[cups.general] cups reload - what is it doing with queue?

[Helge Blischke]

Jiri B. wrote:

> Hello,
> 
> we use a script to update printers.conf for CUPS. To tell CUPS to
> re-read config file I tell CUPS to reload (`service cups reload' which
> is sending HUP signal to his daemon).
> 
> My question which also is important for customer:
> - what happens behind reload? It is cleaning printing queues? Would
>   that impact currently running printing?
> 
> I could not find exact answer in documentation.
> 
> Thank you in advance for your explanation.
> 
> Jiri

As the scheduler itself (re)writes the printers.conf file (e.g. to store the 
latest INFO or WARNING message etc.), it is only save to edit this file when 
the schedulder is not running.

So you need in your script
(1) shut down cupsd
(2) update printers.conf
(3) start cupsd again.

The "officially" recommended way to do things like this would be to execute 
appropriate lpadmin commands instead in your script, which as the advantage 
not to interrupt the CUPS service at all.

Helge