title: What does -ex option used in bash | #!/bin/bash -ex mean
body: <p>We are using the script below as user data for EC2 instances. I don't understand what is <code>-ex</code> option is being used for?</p>
  
  <pre><code>#!/bin/bash -ex
  
  yum update -y
  yum groupinstall -y "Web Server" "MySQL Database" "PHP Support"
  service httpd start
  chkconfig httpd on
  </code></pre>