STREAMS-UX Programmer's Guide (February 2007)

STREAMS Utilities Supported by HP-UX
Appendix B
154
NAME
backq () – Returns a pointer to the queue behind a specified queue.
SYNOPSIS
#include <sys/stream.h>
queue_t *backq (queue_t *q);
ARGUMENTS
q Pointer to the head of the queue for a stream queue whose back queue is to be returned.
RETURN VALUES
backq() walks backwards from the specified q and returns a pointer to the queue whose q_next pointer is q .
If no such queue exists, backq() returns NULL.
CONSTRAINTS
backq() can be called from thread or interrupt context. Spinlocks can be held across this call.