Utilities.org

Emacs Utilities

Emacs Utilities

Overview

Some Emacs utilities and goodness.

Feature	Entry Point	Description
Help Commands
Help for all help commads	M-x help-for-help
Emacs built-in tutorial	M-x help-with-tutorial	Open Emacs tutorial.
Emacs built-in localized tutorial	M-x help-with-tutorial-spec-language	Emacs built-in tutorial in many languages like Russian, Portuguese …
Package Manager
Package Manager	M-x list-packages	List all packages available.
	M-x package-install	Install some package
Info page and Man page - Unix docs
Info page	M-x info / M-x heml-info	Info page reader. The helm-version is provided by heml package.
Manpage	M-x woman / M-x helm-man-woman	Manpage Reader
File Manager and edit remote files
File manager	M-x dired or C-x d	File manager and directory editor
Tramp mode		Tramp mode - edit remote files, edit as super user and open
		remote directories through ssh, sftp, telnet and ftp
Programming
Compile mode	M-x compile	Run any compilation command, compiler or build automation tool like make or ant.
GNU Debugger Interface	M-x gdb
Git Version Control System	M-x magit-status	Git user interface provided by the magit package.
Diff files	M-x ediff	File diff viwer
Diff buffers	M-x ediff-buffers	Buffers diff viewer like ediff
VIM Emulation	M-x evil-mode	Emulates VI/VIM editor behavior. It is provided by the evil package.
Shells
Shell Command	M-x shell-command	Run a batch shell command like ifconfig or dmesg (Linux)
Async shell command	M-x async-shell-command	Run any shell command asynchronously.
Eshel	M-x eshell	Multi platform shell written in Elisp and highly integrated to Emacs.
Ielm	M-x ielm	Elisp Interactive shell to control and Debug Emacs
System Related Commands
Copy file	M-x copy-file	Copy a file. Prompt user for a file to copy.
Delete file	M-x delete-file	Prompt user for a file to delete.
Make directory	M-x make-directory	Creates a new directory. Equivalent to shell command $ mkdir
Delete directory	M-x delete-directory	Delete a directory. Promps the user for a directory to delete.
Copy directory	M-x copy-directory	Copy directory.
Task manager/ Process manager	M-x proced	Htop like multi platform task manager.
Network Tools
Network information	M-x ifconfig	Show iformation about network interfaces
Ping	M-x ping	Ping a host name or ip address
Traceroute	M-x traceroute	Traceroute a host name or ip address
ARP	M-x arp	Display the command arp output.
Routing Table	M-x route	Show routing table.
Whois	M-x whois	Run whois command to show information about route.
Telnet	M-x telnet	Telnet login. It is the acient version of SSH.
Misc
Calculator	M-x calc	RPN (Reverse Polish Notation) calculator like HP-48g engineering calculator.
Color Pallete	M-x list-colors-display	Display a collor pallete.

Note:

• M-x ifconfig - runs ipconfig on Windows and ifconfig or ip on Linux. It is platform agnostic.
• To Emacs’ tutorial (help-with-tutorial) work the cua-mode must be disabled (M-x cua-mode to disable it).

Fun

Command	Description
M-x doctor	If you fell bad, your country is in a endless recession …
M-x life	Run Conway’s Life simulation.
M-x dunnet	Text based adventure game
M-x tetris	Play Tetris.
M-x hanoi	Towers of Hanoi.
M-x zone	Make buffers go crazy!!
M-x zone-leave-me-alone	Stop zoning out.

Shells

Emacs have built-in commands to run shells.

Name	Command: M-x <command>	Description
shell	M-x shell	Runs an inferior shell app. It can run bash, zsh and etc.
term	M-x term	Emacs’ terminal emulator that can run apps like top, vim, bash and etc.
		It alows command line line completion inside Emacs in apps like bash, zsh and python .
eshell	M-x eshell	Emacs’ built-in shell written in Elisp. it has elisp implementation of cd, ls, pwd
		and other standard Unix commands and apps. Works on all operating systems. Eshell
		also can run Elisp functions. It is a good alternative to Microsoft Windows
		terminal emulator cmd.exe.
ielm	M-x ielm	Emacs’ elisp shell that can be used to control, test and interact with Emacs.

