core: allow RO commands to run as root

core/cmd/dms/main.go

@@ -31,7 +31,7 @@ func init() {
 func main() {
 	clipboard.MaybeServeAndExit()
 
-	if os.Geteuid() == 0 {
+	if os.Geteuid() == 0 && !isReadOnlyCommand(os.Args) {
 		log.Fatal("This program should not be run as root. Exiting.")
 	}
 

core/cmd/dms/main_distro.go

@@ -28,7 +28,7 @@ func init() {
 func main() {
 	clipboard.MaybeServeAndExit()
 
-	if os.Geteuid() == 0 {
+	if os.Geteuid() == 0 && !isReadOnlyCommand(os.Args) {
 		log.Fatal("This program should not be run as root. Exiting.")
 	}
 

core/cmd/dms/utils.go

@@ -7,6 +7,22 @@ import (
 	"strings"
 )
 
+// isReadOnlyCommand returns true if the CLI args indicate a command that is
+// safe to run as root (e.g. shell completion, help).
+func isReadOnlyCommand(args []string) bool {
+	for _, arg := range args[1:] {
+		if strings.HasPrefix(arg, "-") {
+			continue
+		}
+		switch arg {
+		case "completion", "help", "__complete":
+			return true
+		}
+		return false
+	}
+	return false
+}
+
 func isArchPackageInstalled(packageName string) bool {
 	cmd := exec.Command("pacman", "-Q", packageName)
 	err := cmd.Run()