title: File in /etc/sudoers.d file not being read by sudo
body: <p>I want to add a user in the sudoers file and I don't want to touch the original <code>/etc/sudoers</code> file, so I added a new file under directory <code>/etc/sudoers.d</code>. </p>
  
  <p>The interesting thing is about the name of the newly added file. Initially, I named the file as <code>sudoers.local</code>, the file never got effective; then I renamed the file as <code>customize</code>, it got effective immediate. The file name <code>sudoers.customize</code> doesn't work either. It seems any file name containing <code>sudoers</code> doesn't work. Someone know the reason? In all three cases, the file has the proper permission <code>-r--r-----</code>.</p>
  
  <p>The OS is 64 bits CentOS 6.5.</p>