Re: dbus-deamon avoiding reboot after upgrade
On Fri 16 Aug 2019 at 22:39:09 +0300, Reco wrote:
> On Fri, Aug 16, 2019 at 07:14:58PM +0100, Brian wrote:
> > On Fri 16 Aug 2019 at 09:51:15 +0300, Reco wrote:
> >
> > > On Thu, Aug 15, 2019 at 08:47:34PM +0100, Brian wrote:
> > >
> > > > Nowadays that system often relies on printer/print queue Bonjour
> > > > broadcasts.
> > >
> > > And that is called "jumping to conclusions".
> > > Printing itself haven't changed a bit for last 15 years - a print server
> > > takes user's PS or PDF, mangles it to fit printer's representation (be
> > > it PCL or something else), and feeds it to the printer. By utilizing
> > > unicasts of course.
> >
> > I was going to let this go because it takes us beyond the server
> > situation we are discussing and is a reasonable, succinct description
> > of classic printing (which will become unsupported by CUPS in a few
> > years time).
> >
> > However, modern printers will accept and print jobs (e.g. PDF and JPEG)
> > without the mangling. These AirPrint-enabled, IPP printers completely
> > do away with having to use non-free software or plugins also. What is
> > there to dislike about that?
>
> Nothing. But it also means that one only needs something like ipptool
> ([1]) on client-side, leaving CUPS (and a whole notion of a "print
> server") out of the equation completely.
ipptool depends on libcups2.
> > > A user can discover a print server via mDNS multicasts (*not*
> > > broadcasts). Or a user can be told a location of such print server.
> >
> > So - I give my VIP, Android-using customer a piece of paper with a URI
> > to type into his phone rather than telling him which printer to use to
> > print out the multimillion Euro contract he has just signed?
> > Very last century.
>
> Multicasts are limited to a single L2 network segment by their very
> definition.
DNS-SD/Bonjour not scaling on typical multi-segment networks is a
recognised issue by CUPS upstream. Developments at
https://tools.ietf.org/wg/dnssd/
could produce a solution that CUPS could take advantage of.
> Putting your printers (or print servers) within a guest network (WiFi
> for Android customers) - that's a last century indeed.
>
> Besides, "multimillion Euro contract" can involve some pretty secretary
> lady who's happy to print said contract. Just saying.
I have no idea whether a secretary likes to be typecast, but is being
pretty, male and amenable a prerequisite to obtaining the post?
Anyway, the secretary has knocked off and I am left to instruct my VIP
how to use his Android phone to type the printer location without a
mistype:
dnssd://ENVY4500._ipp._tcp.local/?uuid=1c852a4d-b800-1f08-abcd-308d99fafac2
So much for telling a user a location. While he is typing I could rivet
him with describing the difference between a broadcast and a multicast.
--
Brian.
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