If an X server is available, it can be reached/detected via the %ENV hash:

if ($ENV{DISPLAY}) {
  print "Found X server at $ENV{DISPLAY}\n";
};

[download]

Keep in mind that it might be practical if the UI-less variant can be used even when there is an X server available; examples are shell-scripts and pipes...

In reply to Re: How to detect X? by Corion
in thread How to detect X? by blazar

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