title: Is there a command to list all Unix group names?
body: <p>I know there is the <code>/etc/group</code> file that lists all users groups.</p>
  
  <p>I would like to know if there is a simple command to list all user group names in spite of parsing the world readable <code>/etc/group</code> file. I am willing to create an administrator web page that lists Linux accounts' group names.</p>