FreeLists / argyllcms / [argyllcms] Re: More on instrument access

[Leonard Evens <len@xxxxxxxxxxxxxxxxxxxxx>]

On Mon, 2008-01-07 at 13:21 +1100, Graeme Gill wrote:
 In response to what I had said previously
> 
> > One of the strange things I found is the following.  The argylll web
> > page suggests as an earlier approach the rule
> > 
> > SYSFS{idVendor}=="0971", SYSFS{idProduct}=="2003", PROGRAM="/bin/sh -c
> > 'K=%k; K=$${K#usbdev}; printf bus/usb/%%03i/%%03i $${K%%%%.*}
> > $${K#*.}'", NAME="%c",  MODE="666"
> 
> > This actually sets the permissions properly on the device, although the
> > PROGRAM statement returns with error status 1, in which case the NAME
> > assignment is not made. That is because %k has the value 4-1 and the
> > shell syntax results in something printf can't parse. 
> 
> I don't understand why that is. I couldn't actually test this
> stuff myself (since my Linux system uses hotplug rather than
> udev, and hotplug is considerably easier to tame), but I did try
> the shell program at one stage, and it seemed to work, and this is
> copied directly from other suggestions of what works - see
> <http://forums.gentoo.org/viewtopic-t-459308-highlight-camera+root.html?sid=a322727f7ea0a94aafd84fd0e13604ef>
> 

I looked at the link you gave.  He changed the file
/etc/udev/rules.d/50-udev.rules.

I could also have done it that way.  Indeed I tried something like that
at one point to see if it would work, and it did. (I didn't check why.)
But it is not a good idea to change any of the given rules files.  You
are supposed to add a new file.  It was the new file 10-Argyll.rules
that I was having problems with.

   
As to whether or not Linux is difficult, I haven't found it to be.  In
most cases, everything just works.  And in cases where it doesn't work,
there is almost always enough information available to find a solution.

I think the solution I ultimately came up with will work with any Linux
with a recent kernel.