Reading data from the network without knowing the size of the buffer that is coming

[Vladimir Panteleev]

On Thursday, 21 March 2019 at 16:54:01 UTC, Roman Sztergbaum 
wrote:
> I would like to get rid of the "ubytes[256]" because I do not 
> know the size of the data that is comming, I would like to read 
> the entire buffer that I send at once. Can someone point me?

If you do not know the size of the response, then how can you 
know when you should stop waiting for more bytes?

Some connections are stream-oriented, and some are 
datagram-oriented. With a datagram-oriented connection, each 
packet has a fixed size (though there is a maximum size). You 
mentioned this is a UNIX socket connection, and I believe UNIX 
sockets can be either stream-oriented or datagram-oriented.

If the socket is stream-oriented, there should generally be a way 
for the other end to signal when it's done sending bytes. This 
can be in the form of a fixed-size "header" containing the body 
length, or maybe the other end just closes the connection when 
it's done writing. Other approaches, like reading until there are 
no more bytes in the buffer (though more may yet to arrive one 
millisecond later) are generally not reliable.

Perhaps you should include more information like what program you 
are trying to talk to, or the protocol being used.