ISO_sys_id
sysid = (char *)ISO_sys_id(h->iso_buf);
sysid = (char *)ISO_sys_id(h->unix_buf);
copystring(sysid, (char *)ISO_sys_id(unix_buf), 32);
copystring(sysid, (char *)ISO_sys_id(iso_buf), 32);
sysid = (char *)ISO_sys_id(iso_buf);
sysid = (char *)ISO_sys_id(unix_buf);
#define ISO_SYS_ID(x) ISO_sys_id(x)