I agree it should be in the core. In fact this entire plugin should be in the core. But since it's not, and since the plugin is kinda "file manager" itself, with some useful OS functions, adding a command to open a default file manager would be quite aligned with the rest of its functionality.
--- Reply to this email directly or view it on GitHub: https://github.com/geany/geany-plugins/issues/380#issuecomment-192229299