Terminal string styling done right
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. Although there are other
ones, they either do too much or not enough.
Chalk is a clean and focused alternative.
- Highly performant
- Doesn't extend
String.prototype
- Expressive API
- Ability to nest styles
- Clean and focused
- Auto-detects color support
- Actively maintained
- Used by 1700+ modules
npm install --save chalk
Chalk comes with an easy to use composable API where you just chain and nest the styles you want.
var chalk = require('chalk');
// style a string
chalk.blue('Hello world!');
// combine styled and normal strings
chalk.blue('Hello'), 'World' + chalk.red('!');
// compose multiple styles using the chainable API
chalk.blue.bgRed.bold('Hello world!');
// pass in multiple arguments
chalk.blue('Hello', 'World!', 'Foo', 'bar', 'biz', 'baz');
// nest styles
chalk.red('Hello', chalk.underline.bgBlue('world') + '!');
// nest styles of the same type even (color, underline, background)
chalk.green(
'I am a green line ' +
chalk.blue.underline.bold('with a blue substring') +
' that becomes green again!'
);
Easily define your own themes.
var chalk = require('chalk');
var error = chalk.bold.red;
console.log(error('Error!'));
Take advantage of console.log string substitution.
var name = 'Sindre';
console.log(chalk.green('Hello %s'), name);
//=> Hello Sindre
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.
Color support is automatically detected, but you can override it.
Detect whether the terminal supports color.
Can be overridden by the user with the flags --color
and --no-color
.
Used internally and handled for you, but exposed for convenience.
Exposes the styles as ANSI escape codes.
Generally not useful, but you might need just the .open
or .close
escape
code if you're mixing externally styled strings with your own.
var chalk = require('chalk');
console.log(chalk.styles.red);
//=> {open: '\u001b[31m', close: '\u001b[39m'}
console.log(chalk.styles.red.open + 'Hello' + chalk.styles.red.close);
Check whether a string has color.
Strip color from a string.
Can be useful in combination with .supportsColor
to strip color on externally
styled text when it's not supported.
Example:
var chalk = require('chalk');
var styledString = getText();
if (!chalk.supportsColor) {
styledString = chalk.stripColor(styledString);
}
reset
bold
dim
italic
(not widely supported)underline
inverse
hidden
strikethrough
(not widely supported)
black
red
green
yellow
blue
magenta
cyan
white
gray
bgBlack
bgRed
bgGreen
bgYellow
bgBlue
bgMagenta
bgCyan
bgWhite
Chalk does not support support anything other than the base eight colors, which
guarantees it will work on all terminals and systems. Some terminals,
specifically xterm
compliant ones, will support the full range of 8-bit
colors. For this the lower level
ansi-256-colors package can be
used.
MIT © Sindre Sorhus