将stdin复制到缓冲区

Question

I want to copy a os.Stdin string to a buffer, to check for a user inputted text (e.g. "hibye") and put an if statement against it.

My current code just handles simple stdin stdiout copy operations (no buffer):

func interact(c net.Conn) {
    // Read from Reader and write to Writer until EOF()
    copy := func(r io.ReadCloser, w io.WriteCloser) {
        defer func() {
            r.Close()
            w.Close()
        }()
        n, err := io.Copy(w, r)
        if err != nil {
            log.Printf("[%s]: ERROR: %s
", c.RemoteAddr(), err)
            log.Println(n)
        }
    }

    go copy(c, os.Stdout)
    go copy(os.Stdin, c)
}

Question: What is the most efficient way to implement a use of a buffer to have control over the passed strings?

bad example (failed attempt):

buf := make([]byte, 1024)
go copy (os.Stdin, []byte(buf))
if buf == "hibye" {
do stuff
}