TCP/IP Illustrated

Chapter 16. Socket I/O

16.1. Introduction

In this chapter we discuss the system calls that read and write data on a network connection. The chapter is divided into three parts.

The first part covers the four system calls for sending data: write, writev, sendto, and sendmsg. The second part covers the four system calls for receiving data: read, readv, recvfrom, and recvmsg. The third part of the chapter covers the select system call, which provides a standard way to monitor the status of descriptors in general and sockets in particular.

The core of the socket layer is the sosend and soreceive functions. They handle all I/O between the socket layer and the protocol layer. As we’ll see, the semantics of the various types ...