Added detection of OS version

for macOS, iOS, Windows and Android at the moment. Backwards compatible.

browser.go

@@ -32,6 +32,14 @@ var browsers = map[string]*url.URL{
 	"WebView":   u("http://developer.android.com/guide/webapps/webview.html"),
 }
 
+const (
+	osAndroid = "Android"
+	osMacOS   = "Mac OS X"
+	osIOS     = "iOS"
+	osLinux   = "GNU/Linux"
+	osWindows = "Windows"
+)
+
 func parseBrowser(l *lex) *UserAgent {
 	for _, f := range []parseFn{parseGecko, parseChromeSafari, parseIE1, parseIE2} {
 		if ua := f(newLex(l.s)); ua != nil {
@@ -67,7 +75,7 @@ func parseMozillaLike(l *lex, ua *UserAgent) bool {
 		parseUnixLike(l, ua)
 	case l.match("Android"):
 		ua.Security = parseSecurity(l)
-		ua.OS = "Android"
+		ua.OS = osAndroid
 		if l.match("; Mobile") {
 			ua.Mobile = true
 		} else if l.match("; Tablet") {
@@ -76,16 +84,16 @@ func parseMozillaLike(l *lex, ua *UserAgent) bool {
 	case l.match("Linux; "):
 		ua.Security = parseSecurity(l)
 		if l.match("Android") {
-			ua.OS = "Android"
+			ua.OS = osAndroid
 		} else {
 			return false
 		}
 	case l.match("Windows"):
 		ua.Security = parseSecurity(l)
-		ua.OS = "Windows"
+		ua.OS = osWindows
 	case l.match("Macintosh"):
 		ua.Security = parseSecurity(l)
-		ua.OS = "Mac OS X"
+		ua.OS = osMacOS
 	case l.match("Mobile; "):
 		ua.Security = parseSecurity(l)
 		ua.OS = "Firefox OS"
@@ -96,11 +104,11 @@ func parseMozillaLike(l *lex, ua *UserAgent) bool {
 		ua.Tablet = true
 	case l.match("iPad; "):
 		ua.Security = parseSecurity(l)
-		ua.OS = "iOS"
+		ua.OS = osIOS
 		ua.Tablet = true
 	case l.match("iPhone; ") || l.match("iPod; ") || l.match("iPod touch; "):
 		ua.Security = parseSecurity(l)
-		ua.OS = "iOS"
+		ua.OS = osIOS
 		ua.Mobile = true
 	case l.match("Unknown; "):
 		ua.Security = parseSecurity(l)
@@ -109,6 +117,9 @@ func parseMozillaLike(l *lex, ua *UserAgent) bool {
 		return false
 	}
 
+	// swallow the error to preserve backwards compatibility
+	_ = parseOSVersion(l, ua)
+
 	if _, ok := l.span(") "); !ok {
 		return false
 	}
@@ -120,7 +131,7 @@ func parseMozillaLike(l *lex, ua *UserAgent) bool {
 func parseUnixLike(l *lex, ua *UserAgent) bool {
 	switch {
 	case l.match("Linux") || l.match("Ubuntu"):
-		ua.OS = "GNU/Linux"
+		ua.OS = osLinux
 	case l.match("FreeBSD"):
 		ua.OS = "FreeBSD"
 	case l.match("OpenBSD"):
@@ -236,11 +247,18 @@ func parseIE1(l *lex) *UserAgent {
 		return nil
 	}
 	ua.Name = "MSIE"
-	ua.OS = "Windows"
 	if !parseVersion(l, ua, ";") {
 		return nil
 	}
 
+	if !l.match(" Windows NT") {
+		return nil
+	}
+
+	ua.OS = osWindows
+	// swallow the error to preserve backwards compatibility
+	_ = parseOSVersion(l, ua)
+
 	return ua
 }
 
