class input_stream :Make an?len:int -> ?block_size:int -> Netchannels.in_obj_channel ->in_obj_stream
in_obj_stream on top of an in_obj_channel. The block_size
can be specified; it defaults to 4096.
If len is passed, this parameter limits the length of the channel:
Only the first len bytes are read from the input channel, then an EOF
is simulated even if the input channel is longer.