chalk/chalk


🖍 Terminal string styling done right

License: MIT

Language: JavaScript

Keywords: ansi, ansi-escape-codes, chalk, cli, color, commandline, console, javascript, strip-ansi, terminal, terminal-emulators




Chalk


Terminal string styling done right

Build Status Coverage Status npm dependents Downloads XO code style TypeScript-ready


Get professional support for Chalk with a Tidelift subscription
Tidelift helps make open source sustainable for maintainers while giving companies
assurances about security, maintenance, and licensing for their dependencies.

Highlights

Install

$ npm install chalk

Usage

const chalk = require('chalk');

console.log(chalk.blue('Hello world!'));

Chalk comes with an easy to use composable API where you just chain and nest the styles you want.

const chalk = require('chalk');
const log = console.log;

// Combine styled and normal strings
log(chalk.blue('Hello') + ' World' + chalk.red('!'));

// Compose multiple styles using the chainable API
log(chalk.blue.bgRed.bold('Hello world!'));

// Pass in multiple arguments
log(chalk.blue('Hello', 'World!', 'Foo', 'bar', 'biz', 'baz'));

// Nest styles
log(chalk.red('Hello', chalk.underline.bgBlue('world') + '!'));

// Nest styles of the same type even (color, underline, background)
log(chalk.green(
	'I am a green line ' +
	chalk.blue.underline.bold('with a blue substring') +
	' that becomes green again!'
));

// ES2015 template literal
log(`
CPU: ${chalk.red('90%')}
RAM: ${chalk.green('40%')}
DISK: ${chalk.yellow('70%')}
`);

// ES2015 tagged template literal
log(chalk`
CPU: {red ${cpu.totalPercent}%}
RAM: {green ${ram.used / ram.total * 100}%}
DISK: {rgb(255,131,0) ${disk.used / disk.total * 100}%}
`);

// Use RGB colors in terminal emulators that support it.
log(chalk.keyword('orange')('Yay for orange colored text!'));
log(chalk.rgb(123, 45, 67).underline('Underlined reddish color'));
log(chalk.hex('#DEADED').bold('Bold gray!'));

Easily define your own themes:

const chalk = require('chalk');

const error = chalk.bold.red;
const warning = chalk.keyword('orange');

console.log(error('Error!'));
console.log(warning('Warning!'));

Take advantage of console.log string substitution:

const name = 'Sindre';
console.log(chalk.green('Hello %s'), name);
//=> 'Hello Sindre'

API

chalk.<style>[.<style>...](string, [string...])

Example: chalk.red.bold.underline('Hello', 'world');

Chain styles and call the last one as a method with a string argument. Order doesn't matter, and later styles take precedent in case of a conflict. This simply means that chalk.red.yellow.green is equivalent to chalk.green.

Multiple arguments will be separated by space.

chalk.enabled

Color support is automatically detected, as is the level (see chalk.level). However, if you'd like to simply enable/disable Chalk, you can do so via the .enabled property. When chalk.enabled is true, chalk.level must also be greater than 0 for colored output to be produced.

Chalk is enabled by default unless explicitly disabled via new chalk.Instance() or chalk.level is 0.

If you need to change this in a reusable module, create a new instance:

const ctx = new chalk.Instance({enabled: false});

chalk.level

Color support is automatically detected, but you can override it by setting the level property. You should however only do this in your own code as it applies globally to all Chalk consumers. When chalk.level is greater than 0, chalk.enabled must also be true for colored output to be produced.

If you need to change this in a reusable module, create a new instance:

const ctx = new chalk.Instance({level: 0});

Levels are as follows:

  1. All colors disabled
  2. Basic color support (16 colors)
  3. 256 color support
  4. Truecolor support (16 million colors)

chalk.supportsColor

Detect whether the terminal supports color. Used internally and handled for you, but exposed for convenience.

Can be overridden by the user with the flags --color and --no-color. For situations where using --color is not possible, add the environment variable FORCE_COLOR=1 to forcefully enable color or FORCE_COLOR=0 to forcefully disable. The use of FORCE_COLOR overrides all other color support checks.

Explicit 256/Truecolor mode can be enabled using the --color=256 and --color=16m flags, respectively.

Styles

Modifiers

  • reset - Resets the current color chain.
  • bold - Make text bold.
  • dim - Emitting only a small amount of light.
  • italic - Make text italic. (Not widely supported)
  • underline - Make text underline. (Not widely supported)
  • inverse- Inverse background and foreground colors.
  • hidden - Prints the text, but makes it invisible.
  • strikethrough - Puts a horizontal line through the center of the text. (Not widely supported)
  • visible- Prints the text only when Chalk is enabled. Can be useful for things that are purely cosmetic.

Colors

  • black
  • red
  • green
  • yellow
  • blue (On Windows the bright version is used since normal blue is illegible)
  • magenta
  • cyan
  • white
  • gray ("bright black")
  • redBright
  • greenBright
  • yellowBright
  • blueBright
  • magentaBright
  • cyanBright
  • whiteBright

Background colors

  • bgBlack
  • bgRed
  • bgGreen
  • bgYellow
  • bgBlue
  • bgMagenta
  • bgCyan
  • bgWhite
  • bgBlackBright
  • bgRedBright
  • bgGreenBright
  • bgYellowBright
  • bgBlueBright
  • bgMagentaBright
  • bgCyanBright
  • bgWhiteBright

Tagged template literal

Chalk can be used as a tagged template literal.

const chalk = require('chalk');

const miles = 18;
const calculateFeet = miles => miles * 5280;

console.log(chalk`
  There are {bold 5280 feet} in a mile.
  In {bold ${miles} miles}, there are {green.bold ${calculateFeet(miles)} feet}.
`);

Blocks are delimited by an opening curly brace ({), a style, some content, and a closing curly brace (}).

