Color conversion script.

bin/color.js

@@ -0,0 +1,110 @@
+#!/usr/bin/env node
+
+/**
+ * HTML color converter
+ * Convert #hex colors to HSL/HSLA (by default) or RGB/RGBA (if `--rgb` key specified).
+ *
+ * Usage: color [--rgb] [#]dead00 [alpha]
+ *
+ * Author: Artem Sapegin, sapegin.me
+ * Based on https://github.com/LeaVerou/CSS.coloratum
+ */
+
+//jshint node:true
+
+var format = 'hsl';
+var args = process.argv.splice(2);
+if (!args.length) helpme();
+
+if (args[0] == '--rgb') {
+	format = 'rgb';
+	args = args.splice(1);
+}
+if (!args.length) helpme();
+
+var rgb = hex2rgb(args[0]);
+if (!rgb) helpme();
+
+var alpha = args[1];
+
+if (format == 'hsl') {
+	console.log(toHslString(rgb2hsl(rgb), alpha));
+}
+else {
+	console.log(toRgbString(rgb, alpha));
+}
+
+
+function helpme() {
+	console.log('Usage: color [--rgb] [#]dead00 [alpha]');
+	process.exit(1);
+}
+
+function hex2rgb(rgbString) {
+	// Remove leading `#`
+	rgbString = rgbString.replace(/^#/, '');
+
+	// Parse `dead00` and `f00`
+	var channels = [];
+	if (rgbString.length === 3) {
+		channels = rgbString.match(/([0-9a-f])/g);
+		channels = channels.map(function(hex) {
+			return hex + hex;
+		});
+	}
+	else {
+		channels = rgbString.match(/([0-9a-f]){2}/g);
+	}
+	if (channels.length !== 3) {
+		return null;
+	}
+
+	// Convert to integers
+	channels = channels.map(function(hex) {
+		return parseInt(hex, 16);
+	});
+
+	return channels;
+}
+
+function rgb2hsl(rgb) {
+	rgb = rgb.map(function(a) {
+		return a / 2.55;
+	});
+
+	var hsl = [];
+	var max = Math.max.apply(Math, rgb);
+	var min = Math.min.apply(Math, rgb);
+
+	hsl[2] = Math.round((min + max)/2);
+
+	var d = max - min;
+
+	if(d !== 0) {
+		hsl[1] = Math.round(d*100 / (100 - Math.abs(2*hsl[2] - 100))) + '%';
+
+		switch(max){
+			case rgb[0]: hsl[0] = (rgb[1] - rgb[2]) / d + (rgb[1] < rgb[2] ? 6 : 0); break;
+			case rgb[1]: hsl[0] = (rgb[2] - rgb[0]) / d + 2; break;
+			case rgb[2]: hsl[0] = (rgb[0] - rgb[1]) / d + 4;
+		}
+
+		hsl[0] = Math.round(hsl[0]*60);
+	}
+	else {
+		hsl[0] = 0;
+		hsl[1] = '0%';
+	}
+
+	hsl[2] += '%';
+
+	return hsl;
+}
+
+function toRgbString(rgb, alpha) {
+	return 'rgb' + (alpha < 1 ? 'a' : '') + '(' + rgb.join(',') + ((alpha < 1 ? ',' + alpha : '') + ')').replace(/\b0\./, '.');
+}
+
+function toHslString(hsl, alpha) {
+	return 'hsl' + (alpha < 1 ? 'a' : '') + '(' + hsl.join(',') + ((alpha < 1 ? ',' + alpha : '') + ')').replace(/\b0\./, '.');
+}