STREAMS-based terminal subsystem

Beginning with UNIX System V Release 4, the terminal subsystem is implemented by STREAMS. The STREAMS-based terminal subsystem (see ``STREAMS-based terminal subsystem'') provides many benefits:

• Reusable line discipline modules. The same module can be used in many STREAMS where the configuration of these STREAMS may be different.

• Line discipline substitution. Although UNIX System V provides a standard terminal line discipline module, another one conforming to the interface may be substituted. For example, a remote login feature may use the terminal subsystem line discipline module to provide a terminal interface to the user.

• Internationalization. The modularity and flexibility of the STREAMS-based terminal subsystem enables an easy implementation of a system that supports multiple byte characters for internationalization. This modularity also allows easy addition of new features to the terminal subsystem.

• Easy customizing. Users may customize their terminal subsystem environment by adding and removing modules of their choice.

• The pseudo-terminal subsystem. The pseudo-terminal subsystem can be easily supported.

• Merge with networking. By pushing a line discipline module on a network line, you can make the network look like a terminal line.

STREAMS-based terminal subsystem

The initial setup of the STREAMS-based terminal subsystem is handled with the ttymon(1M) command within the framework of the Service Access Facility (SAF) or the autopush facility.

The STREAMS-based terminal subsystem supports termio, the termios specification of the POSIX standard, multiple byte characters for internationalization, the interface to asynchronous hardware flow control and peripheral controllers for asynchronous terminals (see 7termio( )7 termiox(7)). BSD compatibility can also be provided by pushing the ttcompat module (see ttcompat(7)).