getOS: function that returns the name and version of the operating system

getos.js

// returns the os name, type and version, and sets body classes
// detects major desktop and mobile os: Windows, Windows Phone, Mac, iOS, Android, Ubuntu, Fedora, ChromeOS
// based on bowser: https://github.com/ded/bowser
// list of user agent strings: http://www.webapps-online.com/online-tools/user-agent-strings/dv
function getOS() {
	var ua = navigator.userAgent, os;

	// helper functions to deal with common regex
	function getFirstMatch(regex) {
		var match = ua.match(regex);
		return (match && match.length > 1 && match[1]) || '';
	}

	function getSecondMatch(regex) {
		var match = ua.match(regex);
		return (match && match.length > 1 && match[2]) || '';
	}

	if(/(ipod|iphone|ipad)/i.test(ua)) {
		os = {
			name: 'iOS',
			type: 'ios',
			version: getFirstMatch(/os (\d+([_\s]\d+)*) like mac os x/i).replace(/[_\s]/g, '.')
		}
	} else if(/windows phone/i.test(ua)) {
		os = {
			name: 'Windows Phone',
			type: 'windowsphone',
			version: getFirstMatch(/windows phone (?:os)?\s?(\d+(\.\d+)*)/i)
		}
	} else if(!(/like android/i.test(ua)) && /android/i.test(ua)) {
		os = {
			name: 'Android',
			type: 'android',
			version: getFirstMatch(/android[ \/-](\d+(\.\d+)*)/i)
		}
	} else if(/windows nt/i.test(ua)) {
		os = {
			name: 'Windows',
			type: 'windows',
			version: getFirstMatch(/windows nt (\d+(\.\d+)*)/i)
		}
	} else if(/mac os x/i.test(ua)) {
		os = {
			name: 'Mac OS X',
			type: 'macosx',
			version: getFirstMatch(/mac os x (\d+([_\s]\d+)*)/i).replace(/[_\s]/g, '.')
		}
	} else if(/ubuntu/i.test(ua)) {
		os = {
			name: 'Ubuntu',
			type: 'ubuntu',
			version: getFirstMatch(/ubuntu\/(\d+(\.\d+)*)/i)
		}
	} else if(/fedora/i.test(ua)) {
		os = {
			name: 'Fedora',
			type: 'fedora',
			version: getFirstMatch(/fedora\/(\d+(\.\d+)*)/i)
		}
	} else if(/CrOS/.test(ua)) {
		os = {
			name: 'Chrome OS',
			type: 'chromeos',
			version: getSecondMatch(/cros (.+) (\d+(\.\d+)*)/i)
		}
	}

	return os;
},