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?

No.

>>2
Then is there some number which, in practice, almost never requires blocking? Maybe a page size...?

>>3
not really. there might be one on HDDs, but sockets and friends are arbitrary.

1

>>4
Well, thanks anyway, but it's not that important. It's just some homework I've already done, but it felt wrong to read and write only one byte at a time, so I wanted to optimize it. (The program is a simple server that writes whatever it receives to each connected client, and the clients send each typed character to the server and write any responses to the terminal.)

>>6
you might just as well used netcat

>>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.

>>8
And netcat is just a non-generic, shittier version of socat.

>>6,1
If you don't want to block, why are you using blocking file descriptors?

>>9
Because the assignment mandates it. We're supposed to avoid blocking by using select(), and we must open the file descriptors as blocking (which is the default, anyways.)