int QSopt_dual (QSprob p, int *status)
int status, rval;

/* p is a QSprob, a handle to an existing LP problem */

rval = QSopt_dual (p, &status);
if (rval) {
    fprintf (stderr, "QSopt_dual failed with return code %d\n", rval);
} else {
    switch (status) {
    case QS_LP_OPTIMAL:
        printf ("Found optimal solution to LP\n");
        break;
    case QS_LP_INFEASIBLE:
        printf ("No feasible solution exists for the LP\n");
        break;
    case QS_LP_UNBOUNDED:
        printf ("The LP objective is unbounded\n");
        break;
    default:
        printf ("LP could not be solved, status = %d\n", status);
        break;
    }
}