Terminal Control the Hard Way

• Controlling terminals under Linux is covered. It will show you the low-level APIs for controlling terminals and for controlling screen output in Linux applications.
• The notion of terminal control is a holdover from computing's earliest days, when users interacted with the CPU from dumb terminals.
• The Terminal Interface;
  • The terminal, or tty, interface derives from the days when users sat in front of a typewriter attached to a printer.
  • The tty interface is based on a hardware model that assumes a keyboard and printer combination is connected to a remote computer system using a serial port. This model is a distant relative of the current client-server computing architecture.
  • The model is sufficiently general that almost every situation in which a program needs to interact with some sort of input or output device, such as a printer, the console, xterms, or network logins, can be described as a subset of the general case.
  • As a result, the model actually simplifies the programmer's task because it provides a consistent programming interface that can be applied in a wide variety of situations.
  • Consider all of the different keyboard models, mice, joysticks, and other devices used to transmit user input. Add to that set all of the different kinds of output devices, such as modems, printers, plotters, serial devices, video cards, and monitors. The terminal interface has to accommodate all of these devices.