Lists a directory.

def Run(self, args):
    """Lists a directory."""
    try:
      directory = vfs.VFSOpen(args.pathspec, progress_callback=self.Progress)
    except (IOError, OSError) as e:
      self.SetStatus(rdf_flows.GrrStatus.ReturnedStatus.IOERROR, e)
      return

    files = list(directory.ListFiles())
    files.sort(key=lambda x: x.pathspec.path)

    for response in files:
      self.SendReply(response)