Template styles are chained exactly like normal Chalk styles. The following two statements are equivalent:

console.log(chalk.bold.rgb(10, 100, 200)('Hello!'));
console.log(chalk`{bold.rgb(10,100,200) Hello!}`);

Note that function styles (rgb(), hsl(), keyword(), etc.) may not contain spaces between parameters.

All interpolated values (chalk`${foo}`) are converted to strings via the .toString() method. All curly braces ({ and }) in interpolated value strings are escaped.

256 and Truecolor color support

Chalk supports 256 colors and Truecolor (16 million colors) on supported terminal apps.

Colors are downsampled from 16 million RGB values to an ANSI color format that is supported by the terminal emulator (or by specifying {level: n} as a Chalk option). For example, Chalk configured to run at level 1 (basic color support) will downsample an RGB value of #FF0000 (red) to 31 (ANSI escape for red).

Examples:

  • chalk.hex('#DEADED').underline('Hello, world!')
  • chalk.keyword('orange')('Some orange text')
  • chalk.rgb(15, 100, 204).inverse('Hello!')

Background versions of these models are prefixed with bg and the first level of the module capitalized (e.g. keyword for foreground colors and bgKeyword for background colors).

  • chalk.bgHex('#DEADED').underline('Hello, world!')
  • chalk.bgKeyword('orange')('Some orange text')
  • chalk.bgRgb(15, 100, 204).inverse('Hello!')

The following color models can be used:

  • rgb - Example: chalk.rgb(255, 136, 0).bold('Orange!')
  • hex - Example: chalk.hex('#FF8800').bold('Orange!')
  • keyword (CSS keywords) - Example: chalk.keyword('orange').bold('Orange!')
  • hsl - Example: chalk.hsl(32, 100, 50).bold('Orange!')
  • hsv - Example: chalk.hsv(32, 100, 100).bold('Orange!')
  • hwb - Example: chalk.hwb(32, 0, 50).bold('Orange!')
  • ansi16
  • ansi256

Windows

If you're on Windows, do yourself a favor and use cmder instead of cmd.exe.

Origin story

colors.js used to be the most popular string styling module, but it has serious deficiencies like extending String.prototype which causes all kinds of problems and the package is unmaintained. Although there are other packages, they either do too much or not enough. Chalk is a clean and focused alternative.

Security

To report a security vulnerability, please use the Tidelift security contact. Tidelift will coordinate the fix and disclosure.

Related

Maintainers

License

MIT

Project Statistics

Sourcerank 24
Repository Size 655 KB
Stars 12,230
Forks 464
Watchers 138
Open issues 19
Dependencies 13
Contributors 45
Tags 25
Created
Last updated
Last pushed

Top Contributors See all

Sindre Sorhus Qix Steve Mao Kevin Mårtensson Sean McArthur Chris Harwood Alexander Craggs Vadim Demedes LitoMore Caleb Boyd Benjamin E. Coe Andrew Kennedy Timothy Yung Jorrit Schippers Daniel Husar Luke Page Sakthipriyan Vairamani Jamie Kyle Charlike Mike Reagent Wei Kin Huang

Packages Referencing this Repo

chalk-optimiser
This module is based on the npm chalk module and it´s 80% faster than the original by using multi...
Latest release 1.8.6 - Updated - 12.2K stars
chalk
Terminal string styling done right
Latest release 2.4.2 - Updated - 12.2K stars
org.webjars.bowergithub.chalk:chalk
WebJar for chalk
Latest release 1.1.3 - Published - 12.2K stars
org.webjars.npm:chalk
WebJar for chalk
Latest release 2.4.2 - Updated - 12.2K stars
chalk
🖍 Terminal string styling done right
Latest release v2.4.2 - Published - 12.2K stars

Recent Tags See all

v2.4.2 January 05, 2019
v2.4.1 April 26, 2018
v2.4.0 April 17, 2018
v2.3.2 March 02, 2018
v2.3.1 February 11, 2018
v2.3.0 October 24, 2017
v2.2.2 October 24, 2017
v2.2.1 October 24, 2017
v2.2.0 October 18, 2017
v2.1.0 August 07, 2017
v2.0.1 June 30, 2017
v2.0.0 June 29, 2017
v1.1.3 March 29, 2016
v1.1.2 March 28, 2016
v1.1.1 August 19, 2015

Interesting Forks See all

Kamos86/chalk
🖍 Terminal string styling done right
JavaScript - MIT - Updated - 1 stars
Web5design/chalk
Terminal string styling done right
JavaScript - MIT - Updated - 1 stars - 1 forks
kevva/chalk
🖍 Terminal string styling done right
JavaScript - Last pushed - 1 stars
defconcepts/chalk
Terminal string styling done right
JavaScript - Published - 1 stars
jbnicolai/chalk
Terminal string styling done right
JavaScript - MIT - Last pushed - 1 stars

Something wrong with this page? Make a suggestion

Last synced: 2019-05-29 18:09:41 UTC

Login to resync this repository