Hallo Louis, Am 05.12.2012 18:25, schrieb Louis Lagendijk: > hello dear Sane developers > I am in the process of packaging scanbd for Fedora. One thing that > bothers me is the fact that I need to copy all <scanner>.conf files as > scanbd relies on the user using the net backend, while scanbd acts as a > saned proxy. But scanbd/saned requires a dll.conf that specifies the > used backends while the user dll.conf only uses the net backend. An > right now we can only have different dll.conf's inb different > directories as pointed out by SANE_CONFIG_DIR. > > Alternative 1) > ============== > It would be nice if the calling binary could specify a dll.conf to be > used. The user not specifying anything would get the normal dll.conf, > while a binary like saned or scanbd would see its own dll.conf (e.g. > saned-dll.conf). Would it be acceptable to modify dll.c to set the conf > filename (and not SANE_CONFIG_DIR) to load the required dll.conf? I am > thinking of adding a SANE_DLL_PREFIX environment var that gets prepended > to the dll.conf string (and dll.aliases) if defined. This way we do > ensure that we do not break compatibility. E.g. if SANE_DLL_PREFIX is > set to saned, we would load saned-dll.conf. > > My saned-dll could then specify all backends, while dll.conf would only > have the net backend. > > Alternative 2) > ============== > As above, but: > I consider changing / overwriting the default distributions dll.conf > undesirable. We could even prepend a user to dll.conf (user-dlll.conf) > even when no if the new env. var SANE_DLL_PREFIX is not defined and use > that (if the file exists) but fallback to dll.conf if that does not > exist. > In this case I could leave the default dll.conf intact, but add a > user-dll.conf that contains only the net backend from the scanbd package > in addition to the sane-dll.conf (or whatever). This avoids having a > file ownership issue with the standard dll.conf.
I can imagine to more alternatives: 3) use env-var SANE_CONFIG_FILE for getting the filename of the real dll.conf in the SANE_CONFIG_DIR 4) add a function to the programming interface to set the name / dir for the config-file (sane_init) -- Wilhelm
