On 10/5/09 11:00 PM, "Bernie VK2KAD" <vk2...@hotmail.com> wrote:
> I am running a windows desktop so I downloaded Xming to use as the Xserver - > It installed OK - I then ran Xlaunch to get it going - xming.exe appears as > a running process in Task Manager - to configure I selected display number 0 > (zero) and accepted all other defaults. So far, so good. > On my Zlinux I issued > -bash-4.0# set DISPLAY=20.250.180.96:0,0;export DISPLAY That should be a period (.) between the last pair of 0s, eg set DISPLAY=foo.bar.baz:0.0;export DISPLAY You're specifying video-adapter.display attached to adapter with that :0.0. The comma is a syntax error. > Then to test I issued > -bash-4.0# xeyes > Error: Can't open display: > > I can ping 20.250.180.96 from zLinux and in a Putty SSH session so I know I > have IP connectivity. There's one more step... > I'm not sure what " make sure you have run 'xhost +remote.linux.system' on > the desktop system" means in the context of the above config. On top of connectivity between client and server, X also has a crude permission scheme that controls what hosts are allowed to project client windows onto your screen. The whole X protocol is a series of transactions between the client application and the X server -- the X server is basically a rendering engine for a set of standard primitives supplied by the client, and sends mouse movements and key presses back to the client as standardized event structures. The xhost application is the key to authorizing a host to project events onto your X server and/or receive events back -- if you haven't told the X server on your Windows machine that clients on "remote.linux.system" are allowed to project things, you get the Can't open display error (although in your case, I think the comma in the DISPLAY spec is what's messing you up). You can get there, but the host doesn't have permission to use that display. Running 'xhost +remote.linux.system' allows the remote.linux.system host to use the display currently pointed to by the DISPLAY environment variable. You could just do "xhost +" (which allows the whole world to connect), but that also allows ANYONE to inject ANY X event into your X server -- or grab any event coming FROM your X server, like typing your password. You typically need to do this on the local system running the X server (there's a chicken/egg problem here in that you need to authorize the remote system to connect and do things, but you can't do that until you authorize the remote system....), so there's some special case code in xhost and the X server to check if they're on the same system and let the request through. Most non-Unix PC implementations finesse this by just automatically authorizing everyone, but they really shouldn't. > I used xeyes > as a test because I don't have xterm (my Zlinux is Fedora11 and xterm > doesn't appear when I enter z + TAB in bash. Ouch. Xeyes will work, but realize that it processes EVERY mouse movement you make as a stream of events, which will burn CPU like crazy. ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
