title: How to send USR2 signal?
body: <p>I read that to upgrade nginx involves among other things sending the <code>USR2</code> signal with <code>kill -USR2 pid</code>. So I tried <code>sudo kill -USR2 3049</code> but got </p>
  
  <pre><code>$ sudo kill –USR2 3049
  kill: failed to parse argument: '–USR2'
  </code></pre>