int strqget(queue_t *q, qfields_t what, unsigned char pri, void *valp);
Architecture independent level 1 (DDI/DKI).
q Pointer to the queue.
what Field of the queue structure for (or the specified priority band) to return information about. Valid values are one of:
QHIWAT High water mark.
QLOWAT Low water mark.
QMAXPSZ Largest packet accepted.
QMINPSZ Smallest packet accepted.
QCOUNT Approximate size (in bytes) of data.
QFIRST First message.
QLAST Last message.
pri Priority band of interest.
valp The address of where to store the value of the requested field.
The strqget() function gives drivers and modules a way to get information about a queue or a particular band of a queue without directly accessing STREAMS data structures, thus insulating them from changes in the implementation of these data structures from release to release.
On success, 0 is returned and the value of the requested field is stored in the location pointed to by valp. An error number is returned on failure.
The strqget() function can be called from user, interrupt, or kernel context.
Writing Device Drivers
STREAMS Programming Guide