Re: [gpsd-users] raspbian gpsd:ERROR: read-only device open failed: Permission denied

[Sebastian E. Ovide]

Yo Gary !

thanks for that. In that case I'll contact the raspbian guys (or the Debian Weezy?) as the only thing I did to get gpsd running is install gpsd and gpsd-clients packages via apt-get install. So there must be a bug in the package.

I see that the package creates a gpsd.hotplug script which creates the /dev/ttyUSB0 with rw-rw---T privileges and belonging to the group dialout... so "nobody" doesn't have permissions. (Adding a chmod a+rw in that script fix the problem). What privileges would you expect to see in that file ?

Cheers

On 30 July 2015 at 19:58, Gary E. Miller <address@hidden> wrote:

Yo Sebastian!

On Thu, 30 Jul 2015 14:03:09 +0100
"Sebastian E. Ovide" <address@hidden> wrote:

> I'm using a GPS dongle on a raspberryPI. (raspbian)

Cool.

> which is gpsd runs as "nobody" but /dev/ttyUSB0 as no read privileges
> for nobody !

You should be running gpsd as root, and letting gpsd do the dropping
of priveledges.  Otherwise, as you see, it breaks a lot of things.

> If I do chmod a+r  /dev/ttyUSB0 it would work but as soon as I reboot
> the device or I unplug and plug the GPS back again, udev would
> recreate the folder and therefore revert the permissions ?

Which is why you need to fix your udev rules to create /dev/ttyUSBx in
a way compatible with the over limited way you start gpsd.

> I could change the scripts but just wondering... is it a bug ?it
> should work out of the box without hacking system scripts...

Yes, a bug in your setup that your permeissions are not self consistent.

RGDS
GARY
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