Check if the path to rename is too broad as safety measure

main.go

@@ -11,6 +11,7 @@ import (
 const defaultAllowedExtensions = "jpg,jpeg,png,gif,avi,mp4,mov"
 
 var extensions = flag.String("extensions", defaultAllowedExtensions, "Comma separated extensions to allow")
+var force = flag.Bool("force", false, "Force execution without safety checks")
 
 func stringInSlice(a string, list []string) bool {
 	for _, b := range list {
@@ -50,6 +51,18 @@ func main() {
 		panic(err)
 	}
 
+	if !*force {
+		// Count the number of paths separators and don't allow executing
+		// if the path is too close to the root folder without the force
+		// flag
+		sublevels := strings.Split(path, string(filepath.Separator))[1:]
+		if len(sublevels) < 3 {
+			fmt.Printf("%s seems too broad.\n", path)
+			fmt.Println("If you're sure use the -force flag.")
+			os.Exit(1)
+		}
+	}
+
 	fmt.Printf("Walking by %s...\n", path)
 
 	err2 := filepath.Walk(path, readDir)