[FreeNX-kNX] Screen snapshot

[Seb James]

On Thu, 2007-01-18 at 11:30 -0800, Simon Gao wrote:
> Hi,
> 
> Anyone knows how to make screen snapshots on remote X desktop using 
> nxclient (not from local host machine since running different OSes)?
> 

Hello Simon,

I obtain screenshots of the X session that I'm running in nxclient on a
machine called, say, nxClient by using imagemagick on a Linux machine on
my network, lets call that randomLinux.

To do this capture over the network, X must be started on nxClient with
-ac (you can change this in the startx script).

On randomLinux machine run:

import -display nxClient.mylan:0 -window root screenshot.png

Of course, this works only if nxClient is running X/Unix/Linux, but it
might provide a clue to what I think you want to do which is this
(correct me if I'm wrong): 

"Take a snapshot of an NX session which is running on some nxclient (on
mac, windows, whatever) but whilst *sitting at the NX server*. i.e.: You
need to access the piece of memory which holds the image of the root
window of the running nx session."

If you can hack the nxserver scripts to start the _NX_ X server with the
-ac switch, then you should be able to get an image of the root window
of the _NX_ X server.

When I say the "_NX_ X server" I mean nxagent. You can look at the
nxnode script to add the -ac switch to nxagent, assuming it is available
(I don't know how nxagent was compiled). You can also look at that
script to see which display number the nxagent instance will have, so
that you can run your imagemagick command something like this:

import -display nxServer.mylan:6001 -window root screenshot.png

Good luck,

Seb James
--
William Matthew Ltd. Tel: +44 (0)845 4580277
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