[sane-devel] still problems from xinetd

[Henning Meier-Geinitz]

Hi,

On Fri, Apr 11, 2003 at 06:38:12AM +0200, Joerg Napp wrote:
> after solving the PATH issue with the AS6E driver I ran into another
> problem which prevents saned from being started from xinetd.
> 
> Thhe situation is: sane Version 1.0.11, as6edriver version 0.4.9, scanning
> from a workstation after runnding saned -d on the linux box works fine.
> 
> When I try to aquire a preview (no matter if i try from sanetwain or xsane
> runnin on the windows box or scanimage -d net:... from the linux box) the
> scanner makes some moves and stops then; on the corresponding client
> program an errort message is issued (except for xsane which dies...).
> 
> Running tcpdump shows that the debug messages from as6edriver are sent to
> the client. Could this be the reason?

Yes, that's most probably the reason. inetd and xinetd communicate
with saned over standard in/out so any message printed by the backend
or the as6edriver program will corrupt the data stream. If the driver
prints messages to stdout, it's broken.

> I append the results of scanimage and a snippet of tcpdump results. Any
> help is greatly appreciated.

Looks liek you are right. scanimage >image.pnm may also break even
without net because the image data may be mixed with the messages from
the driver...

> BTW: Is this really the right place for this kind of questions or is there
> another list?

The list is the right one. Have you got any answers from the author of
the backend? If not, I guess it's up to you to stop the driver from
pronting these messages. I guess changing printf (...) to
fprintf (stderr, ...) may be enough but I haven't even loked at the
code.

Bye,
  Henning