Advanced Programming in the UNIX® Environment, Third Edition

19. Pseudo Terminals

19.1. Introduction

In Chapter 9, we saw that terminal logins come in through a terminal device, automatically providing terminal semantics. A terminal line discipline (Figure 18.2) exists between the terminal and the programs that we run, so we can set the terminal’s special characters (e.g., backspace, line erase, interrupt) and the like. When a login arrives on a network connection, however, a terminal line discipline is not automatically provided between the incoming network connection and the login shell. Figure 9.5 showed that a pseudo terminal device driver is used to provide terminal semantics.

In addition to network logins, pseudo terminals have other uses that we explore in this chapter. We start with an overview ...