} else {
			_, _, err1 = RawSyscall(SYS_DUP2, uintptr(pipe), uintptr(nextfd), 0)
			if err1 != 0 {
				goto childerror
			}
			_, _, err1 = RawSyscall(SYS_FCNTL, uintptr(nextfd), F_SETFD, FD_CLOEXEC)
		}
		if err1 != 0 {
			goto childerror
		}
		pipe = nextfd
		nextfd++
	}
	for i = 0; i < len(fd); i++ {
		if fd[i] >= 0 && fd[i] < i {
			if nextfd == pipe { // don't stomp on pipe

			_, _, err1 = rawSyscall(dupTrampoline, uintptr(pipe), uintptr(nextfd), 0)
			if err1 != 0 {
				goto childerror
			}
			_, _, err1 = rawSyscall(abi.FuncPCABI0(libc_fcntl_trampoline), uintptr(nextfd), F_SETFD, FD_CLOEXEC)
		}
		if err1 != 0 {
			goto childerror
		}
		pipe = nextfd
		nextfd++
	}
	for i = 0; i < len(fd); i++ {
		if fd[i] >= 0 && fd[i] < i {
			if nextfd == pipe { // don't stomp on pipe

		default:
			_, err1 = dup2child(uintptr(pipe), uintptr(nextfd))
			if err1 != 0 {
				goto childerror
			}
			_, err1 = fcntl1(uintptr(nextfd), F_SETFD, FD_CLOEXEC)
		}
		if err1 != 0 {
			goto childerror
		}
		pipe = nextfd
		nextfd++
	}
	for i = 0; i < len(fd); i++ {
		if fd[i] >= 0 && fd[i] < i {
			if nextfd == pipe { // don't stomp on pipe

	b := make([]byte, n)
	n = 0
	for i, s := range ss {
		bb[i] = &b[n]
		copy(b[n:], s)
		n += len(s) + 1
	}
	return bb, nil
}

func CloseOnExec(fd int) { fcntl(fd, F_SETFD, FD_CLOEXEC) }

func SetNonblock(fd int, nonblocking bool) (err error) {
	flag, err := fcntl(fd, F_GETFL, 0)
	if err != nil {
		return err
	}
	if (flag&O_NONBLOCK != 0) == nonblocking {
		return nil
	}

	err = socketpair(domain, typ, proto, &fdx)
	if err == nil {
		fd[0] = int(fdx[0])
		fd[1] = int(fdx[1])
	}
	return
}

var ioSync int64

func CloseOnExec(fd int) { fcntl(fd, F_SETFD, FD_CLOEXEC) }

func SetNonblock(fd int, nonblocking bool) (err error) {
	flag, err := fcntl(fd, F_GETFL, 0)
	if err != nil {
		return err
	}
	if (flag&O_NONBLOCK != 0) == nonblocking {
		return nil
	}

	EPOLLWRBAND              = 0x0008
	EPOLLPRI                 = 0x0010
	EPOLLERR                 = 0x0020
	EPOLLHUP                 = 0x0040
	EPOLLEXCLUSIVE           = 0x20000000
	EPOLLONESHOT             = 0x40000000
	FD_CLOEXEC               = 0x01
	FD_CLOFORK               = 0x02
	FD_SETSIZE               = 0x800
	FNDELAY                  = 0x04
	F_CLOSFD                 = 9
	F_CONTROL_CVT            = 13
	F_DUPFD                  = 0

	EMPTY_SET                     = 0x0
	EMT_CPCOVF                    = 0x1
	EQUALITY_CHECK                = 0x0
	EXTA                          = 0xe
	EXTB                          = 0xf
	FD_CLOEXEC                    = 0x1
	FD_NFDBITS                    = 0x40
	FD_SETSIZE                    = 0x10000
	FLUSHALL                      = 0x1
	FLUSHDATA                     = 0x0
	FLUSHO                        = 0x2000

	EXTB                          = 0xf
	EXTRAP                        = 0x1
	EYEC_RTENTRYA                 = 0x257274656e747241
	EYEC_RTENTRYF                 = 0x257274656e747246
	E_ACC                         = 0x0
	FD_CLOEXEC                    = 0x1
	FD_SETSIZE                    = 0xfffe
	FF0                           = 0x0
	FF1                           = 0x2000
	FFDLY                         = 0x2000

	EXTB                          = 0xf
	EXTRAP                        = 0x1
	EYEC_RTENTRYA                 = 0x257274656e747241
	EYEC_RTENTRYF                 = 0x257274656e747246
	E_ACC                         = 0x0
	FD_CLOEXEC                    = 0x1
	FD_SETSIZE                    = 0xfffe
	FF0                           = 0x0
	FF1                           = 0x2000
	FFDLY                         = 0x2000

	EV_RECEIPT                        = 0x40
	EV_SYSFLAGS                       = 0xf800
	EXTA                              = 0x4b00
	EXTB                              = 0x9600
	EXTPROC                           = 0x800
	FD_CLOEXEC                        = 0x1
	FD_SETSIZE                        = 0x400
	FLUSHO                            = 0x800000
	F_DUPFD                           = 0x0
	F_DUPFD_CLOEXEC                   = 0xa