What is the Difference between ConditionPathExists= and ConditionPathExists=| in systemd?
<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>