ============================================================
;; running external lisp from within Emacs
;; in this case, it is SBCL that is being used
(setq inferior-lisp-program "/usr/local/bin/sbcl --noinform")

;; unlock the treemacs window width
(setq treemacs-width-is-initially-locked nil)

4.3. Correct PATH in shell

Aside from .bashrc and .bash_profile, macOS also updates $PATH based on content from /etc/paths.d/, which isn't recognized by inferior shell in Emacs. This could be corrected in init.el either through setting exec-path manually, or install package exec-path-from-shell⁹ from NonGNU ELPA or MELPA¹⁰ and introduce following content there:

;; ref: ~/.emacs.d/init.el
;; correct exec-path in inferior shell
(use-package exec-path-from-shell
  :ensure t
  :init
  (exec-path-from-shell-initialize))

Although this package is already available through the default nongnu archive, it is also provided on MELPA, which could be enabled like this:

;; ref: ~/.emacs.d/init.el
(require 'package)
(add-to-list 'package-archives '("melpa" . "https://melpa.org/packages/") t)
;; Or use the melpa-stable version instead
;;(add-to-list 'package-archives '("melpa-stable" . "https://stable.melpa.org/packages/") t)
(package-initialize)

4.4. Connect to Database

Although we could connect to database in inferior shell, there is SqlMode provided by sql.el¹¹ to offer a dedicated experience. Run command sql-help to see databases supported, e.g.

Use the following commands to start a specific SQL interpreter:

    MariaDB:	M-x sql-mariadb
    MySQL:	M-x sql-mysql
    Postgres:	M-x sql-postgres
    SQLite:	M-x sql-sqlite

Take PostgreSQL as an example, run sql-postgres and input connection info (i.e. username, database, host, password, etc.) and you will end up with a *SQL: Postgres* buffer within sql-interactive-mode.