7.4. The Sockets Model

BSD sockets are built on the basic UNIX® model: Everything is a file. In our example, then, sockets would let us receive an HTTP file, so to speak. It would then be up to us to extract the PNG file from it.

Because of the complexity of internetworking, we cannot just use the open system call, or the open() C function. Instead, we need to take several steps to opening a socket.

Once we do, however, we can start treating the socket the same way we treat any file descriptor: We can read from it, write to it, pipe it, and, eventually, close it.

All FreeBSD documents are available for download at https://download.freebsd.org/ftp/doc/

Questions that are not answered by the documentation may be sent to <freebsd-questions@FreeBSD.org>.
Send questions about this document to <freebsd-doc@FreeBSD.org>.