Tk OSX couldn't connect to display :0

Washizu has asked for the wisdom of the Perl Monks concerning the following question:

I'm trying to run a Perl/Tk app on Mac OSX 10.4.8 (Tiger) and ran into an error message when I tried to create a new MainWindow object.

couldn't connect to display ":0" at usr/local/ActivePerl-5.8/lib/Tk/Ma
+inWindow.pm line 55
[download]

So I tried a the basic MainWindow example script and came up with the same error.

use Tk;
# Main Window
my $mw = new MainWindow;
my $label = $mw -> Label(-text=>"Hello World") -> pack();
my $button = $mw -> Button(-text => "Quit", 
        -command => sub { exit })
    -> pack();
MainLoop;
[download]

The Tk module is up to date, so I'm not sure what is going on here Any ideas?

-----------------------------------
Washizu
Odd Man In: Guns and Game Theory

Comment on Tk OSX couldn't connect to display :0 Select or Download Code

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Re: Tk OSX couldn't connect to display :0 by neniro (Priest) on Nov 26, 2006 at 18:47 UTC
Start your X11.app first. EDIT:If you work in a terminal-window you can type `open /Applications/Utilities/X11.app/` to start the X11.app.	[reply] [d/l]
Re^2: Tk OSX couldn't connect to display :0 by Washizu (Scribe) on Nov 26, 2006 at 20:34 UTC
Thanks for your help. I thought X11 was installed, because when I tried to install it from apple's site it said I already had it. It turned out I had to install it from the installation DVD and now it works. Of course, my app doesn't run exactly right but it at least runs now! ----------------------------------- Washizu Odd Man In: Guns and Game Theory	[reply]
Re: Tk OSX couldn't connect to display :0 by Fletch (Bishop) on Nov 26, 2006 at 18:56 UTC
Aside from making sure that X11.app is running, check that you can run another X program from a Terminal window (say `xterm` and/or `xhost`). Some things can confuzzle the xauth authentication, such as disappearing network connections (disconnecting from a WiFi network, or disconnecting a modem connection).	[reply]
Re^2: Tk OSX couldn't connect to display :0 by chargrill (Parson) on Nov 26, 2006 at 22:00 UTC
Indeed. I don't recall if it's actually necessary on OSX, but some time ago I ended up putting the following in my .profile or .bashrc so I never have to think about it ever again: `export DISPLAY=localhost:0.0` [download] --chargrill `s*lil; $=join'',sort split q; s;.;grr; &&s+(.(.)).+$2$1+; $; = qq-$_-;s,.,ahc,;$,.=chop for split q,,,reverse;print for($,,$;,$,$/)` [download]	[reply] [d/l] [select]
Re^3: Tk OSX couldn't connect to display :0 by andyford (Curate) on Nov 27, 2006 at 01:28 UTC
Which could be OK in your case, but if you use ssh and X forwarding, your exported DISPLAY will overwrite the special one that ssh gave you. The result will be that your X app will try to run on the machine that you ssh'd to instead of the machine that you ssh'd from. Usually not what you want. non-Perl: Andy Ford	[reply]
Re^4: Tk OSX couldn't connect to display :0 by chargrill (Parson) on Nov 27, 2006 at 04:39 UTC
Re^4: Tk OSX couldn't connect to display :0 by Fletch (Bishop) on Nov 27, 2006 at 02:03 UTC
Re: Tk OSX couldn't connect to display :0 by Anonymous Monk on Aug 22, 2015 at 23:21 UTC
Afte some struggle with my PTKDB perl debugger. Here is how I fix it. Get the latest download from the PERL/PTKDB team: http://ptkdb.sourceforge.net/download.html Best luck to you!	[reply]