BACKQ(9F)BACKQ(9F)NAMEbackq - get pointer to the queue behind the current queue
queue_t *backq(queue_t *cq);
Architecture independent level 1 (DDI/DKI).
The pointer to the current queue. queue_t is an alias for the
The backq() function 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.
If successful, backq() returns a pointer to the queue preceding the
current queue. Otherwise, it returns NULL.
The backq() function can be called from user, interrupt, or kernel con‐
Writing Device Drivers
STREAMS Programming Guide
Jan 16, 2006 BACKQ(9F)