Permissions problems are being a huge PIMA

Tue Feb 1 01:37:00 UTC 2011

On Monday, January 31, 2011 08:08:28 pm Tom H did opine:

> On Mon, Jan 31, 2011 at 6:21 PM, gene heskett <gheskett at wdtv.com> wrote:
> > On Monday, January 31, 2011 05:54:33 pm Tom H did opine:
> >> On Mon, Jan 31, 2011 at 2:19 PM, gene heskett <gheskett at wdtv.com> 
wrote:
> >> > On Monday, January 31, 2011 02:18:25 pm Tom H did opine:
> >> >> On Mon, Jan 31, 2011 at 10:46 AM, gene heskett <gheskett at wdtv.com>
> > 
> > wrote:
> >> >> > I do the 99.999999999% of my email activities from a nice comfy
> >> >> > chair, in a nice comfy heated house.
> >> >> > 
> >> >> > The machine in the shop runs 24/7 though, so it is 'mounted' as
> >> >> > a cifs share, and this is where the PIMA starts.
> >> >> > 
> >> >> > Because the *buntu's start their user number schemes at 1000,
> >> >> > whereas the rest of the known universe starts at 500, even
> >> >> > though I am the user gene on both boxes, I have no write perms
> >> >> > via cifs in the /home/gene tree on the milling machines kubuntu
> >> >> > install.
> >> >> > 
> >> >> > So that I can save a useful bit of rs-274 nc code directly from
> >> >> > an email received on this machine, directly to the
> >> >> > /home/gene/emc/nc_files directory on that *buntu box in the
> >> >> > shop, what then is the std procedure to establish that the user
> >> >> > gene=500 on this box, is the user gene=1000 on that box?
> >> >> 
> >> >> The "UID_MIN 1000" setting is a Debianism that you can modify in
> >> >> "/etc/login.defs".
> >> > 
> >> > As that is set at install time, from read-only media, that doesn't
> >> > sound practical to do now.
> >> 
> >> You can boot into single user mode and do either of the following:
> >> 
> >> 1. Delete the user created at install, modify "/etc/login.defs", and
> >> re-create the user. (Only useful at first boot!)
> > 
> > That was 6 months and a lot of carved steel before. :)
> > 
> >> 2. Modify the uid of the user, �modify "/etc/login.defs", and chown
> >> the user's home directory recursively with the new uid.
> > 
> > In this order? �I am currently ssh -Y'd into that box and I'd hate
> > doing half of it and being locked out. �So, I first modified
> > /etc/adduser.conf, then /etc/group, finally /etc/passwd (all as sudo
> > -i), then cd'd to /home and did the chown -R gene:gene gene bit. �A
> > couple of ls -l's seem to indicate it all worked. �Backed out of the
> > sudo with a ctrl-d. But emc wouldn't run, something about a BadWindow
> > error. Sudo reboot, & close the link. �Waited for a ping to work then
> > it took 3 passes before it bought my password again, but I'm back in
> > with an "ssh -Y shop" as gene on this box.
> > 
> > But, emc still has a tummy ache over X and exits. �Humm, that box was
> > sitting at a local login prompt when I started, and is sitting there
> > again as I doubt my ssh login starts the x server.
> > 
> > Does that fit with this error exit on emc's part?
> > 
> > gene at shop:~$ cd emc2
> > gene at shop:~/emc2$ emc -l
> > EMC2 - 2.4.6
> > Machine configuration directory is
> > '/home/gene/emc2/configs/genes-mill' Machine configuration file is
> > 'genes-mill.ini'
> > Starting EMC2...
> > X Error of failed request: �BadWindow (invalid Window parameter)
> > �Major opcode of failed request: �3 (X_GetWindowAttributes)
> > �Resource id in failed request: �0xffffffff
> > �Serial number of failed request: �749
> > �Current serial number in output stream: �750
> > Shutting down and cleaning up EMC2...
> > Cleanup done
> > EMC terminated with an error. �You can find more information in the
> > log: � �/home/gene/emc_debug.txt
> > and
> > � �/home/gene/emc_print.txt
> > as well as in the output of the shell command 'dmesg' and in the
> > terminal
> > 
> > Or have I royally screwed the moose here?
> 
> Royally, I don't think so. Screwed the moose, possibly.
> 
> I definitely wouldn't have made these changes with an X session open,
> especially not a gene X session.
> 
I don't think an x session existed, the machines own console was sittin at 
the user's login screen after a reboot.  Still is I believe.

> Also I would've used 500 rather than gene for the chmod.

ls -ln verifies that.  Yup, everything is 500, user and group.
> 
> I don't know what more to say, especially since I have no idea what
> "emc -l" is or does.

Emc is a machine control program, initially funded by NIST many years ago, 
always in constant development, suitable for running almost any sort of a 
robot needing very precise positioning (of a rotating cutting bit for 
instance) in 3d (or more) space.  The "or more" means it can handle up to 9 
degrees of motion, and all totally co-ordinated.  My own machine only has 4 
motions setup, but the 4th one can occupy the 4th, 5th, or 6th position in 
the cartesian space depending on how that axis is bolted to the table the 
1st 2 axis's move.

One of the multi axis milling machines that takes a raw casting for a Toy 
engine into its clamps at an arbitrary time of the day, and delivers that 
engine block, ready for pistons, crankshaft and other parts to be 
installed, and does it in about 2/3rds the time that $50,000 a seat 
commercial software is doing it on an otherwise similar milling center 
sitting beside it.  Toy has been pretty quiet since that video was released 
on youtube a year+ back up the log, but we've heard they are retrofitting 
other machines with emc.  And its free. See links to get it on 
linuxcnc.org, or search for videos of it working on youtube.

The -l option tells emc to load the same set of configuration files that it 
used the last time it was ran.  Which is  handy since one can unplug the 
motors on the milling machine, move the cables to the motors on a lathe, 
load that configuration and run the lathe, rather handy for a one man shop.

-- 
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 is a hospital in which every patient is possessed by the desire to
change his bed.
		-- Charles Baudelaire