ssh -Y -l user etc,etc

[gene heskett]

On Thursday, February 24, 2011 12:41:00 pm Eirik Byrkjeflot Anonsen did 
opine:

> gene heskett <gheskett at wdtv.com> writes:
> > On Wednesday, February 23, 2011 04:30:52 pm Adam Jackson did opine:
> >> On 2/22/11 11:11 AM, gene heskett wrote:
> >> > Where can I find a good tutorial on making this Just Work(TM) when
> >> > the user numbers are disparate, as they will be between a debian
> >> > based system and the rest of the world.  I did have this working 6
> >> > months ago, but every time *buntu updates the ssh stuff on the LTS
> >> > releases, it all goes away again.
> >> 
> >> You're going to have to be a lot more precise than that about what
> >> kind of problems you're seeing.  I routinely ssh forward X
> >> connections between accounts with differing UIDs on different
> >> machines, nothing more complicated than ssh -Y needed.
> >> 
> >> - ajax
> > 
> > In this case, emc is not running on the target, ubuntu machine.  I
> > launch it from this ssh -Y login, see the initial splash image, which
> > goes away after its initial timeout, and the cli then reports it
> > couldn't get a screen, so the whole thing exits.
> 
> But other X applications (e.g. xterm) works?
> 
> > The failure messages are somewhat less than worthless (to me at any
> > rate)
> 
> > but it does write a pair of files:
> You could include the error message anyway.  Maybe they mean something
> to someone.
> 
> [...]
> 
> > =================
> > RUN_IN_PLACE=no
> > EMC2_DIR=
> 
> [...]
> 
> > DISPLAY=axis
> 
> Hopefully this is not the X11 DISPLAY actually used by emc, but means
> something else...

No, axis is the name of one of the gui's emc can use for its display, 
written I believe in python IIRC.  There are others including tkemc, and 
even a text mode to run canned programs in a production environment where 
the parts being worked on are exchanged on a pallet, all tools are in an 
automatic tool changer so cutting bit changes are just part of the program.  
You can, once things are running nicely, turn out the lights and let the 
machine do its thing all night till the day shift arrives to service the 
raw and completed parts bins.

Axis is just one of the gui's usable with emc.  Its largely self 
configuring so that if I add say fwd/rev functions to the spindle power & 
speed controls section of the .hal file, the gui automatically adds those 
buttons and spindle speed and direction are then just mouse clicks.

Emc is versatile.  Its free.  It carves engine blocks for Toy, and does it 
faster than any commercial SW can.  Any machine capable of having motors 
fitted, and when you are a machinist (I'm not really) that means _all_, and 
then run with emc.  One gentleman even has a 100,000 lb Cinnci 'MilliCron' 
being run with it.  Its bed is 26 feet long. Oscillating servos are 
detectable by seismic monitors.  ;)

> [...
> 
> > Now, the fix that did make it work before is still there:
> > 
> > gene at shop:~/emc2/configs/genes-mill$ echo $DISPLAY
> > localhost:10.0
> 
> I assume you haven't set that yourself, but that it gets automatically
> set by ssh?

No, but I forget where I put it, so a "grep -R 'DISPLAY=localhost:10.0' /" 
is pounding the 'shop' machines drive looking for it now.

In any event, $DISPLAY is :0 on this box, session owned by gene.  And grep 
hasn't found where that is set on this box either.

> > So, do I need to add something to this machine?  Its running pclos-32
> > bit, 2010, uptodate except for tar as 1.24 and 1.25 are broken and
> > will not work with amanda.
> > 
> > What happens if I change $DISPLAY to = coyote.coyote.den:10.0
> > That is this machine, or I could use this machines IP too, but then
> > either marries it to this machine only, not a real fix IMO.
> 
> I assume coyote.coyote.den is the machine running the X server, rather
> than the machine running emc?  Then you probably want
> coyote.coyote.den:0.0, but you would need to set up proper access
> controls (etc.)

In fact, both machines are running X.  And neither is directly exposed to 
the internet.  I run an old x86 box all stripped out and booting dd-wrt as 
my router, and everything here is behind that.  In 5 years, no one I didn't 
give the routers passwd to has accessed anything here.  I do run a local AP 
for my lappy but with alu siding on the house, and still on the end of the 
house where I added a garage/shop 2 years ago, it is not usable, and only 
faintly detectable beyond the house so I've got cat5 strung to the shop 
where the emc machine lives, and back to the garage where my sacrificial 
goat machine lives.

> eirik

Thanks eirik.

-- 
Cheers, Gene
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
<http://tinyurl.com/ddg5bz>
Life in the state of nature is solitary, poor, nasty, brutish, and short.
- Thomas Hobbes, Leviathan