title: What is the Difference between ConditionPathExists= and ConditionPathExists=| in systemd?
body: <p>I need check a file not exist before i start my service in Systemd. I see two case in [Unit]:</p>
  
  <pre><code>ConditionPathExists=!/tmp/abc
  </code></pre>
  
  <p>and</p>
  
  <pre><code>ConditionPathExists=|!/tmp/abc
  </code></pre>
  
  <p>are they the same? Can anybody help me explain if they are different?</p>