ISO_vol_set_id
volsetid = (char *)ISO_vol_set_id(h->iso_buf);
volsetid = (char *)ISO_vol_set_id(h->unix_buf);
copystring(volsetid, (char *)ISO_vol_set_id(unix_buf), 128);
copystring(volsetid, (char *)ISO_vol_set_id(iso_buf), 128);
volsetid = (char *)ISO_vol_set_id(iso_buf);
volsetid = (char *)ISO_vol_set_id(unix_buf);
#define ISO_VOL_SET_ID(x) ISO_vol_set_id(x)