Ah I see. I guess it’s a language/cultural thing.
Here hot dog refers to the combination of the sausage with the bun. E.g. you can use the bun for making a sandwich instead and the sausage (usually a Wiener Würstchen or Frankfurter Würstchen) in a soup or together with potatoes, or in other meals.
So when you need to file something, doesn’t matter if it’s made of wood or metal, you need a system.