supports-color
Detect whether a terminal supports color
Install
npm install supports-color
Usage
import supportsColor from 'supports-color';
if (supportsColor.stdout) {
console.log('Terminal stdout supports color');
}
if (supportsColor.stdout.has256) {
console.log('Terminal stdout supports 256 colors');
}
if (supportsColor.stderr.has16m) {
console.log('Terminal stderr supports 16 million colors (truecolor)');
}
API
Returns an object with a stdout and stderr property for testing either streams. Each property is an Object, or false if color is not supported.
The stdout/stderr objects specifies a level of support for color through a .level property and a corresponding flag:
.level = 1 and .hasBasic = true: Basic color support (16 colors).level = 2 and .has256 = true: 256 color support.level = 3 and .has16m = true: Truecolor support (16 million colors)
Custom instance
The package also exposes the named export createSupportColor function that takes an arbitrary write stream (for example, process.stdout) and an optional options object to (re-)evaluate color support for an arbitrary stream.
import {createSupportsColor} from 'supports-color';
const stdoutSupportsColor = createSupportsColor(process.stdout);
if (stdoutSupportsColor) {
console.log('Terminal stdout supports color');
}
// `stdoutSupportsColor` is the same as `supportsColor.stdout`
The options object supports a single boolean property sniffFlags. By default it is true, which instructs the detection to sniff process.argv for the multitude of --color flags (see Info below). If false, then process.argv is not considered when determining color support.
Info
It obeys the --color and --no-color CLI flags.
For situations where using --color is not possible, use the environment variable FORCE_COLOR=1 (level 1), FORCE_COLOR=2 (level 2), or FORCE_COLOR=3 (level 3) 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.
Related
Maintainers
