{4, "EINTR", "interrupted system call"},
	{5, "EIO", "input/output error"},
	{6, "ENXIO", "no such device or address"},
	{7, "E2BIG", "argument list too long"},
	{8, "ENOEXEC", "exec format error"},
	{9, "EBADF", "bad file descriptor"},
	{10, "ECHILD", "no child processes"},
	{11, "EAGAIN", "resource temporarily unavailable"},
	{12, "ENOMEM", "cannot allocate memory"},
	{13, "EACCES", "permission denied"},

	{4, "EINTR", "interrupted system call"},
	{5, "EIO", "input/output error"},
	{6, "ENXIO", "no such device or address"},
	{7, "E2BIG", "argument list too long"},
	{8, "ENOEXEC", "exec format error"},
	{9, "EBADF", "bad file descriptor"},
	{10, "ECHILD", "no child processes"},
	{11, "EAGAIN", "resource temporarily unavailable"},
	{12, "ENOMEM", "cannot allocate memory"},
	{13, "EACCES", "permission denied"},

	{4, "EINTR", "interrupted system call"},
	{5, "EIO", "input/output error"},
	{6, "ENXIO", "no such device or address"},
	{7, "E2BIG", "argument list too long"},
	{8, "ENOEXEC", "exec format error"},
	{9, "EBADF", "bad file descriptor"},
	{10, "ECHILD", "no child processes"},
	{11, "EAGAIN", "resource temporarily unavailable"},
	{12, "ENOMEM", "cannot allocate memory"},
	{13, "EACCES", "permission denied"},

	RENAME_NOREPLACE                = 1 << 0
)

const (
	EDOM               = Errno(1)
	ERANGE             = Errno(2)
	EACCES             = Errno(111)
	EAGAIN             = Errno(112)
	EBADF              = Errno(113)
	EBUSY              = Errno(114)
	ECHILD             = Errno(115)
	EDEADLK            = Errno(116)
	EEXIST             = Errno(117)
	EFAULT             = Errno(118)

	// for standard input and outputs.
	for preopenFd := int32(3); ; preopenFd++ {
		var prestat prestat

		errno := fd_prestat_get(preopenFd, unsafe.Pointer(&prestat))
		if errno == EBADF {
			break
		}
		if errno == ENOTDIR || prestat.typ != preopentypeDir {
			continue
		}
		if errno != 0 {
			panic("fd_prestat: " + errno.Error())
		}