Hi there,
Thanks very much for the reply and the explanation. All understood,
and it's surely not going to be worth a great deal of effort for the
odd occasion that a library gets corrupted. I can't say I'm aware of
it happening here before now (in approaching 40 years of support for
busy offices), I suppose it must have done but then there's no reason
why a gremlin should prefer a library used by the scannning system.
Perhaps something like this patch to the documentation?
8<----------------------------------------------------------------------
$ diff -U3 ./Operations.html~ ./Operations.html
--- ./Operations.html~ 2024-11-25 08:51:28.805536970 +0000
+++ ./Operations.html 2024-11-25 08:55:13.096924545 +0000
@@ -140,6 +140,8 @@
is available.
<dt><tt>SANE_STATUS_ACCESS_DENIED</tt>:<dd> Access to the device has
been denied due to insufficient or invalid authentication.
+<dt><tt>SANE_STATUS_UNSUPPORTED</tt>:<dd> Something else went wrong.
+ It could be anything - even including a damaged executable.
</dl>
</blockquote>
8<----------------------------------------------------------------------
--
73,
Ged.
On Sun, 24 Nov 2024, Ralph Little wrote:
This is a difficult one. Interfaces with the backends are fairly simple. I
wasn't involved when this was formulated but I assume that the simplicity
is deliberate on purpose to keep it flexible.
Generally, I find that this error is returned from a lower level operation
not working as intended. Some of the backends are quite complex and nuance
in the reporting back of issues is often not really possible.
SANE_STATUS_INVAL is a case in point. It could mean practically anything.
If could be that we could expand the API somewhat to allow more verbose
reporting from a backend through a new function call. However, although we
could expand what such as the DLL layer can report back, it would be a bit
of work adding that in. Also it is unlikely that backends would be updated
to make of it, at least in the short term. Many of our backends don't even
have maintainers.
Cheers,
Ralph
On Sun, Nov 24, 2024 at 7:15 AM G.W. Haywood <[email protected]>
wrote:
Hi there,
... upgraded to Bullseye. ... scanner wasn't found by scanimage -L.
... tracked down ... damaged shared library. ... almost by accident
... not really satisfied with that.
...
http://www.sane-project.org/html/doc012.html
...
4.3.4 (sane_open) claims that the possible returned values are:
SANE_STATUS_DEVICE_BUSY
SANE_STATUS_INVAL
SANE_STATUS_IO_ERROR
SANE_STATUS_NO_MEM
SANE_STATUS_ACCESS_DENIED
but the returned value that I saw in the debug output from the command
...
SANE_STATUS_UNSUPPORTED
...
