title: Remove chkconfig header from output
body: <p>On my CentOS machine I wrote a script which tells me whether a service is installed or not.
  Here is the script</p>
  
  <pre><code>count=$(chkconfig --list | grep -c "$1")
  if [ $count = 0 ]; then
      echo "False"
  else
      echo "True"
  fi
  </code></pre>
  
  <p>The problem is that the output of the command always includes the starting lines of the <code>chkconfig</code> output. For example here is the output of <code>script.sh network</code></p>
  
  <pre><code>[root@vm ~]# ./script.sh network
  
  Note: This output shows SysV services only and does not include native
        systemd services. SysV configuration data might be overridden by native
        systemd configuration.
  
        If you want to list systemd services use 'systemctl list-unit-files'.
        To see services enabled on particular target use
        'systemctl list-dependencies [target]'.
  
  True
  </code></pre>
  
  <p>It seems that the count variable correctly contains the count of grep occurrences but the script will always output the chkconfig header lines, even though I echo only "True" or "False" in the script.</p>
  
  <p>Why does this happen? And how to hide those lines?</p>