switch (drv->type) {
case drv_a: /* a.filename and a.format are optargs, don't free them */ break;
case drv_d: /* d.filename is optarg, don't free it */ break;
case drv_N:
free (drv->N.filename);
switch (drv->type) {
case drv_a: /* a.filename and a.format are optargs, don't free them */ break;
case drv_d: /* d.filename is optarg, don't free it */ break;
case drv_N:
free (drv->N.filename);