Emacs also have commands to run programming languages shells:

Language	Command	Package
Python	M-x run-python	-
Octave	M-x run-octave	-
Ruby	M-x run-ruby	inf-ruby
Elisp (Emacs Lisp)	M-x ielm	-
Scheme	M-x run-scheme	-
Lisp	M-x run-lisp	-

Async Shell Command

It can run any repls or interactive shell applications, except ncurses-based apps like htop.

Example: M-x async-shell-command “java -jar clojure.jar”.

It is useful to run programming languages shells even if there is no mode or package installed for it. It is possible to rename the shell buffer with M-x rename-buffer in order to make easier to identify the buffer.

Examples:

Run sqlite3:

• M-x async-shell-command sqlite3

Run scala repl:

• M-x async-shell-command scala and then M-x rename-buffer *scala*

to change the default buffer name to a more readable name *scala*.

Run mono’s csharp repl:

• M-x async-shell-command csharp

Run Windows powershell:

• M-x async-shell-command powershell -Command -

Run Java bean shell (Java Interpreter):

• M-x async-shell-command “java -cp ~/opt/bsh-2.0b4.jar bsh.Interpreter”

or programatically:

(async-shell-command "java -cp ~/opt/bsh-2.0b4.jar bsh.Interpreter")

Defining a command:

(defun run-bsh ()
    "Run Java bean shell."
    (interactive)
    (async-shell-command "java -cp ~/opt/bsh-2.0b4.jar bsh.Interpreter"))

Example: Running Haskell REPL.

• M-x async-shell-command stack ghci

http://i.imgur.com/I90yeoX.gif

Example: Install a Haskell package

• M-x async-shell-command stack instal turtle

http://i.imgur.com/btfaK3k.gif

Example: Running Fsharp REPL

• M-x async-shell-command fsi

http://i.imgur.com/tRKPfXG.gif

Example: Ping a server to test connection 8.8.8.8 (Google’s DNS)

• M-x async-shell-command ping 8.8.8.8

http://i.imgur.com/3OeuGNj.gif

Compiling in Emacs - M-x compile

Compilation Commands

To compile any code use:

• To compile: M-x compile <compilation command>
• To recompile: M-x recompile or type g at the compilation buffer.

Compilation Commands

Command	Key binding	Description
M-x compile		Run a compilation command
M-x recompile	g (compilation buffer)	Run a compilation command again.
M-x kill-compilation	C-c C-k (compilation bufffer)	Stop compilation process.
M-x compilation-next-error	M-n	Go to next error
M-x compilation-previous-error	M-p	Go to previous error

Compilation Buffer Key bindings

• Note: The command M-x compile provides completion for Makefile targets by typing M-x compile make <tab>.

Command	Key binding	Description
M-x recompile	g	Compile again running same compilation command.
M-x quit-window	q	Quit compilation buffer
M-x kill-compilation	C-c C-k	Stop compilation process
	<	Go to beginning of compilation buffer.
	>	Go to end of compilation buffer.
M-x describe-mode	h
	RET	Typing Return at compilation error goes to error location.
M-x rename-buffer		To use multiple compilation buffers, rename it with this command.

Setting compilation key bindings

The code block bellow will set the key bindings as shown in the following tables:

Key bindings for outside compilation buffer.

Key binding	Description
f9	Run M-x compile
Windows-Key/Super-f9	Run M-x
M-[	Go to next compilation error
M-]	Go to previous compilation erro

Key bindings for compilation buffer

Key binding	Description
q	Quit compilation buffer (default)
g	Run M-x recompile (default)
c	Run a new compilation command
k	Kill compilation
mm	Run make - M-x compile ‘make’
mc	Run make clean - M-x compile ‘make clean’
mp	Run make clean and make again.

