Queries the number of elements in a queue.

#define INCL_DOSQUEUES
#include <os2.h>

HQUEUE    hq;          /*  The handle of the queue to be queried. */
PULONG    pcbEntries;  /*  A pointer to the number of elements in the queue. */
APIRET    ulrc;        /*  Return Code. */

ulrc = DosQueryQueue(hq, pcbEntries);