howto convert configfile on library update?

[Hans de Goede]

Bill Nottingham wrote:
> Hans de Goede (j.w.r.degoede at hhs.nl) said: 
>> But how / when do I run this script, obviously it should get run on %post, 
>> and only if this is an update. But when?
> 
> %triggerpostun lm_sensoros <= (last version) would be one way to make
> sure it runs once and only once.
> 

Thanks,

Is there any good documentation on triggers anywhere?

BTW shouldn't that be %preun, after uninstall of the old version, the old 
config file will be no more, correct?

Is there a way to check if the configfile was modified?

Regards,

Hans