sunos man page for backq

backq(9F)						   Kernel Functions for Drivers 						 backq(9F)

NAME
       backq - get pointer to the queue behind the current queue

SYNOPSIS
       #include <sys/stream.h>

       queue_t *backq(queue_t *cq);

INTERFACE LEVEL
       Architecture independent level 1 (DDI/DKI).

PARAMETERS
       cq	The pointer to the current queue.   queue_t is an alias for the queue(9S) structure.

DESCRIPTION
       backq()	returns a pointer to the queue preceding  cq (the current queue).  If  cq is a read queue,  backq() returns a pointer to the queue
       downstream from	cq, unless it is the stream end. If  cq is a write queue,  backq() returns a pointer to the next queue upstream from   cq,
       unless it is the stream head.

RETURN VALUES
       If successful,  backq() returns a pointer to the queue preceding the current queue.  Otherwise, it returns  NULL.

CONTEXT
       backq() can be called from user or interrupt context.

SEE ALSO
       queue(9S)

       Writing Device Drivers

       STREAMS Programming Guide

SunOS 5.10							    11 Apr 1991 							 backq(9F)