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From: kobuchi%hoover.DECnet@win1.ims.abb.COM ("HOOVER::KOBUCHI")
Newsgroups: comp.windows.x
Subject: DECwindows DisplayString
Message-ID: <9101240224.AA17026@uc.msc.edu>
Date: 24 Jan 91 02:03:00 GMT
Sender: daemon@athena.mit.edu (Mr Background)
Organization: The Internet
Lines: 53

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|In article <9101222319.AA10945@uc.msc.edu>, 
|kobuchi%hoover.DECnet@win1.ims.abb.COM ("HOOVER::KOBUCHI") writes:
||> I've just encountered a problem with obtaining the display name, using
||> DisplayString.  We just upgraded our VAXes to VMS 5.4.  In this upgrade, DEC
||> changed DECwindows so that DisplayString returns a VAX/VMS device name 
|instead
||> of a string like "nodename::0.0".
||>
||> 
||>             display = XOpenDisplay("");
|
|
|I think you're asking 2 different questions here:
|
|1.  does the VMS implementation violate the X11R4 specification?  X11R4
|only specifies what happens when you XOpenDisplay(NULL) on a POSIX
|system, but I think the current VMS implementation more closely matches
|the spirit of the spec than does the old implementation of creating a
|pseudo-string.
|
|2.  can you assume that valid display specifiers will contain the node
|name?  The specification never says this and, in fact, many high level
|network interfaces, such as OSI, try hard to hide node names from you.
|I recommend that you avoid writing code that requires node names.
|
|-- 
|Ken Lee
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	Alright, let's see if I've got this straight.

	When I do XOpenDisplay(""), X does not guarantee me what DisplayString
	will return, i.e, the string might be in the format
	"nodename::servernum.screennum" or it might be in different format.

	If that's true, then there seems to be no machine-independent way to
	open connections to each screen of a dual-monitor X workstation.

	I had assumed the way to open up the two connections was to call
	XtOpenDisplay twice:

		display_screen0 = XtOpenDisplay( app_con, "nodename::0.0",...

		display_screen1 = XtOpenDisplay( app_con, "nodename::0.1",...

	Am I missing something here?  Has my brain turned into mush?

Kent Kobuchi
ABB Engineering Automation
Internet: kobuchi%pasceg.decnet@win1.ims.abb.com
Voice:    (415) 748-4791