samba - Oct 2004 - Using parameters in lpq command conflicts with background lpq

I have an application than makes use of the "lpq command" and uses the
%U parameter in the command string.  The application returns a personalized
queue list based on the value of %U.  This technique worked well in older
versions of Samba (circa RedHat 8), but I have run into some trouble with Samba
3.  The issue appears to be twofold.

    1)  The lpq command is now run from the background lpq monitoring process,
which does not have a "user" (%U) per-se associated with it.

    2)  The background lpq process maintains its cache(s) based on the service
name.  IIRC, the older caching system maintained a cache for each unique
"lpq command" line.

I've temporarily solved the problem by running smbd from inetd - this
prevents the background lpq process from running and causes each user's
process to invoke their own lpq command (complete with %U substitution).

Would it be possible to update the background lpq code to use the (fully
substituted) lpq command as the cache identifier instead of (or in addition to)
the service name?  My application aside, I think it would be best if Samba's
behavior was consistent in both daemon and non-daemon modes.  I'd be willing
to lend my mediocre programming skills to the task if it would help.

Thank you
-Jerry

Hi Jerry, (and rest of list)
>
>I have an application than makes use of the "lpq command" and uses
the
>%U parameter in the command string.  The application returns a 
>personalized queue list based on the value of %U.  This technique worked 
>well in older versions of Samba (circa RedHat 8), but I have run into 
>some trouble with Samba 3.  The issue appears to be twofold.
>
>    1)  The lpq command is now run from the background lpq monitoring 
>process, which does not have a "user" (%U) per-se associated with
it.
>
>    2)  The background lpq process maintains its cache(s) based on the 
>service name.  IIRC, the older caching system maintained a cache for 
>each unique "lpq command" line.
Indeed it did.  In fact the whole (tdb-based) lpq monitoring system has
a whole heap of changes from previous Samba versions (we jumped from
1.9.18p8 to 3.0.6) and all sorts of strange things happen now.

>
>I've temporarily solved the problem by running smbd from inetd - this 
>prevents the background lpq process from running and causes each user's 
>process to invoke their own lpq command (complete with %U substitution).
Fab!  Thanks for finding this workaround.  I'll give it a shot.

>
>Would it be possible to update the background lpq code to use the (fully 
>substituted) lpq command as the cache identifier instead of (or in 
>addition to) the service name?  My application aside, I think it would 
>be best if Samba's behavior was consistent in both daemon and non-daemon
>modes.  I'd be willing to lend my mediocre programming skills to the 
>task if it would help.
I agree about the damon vs. non-daemon mode, very odd that the behaviour is
inconsistent.

                               Mac
          Assistant Systems Adminstrator @nibsc.ac.uk
                        dmccann@nibsc.ac.uk
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