title: how to ping each ip in a file?
body: <p>I have a file named "ips" containing all ips I need to ping. In order to ping those IPs, I use the following code:</p>
  
  <pre><code>cat ips|xargs ping -c 2
  </code></pre>
  
  <p>but the console show me the usage of ping, I don't know how to do it correctly. I'm using Mac os </p>