if n == fd1 || n == fd2 {
		return
	}
	for _, fd := range fds {
		if n == fd {
			return
		}
	}
	RawSyscall(SYS_CLOSE, uintptr(n), 0, 0)
}

func cexecPipe(p []int) error {
	e := Pipe(p)
	if e != nil {
		return e
	}

	fd, e := Open("#d/"+itoa.Itoa(p[1]), O_RDWR|O_CLOEXEC)
	if e != nil {
		Close(p[0])
		Close(p[1])
		return e
	}