title: How to concatenate stdin in to a pipe?
body: <p>I want to send the output of a pipe and stdin to a pipe in bash.</p>
  
  <p>I.e: </p>
  
  <pre><code>gen_input | cat - | parse_input_and_stdin
  </code></pre>
  
  <p>would send the output of <code>gen_input</code> to <code>parse_input_and_stdin</code> and then leave stdin open for more interactive input.</p>