(global-set-key [f9]    #'compile)

;; Not s-f9 means Windows Key/f9
(global-set-key [s-f9]  #'recompile)

(global-set-key (kbd "M-[") #'compilation-previous-error)
(global-set-key (kbd "M-]") #'compilation-next-error)

(define-key compilation-mode-map "c" #'compile)
(define-key compilation-mode-map "k" #'kill-compilation)

(define-key compilation-mode-map "mm" (lambda () (interactive)
                                        (compile "make")))

(define-key compilation-mode-map "mc" (lambda () (interactive)
                                        (compile "make clean")))

(define-key compilation-mode-map "mp" (lambda () (interactive)
                                        (compile "make clean && make")))

Creating custom compilation commands

Compile Haskell

Compile single-file haskell apps with stack:

(defun compile-haskell ()
  "Compile a haskell .hs file."
  (interactive)
  (save-buffer)
  (compile (format "stack exec -- ghc %s -o %s.bin"
                   (buffer-file-name)
                   (file-name-base (buffer-file-name))
                   )))


(defun compile-haskell-run ()
  "Compile a haskell .hs file and runs the executable."
  (interactive)
  (save-buffer)
  (compile (format "stack exec -- ghc %s -o %s.bin && ./%s.bin"
                   (buffer-file-name)
                   (file-name-base (buffer-file-name))
                   (file-name-base (buffer-file-name))
                   )))

The command M-x compile-haskell can be used to compile this code bellow that will produce the executable myApp.bin.

The command M-x compile-haskell-run compiles the code and runs the app.

File: file:codes/myApp.hs

import qualified System.Directory as D

main :: IO ()
main = do 
  putStrLn "Hello World Haskell!"
  D.getDirectoryContents "/" >>= mapM_ putStrLn    

Compile F# (Fsharp)

The command M-x compile-fsharp-run compiles a F# app .fsx to .exe and runs it with mono.

(defun compile-fsharp-run ()
  "Compile a Fhsarp .fsx file to .exe .NET executable."
  (interactive)
  (save-buffer)
  (compile (format "fsc --target:winexe --platform:anycpu --standalone %s --out:%s.exe && mono %s.exe"
                   (buffer-file-name)
                   (file-name-base (buffer-file-name))
                   (file-name-base (buffer-file-name))                   
                   )))

This command can be used to compile the file helloWinform.fsx to helloWinform.exe and run it.

File: file:codes/helloWinform.fsx

open System.Windows.Forms
open System.Drawing 

let f = new Form () 
f.Text <- "Hello world"
f.Name <- "Form1"
f.BackColor <- Color.Blue

let btn = new Button (Text= "Click Me", BackColor = Color.Green)
f.Controls.Add(btn)
btn.Click.Subscribe(fun _ -> printfn "Click me again")

Application.Run(f)

Example

Example: Running a F# script. To see the image fullscreen open: http://imgur.com/a/7Hvrz and click at the image.

http://i.imgur.com/mBMJmqp.gif

In this case was used the command M-x compile fsi helloWinform.fsx. That runs a F# script performing and all syntax errors and value errors will be shown at the compilation buffer.

Note: This code also works in Linux or OSX. It was recorded in Windows because there was no good GIF recording apps available for Linux at the time this was recorded.

Code used in this example: File - helloWinform.fsx

open System.Windows.Forms
open System.Drawing 

let f = new Form () 
f.Text <- "Hello world"
f.Name <- "Form1"
f.BackColor <- Color.Blue

let btn = new Button (Text= "Click Me", BackColor = Color.Green)
f.Controls.Add(btn)
btn.Click.Subscribe(fun _ -> printfn "Click me again")

Application.Run(f)

Emacs in Terminal

Running Emacs in terminal:

• emacs -nw

Running Emacs fast without read ~/emacs.d/init.el or ~/.emacs startup file:

• emacs -nw -Q
• Start Emacs in terminal running Eshell:

Running Emacs in terminal or executing some Elisp command or app:

$ emacs -nw -q --eval '(eshell)'

• Start Emacs in terminal running python:

$ emacs -nw -q --eval '(progn (run-python "python3") (switch-to-buffer "*Python*"))'

See also:

• Eshell Manual: Eshell: The Emacs Shell
• Running Shell Commands from Emacs

• What is the difference between shell, eshell, and term in Emacs? - Unix & Linux Stack Exchange
• EmacsWiki: Multi Term

• Emacs is My New Window Manager

• Emacs Is My New Window Manager | Hacker News

• Emacs standing alone on a Linux Kernel

Manpage Reader

To read manpages enter M-x woman.

