Standard compliance

use NAME_MAX and not MAXNAMLEN, the latter is UFS specific
use PATH_MAX and not MAXPATHLEN, the latter is BSD
va_arg has to be called with promoted types:
va_arg(ap, short) is implementation defined (GCC builtin: abort())
va_arg(ap, int) is correct to get shorts
important for mode_t (16bit vs 32bit)
on my build machine, GCC treats it as error
no O_SYNC, use O_FSYNC instead
use of FILE