[Pkg-cups-devel] CUPS trigger files for updating ppds attached to queues

[Didier 'OdyX' Raboud]

Hi Paul, 

Le dimanche, 5 août 2012 15.29:40, Paul Newall a écrit :
> I am using a python ppd updater in the upstream package c2esp and wondering
> if I should change to use the trigger file method that you are using in the
> ubuntu version of c2esp.
> 
> I'd like to know:
> In which version of cups was the trigger file method first added? (I have
> some users using quite old versions)

This trigger is a distribution-specific mechanism implemented in dpkg, see 
[0], [1].

In short, .deb packages can declare their interest having some of their 
packaging scripts run when files are installed by other packages. In our case, 
cups "declares a dpkg trigger" by shipping a "triggers" control file that has

	interest /usr/share/cups/ppd-updaters

as only content. This files ensures that dpkg runs the cups "postinst" control 
file as soon as another package installs something under /usr/share/cups/ppd-
updaters.

[0] http://wiki.debian.org/DpkgTriggers
[1] http://www.seanius.net/blog/2009/09/dpkg-triggers-howto/

> Is there any document that explains how to use the trigger file method? - I
> am not quite sure what the contents of the trigger file mean.

This is not something that you can implement as upstream maintainer as it _is_ 
distribution-specific.

Cheers,

OdyX