Example: Rsync manpage.

file:images/utilities_manpage.png

Info Page Reader

• To Browser info pages and also the Emacs documentation. M-x info
• Search Info pages. M-x info-apropos

Example: Top info page.

file:images/utilities_infopage_root.png

file:images/utilities_infopage_tramp.png

Calculator - M-x calc

Overview:

• RPN Calculation (Like HP48g series)
• Good for small calculation and verify expected values.
• Scientific calculator
• Bitwise operation: Useful for low level programming like: C-programming, embedded systems, network and machine instructions
• Units - Convert units like meters, inches, feets, min, seconds, bits, bytes …
• Functions (cos, sin, exp bound to keybindings)
• Date calculations
• Symbolic Math

Documentation

Describe keybindings	C-h m
Calc Info manual	M-x calc-info

Stack Commands

Dup	RET	Duplicate last number of stack.
Swap	Tab	Swap the last two numbers of stack.

Scientific Functions

Function	Key
set precision	p
change sign	n
reciprocal 1/n	&
square root	Q
ln	L
exp (e^x)	E
10^x	H E
sin	S
cos	C
tan	T
radian mode	m r
degree mode	m d
pi π (3.415…)	P
factorial	!, k d
Prime factorization	k f
GCD	k g
LCM	k l
Error function - erf	f e
Error fuinction - erfc	I f e

Financial Functions

Enter percentage	M-%
Convert to percentage	c %
Percentage change	b %
present value	b P
future value	b F
rate of return	b T
number of payments	b #
size of payments	b M
net present value, int rate of return	b N, b I

Formula transformation

Description	Key binding	Output
Enter a formula	’ (-b + sqrt(b^2 - 4*a*c) / (2 * a))
Print the formula in Latex mode	dL	\frac{\sqrt{b^2 - 4 a c} - b}{2 a}
Creates a C-lanaguage code	dC	(sqrt(pow(b, 2) - 4*(a*c)) - b) / (2*a)
Normal Language	dN	_' (-b + sqrt(b^2 - 4*a*c) / (2 * a))_
Show formula in big display mode	dB

Unit Conversions

Description	M-x command
Enter number with unites	’ 100 ft/hr
Convert to new unit, base unit	u c, u b
Convert temperature units	u t
Simplify unit expression	u s
View unit table	u v

Numbers with different base

Description	Emacs Calc	Base 10
Binary	2#11110101	245
Octal	8#27	23
Hexadecimal	16#FFFF	65535

Bitwise Operations

Keybinding	M-x command	Description
		Number Representation
d 0		Decimal (Standard )
d 2		Number representation to binary 2#00100111
0 d 2		Two-complement binary
d 6		Hexadecimal
		Word Size
b w		Set word size (8 bits, 16 bits, 32 bits …)
b c	calc-clip	Clip the current number to current word size.
		Bitwise operation
b a	calc-and	Bitwise AND
b o	calc-or	Bitwise OR
b x	calc-xor	Bitwise XOR
b n	calc-not	Bitwise NOT
b d	calc-diff	Bitwise difference
b r	calc-rshift-binary	Bitwise right shift by 1 bit
b l	calc-lshift-binary	Bitwise left shift by 1 bit

See also

• Emacs Calc for Programmers and Computer Scientists - Florian Adamsky

• The Emacs calculator calc

• Calc mode reference card.

• An Emacs Calc-Mode Epiphany - YouTube

• DrLock.com » Blog Archive » The GNU Emacs Calculator

• Emacs-Calc: The Poor Man’s Mathematica on Vimeo

• Calc, the King of Calculators

• Common calculations in Emacs/Calc | Truong’s Weblog

• Make typing mathematical equations in LaTeX easier with Emacs’ Calc | Truong’s Weblog

• The Emacs Calculator : emacs

• EmacsWiki: Calc Tutorials by Andrew Hyatt

• How to completely erase Emacs Calc’s state? - Stack Overflow

• GNU Emacs Calc 2.02 Manual - Getting Started

Magit - Emacs Interface to GIT

See:

• http://stackapps.com/questions/3950/sx-stack-exchange-for-emacs

Magit Remote Branches

• http://jr0cket.co.uk/2012/12/driving-git-with-emacs-pure-magic-with.html

Magit Reference Card:

