Function pipe

user/src/file.rs:22–24

(pipe_fd: &mut [usize])

    sys_close(fd)
}
pub fn pipe(pipe_fd: &mut [usize]) -> isize {
    sys_pipe(pipe_fd)
}
pub fn read(fd: usize, buf: &mut [u8]) -> isize {
    sys_read(fd, buf)
}