title: Write non-ASCII characters to stdin of a progam on a tty (over ssh)
body: <p>I'm SSHd into a remote server with some binary challenges. </p>
  
  <p>At one point it asks for me to input text. I know it's using <code>fgets()</code> to read <code>stdin</code>, and that I can overflow where it is being copied to and overwrite a nearby variable. </p>
  
  <p>The problem is I don't know how to type the address values I need, <code>\x84</code> and <code>\x04</code> etc. If I were able to use bash I would <code>echo -ne "\x84"</code> or use a C hex array but I can't do that kind of thing here. </p>
  
  <p>I've tried using a hex to ASCII converter and copying the binary character and also using expect script to send the binary values but both have the same issue. x84 adds an extra char and x04 won't write at all. </p>
  
  <p>Any idea the best way to reliably write values to memory that can't be represented by ASCII characters over ssh on a Unix tty?</p>