Path: utzoo!utgpu!news-server.csri.toronto.edu!clyde.concordia.ca!uunet!snorkelwacker!bloom-beacon!EXPO.LCS.MIT.EDU!keith
From: keith@EXPO.LCS.MIT.EDU (Keith Packard)
Newsgroups: comp.windows.x
Subject: Re: X Toolkit Error: Can't Open display
Message-ID: <9008130527.AA19565@expo.lcs.mit.edu>
Date: 13 Aug 90 05:27:56 GMT
References: <1204@cs.nps.navy.mil>
Sender: daemon@athena.mit.edu (Mr Background)
Organization: The Internet
Lines: 19


> Recently, everytime I come in after a weekend and unlock my screen, my
> Xserver forgets where the display is.  Everything was fine friday, I just
> locked the screen and went home.  When I come in and unlocked the screen,
> everything seems to work ok as far as executing programs in the
> existing applications (like maker, xterms and so on..) Anything I try
> to do that requires opening a window gets 
> 	"X Toolkit Error: Can't Open display"

This one may seems mysterious, but has a simple solution.  The X server
rendezvous with the client using a unix domain socket named
/tmp/.X11-unix/Xn (where n is the display number).

When your system goes about cleaning up unused files in /tmp it ends up
removing this file, as the file is only used when a new client connects to
the server.  This causes the X client run on monday morning to be unable to
find the X server.

You'll have to fix the cron entry which deletes unused files in /tmp.