Test if user has admin privileges on Windows.

powerline.go

@@ -32,6 +32,7 @@ type powerline struct {
 	args                   args
 	cwd                    string
 	userInfo               user.User
+	userIsAdmin            bool
 	hostname               string
 	username               string
 	pathAliases            map[string]string
@@ -76,6 +77,7 @@ func newPowerline(args args, cwd string, priorities map[string]int, align alignm
 			p.username = usernameWithAd[1]
 		}
 	}
+	p.userIsAdmin = userIsAdmin()
 
 	p.theme = themes[*args.Theme]
 	p.shellInfo = shellInfos[*args.Shell]

segment-username.go

@@ -2,7 +2,6 @@ package main
 
 import (
 	pwl "github.com/justjanne/powerline-go/powerline"
-	"os"
 )
 
 func segmentUser(p *powerline) []pwl.Segment {
@@ -16,7 +15,7 @@ func segmentUser(p *powerline) []pwl.Segment {
 	}
 
 	var background uint8
-	if os.Getuid() == 0 {
+	if p.userIsAdmin {
 		background = p.theme.UsernameRootBg
 	} else {
 		background = p.theme.UsernameBg

user-is-admin.go

@@ -0,0 +1,11 @@
+// +build !windows
+
+package main
+
+import (
+	"os"
+)
+
+func userIsAdmin() bool {
+	return os.Getuid() == 0
+}

user-is-admin_windows.go

@@ -0,0 +1,33 @@
+// +build windows
+
+package main
+
+import (
+	"golang.org/x/sys/windows"
+)
+
+func userIsAdmin() bool {
+	var sid *windows.SID
+
+	err := windows.AllocateAndInitializeSid(
+		&windows.SECURITY_NT_AUTHORITY,
+		2,
+		windows.SECURITY_BUILTIN_DOMAIN_RID,
+		windows.DOMAIN_ALIAS_RID_ADMINS,
+		0, 0, 0, 0, 0, 0,
+		&sid,
+	)
+	if err != nil {
+		return false
+	}
+	defer windows.FreeSid(sid)
+
+	t := windows.Token(0)
+
+	member, err := t.IsMember(sid)
+	if err != nil {
+		return false
+	}
+
+	return member
+}