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