Question about UNIX select()

I know that select() tells you if a file descriptor is ready for reading or writing without blocking, but how do you know how many bytes can be sent before it must be blocked? Is there some minimum in a header that I can rely on?

>>7
Actually, netcat doesn't work with named sockets, which is what the assignment specified to use. But you're right that the client program is basically just a non-generic, shittier version of netcat.