drivepath
warnx("couldn't get controller/drive for %s", drivepath(unit));
if ((fd = open(drivepath(unit), 0)) < 0) {
warn("can't open %s", drivepath(unit));
if ((fd = open(drivepath(unit), 0)) < 0) {
warn("can't open %s", drivepath(unit));
if ((fd = open(drivepath(i), 0)) >= 0)
extern char *drivepath(int unit);