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- Path: sparky!uunet!mcsun!uknet!lsl!snail
- From: snail@lsl.co.uk
- Newsgroups: comp.windows.x
- Subject: Re: XOpenDisplay
- Message-ID: <1993Jan22.110312.2958@lsl.co.uk>
- Date: 22 Jan 93 11:03:12 GMT
- References: <1993Jan21.144250.5872@newton.bioch.ox.ac.uk>
- Organization: Laser-Scan Ltd., Cambridge
- Lines: 53
-
- In article <1993Jan21.144250.5872@newton.bioch.ox.ac.uk>, mikes@bioch.ox.ac.uk (Mike Smith) writes:
- >
- > Dear dudes,
- >
- > I am a beginner into X programming, and am being frustrated by the following
- > three lines:
- >
- > Display *display;
- > char *display_name = NULL;
- > display=XOpenDisplay(display_name);
- >
- > (of course I have #include <X11/Xlib.h> and #include <X11/Xutil.h> at the top).
- >
- > It seems to work Ok on those rare occasions when I can get on the computer where
- > it is being executed
-
- I assume you mean a remote login, or displaying on a different machine to the
- one you are running on? If that is the case, then it maybe that you have not
- told the application where to display itself. This can be done as follows
-
- either
-
- 1) use the -display <display address> option on the command line.
-
- eg: myprog -display lsld5g:0.0
- runs the program myprog on machine lsld5g, using display 0 and screen 0
-
- or
-
- 2) use the DISPLAY (unix) environment variable or DECW$DISPLAY (VMS) logical
- (is it a logical? or something else?).
-
- eg: setenv DISPLAY lsld5g:0.0
- to run the program:- myprog
- this has the same effect as 1).
-
- if you are using the machine at the console, but logged in on a seperate
- xterm (for example) you can setenv DISPLAY :0.0 or setenv DISPLAY unix:0.0
-
- > from but otherwise I get a segmentation fault, when according
- > to the man pages I should wither get a Display structure from XOpenDisplay, or a
- > NULL. I seem to be getting neither!
-
- Funnily enough, we get a seg fault if the DISPLAY variable isn't set.
-
- Hope it helps.
- --
- snail@lsl.co.uk
-
- "Washing one's hands of the conflict between the powerful and the powerless
- means to side with the powerful, not to be Neutral."
- Quote by Freire.
- Poster by OXFAM.
-