[sane-devel] SANE_Device issue

[Ben Olden-Cooligan]

It's very hacky but I get around this in NAPS2 by creating a temporary
config dir with only the one backend for the specified device.

https://github.com/cyanfish/naps2/blob/master/NAPS2.Sdk/Scan/Internal/Sane/SaneScanDriver.cs#L324

Certainly it would be nice if there was an API for this but there doesn't
seem to be.


On Wed, May 28, 2025, 21:24 Ralph Little <skelband at gmail.com> wrote:

> Hi Devs,
> I'm looking at an issue that affects xsane that I have had a number of
> complaints about.
>
> When xsane starts, it calls sane_get_devices() regardless of whether or
> not a specific device was specified by the user. The main issue is the long
> delay before xsane starts up while device polling is happening, which *can*
> be annoying long.
>
> On the face of it, this seems pointless if we already know which device
> the user wants to use. However, in various places, xsane uses the
> descriptive information for that device that we get in the SANE_Device
> structure which can only be got from sane_get_devices() This seems like a
> gaping hole in the protocol that the information about a specific device
> cannot be determined without searching for all devices.
>
> Does anyone have any ideas how we might get around this without breaking
> backwards compatibility in the SANE API and have I missed some official
> method whereby this information might be obtained?
>
> Cheers,
> Ralph
>
>
>
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