clean up

register_unix.go

@@ -4,7 +4,11 @@
 
 package spm
 
-import "fmt"
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+)
 
 // RegisterApp is not supported on non-Windows platforms.
 func RegisterApp() error {
@@ -15,3 +19,19 @@ func RegisterApp() error {
 func UnregisterApp() error {
 	return fmt.Errorf("UnregisterApp is only available on Windows")
 }
+
+// IsRegistered returns true if the application is detected as installed.
+// On Linux, we assume it is installed if the main executable exists in the install directory.
+func IsRegistered() bool {
+	installDir, err := GetInstallDir()
+	if err != nil {
+		return false
+	}
+
+	// Assume the executable is named "spitfire" and is located in installDir.
+	exePath := filepath.Join(installDir, "browser", "spitfire")
+	if _, err := os.Stat(exePath); err == nil {
+		return true
+	}
+	return false
+}