[cups] Fwd: Re: Problem with lpadmin

[Jörg Thümmler]

Am 23.02.22 um 17:29 schrieb Ken Wright:
> On Wed, 2022-02-23 at 08:01 +0100, Jörg Thümmler wrote:
>> Hi,
>>
>> i think, you have to quote this with single quotation marks ('). And
>> i don't think, there is an deviceURI ending with a "/"...
> 
> I re-entered the command, with quotes around the URI and deleted the
> final /.  The server accepted the command with no problem, but I still
> don't get any output from the printer.
> 
>> What i don't understand is why you don't do this using webinterface
>> http://localhost:631 . This will be a lot easier as it - if printer
>> is connected and online - will find the deviceURI correctly with all
>> these find the exactly "M15a".
> 
> Because the web interface shows me the printers, but when I try any
> admin task it crashes.
> 
> Ken
> 
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Hi Ken,

i see a coherence in this. If the cups webinterface runs and then 
crashes when you try admin tasks, i would say, some config file is 
damaged in a way cups webinterface can't accept. What happens if it 
"crashes"? Just nothing? Must and can you authentificate yourself (try 
root and root pw therefore) or aren't you asked for log in?

lpadmin maybe accepts errornous arguments as it doesn't "self-control" 
itself in the way web interface does. But that means it will add nearly 
anything to your printers.conf.

A question we didn't talk about all time or i deleted these msgs: what 
do the logfiles in /var/log/cups show? Any "interesting" information?
There should by entries like
   localhost - - [14/Feb/2022:07:40:01 +0100] "POST /admin/ HTTP/1.1"
for your tries to start admin tasks in access log and surely some 
entries in the error log, when this crashes...

Generally i would suggest to backup /etc/cups and then to deinstall and 
re-install cups, as you get "clean" /etc/cups by this.
Then i would start cups webinterface admin tasks and try to add a 
printer. If that crashes with a "clean" new installation there must be a 
problem in another installed program or config. I would blame it on some 
security things then.

If you have other printers running OK, i would after that stop cupsd and 
copy their entries from the backup of /etc/cups/printers.conf into the 
new installed /etc/cups/printers.conf. Then start cupsd. Are they 
running well? If you have installed special ppds you will find them in 
your backup of /etc/cups/ppd.

-- 
cu

jth