Read from socket: Is it guaranteed to at least get x bytes?

Question

I have a rare bug that seems to occur reading a socket.

It seems, that during reading of data sometimes I get only 1-3 bytes of a data package that is bigger than th

Answer 1

If the sender sends 515 bytes, and your BUFSIZE is 512, then the first recv will return 512 bytes, and the next will return 3 bytes... Could this be what's happening?

(This is just one case amongst many which will result in a 3-byte recv from a larger send...)