The Sockets Networking API: UNIX® Network Programming Volume 1, Third Edition

Chapter 7. Socket Options

Introduction

There are various ways to get and set the options that affect a socket:

• The getsockopt and setsockopt functions

• The fcntl function

• The ioctl function

This chapter starts by covering the setsockopt and getsockopt functions, followed by an example that prints the default value of all the options, and then a detailed description of all the socket options. We divide the detailed descriptions into the following categories: generic, IPv4, IPv6, TCP, and SCTP. This detailed coverage can be skipped during a first reading of this chapter, and the individual sections referred to when needed. A few options are discussed in detail in a later chapter, such as the IPv4 and IPv6 multicasting options, which we will describe with ...