@@ -252,14 +270,21 @@ func parseIE2(l *lex) *UserAgent {
 	if !l.match("Mozilla") {
 		return nil
 	}
+	if _, ok := l.span("(Windows NT"); !ok {
+		return nil
+	}
+	ua.OS = osWindows
+
+	// swallow the error to preserve backwards compatibility
+	_ = parseOSVersion(l, ua)
+
 	if _, ok := l.span("Trident/"); !ok {
 		return nil
 	}
 	if _, ok := l.span("rv:"); !ok {
 		return nil
 	}
 	ua.Name = "MSIE"
-	ua.OS = "Windows"
 	if !parseVersion(l, ua, ")") {
 		return nil
 	}

lex.go

@@ -16,6 +16,7 @@
 package useragent
 
 import (
+	"regexp"
 	"strings"
 )
 
@@ -56,3 +57,17 @@ func (l *lex) spanAny(chars string) (string, bool) {
 	l.p += i + len(chars)
 	return s, true
 }
+
+// assumes the first group is the bit we want
+func (l *lex) spanRegexp(re *regexp.Regexp) (before string, match string, success bool) {
+	loc := re.FindStringSubmatchIndex(l.s[l.p:])
+	if loc == nil {
+		return "", "", false
+	}
+	success = true
+	start, end := loc[2], loc[3]
+	before = l.s[l.p : l.p+start]
+	match = l.s[l.p:][start:end]
+	l.p += end
+	return
+}

parse.go

@@ -20,6 +20,7 @@ import (
 	"fmt"
 	"github.com/blang/semver"
 	"net/url"
+	"regexp"
 	"strings"
 )
 
@@ -107,8 +108,9 @@ type UserAgent struct {
 	//  CrOS
 	//   etc.
 	// If the os is not known, OS will be `unknown'.
-	OS       string
-	Security Security
+	OS        string
+	OSVersion semver.Version
+	Security  Security
 	// URL with more information about the user agent (in most cases it's the home page).
 	// If unknown is nil.
 	URL *url.URL
@@ -123,9 +125,10 @@ func (ua *UserAgent) String() string {
 Name: %v
 Version: %v
 OS: %v
+OSVersion: %v
 Security: %v
 Mobile: %v
-Tablet: %v`, ua.Type, ua.Name, ua.Version, ua.OS, ua.Security, ua.Mobile, ua.Tablet)
+Tablet: %v`, ua.Type, ua.Name, ua.Version, ua.OS, ua.OSVersion, ua.Security, ua.Mobile, ua.Tablet)
 }
 
 func new() *UserAgent {
@@ -201,6 +204,46 @@ func parseVersion(l *lex, ua *UserAgent, sep string) bool {
 	return true
 }
 
+var appleVersionRegexp = regexp.MustCompile(`(?:[^\)]+?)\b(\d+_\d+(_\d+)?)\b`)
+var genericVersionRegexp = regexp.MustCompile(`(?:[^\)]*?) (\d+\.\d+(\.\d+)?)\b`)
+
+func parseOSVersion(l *lex, ua *UserAgent) bool {
+	switch ua.OS {
+	case osMacOS, osIOS:
+		_, s, ok := l.spanRegexp(appleVersionRegexp)
+		if !ok {
+			return true
+		}
+
+		s = strings.Replace(s, "_", ".", -1)
+
+		v, err := semver.ParseTolerant(s)
+		if err != nil {
+			return false
+		}
+
+		ua.OSVersion = v
+		return true
+
+	case osAndroid, osWindows:
+		_, s, ok := l.spanRegexp(genericVersionRegexp)
+		if !ok {
+			return true
+		}
+
+		v, err := semver.ParseTolerant(s)
+		if err != nil {
+			return false
+		}
+
+		ua.OSVersion = v
+		return true
+
+	default:
+		return false
+	}
+}
+
 func parseNameVersion(l *lex, ua *UserAgent) bool {
 	var s string
 	var ok bool