title: How do I kill a running process in Emacs
body: <p>When I compile the c++ file, emacs displays：</p>
  
  <blockquote>
    <p>a compilation process is running;kill it?(y or n).</p>
  </blockquote>
  
  <p>But <code>y</code> has no effect. How do I kill an active process in Emacs? there are many running processes in <em>process list</em>.</p>