[SOLVED] Re: Hotplugging USB sccanner in FC5, device not detected

[Richard England]

Richard England wrote:
> I tried this in the previous thread but perhaps it was to buried in 
> the thread to be picked up on.  One more time and I'll leave everyone 
> in peace.
>
>
> When I plug in my Canon LiDE 30 USB scanner into my FC5 box and fire 
> up Xsane, it announces that it cannot find a scanner.  However, if I 
> leave it plugged in, logout, and log back in, then Xsane finds the 
> scanner and every thing works swimmingly.   Under FC3  it does not 
> seem to matter.  Hot plugging the scanner works fine.
>
> Can anyone shed light on why the "hot plug" capability is not working 
> for FC5?  I did notice the "hot plug" scripts are gone but I assumed 
> that was because UDEV (or HAL, or something else) was suppose to take 
> care of this.
>
> Any assistance or enlightenment would be appreciated.   Is there a 
> good tutorial on UDEV etc. that might tell me what is suppose to take 
> place so I can attempt a debug?
>
> Thank you,
>
Solved, at least to my satisfaction.

hotplug script were apparently removed, as I suspected, in lieu of UDEV.   

/etc/udev/rules/60-libsane.rules

contains a list of the various USB plotters Sane knows about. For my 
scanner, the lines read:

#Canon Inc. | CanoScan N1240U/LIDE 30
SYSFS{idVendor}=="04a9", SYSFS{idProduct}=="220e", SYMLINK+="scanner-%k"

By changing the second of the two lines to read:

SYSFS{idVendor}=="04a9", SYSFS{idProduct}=="220e", 
SYMLINK+="scanner-%k",  MODE="0666"

I can successfully hotplug the scanner and use at as a normal user.

I understand that "0666" is a little wide open but without physical 
access to the machine, no one is likely to be able to connect the 
scanner anyway.

I tried limiting this by adding  GROUP="scanner" to the UDEV rule, 
creating the group "scanner" and adding my account to that group but it 
seems that unless I do a "newgrp scanner" to change my primary group, I 
can't access it.

I'd be glad to learn the proper way to limit this further, or the 
Gnu-Linux-proper way to use groups (they don't seem to be exactly as I'm 
used to on Unix)  if anyone wants to enlighten me.

Thanks for listening.

-- 
--R
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