18.04 has no support for my printer

[Brian]

On Tue 16 Oct 2018 at 00:20:35 +0100, Peter Flynn wrote:

> On 16/10/18 00:01, Brian wrote:
> > On Mon 15 Oct 2018 at 22:06:44 +0100, Peter Flynn wrote:

[...]
 
> >>> warning: Failed to read /etc/cups/ppd/Deskjet_1510_1804.ppd ppd file
> >>
> >> That's the one it's looking for. Sometimes the CUPS that comes with
> >> distros simply omits a driver. I always use a fresh hplip to install.
> > 
> > Whatever you think that iwarning means (and you do not say) - it does
> > not mean what you think it means. Your interpretation is about as far
> > from reality as it is possible to get.
> 
> I interpret the error message to mean that it can't find the PPD file it
> was looking for: /etc/cups/ppd/Deskjet_1510_1804.ppd
> 
> If it means something else then I have misunderstood the message.

It is to do with permissions. On my machine:

brian at desktop:~$ ls -l /etc/cups/ppd/
total 144
-rw-r----- 1 root lp 24362 Sep 11 16:19 LaserJet-300.ppd
-rw-r----- 1 root lp 22243 Jan 26  2018 PDF.ppd
-rw-r----- 1 root lp 22243 Sep 10 23:51 realq.ppd
-rw-r----- 1 root lp 22243 Aug 12 18:44 realq.ppd.O

> > CUPS (do you really mean CUPS?) has very few driver+++s and is not likely
> > to omit any.
> 
> I have always assumed that CUPS is shipped with a large number of PPD
> files. These appear to be the "drivers" that it lists in the very long
> per-manufacturer selection list when installing a new printer. If not,
> then I don't know where it gets them from.

"CUPS" is often used as shorthand for "printing system", which is a
collection of software from different sources. On occasion this is
not very helpful. I would take CUPS to be the software at cups.org.

As far as the drivers it provides:

# /usr/lib/cups/daemon/cups-driverd dump | grep sample | wc -l
15

/usr/share/cups/drv/sample.drv is in the cups-common package.

Many other drivers can indeed be listed by the web interface - but
they are not shipped by CUPS.

-- 
Brian.