The STREAMS mechanism in UNIX System V Release 4 provides the framework on which communication services can be built. These services include communication between terminals and a host computer, between processes on the same computer, and between processes on different computers. This chapter will describe what makes up the STREAMS mechanism and how applications can use it to build communication services.
The STREAMS subsystem [not to be confused with the streams returned by
fopen(3C)] was designed to unify disparate and often ad hoc mechanisms that previously existed in the UNIX operating system to support different kinds of character-based I/O. In particular, it was intended to replace the
clist mechanism ...