This chapter describes functions that are specific to terminal devices.
You can use these functions to do things like turn off input echoing;
set serial line characteristics such as line speed and flow control; and
change which characters are used for end-of-file, command-line editing,
sending signals, and similar control functions.
Most of the functions in this chapter operate on file descriptors.
See Low-Level I/O, for more information about what a file
descriptor is and how to open a file descriptor for a terminal device.
Is It a Terminal: How to determine if a file is a terminal
device, and what its name is.