STREAMS Programming Guide

Structure of a STREAMS Device Driver

STREAMS device drivers are structurally similar to STREAMS modules and character device drivers. The STREAMS interfaces to driver routines are identical to the interfaces used for modules. For instance they must both declare open, close, put, and service entry points.

There are some significant differences between modules and drivers.

A driver:

Both drivers and modules can pass signals, error codes, and return values to processes using message types provided for that purpose.