sig val seek_out : Pervasives.out_channel -> int64 -> unit val pos_out : Pervasives.out_channel -> int64 val out_channel_length : Pervasives.out_channel -> int64 val seek_in : Pervasives.in_channel -> int64 -> unit val pos_in : Pervasives.in_channel -> int64 val in_channel_length : Pervasives.in_channel -> int64