I made a quickie module (sorry, can't post it) for work. A first-check is for the environment variable DISPLAY. If you don't have it, the user's not accessing the shell with an X service available. This is pseudocode: 
sub hasX
{
   return undef if not defined $ENV{DISPLAY};
   return undef if port_not_listening($ENV{DISPLAY});
   return 1;
}

[download]
It's not foolproof. But after you get a hint from these, you can look at CPAN's X11 modules for more support.

--
[ e d @ h a l l e y . c c ]

In reply to Re: X or console? by halley
in thread X or console? by batkins

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