Bob van der Poel (
Mon, 22 Nov 1999 05:03:36 +0000

> Redhat 6.0 defaults "600" permissions on sg devices. Therefore
> without read permissions, normal users cannot open sg devices.
> One of the first questions I asked to a Linux newsgroup was
> why a logical read operation such as scanning a document needed
> write permissions. From memory the answer was something like
> that that is just the way things are. Should it be?

I think that the real problem is in install programs/methods. If we were
to use Oliver's suggestion (creating a group 'scanner'), setting the
owner of /dev/sgX to 'scanner', its permissions to 660, and the scanner
binaries to be owned by 'scanner' we'd solve a whole heap of
problems.... But even with a great install, problems remain:

- What users should be granted entrance to 'scanner' group?
- What device to set. Could be that the device changes?

I suppose that the install program could do some checking (to see if
there is a 'scanner' group already, etc), and then do a dialogue to
asking for the information from the user (with some reasonable

A well thought out install (even if it calls for later root
intervention, or even a 'scanner permissions' program) might solve a lot
of the problems we're seeing on the list with permission problems.

  /  )      /         Bob van der Poel
 /--<  ____/__
/___/_(_) /_)

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