• https://magit.vc/manual/magit-refcard.pdf

Another Reference Card

• http://wiki-old.lihebi.com/posts/tools/software/emacs/packages/magit/

• http://ergoemacs.org/emacs/emacs_magit-mode_tutorial.html

Command M-x	Key bind	GIT
	magit-status
magit-status		git status	Magit status is the main entry point to Magit
magit-init		git init	Init a git repository
magit-log		git log
magit-process-bufffer	$		Displays the git command and its output
	g		Update magit status buffer
	l		History
	L		Verbose history
	!!	git <command>	Run a git command
	!s		Magit shell command

Remote Branches

Command M-x
magit-add-remote	Add a remote branch to magit
magit-remote-add	M-a add remote repository
magit-remote-remove	M-d remove remote repository

Untracked files commands:

s	Add untracked file to staging area
C-u S	Stage all untracked and tracked files
i	Add filename to .gitignore
k	Delete untracked file, forever

Staging and Commiting

u	Unstage
C-u s	Prompt file for stagin
U	Unstage everything that has been staged
c	Pop buffer for commit message
C-c C-c	Amend commit message
C-c C-k	Erage magit-log-edit buffer and bury it

Tagging

t t	Create a lightweight tag
t a	Create annotated tag

Stashing

z z	Create new stash
a	Apply stash
A	Pop a stash
k	Drop a stash

Branch

b v	Branch manager
b b	Switch to a different branch
b n	Create a new branch
k	Delete current branch
C-u k	Delte branch event if it hasn’t been merged
m m	Merge the branch in current line to specified
g	Refresh branch list
q	Buries the branch list and deletes the window

Helm utilities

Command	Description
Elisp Programming
M-x helm-M-x	Show all M-x commands
M-x helm-apropos	Apropos with helm interface.
Search Documentation
M-x helm-info	Search Info pages.
M-x helm-man-woman	Search man pages.
Files and buffer
M-x helm-buffers-list	Switch buffers
M-x helm-find-files	Helm equivalent of M-x find-files
Search
M-x helm-occur	Occur-like command with helm interface.
Org-mode
M-x helm-org-in-buffer-headings	Filter org-mode files by headlines.
Code Navigation
M-x helm-imenu	Code navigation with Imenu
Process Manager
M-x helm-top	Task/Process manager like M-x proced
Color Pallete
M-x helm-colors	Select a color and copy to clipboard

Spell Checker

Emacs uses external programs to check the spell. It supports ispell, aspell and hunspell. The variable ispell-program-name sets the spell check software used by Emacs. The default dictionary used by Emacs is US English, but it can be changed with the command M-x ispell-change-dicitonary.

Spell check interface commands:

Command	Default Key Bind	Description
M-x ispell-buffer		Check the spelling of all buffer.
M-x ispell-word	M-$	Check the spell of word at cursor position.
M-x ispell-region		Check the spell of selected text.
M-x ispell-change-dictionary		Change the language of dictionary used by the spell check.
M-x flyspell-mode		Toggle flyspell mode. When active, it will highlight all misspelled .
M-x flyspell-buffer		Check the hole buffer in flyspell minor mode.
M-x ispell-kill-ispell		Kill the Ispell subprocess.

Set the default Spell checker:

(setq ispell-program-name "aspell")

;; or
(setq ispell-program-name "ispell")

;;
(setq ispell-program-name "hunspell")

The dictionary can be changed with the Elisp code:

(ispell-chage-dictionary "en")
(ispell-chage-dictionary "castellano")
(ispell-chage-dictionary "german")


;; M-x ispell-spanish
;;
(defun ispell-spanish ()
 (interactive)
 (ispell-change-diciontary "castellano"))

;; M-x ispell-en
;;
(defun ispell-en ()
  (interactive)
   (ispell-change-diciontary "en"))

To right click in the word and get suggestions use:

(eval-after-load "flyspell"
  '(progn
     (define-key flyspell-mouse-map [down-mouse-3] #'flyspell-correct-word)
     (define-key flyspell-mouse-map [mouse-3] #'undefined)))

The ispell doesn’t check the spell of comments and strings. This behavior can be changed with the code below that allows it to check the spell in all programming modes like python-mode, haskell-mode and so on.

(add-hook 'prog-mode-hook 'flyspell-prog-mode)

See also:

• Spell checking in Emacs
• FlySpell - Emacs Wiki.org
• InteractiveSpell
• Emacs Manual - Check and Correcting Spelling
• Emacs Spell Checker Problems
• What’s the best spell check setup in emacs