title: PHP: Executing Command Line Application That Prompts Users
body: <p>I have a command line application I need to execute from my PHP web application. Say the command is the following:</p>
  
  <pre><code>foo -arg1 -arg2 -arg3
  </code></pre>
  
  <p>Based on certain conditions, the command line application will prompt user to hit the enter key (e.g. "Please press enter to continue.").</p>
  
  <p>From my PHP application, how do I execute the command line AND send the enter key as response to the prompt?</p>
  
  <p>I'm developing on WAMP. Production code is LAMP.</p>