Function tokio_pipe::tee

pub async fn tee(
    pipe_in: &mut PipeRead, 
    pipe_out: &mut PipeWrite, 
    len: usize
) -> Result<usize>

Duplicates up to len bytes of data from pipe_in to pipe_out.

It does not consume the data that is duplicated from pipe_in; therefore, that data can be copied by a subsequent splice.